/********************************************************************
 *                                                                  *
 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
 *                                                                  *
 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2007             *
 * by the Xiph.Org Foundation https://xiph.org/                     *
 *                                                                  *
 ********************************************************************/
/*
 * vorbis decoder.cpp
 * based on Xiph.Org Foundation vorbis decoder
 * adapted for the ESP32 by schreibfaul1
 *
 *  Created on: 13.02.2023
 *  Updated on: 09.09.2024
 */
//----------------------------------------------------------------------------------------------------------------------
//                                     O G G    I M P L.
//----------------------------------------------------------------------------------------------------------------------
#include "vorbis_decoder.h"
#include "lookup.h"
#include "alloca.h"
#include <vector>
using namespace std;

#define __malloc_heap_psram(size) \
    heap_caps_malloc_prefer(size, 2, MALLOC_CAP_DEFAULT | MALLOC_CAP_SPIRAM, MALLOC_CAP_DEFAULT | MALLOC_CAP_INTERNAL)
#define __calloc_heap_psram(ch, size) \
    heap_caps_calloc_prefer(ch, size, 2, MALLOC_CAP_DEFAULT | MALLOC_CAP_SPIRAM, MALLOC_CAP_DEFAULT | MALLOC_CAP_INTERNAL)


// global vars
bool      s_f_vorbisNewSteamTitle = false;  // streamTitle
bool      s_f_vorbisNewMetadataBlockPicture = false;
bool      s_f_oggFirstPage = false;
bool      s_f_oggContinuedPage = false;
bool      s_f_oggLastPage = false;
bool      s_f_parseOggDone = true;
bool      s_f_lastSegmentTable = false;
bool      s_f_vorbisStr_found = false;
uint16_t  s_identificatonHeaderLength = 0;
uint16_t  s_vorbisCommentHeaderLength = 0;
uint16_t  s_setupHeaderLength = 0;
uint8_t   s_pageNr = 0;
uint16_t  s_oggHeaderSize = 0;
uint8_t   s_vorbisChannels = 0;
uint16_t  s_vorbisSamplerate = 0;
uint16_t  s_lastSegmentTableLen = 0;
uint8_t  *s_lastSegmentTable = NULL;
uint32_t  s_vorbisBitRate = 0;
uint32_t  s_vorbisSegmentLength = 0;
uint32_t  s_vorbisBlockPicLenUntilFrameEnd = 0;
uint32_t  s_vorbisCurrentFilePos = 0;
uint32_t  s_vorbisAudioDataStart = 0;
char     *s_vorbisChbuf = NULL;
int32_t   s_vorbisValidSamples = 0;
int32_t   s_commentBlockSegmentSize = 0;
uint8_t   s_vorbisOldMode = 0;
uint32_t  s_blocksizes[2];
uint32_t  s_vorbisBlockPicPos = 0;
uint32_t  s_vorbisBlockPicLen = 0;
int32_t   s_vorbisRemainBlockPicLen = 0;
int32_t   s_commentLength = 0;

uint8_t   s_nrOfCodebooks = 0;
uint8_t   s_nrOfFloors = 0;
uint8_t   s_nrOfResidues = 0;
uint8_t   s_nrOfMaps = 0;
uint8_t   s_nrOfModes = 0;

uint16_t *s_vorbisSegmentTable = NULL;
uint16_t  s_oggPage3Len = 0; // length of the current audio segment
uint8_t   s_vorbisSegmentTableSize = 0;
int16_t   s_vorbisSegmentTableRdPtr = -1;
int8_t    s_vorbisError = 0;
float     s_vorbisCompressionRatio = 0;

bitReader_t            s_bitReader;

codebook_t            *s_codebooks = NULL;
vorbis_info_floor_t  **s_floor_param = NULL;
int8_t                *s_floor_type = NULL;
vorbis_info_residue_t *s_residue_param = NULL;
vorbis_info_mapping_t *s_map_param = NULL;
vorbis_info_mode_t    *s_mode_param = NULL;
vorbis_dsp_state_t    *s_dsp_state = NULL;

vector<uint32_t>s_vorbisBlockPicItem;


bool VORBISDecoder_AllocateBuffers(){
    s_vorbisSegmentTable = (uint16_t*)__calloc_heap_psram(256, sizeof(uint16_t));
    s_vorbisChbuf = (char*)__calloc_heap_psram(256, sizeof(char));
    s_lastSegmentTable = (uint8_t*)__malloc_heap_psram(4096);
    VORBISsetDefaults();
    return true;
}
void VORBISDecoder_FreeBuffers(){
    if(s_vorbisSegmentTable) {free(s_vorbisSegmentTable); s_vorbisSegmentTable = NULL;}
    if(s_vorbisChbuf){free(s_vorbisChbuf); s_vorbisChbuf = NULL;}
    if(s_lastSegmentTable){free(s_lastSegmentTable); s_lastSegmentTable = NULL;}

    clearGlobalConfigurations();
}
void VORBISDecoder_ClearBuffers(){
    if(s_vorbisChbuf) memset(s_vorbisChbuf, 0, 256);
    bitReader_clear();
    if(s_lastSegmentTable) memset(s_lastSegmentTable, 0, 4096);
    if(s_vorbisSegmentTable) memset(s_vorbisSegmentTable, 0, 256);
    s_vorbisSegmentTableSize = 0;
    s_vorbisSegmentTableRdPtr = -1;}
void VORBISsetDefaults(){
    s_pageNr = 0;
    s_f_vorbisNewSteamTitle = false;  // streamTitle
    s_f_vorbisNewMetadataBlockPicture = false;
    s_f_lastSegmentTable = false;
    s_f_parseOggDone = false;
    s_f_oggFirstPage = false;
    s_f_oggContinuedPage = false;
    s_f_oggLastPage = false;
    s_f_vorbisStr_found = false;
    if(s_dsp_state){vorbis_dsp_destroy(s_dsp_state); s_dsp_state = NULL;}
    s_vorbisChannels = 0;
    s_vorbisSamplerate = 0;
    s_vorbisBitRate = 0;
    s_vorbisSegmentLength = 0;
    s_vorbisValidSamples = 0;
    s_vorbisSegmentTableSize = 0;
    s_vorbisCurrentFilePos = 0;
    s_vorbisAudioDataStart = 0;
    s_vorbisOldMode = 0xFF;
    s_vorbisSegmentTableRdPtr = -1;
    s_vorbisError = 0;
    s_lastSegmentTableLen = 0;
    s_vorbisBlockPicPos = 0;
    s_vorbisBlockPicLen = 0;
    s_vorbisBlockPicLenUntilFrameEnd = 0;
    s_commentBlockSegmentSize = 0;
    s_vorbisBlockPicItem.clear();
    s_vorbisBlockPicItem.shrink_to_fit();

    VORBISDecoder_ClearBuffers();
}

void clearGlobalConfigurations() { // mode, mapping, floor etc
    if(s_nrOfCodebooks) {  // if we have a stream with changing codebooks, delete the old one
        for(int32_t i = 0; i < s_nrOfCodebooks; i++) { vorbis_book_clear(s_codebooks + i); }
        s_nrOfCodebooks = 0;
    }
    if(s_codebooks) {
        free(s_codebooks);
        s_codebooks = NULL;
    }
    if(s_dsp_state) {
        vorbis_dsp_destroy(s_dsp_state);
        s_dsp_state = NULL;
    }
    if(s_nrOfFloors) {
        for(int32_t i = 0; i < s_nrOfFloors; i++) floor_free_info(s_floor_param[i]);
        free(s_floor_param);
        s_nrOfFloors = 0;
    }
    if(s_nrOfResidues) {
        for(int32_t i = 0; i < s_nrOfResidues; i++) res_clear_info(s_residue_param + i);
        s_nrOfResidues = 0;
    }
    if(s_nrOfMaps) {
        for(int32_t i = 0; i < s_nrOfMaps; i++) { mapping_clear_info(s_map_param + i); }
        s_nrOfMaps = 0;
    }
    if(s_floor_type) {
        free(s_floor_type);
        s_floor_type = NULL;
    }
    if(s_residue_param) {
        free(s_residue_param);
        s_residue_param = NULL;
    }
    if(s_map_param) {
        free(s_map_param);
        s_map_param = NULL;
    }
    if(s_mode_param) {
        free(s_mode_param);
        s_mode_param = NULL;
    }
}

//----------------------------------------------------------------------------------------------------------------------

int32_t VORBISDecode(uint8_t* inbuf, int32_t* bytesLeft, int16_t* outbuf) {

    int32_t ret = 0;
    int32_t segmentLength = 0;

    if(s_commentBlockSegmentSize) {
        if(s_commentBlockSegmentSize > 8192) {
            s_commentBlockSegmentSize -= 8192;
            s_commentLength -= 8192;
            *bytesLeft -= 8192;
            s_vorbisCurrentFilePos += 8192;
        }
        else {
            *bytesLeft -= s_commentBlockSegmentSize;
            s_vorbisCurrentFilePos += s_commentBlockSegmentSize;
            s_commentLength -= s_commentBlockSegmentSize;
            s_commentBlockSegmentSize = 0;
        }
        if(s_vorbisRemainBlockPicLen <= 0 && !s_f_vorbisNewMetadataBlockPicture) {
            if(s_vorbisBlockPicItem.size() > 0) { // get blockpic data
                // log_i("---------------------------------------------------------------------------");
                // log_i("metadata blockpic found at pos %i, size %i bytes", s_vorbisBlockPicPos, s_vorbisBlockPicLen);
                // for(int32_t i = 0; i < s_vorbisBlockPicItem.size(); i += 2) { log_i("segment %02i, pos %07i, len %05i", i / 2, s_vorbisBlockPicItem[i], s_vorbisBlockPicItem[i + 1]); }
                // log_i("---------------------------------------------------------------------------");
                s_f_vorbisNewMetadataBlockPicture = true;
            }
        }
        return VORBIS_PARSE_OGG_DONE;
    }

    if(!s_vorbisSegmentTableSize) {
        s_vorbisSegmentTableRdPtr = -1; // back to the parking position
        ret = VORBISparseOGG(inbuf, bytesLeft);
        s_f_parseOggDone = true;
        if(!s_vorbisSegmentTableSize) {/* log_w("OggS without segments?") */; }
        return ret;
    }

    // With the last segment of a table, we don't know whether it will be continued in the next Ogg page.
    // So the last segment is saved. s_lastSegmentTableLen specifies the size of the last saved segment.
    // If the next Ogg Page does not contain a 'continuedPage', the last segment is played first. However,
    // if 'continuedPage' is set, the first segment of the new page is added to the saved segment and played.
    if(!s_lastSegmentTableLen){
        if(s_vorbisSegmentTableSize) {
            s_vorbisSegmentTableRdPtr++;
            s_vorbisSegmentTableSize--;
            segmentLength = s_vorbisSegmentTable[s_vorbisSegmentTableRdPtr];
        }
    }

    if(s_pageNr < 4)
        if(VORBIS_specialIndexOf(inbuf, "vorbis", 10) == 1) s_pageNr++;

    switch(s_pageNr) {
        case 0:
            ret = VORBIS_PARSE_OGG_DONE; // do nothing
            break;
        case 1:
            ret = vorbisDecodePage1(inbuf, bytesLeft, segmentLength); // blocksize, channels, samplerates
            break;
        case 2:
            ret = vorbisDecodePage2(inbuf, bytesLeft, segmentLength); // comments
            break;
        case 3:
            ret = vorbisDecodePage3(inbuf, bytesLeft, segmentLength); // codebooks
            break;
        case 4:
            ret = vorbisDecodePage4(inbuf, bytesLeft, segmentLength, outbuf); // decode audio
            break;
        default: log_e("unknown page %s", s_pageNr); break;
    }
    return ret;
}
//------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
int32_t vorbisDecodePage1(uint8_t* inbuf, int32_t* bytesLeft, uint32_t segmentLength){
    int32_t ret = VORBIS_PARSE_OGG_DONE;
    clearGlobalConfigurations(); // if a new codebook is required, delete the old one
    int32_t idx = VORBIS_specialIndexOf(inbuf, "vorbis", 10);
    if(idx == 1) {
        // log_i("first packet (identification segmentLength) %i", segmentLength);
        s_identificatonHeaderLength = segmentLength;
        ret = parseVorbisFirstPacket(inbuf, segmentLength);
    }
    else {
        ret = ERR_VORBIS_NOT_AUDIO; // #651
    }

    *bytesLeft -= segmentLength;
    s_vorbisCurrentFilePos += segmentLength;
    return ret;
}
//------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
int32_t vorbisDecodePage2(uint8_t* inbuf, int32_t* bytesLeft, uint32_t segmentLength){
    int32_t ret = VORBIS_PARSE_OGG_DONE;
    int32_t idx = VORBIS_specialIndexOf(inbuf, "vorbis", 10);
    if(idx == 1) {
        s_vorbisBlockPicItem.clear();
        s_vorbisBlockPicItem.shrink_to_fit();
        s_f_vorbisStr_found = true;
        s_vorbisCommentHeaderLength = segmentLength;
        ret = parseVorbisComment(inbuf, segmentLength);
        s_commentBlockSegmentSize = segmentLength;
         int32_t pLen = _min((int32_t)s_vorbisBlockPicLen, s_vorbisBlockPicLenUntilFrameEnd);
        if(s_vorbisBlockPicLen && pLen > 0){
            s_vorbisBlockPicItem.push_back(s_vorbisBlockPicPos);
            s_vorbisBlockPicItem.push_back(pLen);
        }
        s_vorbisRemainBlockPicLen = s_vorbisBlockPicLen - pLen;
        ret = VORBIS_PARSE_OGG_DONE;
    }
    else {
        s_commentBlockSegmentSize = segmentLength;
        uint32_t pLen = min(s_vorbisRemainBlockPicLen, (int32_t)segmentLength);
        if(s_vorbisRemainBlockPicLen && pLen > 0){
            s_vorbisBlockPicItem.push_back(s_vorbisCurrentFilePos);
            s_vorbisBlockPicItem.push_back(pLen);
        }
        s_vorbisRemainBlockPicLen -= segmentLength;
        ret = VORBIS_PARSE_OGG_DONE;
    }
    return ret;
}
//------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
int32_t vorbisDecodePage3(uint8_t* inbuf, int32_t* bytesLeft, uint32_t segmentLength){
    int32_t ret = VORBIS_PARSE_OGG_DONE;
    int32_t idx = VORBIS_specialIndexOf(inbuf, "vorbis", 10);
    s_oggPage3Len = segmentLength;
    if(idx == 1) {
        // log_i("third packet (setup segmentLength) %i", segmentLength);
        s_setupHeaderLength = segmentLength;
        bitReader_setData(inbuf, segmentLength);
        if(segmentLength == 4080) {
            // that is 16*255 bytes and thus the maximum segment size
            // it is possible that there is another block starting with 'OggS' in which there is information
            // about codebooks. It is possible that there is another block starting with 'OggS' in which
            // there is information about codebooks.
            int32_t l = continuedOggPackets(inbuf + s_oggPage3Len);
            *bytesLeft -= l;
            s_vorbisCurrentFilePos += l;
            s_oggPage3Len += l;
            s_setupHeaderLength += l;
            bitReader_setData(inbuf, s_oggPage3Len);
            log_w("s_oggPage3Len %i", s_oggPage3Len);
            s_pageNr++;
        }
        ret = parseVorbisCodebook();
    }
    else { log_e("no \"vorbis\" something went wrong %i", segmentLength); }
    s_pageNr = 4;
    s_dsp_state = vorbis_dsp_create();

    *bytesLeft -= segmentLength;
    s_vorbisCurrentFilePos += segmentLength;
    return ret;
}
//------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
int32_t vorbisDecodePage4(uint8_t* inbuf, int32_t* bytesLeft, uint32_t segmentLength, int16_t* outbuf){

    if(s_vorbisAudioDataStart == 0){
        s_vorbisAudioDataStart = s_vorbisCurrentFilePos;
    }

    int32_t ret = 0;
    if(s_f_parseOggDone) { // first loop after VORBISparseOGG()
        if(s_f_oggContinuedPage) {
            if(s_lastSegmentTableLen > 0 || segmentLength > 0) {
                if(s_lastSegmentTableLen + segmentLength > 1024) log_e("continued page too big");
                memcpy(s_lastSegmentTable + s_lastSegmentTableLen, inbuf, segmentLength);
                bitReader_setData(s_lastSegmentTable, s_lastSegmentTableLen + segmentLength);
                ret = vorbis_dsp_synthesis(s_lastSegmentTable, s_lastSegmentTableLen + segmentLength, outbuf);
                uint16_t outBuffSize = 2048 * 2;
                s_vorbisValidSamples = vorbis_dsp_pcmout(outbuf, outBuffSize);
                s_lastSegmentTableLen = 0;
                if(!ret && !segmentLength) ret = VORBIS_CONTINUE;
            }
            else { // s_lastSegmentTableLen is 0 and segmentLength is 0
                s_vorbisValidSamples = 0;
                ret = VORBIS_CONTINUE;
            }
            s_f_oggContinuedPage = false;
        }
        else { // last segment without continued Page
            if(s_lastSegmentTableLen) {
                bitReader_setData(s_lastSegmentTable, s_lastSegmentTableLen);
                ret = vorbis_dsp_synthesis(s_lastSegmentTable, s_lastSegmentTableLen, outbuf);
                uint16_t outBuffSize = 2048 * 2;
                s_vorbisValidSamples = vorbis_dsp_pcmout(outbuf, outBuffSize);
                s_lastSegmentTableLen = 0;
                if(ret == OV_ENOTAUDIO || ret == 0) ret = VORBIS_CONTINUE; // if no error send continue
            }
            else {
                bitReader_setData(inbuf, segmentLength);
                ret = vorbis_dsp_synthesis(inbuf, segmentLength, outbuf);
                uint16_t outBuffSize = 2048 * 2;
                s_vorbisValidSamples = vorbis_dsp_pcmout(outbuf, outBuffSize);
                ret = 0;
            }
        }
    }
    else { // not s_f_parseOggDone
        if(s_vorbisSegmentTableSize || s_f_lastSegmentTable) {
            // if(s_f_oggLastPage) log_i("last page");
            bitReader_setData(inbuf, segmentLength);
            ret = vorbis_dsp_synthesis(inbuf, segmentLength, outbuf);
            uint16_t outBuffSize = 2048 * 2;
            s_vorbisValidSamples = vorbis_dsp_pcmout(outbuf, outBuffSize);
            ret = 0;
        }
        else { // last segment
            if(segmentLength) {
                memcpy(s_lastSegmentTable, inbuf, segmentLength);
                s_lastSegmentTableLen = segmentLength;
                s_vorbisValidSamples = 0;
                ret = 0;
            }
            else {
                s_lastSegmentTableLen = 0;
                s_vorbisValidSamples = 0;
                ret = VORBIS_PARSE_OGG_DONE;
            }
        }
        s_f_oggFirstPage = false;
    }
    s_f_parseOggDone = false;
    if(s_f_oggLastPage && !s_vorbisSegmentTableSize) { VORBISsetDefaults(); }

    if(ret != VORBIS_CONTINUE){ // nothing to do here, is playing from lastSegmentBuff
        *bytesLeft -= segmentLength;
        s_vorbisCurrentFilePos += segmentLength;
    }
    return ret;
}

//----------------------------------------------------------------------------------------------------------------------

uint8_t VORBISGetChannels(){
    return s_vorbisChannels;
}
uint32_t VORBISGetSampRate(){
    return s_vorbisSamplerate;
}
uint8_t VORBISGetBitsPerSample(){
    return 16;
}
uint32_t VORBISGetBitRate(){
    return s_vorbisBitRate;
}
uint32_t VORBISGetAudioDataStart(){
    return s_vorbisAudioDataStart;
}
uint16_t VORBISGetOutputSamps(){
    return s_vorbisValidSamples; // 1024
}
char* VORBISgetStreamTitle(){
    if(s_f_vorbisNewSteamTitle){
        s_f_vorbisNewSteamTitle = false;
        return s_vorbisChbuf;
    }
    return NULL;
}
vector<uint32_t> VORBISgetMetadataBlockPicture(){
    if(s_f_vorbisNewMetadataBlockPicture){
        s_f_vorbisNewMetadataBlockPicture = false;
        return s_vorbisBlockPicItem;
    }
    if(s_vorbisBlockPicItem.size() > 0){
        s_vorbisBlockPicItem.clear();
        s_vorbisBlockPicItem.shrink_to_fit();
    }
    return s_vorbisBlockPicItem;
}
//----------------------------------------------------------------------------------------------------------------------
int32_t parseVorbisFirstPacket(uint8_t *inbuf, int16_t nBytes){ // 4.2.2. Identification header
                                                            // https://xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-820005
    // first bytes are: '.vorbis'
    uint16_t pos = 7;
    uint32_t version     = *(inbuf + pos);
             version    += *(inbuf + pos + 1) << 8;
             version    += *(inbuf + pos + 2) << 16;
             version    += *(inbuf + pos + 3) << 24; (void)version;

    uint8_t  channels    = *(inbuf + pos + 4);

    uint32_t sampleRate  = *(inbuf + pos + 5);
             sampleRate += *(inbuf + pos + 6) << 8;
             sampleRate += *(inbuf + pos + 7) << 16;
             sampleRate += *(inbuf + pos + 8) << 24;

    uint32_t br_max      = *(inbuf + pos + 9);
             br_max     += *(inbuf + pos + 10) << 8;
             br_max     += *(inbuf + pos + 11) << 16;
             br_max     += *(inbuf + pos + 12) << 24;

    uint32_t br_nominal  = *(inbuf + pos + 13);
             br_nominal += *(inbuf + pos + 14) << 8;
             br_nominal += *(inbuf + pos + 15) << 16;
             br_nominal += *(inbuf + pos + 16) << 24;

    uint32_t br_min      = *(inbuf + pos + 17);
             br_min     += *(inbuf + pos + 18) << 8;
             br_min     += *(inbuf + pos + 19) << 16;
             br_min     += *(inbuf + pos + 20) << 24;

    uint8_t  blocksize   = *(inbuf + pos + 21);

    s_blocksizes[0] = 1 << ( blocksize & 0x0F);
    s_blocksizes[1] = 1 << ((blocksize & 0xF0) >> 4);

    if(s_blocksizes[0] < 64){
        log_e("blocksize[0] too low");
        return -1;
    }
    if(s_blocksizes[1] < s_blocksizes[0]){
        log_e("s_blocksizes[1] is smaller than s_blocksizes[0]");
        return -1;
    }
    if(s_blocksizes[1] > 8192){
        log_e("s_blocksizes[1] is too big");
        return -1;
    }

    if(channels < 1 || channels > 2){
        log_e("nr of channels is not valid ch=%i", channels);
        return -1;
    }
    s_vorbisChannels = channels;

    if(sampleRate < 4096 || sampleRate > 64000){
        log_e("sampleRate is not valid sr=%i", sampleRate);
        return -1;
    }
    s_vorbisSamplerate = sampleRate;

    s_vorbisBitRate = br_nominal;

    return VORBIS_PARSE_OGG_DONE;

}
//----------------------------------------------------------------------------------------------------------------------
int32_t parseVorbisComment(uint8_t *inbuf, int16_t nBytes){      // reference https://xiph.org/vorbis/doc/v-comment.html

    // first bytes are: '.vorbis'
    uint32_t pos = 7;
    uint32_t vendorLength       = *(inbuf + pos + 3) << 24; // lengt of vendor string, e.g. Xiph.Org libVorbis I 20070622
             vendorLength      += *(inbuf + pos + 2) << 16;
             vendorLength      += *(inbuf + pos + 1) << 8;
             vendorLength      += *(inbuf + pos);

    if(vendorLength > 254){  // guard
       log_e("vorbis comment too long, vendorLength %i", vendorLength);
       return 0;
    }

    memcpy(s_vorbisChbuf, inbuf + 11, vendorLength);
    s_vorbisChbuf[vendorLength] = '\0';
    pos += 4 + vendorLength;
    s_vorbisCommentHeaderLength -= (7 + 4 + vendorLength);

    // log_i("vendorLength %x", vendorLength);
    // log_i("vendorString %s", s_vorbisChbuf);

    uint8_t nrOfComments = *(inbuf + pos);
    // log_i("nrOfComments %i", nrOfComments);
    pos += 4;
    s_vorbisCommentHeaderLength -= 4;

    int32_t idx = 0;
    char* artist = NULL;
    char* title  = NULL;
    uint32_t commentLength = 0;
    for(int32_t i = 0; i < nrOfComments; i++){
        commentLength  = 0;
        commentLength  = *(inbuf + pos + 3) << 24;
        commentLength += *(inbuf + pos + 2) << 16;
        commentLength += *(inbuf + pos + 1) << 8;
        commentLength += *(inbuf + pos);
        s_commentLength = commentLength;

        uint8_t cl = min((uint32_t)254, commentLength);
        memcpy(s_vorbisChbuf, inbuf + pos +  4, cl);
        s_vorbisChbuf[cl] = '\0';

        // log_i("commentLength %i comment %s", commentLength, s_vorbisChbuf);

        idx =        VORBIS_specialIndexOf((uint8_t*)s_vorbisChbuf, "artist=", 10);
        if(idx != 0) idx =  VORBIS_specialIndexOf((uint8_t*)s_vorbisChbuf, "ARTIST=", 10);
        if(idx == 0){ artist = strndup((const char*)(s_vorbisChbuf + 7), commentLength - 7); s_commentLength = 0;}

        idx =        VORBIS_specialIndexOf((uint8_t*)s_vorbisChbuf, "title=", 10);
        if(idx != 0) idx =  VORBIS_specialIndexOf((uint8_t*)s_vorbisChbuf, "TITLE=", 10);
        if(idx == 0){ title = strndup((const char*)(s_vorbisChbuf + 6), commentLength - 6); s_commentLength = 0;}

        idx =        VORBIS_specialIndexOf((uint8_t*)s_vorbisChbuf, "metadata_block_picture=", 25);
        if(idx != 0) idx =  VORBIS_specialIndexOf((uint8_t*)s_vorbisChbuf, "METADATA_BLOCK_PICTURE", 25);
        if(idx == 0){
            s_vorbisBlockPicLen = commentLength - 23;
            s_vorbisBlockPicPos += s_vorbisCurrentFilePos + 4 +pos + 23;
            s_vorbisBlockPicLenUntilFrameEnd = s_vorbisCommentHeaderLength - 4 - 23;
        }
        pos += commentLength + 4;
        s_vorbisCommentHeaderLength -= (4 + commentLength);
    }
    if(artist && title){
        strcpy(s_vorbisChbuf, artist);
        strcat(s_vorbisChbuf, " - ");
        strcat(s_vorbisChbuf, title);
        s_f_vorbisNewSteamTitle = true;
    }
    else if(artist){
        strcpy(s_vorbisChbuf, artist);
        s_f_vorbisNewSteamTitle = true;
    }
    else if(title){
        strcpy(s_vorbisChbuf, title);
        s_f_vorbisNewSteamTitle = true;
    }
    if(artist){free(artist); artist = NULL;}
    if(title) {free(title);  title = NULL;}

    return VORBIS_PARSE_OGG_DONE;
}
//----------------------------------------------------------------------------------------------------------------------
int32_t parseVorbisCodebook(){

    s_bitReader.headptr += 7;
    s_bitReader.length = s_oggPage3Len;

    int32_t i;
    int32_t ret = 0;

    s_nrOfCodebooks = bitReader(8) +1;
    s_codebooks = (codebook_t*) __calloc_heap_psram(s_nrOfCodebooks, sizeof(*s_codebooks));

    for(i = 0; i < s_nrOfCodebooks; i++){
        ret = vorbis_book_unpack(s_codebooks + i);
        if(ret) log_e("codebook %i returned err", i);
        if(ret) goto err_out;
    }

    /* time backend settings, not actually used */
    i = bitReader(6);
    for(; i >= 0; i--){
        ret = bitReader(16);
        if(ret != 0){
            log_e("err while reading backend settings");
            goto err_out;
        }
    }
    /* floor backend settings */
    s_nrOfFloors  = bitReader(6) + 1;

    s_floor_param = (vorbis_info_floor_t **)__malloc_heap_psram(sizeof(*s_floor_param) * s_nrOfFloors);
    s_floor_type  = (int8_t *)__malloc_heap_psram(sizeof(int8_t) * s_nrOfFloors);
    for(i = 0; i < s_nrOfFloors; i++) {
        s_floor_type[i] = bitReader(16);
        if(s_floor_type[i] < 0 || s_floor_type[i] >= VI_FLOORB) {
            log_e("err while reading floors");
            goto err_out;
        }
        if(s_floor_type[i]){
            s_floor_param[i] = floor1_info_unpack();
        }
        else{
            s_floor_param[i] = floor0_info_unpack();
        }
        if(!s_floor_param[i]){
            log_e("floor parameter not found");
            goto err_out;
        }
    }

    /* residue backend settings */
    s_nrOfResidues = bitReader(6) + 1;
    s_residue_param = (vorbis_info_residue_t *)__malloc_heap_psram(sizeof(*s_residue_param) * s_nrOfResidues);
    for(i = 0; i < s_nrOfResidues; i++){
         if(res_unpack(s_residue_param + i)){
            log_e("err while unpacking residues");
            goto err_out;
         }
    }

    // /* map backend settings */
    s_nrOfMaps = bitReader(6) + 1;
    s_map_param = (vorbis_info_mapping_t *)__malloc_heap_psram(sizeof(*s_map_param) * s_nrOfMaps);
    for(i = 0; i < s_nrOfMaps; i++) {
        if(bitReader(16) != 0) goto err_out;
        if(mapping_info_unpack(s_map_param + i)){
            log_e("err while unpacking mappings");
            goto err_out;
        }
    }

    /* mode settings */
    s_nrOfModes = bitReader(6) + 1;
    s_mode_param = (vorbis_info_mode_t *)__malloc_heap_psram(s_nrOfModes* sizeof(*s_mode_param));
    for(i = 0; i < s_nrOfModes; i++) {
        s_mode_param[i].blockflag = bitReader(1);
        if(bitReader(16)) goto err_out;
        if(bitReader(16)) goto err_out;
        s_mode_param[i].mapping = bitReader(8);
        if(s_mode_param[i].mapping >= s_nrOfMaps){
            log_e("too many modes");
            goto err_out;
        }
    }

    if(bitReader(1) != 1){
        log_e("codebooks, end bit not found");
        goto err_out;
    }
    // if(s_setupHeaderLength != s_bitReader.headptr - s_bitReader.data){
    //     log_e("Error reading setup header, assumed %i bytes, read %i bytes", s_setupHeaderLength, s_bitReader.headptr - s_bitReader.data);
    //     goto err_out;
    // }
    /* top level EOP check */

    return VORBIS_PARSE_OGG_DONE;

err_out:
//    vorbis_info_clear(vi);
    log_e("err in codebook!  at pos %d", s_bitReader.headptr - s_bitReader.data);
    return (OV_EBADHEADER);
}
//----------------------------------------------------------------------------------------------------------------------
int32_t VORBISparseOGG(uint8_t *inbuf, int32_t *bytesLeft){
                                                           // reference https://www.xiph.org/ogg/doc/rfc3533.txt
    int32_t ret = 0; (void)ret;

    int32_t idx = VORBIS_specialIndexOf(inbuf, "OggS", 8192);
    if(idx != 0){
        if(s_f_oggContinuedPage) return ERR_VORBIS_DECODER_ASYNC;
        inbuf += idx;
        *bytesLeft -= idx;
        s_vorbisCurrentFilePos += idx;
    }

    int16_t segmentTableWrPtr = -1;

    uint8_t  version            = *(inbuf +  4); (void) version;
    uint8_t  headerType         = *(inbuf +  5); (void) headerType;
    uint64_t granulePosition    = (uint64_t)*(inbuf + 13) << 56;  // granule_position: an 8 Byte field containing -
             granulePosition   += (uint64_t)*(inbuf + 12) << 48;  // position information. For an audio stream, it MAY
             granulePosition   += (uint64_t)*(inbuf + 11) << 40;  // contain the total number of PCM samples encoded
             granulePosition   += (uint64_t)*(inbuf + 10) << 32;  // after including all frames finished on this page.
             granulePosition   += *(inbuf +  9) << 24;  // This is a hint for the decoder and gives it some timing
             granulePosition   += *(inbuf +  8) << 16;  // and position information. A special value of -1 (in two's
             granulePosition   += *(inbuf +  7) << 8;   // complement) indicates that no packets finish on this page.
             granulePosition   += *(inbuf +  6); (void) granulePosition;
    uint32_t bitstreamSerialNr  = *(inbuf + 17) << 24;  // bitstream_serial_number: a 4 Byte field containing the
             bitstreamSerialNr += *(inbuf + 16) << 16;  // unique serial number by which the logical bitstream
             bitstreamSerialNr += *(inbuf + 15) << 8;   // is identified.
             bitstreamSerialNr += *(inbuf + 14); (void) bitstreamSerialNr;
    uint32_t pageSequenceNr     = *(inbuf + 21) << 24;  // page_sequence_number: a 4 Byte field containing the sequence
             pageSequenceNr    += *(inbuf + 20) << 16;  // number of the page so the decoder can identify page loss
             pageSequenceNr    += *(inbuf + 19) << 8;   // This sequence number is increasing on each logical bitstream
             pageSequenceNr    += *(inbuf + 18); (void) pageSequenceNr;
    uint32_t CRCchecksum        = *(inbuf + 25) << 24;
             CRCchecksum       += *(inbuf + 24) << 16;
             CRCchecksum       += *(inbuf + 23) << 8;
             CRCchecksum       += *(inbuf + 22); (void) CRCchecksum;
    uint8_t  pageSegments       = *(inbuf + 26);        // giving the number of segment entries

    // read the segment table (contains pageSegments bytes),  1...251: Length of the frame in bytes,
    // 255: A second byte is needed.  The total length is first_byte + second byte
    s_vorbisSegmentLength = 0;
    segmentTableWrPtr = -1;

    for(int32_t i = 0; i < pageSegments; i++){
        int32_t n = *(inbuf + 27 + i);
        while(*(inbuf + 27 + i) == 255){
            i++;
            if(i == pageSegments) break;
            n+= *(inbuf + 27 + i);
        }
        segmentTableWrPtr++;
        s_vorbisSegmentTable[segmentTableWrPtr] = n;
        s_vorbisSegmentLength += n;
    }
    s_vorbisSegmentTableSize = segmentTableWrPtr + 1;
    s_vorbisCompressionRatio = (float)(960 * 2 * pageSegments)/s_vorbisSegmentLength;  // const 960 validBytes out

    bool     continuedPage = headerType & 0x01; // set: page contains data of a packet continued from the previous page
    bool     firstPage     = headerType & 0x02; // set: this is the first page of a logical bitstream (bos)
    bool     lastPage      = headerType & 0x04; // set: this is the last page of a logical bitstream (eos)

    uint16_t headerSize    = pageSegments + 27;

    // log_i("headerSize %i, s_vorbisSegmentLength %i, s_vorbisSegmentTableSize %i", headerSize, s_vorbisSegmentLength, s_vorbisSegmentTableSize);
    if(firstPage || continuedPage || lastPage){
    // log_w("firstPage %i  continuedPage %i  lastPage %i", firstPage, continuedPage, lastPage);
    }

    *bytesLeft -= headerSize;
    inbuf += headerSize;
    s_vorbisCurrentFilePos += headerSize;
 //   if(s_pageNr < 4 && !continuedPage) s_pageNr++;

    s_f_oggFirstPage = firstPage;
    s_f_oggContinuedPage = continuedPage;
    s_f_oggLastPage = lastPage;
    s_oggHeaderSize = headerSize;

    if(firstPage) s_pageNr = 0;

    return VORBIS_PARSE_OGG_DONE; // no error
}
//----------------------------------------------------------------------------------------------------------------------
uint16_t continuedOggPackets(uint8_t *inbuf){

    // skip OggS header to pageSegments
    // log_w("%c%c%c%c", *(inbuf+0), *(inbuf+1), *(inbuf+2), *(inbuf+3));
    uint16_t segmentLength = 0;
    uint8_t  headerType    = *(inbuf +  5);
    uint8_t  pageSegments  = *(inbuf + 26);        // giving the number of segment entries

    for(int32_t i = 0; i < pageSegments; i++){
        int32_t n = *(inbuf + 27 + i);
        while(*(inbuf + 27 + i) == 255){
            i++;
            if(i == pageSegments) break;
            n+= *(inbuf + 27 + i);
        }
        segmentLength += n;
    }
    uint16_t headerSize = pageSegments + 27;
    bool continuedPage = headerType & 0x01;

    if(continuedPage){

    //  codebook data are in 2 ogg packets
    //  codebook data must no be interrupted by oggPH (ogg page header)
    //  therefore shift codebook data2 left (oggPH size times) whith memmove
    //  |oggPH| codebook data 1 |oggPH| codebook data 2 |oggPH|
    //  |oppPH| codebook data 1 + 2              |unused|occPH|
log_e("continued page");
        memmove(inbuf , inbuf + headerSize, segmentLength);
        return segmentLength + headerSize;
        return 0;
    }

    return 0;
}
//----------------------------------------------------------------------------------------------------------------------
int32_t VORBISFindSyncWord(unsigned char *buf, int32_t nBytes){
    // assume we have a ogg wrapper
    int32_t idx = VORBIS_specialIndexOf(buf, "OggS", nBytes);
    if(idx >= 0){ // Magic Word found
    //    log_i("OggS found at %i", idx);
        return idx;
    }
    // log_i("find sync");
    return ERR_VORBIS_OGG_SYNC_NOT_FOUND;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t vorbis_book_unpack(codebook_t *s) {
    char   *lengthlist = NULL;
    uint8_t quantvals = 0;
    int32_t i, j;
    int32_t     maptype;
    int32_t     ret = 0;

    memset(s, 0, sizeof(*s));

    /* make sure alignment is correct */
    if(bitReader(24) != 0x564342){
        log_e("String \"BCV\" not found");
        goto _eofout;  // "BCV"
    }

    /* first the basic parameters */
    ret = bitReader(16) ;
    if(ret < 0) printf("error in vorbis_book_unpack, ret =%li\n", (long int)ret);
    if(ret > 255) printf("error in vorbis_book_unpack, ret =%li\n", (long int)ret);
    s->dim = (uint8_t)ret;
    s->entries = bitReader(24);
    if(s->entries == -1) {log_e("no entries in unpack codebooks ?");   goto _eofout;}

    /* codeword ordering.... length ordered or unordered? */
    switch(bitReader(1)) {
        case 0:
            /* unordered */
            lengthlist = (char *)__malloc_heap_psram(sizeof(*lengthlist) * s->entries);

            /* allocated but unused entries? */
            if(bitReader(1)) {
                /* yes, unused entries */

                for(i = 0; i < s->entries; i++) {
                    if(bitReader(1)) {
                        int32_t num = bitReader(5);
                        if(num == -1) goto _eofout;
                        lengthlist[i] = num + 1;
                        s->used_entries++;
                        if(num + 1 > s->dec_maxlength) s->dec_maxlength = num + 1;
                    }
                    else
                        lengthlist[i] = 0;
                }
            }
            else {
                /* all entries used; no tagging */
                s->used_entries = s->entries;
                for(i = 0; i < s->entries; i++) {
                    int32_t num = bitReader(5);
                    if(num == -1) goto _eofout;
                    lengthlist[i] = num + 1;

                    if(num + 1 > s->dec_maxlength) s->dec_maxlength = num + 1;
                }
            }
            break;
        case 1:
            /* ordered */
            {
                int32_t length = bitReader(5) + 1;

                s->used_entries = s->entries;
                lengthlist = (char *)__malloc_heap_psram(sizeof(*lengthlist) * s->entries);

                for(i = 0; i < s->entries;) {
                    int32_t num = bitReader(_ilog(s->entries - i));
                    if(num == -1) goto _eofout;
                    for(j = 0; j < num && i < s->entries; j++, i++) lengthlist[i] = length;
                    s->dec_maxlength = length;
                    length++;
                }
            }
            break;
        default:
            /* EOF */
            goto _eofout;
    }

    /* Do we have a mapping to unpack? */
    if((maptype = bitReader(4)) > 0) {
        s->q_min = _float32_unpack(bitReader(32), &s->q_minp);
        s->q_del = _float32_unpack(bitReader(32), &s->q_delp);

        s->q_bits = bitReader(4) + 1;
        s->q_seq =  bitReader(1);

        s->q_del >>= s->q_bits;
        s->q_delp += s->q_bits;
    }

    switch(maptype) {
        case 0:
            /* no mapping; decode type 0 */
            /* how many bytes for the indexing? */
            /* this is the correct boundary here; we lose one bit to node/leaf mark */
            s->dec_nodeb = _determine_node_bytes(s->used_entries, _ilog(s->entries) / 8 + 1);
            s->dec_leafw = _determine_leaf_words(s->dec_nodeb, _ilog(s->entries) / 8 + 1);
            s->dec_type = 0;
            ret = _make_decode_table(s, lengthlist, quantvals, maptype);
            if(ret != 0) {
                 goto _errout;
            }
            break;

        case 1:
            /* mapping type 1; implicit values by lattice  position */
            quantvals = _book_maptype1_quantvals(s);

            /* dec_type choices here are 1,2; 3 doesn't make sense */
            {
                /* packed values */
                int32_t total1 = (s->q_bits * s->dim + 8) / 8; /* remember flag bit */
                /* vector of column offsets; remember flag bit */
                int32_t total2 = (_ilog(quantvals - 1) * s->dim + 8) / 8 + (s->q_bits + 7) / 8;

                if(total1 <= 4 && total1 <= total2) {
                    /* use dec_type 1: vector of packed values */
                    /* need quantized values before  */
                    s->q_val = __malloc_heap_psram(sizeof(uint16_t) * quantvals);
                    for(i = 0; i < quantvals; i++) ((uint16_t *)s->q_val)[i] = bitReader(s->q_bits);

                    if(oggpack_eop()) {
                        if(s->q_val) {free(s->q_val), s->q_val = NULL;}
                        goto _eofout;
                    }

                    s->dec_type = 1;
                    s->dec_nodeb = _determine_node_bytes(s->used_entries, (s->q_bits * s->dim + 8) / 8);
                    s->dec_leafw = _determine_leaf_words(s->dec_nodeb, (s->q_bits * s->dim + 8) / 8);
                    ret = _make_decode_table(s, lengthlist, quantvals, maptype);
                    if(ret) {
                        if(s->q_val) {free(s->q_val), s->q_val = NULL;}
                        goto _errout;
                    }

                    if(s->q_val) {free(s->q_val), s->q_val = NULL;} /* about to go out of scope; _make_decode_table was using it */
                }
                else {
                    /* use dec_type 2: packed vector of column offsets */
                    /* need quantized values before */
                    if(s->q_bits <= 8) {
                        s->q_val = __malloc_heap_psram(quantvals);
                        for(i = 0; i < quantvals; i++) ((uint8_t *)s->q_val)[i] = bitReader(s->q_bits);
                    }
                    else {
                        s->q_val = __malloc_heap_psram(quantvals * 2);
                        for(i = 0; i < quantvals; i++) ((uint16_t *)s->q_val)[i] = bitReader(s->q_bits);
                    }

                    if(oggpack_eop()) goto _eofout;

                    s->q_pack = _ilog(quantvals - 1);
                    s->dec_type = 2;
                    s->dec_nodeb = _determine_node_bytes(s->used_entries, (_ilog(quantvals - 1) * s->dim + 8) / 8);
                    s->dec_leafw = _determine_leaf_words(s->dec_nodeb, (_ilog(quantvals - 1) * s->dim + 8) / 8);

                    ret = _make_decode_table(s, lengthlist, quantvals, maptype);
                    if(ret){
                        goto _errout;
                    }
                }
            }
            break;
        case 2:
            /* mapping type 2; explicit array of values */
            quantvals = s->entries * s->dim;
            /* dec_type choices here are 1,3; 2 is not possible */

            if((s->q_bits * s->dim + 8) / 8 <= 4) { /* remember flag bit */
                /* use dec_type 1: vector of packed values */

                s->dec_type = 1;
                s->dec_nodeb = _determine_node_bytes(s->used_entries, (s->q_bits * s->dim + 8) / 8);
                s->dec_leafw = _determine_leaf_words(s->dec_nodeb, (s->q_bits * s->dim + 8) / 8);
                if(_make_decode_table(s, lengthlist, quantvals, maptype)) goto _errout;
            }
            else {
                /* use dec_type 3: scalar offset into packed value array */

                s->dec_type = 3;
                s->dec_nodeb = _determine_node_bytes(s->used_entries, _ilog(s->used_entries - 1) / 8 + 1);
                s->dec_leafw = _determine_leaf_words(s->dec_nodeb, _ilog(s->used_entries - 1) / 8 + 1);
                if(_make_decode_table(s, lengthlist, quantvals, maptype)) goto _errout;

                /* get the vals & pack them */
                s->q_pack = (s->q_bits + 7) / 8 * s->dim;
                s->q_val = __malloc_heap_psram(s->q_pack * s->used_entries);

                if(s->q_bits <= 8) {
                    for(i = 0; i < s->used_entries * s->dim; i++)
                        ((uint8_t *)(s->q_val))[i] = bitReader(s->q_bits);
                }
                else {
                    for(i = 0; i < s->used_entries * s->dim; i++)
                        ((uint16_t *)(s->q_val))[i] = bitReader(s->q_bits);
                }
            }
            break;
        default:
            log_e("maptype %i schould be 0, 1 or 2", maptype);
            goto _errout;
    }
    if(oggpack_eop()) goto _eofout;
    if(lengthlist) {free(lengthlist); lengthlist = NULL;}
    if(s->q_val)   {free(s->q_val), s->q_val = NULL;}
    return 0; // ok
_errout:
_eofout:
    vorbis_book_clear(s);
    if(lengthlist) {free(lengthlist); lengthlist = NULL;}
    if(s->q_val)   {free(s->q_val), s->q_val = NULL;}
    return -1; // error
}
//---------------------------------------------------------------------------------------------------------------------

//----------------------------------------------------------------------------------------------------------------------
int32_t VORBIS_specialIndexOf(uint8_t* base, const char* str, int32_t baselen, bool exact){
    int32_t result = -1;  // seek for str in buffer or in header up to baselen, not nullterninated
    if (strlen(str) > baselen) return -1; // if exact == true seekstr in buffer must have "\0" at the end
    for (int32_t i = 0; i < baselen - strlen(str); i++){
        result = i;
        for (int32_t j = 0; j < strlen(str) + exact; j++){
            if (*(base + i + j) != *(str + j)){
                result = -1;
                break;
            }
        }
        if (result >= 0) break;
    }
    return result;
}

//----------------------------------------------------------------------------------------------------------------------
const uint32_t mask[] = {0x00000000, 0x00000001, 0x00000003, 0x00000007, 0x0000000f, 0x0000001f, 0x0000003f,
                         0x0000007f, 0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff, 0x00001fff,
                         0x00003fff, 0x00007fff, 0x0000ffff, 0x0001ffff, 0x0003ffff, 0x0007ffff, 0x000fffff,
                         0x001fffff, 0x003fffff, 0x007fffff, 0x00ffffff, 0x01ffffff, 0x03ffffff, 0x07ffffff,
                         0x0fffffff, 0x1fffffff, 0x3fffffff, 0x7fffffff, 0xffffffff};


void bitReader_clear(){
    s_bitReader.data = NULL;
    s_bitReader.headptr = NULL;
    s_bitReader.length = 0;
    s_bitReader.headend = 0;
    s_bitReader.headbit = 0;
}

void bitReader_setData(uint8_t *buff, uint16_t buffSize){
    s_bitReader.data = buff;
    s_bitReader.headptr = buff;
    s_bitReader.length = buffSize;
    s_bitReader.headend = buffSize * 8;
    s_bitReader.headbit = 0;
}

//----------------------------------------------------------------------------------------------------------------------
/* Read in bits without advancing the bitptr; bits <= 32 */
int32_t bitReader_look(uint16_t nBits){
    uint32_t m = mask[nBits];
    int32_t  ret = 0;

    nBits += s_bitReader.headbit;

    if(nBits >= s_bitReader.headend << 3) {
        uint8_t       *ptr = s_bitReader.headptr;
        if(nBits) {
            ret = *ptr++ >> s_bitReader.headbit;
            if(nBits > 8) {
                ret |= *ptr++ << (8 - s_bitReader.headbit);
                if(nBits > 16) {
                    ret |= *ptr++ << (16 - s_bitReader.headbit);
                    if(nBits > 24) {
                         ret |= *ptr++ << (24 - s_bitReader.headbit);
                        if(nBits > 32 && s_bitReader.headbit) {
                            ret |= *ptr << (32 - s_bitReader.headbit);
                        }
                    }
                }
            }
        }
    }
    else {
        /* make this a switch jump-table */
        ret = s_bitReader.headptr[0] >> s_bitReader.headbit;
        if(nBits > 8) {
            ret |= s_bitReader.headptr[1] << (8 - s_bitReader.headbit);
            if(nBits > 16) {
                ret |= s_bitReader.headptr[2] << (16 - s_bitReader.headbit);
                if(nBits > 24) {
                    ret |= s_bitReader.headptr[3] << (24 - s_bitReader.headbit);
                    if(nBits > 32 && s_bitReader.headbit) ret |= s_bitReader.headptr[4] << (32 - s_bitReader.headbit);
                }
            }
        }
    }

    ret &= (int32_t)m;
    return ret;
}

/* bits <= 32 */
int32_t bitReader(uint16_t nBits) {
    int32_t ret = bitReader_look(nBits);
    if(bitReader_adv(nBits) < 0) return -1;
    return (ret);
}

/* limited to 32 at a time */
int8_t bitReader_adv(uint16_t nBits) {
    nBits += s_bitReader.headbit;
    s_bitReader.headbit = nBits & 7;
    s_bitReader.headend -= (nBits >> 3);
    s_bitReader.headptr += (nBits >> 3);
    if(s_bitReader.headend < 1){
        return -1;
        log_e("error in bitreader");
    }
    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t ilog(uint32_t v) {
    int32_t ret = 0;
    if(v) --v;
    while(v) {
        ret++;
        v >>= 1;
    }
    return (ret);
}
//----------------------------------------------------------------------------------------------------------------------
uint8_t _ilog(uint32_t v) {
    uint8_t ret = 0;
    while(v) {
        ret++;
        v >>= 1;
    }
    return (ret);
}
//---------------------------------------------------------------------------------------------------------------------
/* 32 bit float (not IEEE; nonnormalized mantissa + biased exponent) : neeeeeee eeemmmmm mmmmmmmm mmmmmmmm
 Why not IEEE?  It's just not that important here. */

int32_t _float32_unpack(int32_t val, int32_t *point) {
    int32_t mant = val & 0x1fffff;
    bool    sign = val < 0;

    *point = ((val & 0x7fe00000L) >> 21) - 788;

    if(mant) {
        while(!(mant & 0x40000000)) {
            mant <<= 1;
            *point -= 1;
        }
        if(sign) mant = -mant;
    }
    else { *point = -9999; }
    return mant;
}
//---------------------------------------------------------------------------------------------------------------------
/* choose the smallest supported node size that fits our decode table. Legal bytewidths are 1/1 1/2 2/2 2/4 4/4 */
int32_t _determine_node_bytes(uint32_t used, uint8_t leafwidth) {
    /* special case small books to size 4 to avoid multiple special cases in repack */
    if(used < 2) return 4;

    if(leafwidth == 3) leafwidth = 4;
    if(_ilog((3 * used - 6)) + 1 <= leafwidth * 4) return leafwidth / 2 ? leafwidth / 2 : 1;
    return leafwidth;
}
//---------------------------------------------------------------------------------------------------------------------
/* convenience/clarity; leaves are specified as multiple of node word size (1 or 2) */
int32_t _determine_leaf_words(int32_t nodeb, int32_t leafwidth) {
    if(leafwidth > nodeb) return 2;
    return 1;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t _make_decode_table(codebook_t *s, char *lengthlist, uint8_t quantvals, int32_t maptype) {
    uint32_t *work = nullptr;

    if(s->dec_nodeb == 4) {
        s->dec_table = __malloc_heap_psram((s->used_entries * 2 + 1) * sizeof(*work));
        /* +1 (rather than -2) is to accommodate 0 and 1 sized books, which are specialcased to nodeb==4 */
        if(_make_words(lengthlist, s->entries, (uint32_t *)s->dec_table, quantvals, s, maptype)) return 1;

        return 0;
    }

    work = (uint32_t *)__calloc_heap_psram((uint32_t)(s->used_entries * 2 - 2) , sizeof(*work));
    if(!work) log_e("oom");

    if(_make_words(lengthlist, s->entries, work, quantvals, s, maptype)) {
        if(work) {free(work); work = NULL;}
        return 1;
    }
    s->dec_table = __malloc_heap_psram((s->used_entries * (s->dec_leafw + 1) - 2) * s->dec_nodeb);
    if(s->dec_leafw == 1) {
        switch(s->dec_nodeb) {
            case 1:
                for(uint32_t i = 0; i < s->used_entries * 2 - 2; i++)
                    ((uint8_t *)s->dec_table)[i] = (uint16_t)((work[i] & 0x80000000UL) >> 24) | work[i];
                break;
            case 2:
                for(uint32_t i = 0; i < s->used_entries * 2 - 2; i++)
                    ((uint16_t *)s->dec_table)[i] = (uint16_t)((work[i] & 0x80000000UL) >> 16) | work[i];
                break;
        }
    }
    else {
        /* more complex; we have to do a two-pass repack that updates the node indexing. */
        uint32_t top = s->used_entries * 3 - 2;
        if(s->dec_nodeb == 1) {
            uint8_t *out = (uint8_t *)s->dec_table;

            for(int32_t i = s->used_entries * 2 - 4; i >= 0; i -= 2) {
                if(work[i] & 0x80000000UL) {
                    if(work[i + 1] & 0x80000000UL) {
                        top -= 4;
                        out[top] = (uint8_t)(work[i] >> 8 & 0x7f) | 0x80;
                        out[top + 1] = (uint8_t)(work[i + 1] >> 8 & 0x7f) | 0x80;
                        out[top + 2] = (uint8_t)work[i] & 0xff;
                        out[top + 3] = (uint8_t)work[i + 1] & 0xff;
                    }
                    else {
                        top -= 3;
                        out[top] = (uint8_t)(work[i] >> 8 & 0x7f) | 0x80;
                        out[top + 1] = (uint8_t)work[work[i + 1] * 2];
                        out[top + 2] = (uint8_t)work[i] & 0xff;
                    }
                }
                else {
                    if(work[i + 1] & 0x80000000UL) {
                        top -= 3;
                        out[top]     = (uint8_t)work[work[i] * 2];
                        out[top + 1] = (uint8_t)(work[i + 1] >> 8 & 0x7f) | 0x80;
                        out[top + 2] = (uint8_t)work[i + 1] & 0xff;
                    }
                    else {
                        top -= 2;
                        out[top] = (uint8_t)work[work[i] * 2];
                        out[top + 1] = (uint8_t)work[work[i + 1] * 2];
                    }
                }
                work[i] = top;
            }
        }
        else {
            uint16_t *out = (uint16_t *)s->dec_table;
            for(int32_t i = s->used_entries * 2 - 4; i >= 0; i -= 2) {
                if(work[i] & 0x80000000UL) {
                    if(work[i + 1] & 0x80000000UL) {
                        top -= 4;
                        out[top] = (uint16_t)(work[i] >> 16 & 0x7fff) | 0x8000;
                        out[top + 1] = (uint16_t)(work[i + 1] >> 16 & 0x7fff) | 0x8000;
                        out[top + 2] = (uint16_t)work[i] & 0xffff;
                        out[top + 3] = (uint16_t)work[i + 1] & 0xffff;
                    }
                    else {
                        top -= 3;
                        out[top] = (uint16_t)(work[i] >> 16 & 0x7fff) | 0x8000;
                        out[top + 1] = (uint16_t)work[work[i + 1] * 2];
                        out[top + 2] = (uint16_t)work[i] & 0xffff;
                    }
                }
                else {
                    if(work[i + 1] & 0x80000000UL) {
                        top -= 3;
                        out[top] = (uint16_t)work[work[i] * 2];
                        out[top + 1] = (uint16_t)(work[i + 1] >> 16 & 0x7fff) | 0x8000;
                        out[top + 2] = (uint16_t)work[i + 1] & 0xffff;
                    }
                    else {
                        top -= 2;
                        out[top] = (uint16_t)work[work[i] * 2];
                        out[top + 1] = (uint16_t)work[work[i + 1] * 2];
                    }
                }
                work[i] = (uint32_t)top;
            }
        }
    }
    if(work) {free(work); work = NULL;}
    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
/* given a list of word lengths, number of used entries, and byte width of a leaf, generate the decode table */
int32_t _make_words(char *l, uint16_t n, uint32_t *work, uint8_t quantvals, codebook_t *b, int32_t maptype) {

    int32_t  i, j, count = 0;
    uint32_t top = 0;
    uint32_t marker[33];

    if(n < 2) { work[0] = 0x80000000; }
    else {
        memset(marker, 0, sizeof(marker));

        for(i = 0; i < n; i++) {
            int32_t length = l[i];
            if(length) {
                uint32_t entry = marker[length];
                uint32_t chase = 0;
                if(count && !entry) return -1; /* overpopulated tree! */

                /* chase the tree as far as it's already populated, fill in past */
                for(j = 0; j < length - 1; j++) {
                    uint32_t bit = (entry >> (length - j - 1)) & 1;
                    if(chase >= top) {
                        top++;
                        work[chase * 2] = top;
                        work[chase * 2 + 1] = 0;
                    }
                    else if(!work[chase * 2 + bit]){
                        work[chase * 2 + bit] = top;
                    }
                    chase = work[chase * 2 + bit];
                }
                {
                    int32_t bit = (entry >> (length - j - 1)) & 1;
                    if(chase >= top) {
                        top++;
                        work[chase * 2 + 1] = 0;
                    }
                    work[chase * 2 + bit] = decpack(i, count++, quantvals, b, maptype) | 0x80000000;
                }

                /* Look to see if the next shorter marker points to the node above. if so, update it and repeat.  */
                for(j = length; j > 0; j--) {
                    if(marker[j] & 1) {
                        marker[j] = marker[j - 1] << 1;
                        break;
                    }
                    marker[j]++;
                }

                /* prune the tree; the implicit invariant says all the int32_ter markers were dangling from our
                   just-taken node. Dangle them from our *new* node. */
                for(j = length + 1; j < 33; j++)
                    if((marker[j] >> 1) == entry) {
                        entry = marker[j];
                        marker[j] = marker[j - 1] << 1;
                    }
                    else
                        break;
            }
        }
    }

    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
uint32_t decpack(int32_t entry, int32_t used_entry, uint8_t quantvals, codebook_t *b, int32_t maptype) {
    uint32_t ret = 0;

    switch(b->dec_type) {
        case 0:
            return (uint32_t)entry;

        case 1:
            if(maptype == 1) {
                /* vals are already read into temporary column vector here */
                assert(b->dim >= 0);
                for(uint8_t j = 0; j < b->dim; j++) {
                    uint32_t off = (uint32_t)(entry % quantvals);
                    entry /= quantvals;
                    assert((b->q_bits * j) >= 0);
                    uint32_t shift = (uint32_t)b->q_bits * j;
                    ret |= ((uint16_t *)(b->q_val))[off] << shift;
                }
            }
            else {
                assert(b->dim >= 0);
                for(uint8_t j = 0; j < b->dim; j++) {
                    assert((b->q_bits * j) >= 0);
                    uint32_t shift = (uint32_t)b->q_bits * j;
                    int32_t  _ret = bitReader(b->q_bits) << shift;
                    assert(_ret >= 0);
                    ret |= (uint32_t)_ret;
                }
            }
            return ret;

        case 2:
            assert(b->dim >= 0);
            for(uint8_t j = 0; j < b->dim; j++) {
                uint32_t off = uint32_t(entry % quantvals);
                entry /= quantvals;
                assert(b->q_pack * j >= 0);
                assert(b->q_pack * j <= 255);
                ret |= off << (uint8_t)(b->q_pack * j);
            }
            return ret;

        case 3:
            return (uint32_t)used_entry;
    }
    return 0; /* silence compiler */
}
//---------------------------------------------------------------------------------------------------------------------
/* most of the time, entries%dimensions == 0, but we need to be well defined.  We define that the possible vales at
 each scalar is values == entries/dim.  If entries%dim != 0, we'll have 'too few' values (values*dim<entries), which
 means that we'll have 'left over' entries; left over entries use zeroed values (and are wasted).  So don't generate
 codebooks like that */
/* there might be a straightforward one-line way to do the below that's portable and totally safe against roundoff, but
 I haven't thought of it.  Therefore, we opt on the side of caution */
uint8_t _book_maptype1_quantvals(codebook_t *b) {
    /* get us a starting hint, we'll polish it below */
    uint8_t bits = _ilog(b->entries);
    uint8_t vals = b->entries >> ((bits - 1) * (b->dim - 1) / b->dim);

    while(1) {
        uint32_t acc = 1;
        uint32_t acc1 = 1;

        for(uint8_t i = 0; i < b->dim; i++) {
            acc *= vals;
            acc1 *= vals + 1;
        }
        if(acc <= b->entries && acc1 > b->entries) { return (vals); }
        else {
            if(acc > b->entries) { vals--; }
            else { vals++; }
        }
    }
}
//---------------------------------------------------------------------------------------------------------------------
int32_t oggpack_eop() {
    if(s_bitReader.headptr -s_bitReader.data  > s_setupHeaderLength){
        log_i("s_bitReader.headptr %i, s_setupHeaderLength %i", s_bitReader.headptr, s_setupHeaderLength);
        log_i("ogg package 3 overflow");
         return -1;
    }
    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
void vorbis_book_clear(codebook_t *b) {
    /* static book is not cleared; we're likely called on the lookup and the static codebook beint32_ts to the
   info struct */
    if(b->q_val) free(b->q_val);
    if(b->dec_table) free(b->dec_table);

    memset(b, 0, sizeof(*b));
}
//---------------------------------------------------------------------------------------------------------------------
 vorbis_info_floor_t* floor0_info_unpack() {

    int32_t               j;

    vorbis_info_floor_t *info = (vorbis_info_floor_t *)__malloc_heap_psram(sizeof(*info));
    info->order =    bitReader( 8);
    info->rate =     bitReader(16);
    info->barkmap =  bitReader(16);
    info->ampbits =  bitReader( 6);
    info->ampdB =    bitReader( 8);
    info->numbooks = bitReader( 4) + 1;

    if(info->order < 1) goto err_out;
    if(info->rate < 1) goto err_out;
    if(info->barkmap < 1) goto err_out;

    for(j = 0; j < info->numbooks; j++) {
        info->books[j] = bitReader(8);
        if(info->books[j] >= s_nrOfCodebooks) goto err_out;
    }

    if(oggpack_eop()) goto err_out;
    return (info);

err_out:
    floor_free_info(info);
    return (NULL);
}
//---------------------------------------------------------------------------------------------------------------------
vorbis_info_floor_t* floor1_info_unpack() {

    int32_t j, k, count = 0, maxclass = -1, rangebits;

    vorbis_info_floor_t *info = (vorbis_info_floor_t *)__calloc_heap_psram(1, sizeof(vorbis_info_floor_t));
    /* read partitions */
    info->partitions = bitReader(5); /* only 0 to 31 legal */
    info->partitionclass = (uint8_t *)__malloc_heap_psram(info->partitions * sizeof(*info->partitionclass));
    for(j = 0; j < info->partitions; j++) {
        info->partitionclass[j] = bitReader(4); /* only 0 to 15 legal */
        if(maxclass < info->partitionclass[j]) maxclass = info->partitionclass[j];
    }

    /* read partition classes */
    info->_class = (floor1class_t *)__malloc_heap_psram((uint32_t)(maxclass + 1) * sizeof(*info->_class));
    for(j = 0; j < maxclass + 1; j++) {
        info->_class[j].class_dim = bitReader(3) + 1; /* 1 to 8 */
        info->_class[j].class_subs = bitReader(2);    /* 0,1,2,3 bits */
        if(oggpack_eop() < 0) goto err_out;
        if(info->_class[j].class_subs){
            info->_class[j].class_book = bitReader(8);
        }
        else{
            info->_class[j].class_book = 0;
        }
        if(info->_class[j].class_book >= s_nrOfCodebooks) goto err_out;
        for(k = 0; k < (1 << info->_class[j].class_subs); k++) {
            info->_class[j].class_subbook[k] = (uint8_t)bitReader(8) - 1;
            if(info->_class[j].class_subbook[k] >= s_nrOfCodebooks && info->_class[j].class_subbook[k] != 0xff) goto err_out;
        }
    }

    /* read the post list */
    info->mult = bitReader(2) + 1; /* only 1,2,3,4 legal now */
    rangebits = bitReader(4);

    for(j = 0, k = 0; j < info->partitions; j++) count += info->_class[info->partitionclass[j]].class_dim;
    info->postlist = (uint16_t *)__malloc_heap_psram((count + 2) * sizeof(*info->postlist));
    info->forward_index = (uint8_t *)__malloc_heap_psram((count + 2) * sizeof(*info->forward_index));
    info->loneighbor = (uint8_t *)__malloc_heap_psram(count * sizeof(*info->loneighbor));
    info->hineighbor = (uint8_t *)__malloc_heap_psram(count * sizeof(*info->hineighbor));

    count = 0;
    for(j = 0, k = 0; j < info->partitions; j++) {
        count += info->_class[info->partitionclass[j]].class_dim;
        if(count > VIF_POSIT) goto err_out;
        for(; k < count; k++) {
            int32_t t = info->postlist[k + 2] = bitReader(rangebits);
            if(t >= (1 << rangebits)) goto err_out;
        }
    }
    if(oggpack_eop()) goto err_out;
    info->postlist[0] = 0;
    info->postlist[1] = 1 << rangebits;
    info->posts = count + 2;

    /* also store a sorted position index */
    for(j = 0; j < info->posts; j++) info->forward_index[j] = j;
    vorbis_mergesort(info->forward_index, info->postlist, info->posts);

    /* discover our neighbors for decode where we don't use fit flags (that would push the neighbors outward) */
    for(j = 0; j < info->posts - 2; j++) {
        int32_t lo = 0;
        int32_t hi = 1;
        int32_t lx = 0;
        int32_t hx = info->postlist[1];
        int32_t currentx = info->postlist[j + 2];
        for(k = 0; k < j + 2; k++) {
            int32_t x = info->postlist[k];
            if(x > lx && x < currentx) {
                lo = k;
                lx = x;
            }
            if(x < hx && x > currentx) {
                hi = k;
                hx = x;
            }
        }
        info->loneighbor[j] = lo;
        info->hineighbor[j] = hi;
    }

    return (info);

err_out:
    floor_free_info(info);
    return (NULL);
}
//---------------------------------------------------------------------------------------------------------------------
/* vorbis_info is for range checking */
int32_t res_unpack(vorbis_info_residue_t *info){
    int32_t               j, k;
    memset(info, 0, sizeof(*info));

    info->type =       bitReader(16);
    if(info->type > 2 || info->type < 0) goto errout;
    info->begin =      bitReader(24);
    info->end =        bitReader(24);
    info->grouping =   bitReader(24) + 1;
    info->partitions = bitReader(6) + 1;
    info->groupbook =  bitReader(8);
    if(info->groupbook >= s_nrOfCodebooks) goto errout;

    info->stagemasks = (uint8_t *)__malloc_heap_psram(info->partitions * sizeof(*info->stagemasks));
    info->stagebooks = (uint8_t *)__malloc_heap_psram(info->partitions * 8 * sizeof(*info->stagebooks));

    for(j = 0; j < info->partitions; j++) {
        int32_t cascade = bitReader(3);
        if(bitReader(1)) cascade |= (bitReader(5) << 3);
        info->stagemasks[j] = cascade;
    }

    for(j = 0; j < info->partitions; j++) {
        for(k = 0; k < 8; k++) {
            if((info->stagemasks[j] >> k) & 1) {
                uint8_t book = bitReader(8);
                if(book >= s_nrOfCodebooks) goto errout;
                info->stagebooks[j * 8 + k] = book;
                if(k + 1 > info->stages) info->stages = k + 1;
            }
            else
                info->stagebooks[j * 8 + k] = 0xff;
        }
    }

    if(oggpack_eop()) goto errout;

    return 0;
errout:
    res_clear_info(info);
    return 1;
}
//---------------------------------------------------------------------------------------------------------------------
/* also responsible for range checking */
int32_t mapping_info_unpack(vorbis_info_mapping_t *info) {
    int32_t               i;
    memset(info, 0, sizeof(*info));

    if(bitReader(1)) info->submaps = bitReader(4) + 1;
    else
        info->submaps = 1;

    if(bitReader(1)) {
        info->coupling_steps = bitReader(8) + 1;
        info->coupling = (coupling_step_t *)__malloc_heap_psram(info->coupling_steps * sizeof(*info->coupling));

        for(i = 0; i < info->coupling_steps; i++) {
            int32_t testM = info->coupling[i].mag = bitReader(ilog(s_vorbisChannels));
            int32_t testA = info->coupling[i].ang = bitReader(ilog(s_vorbisChannels));

            if(testM < 0 || testA < 0 || testM == testA || testM >= s_vorbisChannels || testA >= s_vorbisChannels) goto err_out;
        }
    }

    if(bitReader(2) > 0) goto err_out;
    /* 2,3:reserved */

    if(info->submaps > 1) {
        info->chmuxlist = (uint8_t *)__malloc_heap_psram(sizeof(*info->chmuxlist) * s_vorbisChannels);
        for(i = 0; i < s_vorbisChannels; i++) {
            info->chmuxlist[i] = bitReader(4);
            if(info->chmuxlist[i] >= info->submaps) goto err_out;
        }
    }

    info->submaplist = (submap_t *)__malloc_heap_psram(sizeof(*info->submaplist) * info->submaps);
    for(i = 0; i < info->submaps; i++) {
        int32_t temp = bitReader(8);
        (void)temp;
        info->submaplist[i].floor = bitReader(8);
        if(info->submaplist[i].floor >= s_nrOfFloors) goto err_out;
        info->submaplist[i].residue = bitReader(8);
        if(info->submaplist[i].residue >= s_nrOfResidues) goto err_out;
    }

    return 0;

err_out:
    mapping_clear_info(info);
    return -1;
}
//---------------------------------------------------------------------------------------------------------------------
void vorbis_mergesort(uint8_t *index, uint16_t *vals, uint16_t n) {
    uint16_t i, j;
    uint8_t *temp;
    uint8_t *A = index;
    uint8_t *B = (uint8_t *)__malloc_heap_psram(n * sizeof(*B));

    for(i = 1; i < n; i <<= 1) {
        for(j = 0; j + i < n;) {
            uint16_t k1 = j;
            uint16_t mid = j + i;
            uint16_t k2 = mid;
            int32_t      end = (j + i * 2 < n ? j + i * 2 : n);
            while(k1 < mid && k2 < end) {
                if(vals[A[k1]] < vals[A[k2]]) B[j++] = A[k1++];
                else
                    B[j++] = A[k2++];
            }
            while(k1 < mid) B[j++] = A[k1++];
            while(k2 < end) B[j++] = A[k2++];
        }
        for(; j < n; j++) B[j] = A[j];
        temp = A;
        A = B;
        B = temp;
    }

    if(B == index) {
        for(j = 0; j < n; j++) B[j] = A[j];
        free(A);
    }
    else
        free(B);
}
//---------------------------------------------------------------------------------------------------------------------
void floor_free_info(vorbis_info_floor_t *i) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)i;
    if(info) {
        if(info->_class)         {free(info->_class);        }
        if(info->partitionclass) {free(info->partitionclass);}
        if(info->postlist)       {free(info->postlist);      }
        if(info->forward_index)  {free(info->forward_index); }
        if(info->hineighbor)     {free(info->hineighbor);    }
        if(info->loneighbor)     {free(info->loneighbor);    }
        memset(info, 0, sizeof(*info));
        if(info) free(info);
    }
}
//---------------------------------------------------------------------------------------------------------------------
void res_clear_info(vorbis_info_residue_t *info) {
    if(info) {
        if(info->stagemasks) free(info->stagemasks);
        if(info->stagebooks) free(info->stagebooks);
        memset(info, 0, sizeof(*info));
    }
}
//---------------------------------------------------------------------------------------------------------------------
void mapping_clear_info(vorbis_info_mapping_t *info) {
    if(info) {
        if(info->chmuxlist) free(info->chmuxlist);
        if(info->submaplist) free(info->submaplist);
        if(info->coupling) free(info->coupling);
        memset(info, 0, sizeof(*info));
    }
}
//---------------------------------------------------------------------------------------------------------------------
//      ⏫⏫⏫    O G G      I M P L     A B O V E  ⏫⏫⏫
//      ⏬⏬⏬ V O R B I S   I M P L     B E L O W  ⏬⏬⏬
//---------------------------------------------------------------------------------------------------------------------
vorbis_dsp_state_t *vorbis_dsp_create() {
    int32_t i;

    vorbis_dsp_state_t *v = (vorbis_dsp_state_t *)__calloc_heap_psram(1, sizeof(vorbis_dsp_state_t));

    v->work = (int32_t **)__malloc_heap_psram(s_vorbisChannels * sizeof(*v->work));
    v->mdctright = (int32_t **)__malloc_heap_psram(s_vorbisChannels* sizeof(*v->mdctright));

    for(i = 0; i < s_vorbisChannels; i++) {
        v->work[i] = (int32_t *)__calloc_heap_psram(1, (s_blocksizes[1] >> 1) * sizeof(*v->work[i]));
        v->mdctright[i] = (int32_t *)__calloc_heap_psram(1, (s_blocksizes[1] >> 2) * sizeof(*v->mdctright[i]));
    }

    v->lW = 0; /* previous window size */
    v->W = 0;  /* current window size  */

    v->out_end = -1; // vorbis_dsp_restart
    v->out_begin = -1;

    return v;
}
//---------------------------------------------------------------------------------------------------------------------
void vorbis_dsp_destroy(vorbis_dsp_state_t *v) {
    int32_t i;
    if(v) {
        if(v->work) {
            for(i = 0; i < s_vorbisChannels; i++) {
                if(v->work[i]) {free(v->work[i]); v->work[i] = NULL;}
            }
            if(v->work){free(v->work); v->work = NULL;}
        }
        if(v->mdctright) {
            for(i = 0; i < s_vorbisChannels; i++) {
                if(v->mdctright[i]){free(v->mdctright[i]); v->mdctright[i] = NULL;}
            }
            if(v->mdctright){free(v->mdctright); v->mdctright = NULL;}
        }
        free(v);
        v = NULL;
    }
}
//---------------------------------------------------------------------------------------------------------------------
int32_t vorbis_dsp_synthesis(uint8_t* inbuf, uint16_t len, int16_t* outbuf) {

    int32_t mode, i;

    /* Check the packet type */
    if(bitReader(1) != 0)  {
        /* Oops.  This is not an audio data packet */
        return OV_ENOTAUDIO;
    }

    /* read our mode and pre/post windowsize */
    mode = bitReader(ilog(s_nrOfModes));
    if(mode == -1 || mode >= s_nrOfModes) return OV_EBADPACKET;

    /* shift information we still need from last window */
    s_dsp_state->lW = s_dsp_state->W;
    s_dsp_state->W = s_mode_param[mode].blockflag;
    for(i = 0; i < s_vorbisChannels; i++){
        mdct_shift_right(s_blocksizes[s_dsp_state->lW], s_dsp_state->work[i], s_dsp_state->mdctright[i]);
    }
    if(s_dsp_state->W) {
        int32_t temp;
        bitReader(1);
        temp = bitReader(1);
        if(temp == -1) return OV_EBADPACKET;
    }

    /* packet decode and portions of synthesis that rely on only this block */
    {
        mapping_inverse(s_map_param + s_mode_param[mode].mapping);

        if(s_dsp_state->out_begin == -1) {
            s_dsp_state->out_begin = 0;
            s_dsp_state->out_end = 0;
        }
        else {
            s_dsp_state->out_begin = 0;
            s_dsp_state->out_end = s_blocksizes[s_dsp_state->lW] / 4 + s_blocksizes[s_dsp_state->W] / 4;
        }
    }

    return (0);
}
//---------------------------------------------------------------------------------------------------------------------
void mdct_shift_right(int32_t n, int32_t *in, int32_t *right) {
    int32_t i;
    n >>= 2;
    in += 1;

    for(i = 0; i < n; i++) right[i] = in[i << 1];
}
//---------------------------------------------------------------------------------------------------------------------
int32_t mapping_inverse(vorbis_info_mapping_t *info) {

    int32_t     i, j;
    int32_t n = s_blocksizes[s_dsp_state->W];

    int32_t **pcmbundle = (int32_t **)alloca(sizeof(*pcmbundle) * s_vorbisChannels);
    int32_t      *zerobundle = (int32_t *)alloca(sizeof(*zerobundle) * s_vorbisChannels);
    int32_t      *nonzero = (int32_t *)alloca(sizeof(*nonzero) * s_vorbisChannels);
    int32_t **floormemo = (int32_t **)alloca(sizeof(*floormemo) * s_vorbisChannels);

    /* recover the spectral envelope; store it in the PCM vector for now */
    for(i = 0; i < s_vorbisChannels; i++) {

        int32_t submap = 0;
        int32_t floorno;

        if(info->submaps > 1) submap = info->chmuxlist[i];
        floorno = info->submaplist[submap].floor;

        if(s_floor_type[floorno]) {
            /* floor 1 */
            floormemo[i] = (int32_t *)alloca(sizeof(*floormemo[i]) * floor1_memosize(s_floor_param[floorno]));
            floormemo[i] = floor1_inverse1(s_floor_param[floorno], floormemo[i]);
        }
        else {
            /* floor 0 */
            floormemo[i] = (int32_t *)alloca(sizeof(*floormemo[i]) * floor0_memosize(s_floor_param[floorno]));
            floormemo[i] = floor0_inverse1(s_floor_param[floorno], floormemo[i]);
        }

        if(floormemo[i]) nonzero[i] = 1;
        else
            nonzero[i] = 0;
        memset(s_dsp_state->work[i], 0, sizeof(*s_dsp_state->work[i]) * n / 2);
    }

    /* channel coupling can 'dirty' the nonzero listing */
    for(i = 0; i < info->coupling_steps; i++) {
        if(nonzero[info->coupling[i].mag] || nonzero[info->coupling[i].ang]) {
            nonzero[info->coupling[i].mag] = 1;
            nonzero[info->coupling[i].ang] = 1;
        }
    }

    /* recover the residue into our working vectors */
    for(i = 0; i < info->submaps; i++) {
        uint8_t ch_in_bundle = 0;
        for(j = 0; j < s_vorbisChannels; j++) {
            if(!info->chmuxlist || info->chmuxlist[j] == i) {
                if(nonzero[j]) zerobundle[ch_in_bundle] = 1;
                else
                    zerobundle[ch_in_bundle] = 0;
                pcmbundle[ch_in_bundle++] = s_dsp_state->work[j];
            }
        }

        res_inverse(s_residue_param + info->submaplist[i].residue, pcmbundle, zerobundle, ch_in_bundle);
    }

    // for(j=0;j<vi->channels;j++)
    //_analysis_output("coupled",seq+j,vb->pcm[j],-8,n/2,0,0);

    /* channel coupling */
    for(i = info->coupling_steps - 1; i >= 0; i--) {
        int32_t *pcmM = s_dsp_state->work[info->coupling[i].mag];
        int32_t *pcmA = s_dsp_state->work[info->coupling[i].ang];

        for(j = 0; j < n / 2; j++) {
            int32_t mag = pcmM[j];
            int32_t ang = pcmA[j];

            if(mag > 0)
                if(ang > 0) {
                    pcmM[j] = mag;
                    pcmA[j] = mag - ang;
                }
                else {
                    pcmA[j] = mag;
                    pcmM[j] = mag + ang;
                }
            else if(ang > 0) {
                pcmM[j] = mag;
                pcmA[j] = mag + ang;
            }
            else {
                pcmA[j] = mag;
                pcmM[j] = mag - ang;
            }
        }
    }

    // for(j=0;j<vi->channels;j++)
    //_analysis_output("residue",seq+j,vb->pcm[j],-8,n/2,0,0);

    /* compute and apply spectral envelope */

    for(i = 0; i < s_vorbisChannels; i++) {
        int32_t *pcm = s_dsp_state->work[i];
        int32_t      submap = 0;
        int32_t      floorno;

        if(info->submaps > 1) submap = info->chmuxlist[i];
        floorno = info->submaplist[submap].floor;

        if(s_floor_type[floorno]) {
            /* floor 1 */
            floor1_inverse2(s_floor_param[floorno], floormemo[i], pcm);
        }
        else {
            /* floor 0 */
            floor0_inverse2(s_floor_param[floorno], floormemo[i], pcm);
        }

    }

    // for(j=0;j<vi->channels;j++)
    //_analysis_output("mdct",seq+j,vb->pcm[j],-24,n/2,0,1);

    /* transform the PCM data; takes PCM vector, vb; modifies PCM vector */
    /* only MDCT right now.... */
    for(i = 0; i < s_vorbisChannels; i++){
        mdct_backward(n, s_dsp_state->work[i]);
    }

    // for(j=0;j<vi->channels;j++)
    //_analysis_output("imdct",seq+j,vb->pcm[j],-24,n,0,0);

    /* all done! */
    return (0);
}
//---------------------------------------------------------------------------------------------------------------------
int32_t floor0_memosize(vorbis_info_floor_t *i) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)i;
    return info->order + 1;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t floor1_memosize(vorbis_info_floor_t *i) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)i;
    return info->posts;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t *floor0_inverse1(vorbis_info_floor_t *i, int32_t *lsp) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)i;
    int32_t                 j;

    int32_t ampraw = bitReader(info->ampbits);

    if(ampraw > 0) { /* also handles the -1 out of data case */
        int32_t maxval = (1 << info->ampbits) - 1;
        int32_t     amp = ((ampraw * info->ampdB) << 4) / maxval;
        int32_t     booknum = bitReader(_ilog(info->numbooks));

        if(booknum != -1 && booknum < info->numbooks) { /* be paranoid */
            codebook_t        *b = s_codebooks + info->books[booknum];
            int32_t           last = 0;

            if(vorbis_book_decodev_set(b, lsp, info->order, -24) == -1) goto eop;
            for(j = 0; j < info->order;) {
                for(uint8_t k = 0; j < info->order && k < b->dim; k++, j++) lsp[j] += last;
                last = lsp[j - 1];
            }

            lsp[info->order] = amp;
            return (lsp);
        }
    }
eop:
    return (NULL);
}
//---------------------------------------------------------------------------------------------------------------------
int32_t *floor1_inverse1(vorbis_info_floor_t *in, int32_t *fit_value) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)in;

    int32_t                 quant_look[4] = {256, 128, 86, 64};
    int32_t                 i, j, k;
    int32_t                 quant_q = quant_look[info->mult - 1];
    codebook_t         *books = s_codebooks;

    /* unpack wrapped/predicted values from stream */
    if(bitReader(1) == 1) {
        fit_value[0] = bitReader(ilog(quant_q - 1));
        fit_value[1] = bitReader(ilog(quant_q - 1));

    /* partition by partition */
        for(i = 0, j = 2; i < info->partitions; i++) {
            int32_t classv = info->partitionclass[i];
            int32_t cdim = info->_class[classv].class_dim;
            int32_t csubbits = info->_class[classv].class_subs;
            int32_t csub = 1 << csubbits;
            int32_t cval = 0;

            /* decode the partition's first stage cascade value */
            if(csubbits) {
                cval = vorbis_book_decode(books + info->_class[classv].class_book);
                if(cval == -1) goto eop;
            }

            for(k = 0; k < cdim; k++) {
                int32_t book = info->_class[classv].class_subbook[cval & (csub - 1)];
                cval >>= csubbits;
                if(book != 0xff) {
                    if((fit_value[j + k] = vorbis_book_decode(books + book)) == -1) goto eop;
                }
                else { fit_value[j + k] = 0; }
            }
            j += cdim;
        }

        /* unwrap positive values and reconsitute via linear interpolation */
        for(i = 2; i < info->posts; i++) {
            int32_t predicted =
                render_point(info->postlist[info->loneighbor[i - 2]], info->postlist[info->hineighbor[i - 2]],
                            fit_value[info->loneighbor[i - 2]], fit_value[info->hineighbor[i - 2]], info->postlist[i]);
            int32_t hiroom = quant_q - predicted;
            int32_t loroom = predicted;
            int32_t room = (hiroom < loroom ? hiroom : loroom) << 1;
            int32_t val = fit_value[i];

            if(val) {
                if(val >= room) {
                    if(hiroom > loroom) { val = val - loroom; }
                    else { val = -1 - (val - hiroom); }
                }
                else {
                    if(val & 1) { val = -((val + 1) >> 1); }
                    else { val >>= 1; }
                }

                fit_value[i] = val + predicted;
                fit_value[info->loneighbor[i - 2]] &= 0x7fff;
                fit_value[info->hineighbor[i - 2]] &= 0x7fff;
            }
            else { fit_value[i] = predicted | 0x8000; }
        }

        return (fit_value);
    }
    else{
        // log_i("err in br");
        ;
    }
eop:
    return (NULL);
}
//---------------------------------------------------------------------------------------------------------------------
/* returns the [original, not compacted] entry number or -1 on eof *********/
int32_t vorbis_book_decode(codebook_t* book) {
    if(book->dec_type) return -1;
    return decode_packed_entry_number(book);
}
//---------------------------------------------------------------------------------------------------------------------
int32_t decode_packed_entry_number(codebook_t *book) {
    uint32_t chase = 0;
    int32_t      read = book->dec_maxlength;
    int32_t  lok = bitReader_look(read), i;

    while(lok < 0 && read > 1){
        lok = bitReader_look(--read);
    }

    if(lok < 0) {
        bitReader_adv(1); /* force eop */
        return -1;
    }

    /* chase the tree with the bits we got */
    if(book->dec_nodeb == 1) {
        if(book->dec_leafw == 1) {
            /* 8/8 */
            uint8_t *t = (uint8_t *)book->dec_table;
            for(i = 0; i < read; i++) {
                chase = t[chase * 2 + ((lok >> i) & 1)];
                if(chase & 0x80UL) break;
            }
            chase &= 0x7fUL;
        }
        else {
            /* 8/16 */
            uint8_t *t = (uint8_t *)book->dec_table;
            for(i = 0; i < read; i++) {
                int32_t bit = (lok >> i) & 1;
                int32_t next = t[chase + bit];
                if(next & 0x80) {
                    chase = (next << 8) | t[chase + bit + 1 + (!bit || (t[chase] & 0x80))];
                    break;
                }
                chase = next;
            }
            chase &= 0x7fffUL;
        }
    }
    else {
        if(book->dec_nodeb == 2) {
            if(book->dec_leafw == 1) {
                /* 16/16 */
                int32_t idx;
                for(i = 0; i < read; i++) {
                    idx = chase * 2 + ((lok >> i) & 1);
                    chase = ((uint16_t *)(book->dec_table))[idx];
                    if(chase & 0x8000UL){
                        break;
                    }
                }
                chase &= 0x7fffUL;
            }
            else {
                /* 16/32 */
                uint16_t *t = (uint16_t *)book->dec_table;
                for(i = 0; i < read; i++) {
                    int32_t bit = (lok >> i) & 1;
                    int32_t next = t[chase + bit];
                    if(next & 0x8000) {
                        chase = (next << 16) | t[chase + bit + 1 + (!bit || (t[chase] & 0x8000))];
                        break;
                    }
                    chase = next;
                }
                chase &= 0x7fffffffUL;
            }
        }
        else {
            for(i = 0; i < read; i++) {
                chase = ((uint32_t *)(book->dec_table))[chase * 2 + ((lok >> i) & 1)];
                if(chase & 0x80000000UL) break;
            }
            chase &= 0x7fffffffUL;
        }
    }

    if(i < read) {
        bitReader_adv(i + 1);
        return chase;
    }
    bitReader_adv(read + 1);
    log_e("read %i", read);
    return (-1);
}
//---------------------------------------------------------------------------------------------------------------------
int32_t render_point(int32_t x0, int32_t x1, int32_t y0, int32_t y1, int32_t x) {
    y0 &= 0x7fff; /* mask off flag */
    y1 &= 0x7fff;

    {
        int32_t dy = y1 - y0;
        int32_t adx = x1 - x0;
        int32_t ady = abs(dy);
        int32_t err = ady * (x - x0);

        int32_t off = err / adx;
        if(dy < 0) return (y0 - off);
        return (y0 + off);
    }
}
//---------------------------------------------------------------------------------------------------------------------
/* unlike the others, we guard against n not being an integer number * of <dim> internally rather than in the upper
 layer (called only by * floor0) */
int32_t vorbis_book_decodev_set(codebook_t *book, int32_t *a, int32_t n, int32_t point) {
    if(book->used_entries > 0) {
        int32_t *v = (int32_t *)alloca(sizeof(*v) * book->dim);
        int32_t      i;

        for(i = 0; i < n;) {
            if(decode_map(book, v, point)) return -1;
            for(uint8_t j = 0; i < n && j < book->dim; j++) a[i++] = v[j];
        }
    }
    else {
        int32_t i;

        for(i = 0; i < n;) { a[i++] = 0; }
    }

    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t decode_map(codebook_t *s, int32_t *v, int32_t point) {

    uint32_t entry = decode_packed_entry_number(s);

    if(oggpack_eop()) return (-1);

    /* according to decode type */
    switch(s->dec_type) {
        case 1: {
            /* packed vector of values */
            int32_t mask = (1 << s->q_bits) - 1;
            for(uint8_t i = 0; i < s->dim; i++) {
                v[i] = entry & mask;
                entry >>= s->q_bits;
            }
            break;
        }
        case 2: {
            /* packed vector of column offsets */
            int32_t mask = (1 << s->q_pack) - 1;
            for(uint8_t i = 0; i < s->dim; i++) {
                if(s->q_bits <= 8) v[i] = ((uint8_t *)(s->q_val))[entry & mask];
                else
                    v[i] = ((uint16_t *)(s->q_val))[entry & mask];
                entry >>= s->q_pack;
            }
            break;
        }
        case 3: {
            /* offset into array */
            void *ptr = (int32_t *)s->q_val + entry * s->q_pack;

            if(s->q_bits <= 8) {
                for(uint8_t i = 0; i < s->dim; i++) v[i] = ((uint8_t *)ptr)[i];
            }
            else {
                for(uint8_t i = 0; i < s->dim; i++) v[i] = ((uint16_t *)ptr)[i];
            }
            break;
        }
        default:
            return -1;
    }

    /* we have the unpacked multiplicands; compute final vals */
    {
        int32_t     shiftM = point - s->q_delp;
        int32_t add = point - s->q_minp;
        if(add > 0) add = s->q_min >> add;
        else
            add = s->q_min << -add;

        if(shiftM > 0)
            for(uint8_t i = 0; i < s->dim; i++) v[i] = add + ((v[i] * s->q_del) >> shiftM);
        else
            for(uint8_t i = 0; i < s->dim; i++) v[i] = add + ((v[i] * s->q_del) << -shiftM);

        if(s->q_seq)
            for(uint8_t i = 1; i < s->dim; i++) v[i] += v[i - 1];
    }

    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t res_inverse(vorbis_info_residue_t *info, int32_t **in, int32_t *nonzero, uint8_t ch) {
    int32_t               j, k, s;
    uint8_t           m = 0, n = 0;
    uint8_t           used = 0;
    codebook_t         *phrasebook = s_codebooks + info->groupbook;
    uint32_t          samples_per_partition = info->grouping;
    uint8_t           partitions_per_word = phrasebook->dim;
    uint32_t          pcmend = s_blocksizes[s_dsp_state->W];


    if(info->type < 2) {
        uint32_t max = pcmend >> 1;
        uint32_t end = (info->end < max ? info->end : max);
        uint32_t n1 = end - info->begin;

        if(n1 > 0) {
            uint32_t partvals = n1 / samples_per_partition;
            uint32_t partwords = (partvals + partitions_per_word - 1) / partitions_per_word;

            for(uint8_t i = 0; i < ch; i++) {
                if(nonzero[i]) in[used++] = in[i];
            }
            ch = used;

            if(used) {
                char **partword = (char **)alloca(ch * sizeof(*partword));
                for(j = 0; j < ch; j++) {
                    partword[j] = (char *)alloca(partwords * partitions_per_word * sizeof(*partword[j]));
                }
                for(s = 0; s < info->stages; s++) {
                    for(uint32_t i = 0; i < partvals;) {
                        if(s == 0) {
                            /* fetch the partition word for each channel */
                            partword[0][i + partitions_per_word - 1] = 1;
                            for(k = partitions_per_word - 2; k >= 0; k--) {
                                partword[0][i + k] = partword[0][i + k + 1] * info->partitions;
                            }
                            for(j = 1; j < ch; j++) {
                                for(k = partitions_per_word - 1; k >= 0; k--) {
                                    partword[j][i + k] = partword[j - 1][i + k];
                                }
                            }
                            for(n = 0; n < ch; n++) {
                                int32_t temp = vorbis_book_decode(phrasebook);
                                if(temp == -1) goto eopbreak;
                                /* this can be done quickly in assembly due to the quotient
                                 always being at most six bits */
                                for(m = 0; m < partitions_per_word; m++) {
                                    char div = partword[n][i + m];
                                    partword[n][i + m] = temp / div;
                                    temp -= partword[n][i + m] * div;
                                }
                            }
                        }

                        /* now we decode residual values for the partitions */
                        for(k = 0; k < partitions_per_word && i < partvals; k++, i++) {
                            for(j = 0; j < ch; j++) {
                                uint32_t offset = info->begin + i * samples_per_partition;
                                if(info->stagemasks[(int32_t)partword[j][i]] & (1 << s)) {
                                    codebook_t *stagebook = s_codebooks + info->stagebooks[(partword[j][i] << 3) + s];
                                    if(info->type) {
                                        if(vorbis_book_decodev_add(stagebook, in[j] + offset,
                                                                   samples_per_partition, -8) == -1)
                                            goto eopbreak;
                                    }
                                    else {
                                        if(vorbis_book_decodevs_add(stagebook, in[j] + offset,
                                                                    samples_per_partition, -8) == -1)
                                            goto eopbreak;
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    else {
        uint32_t max = (pcmend * ch) >> 1;
        uint32_t end = (info->end < max ? info->end : max);
        uint32_t n = end - info->begin;

        if(n > 0) {
            uint32_t partvals = n / samples_per_partition;
            uint32_t partwords = (partvals + partitions_per_word - 1) / partitions_per_word;

            char *partword = (char *)alloca(partwords * partitions_per_word * sizeof(*partword));
            int32_t   beginoff = info->begin / ch;

            uint8_t i = 0;
            for(i = 0; i < ch; i++)
                if(nonzero[i]) break;
            if(i == ch) return (0); /* no nonzero vectors */

            samples_per_partition /= ch;

            for(s = 0; s < info->stages; s++) {
                for(uint32_t i = 0; i < partvals;) {
                    if(s == 0) {
                        int32_t temp;
                        partword[i + partitions_per_word - 1] = 1;
                        for(k = partitions_per_word - 2; k >= 0; k--)
                            partword[i + k] = partword[i + k + 1] * info->partitions;

                        /* fetch the partition word */
                        temp = vorbis_book_decode(phrasebook);
                        if(temp == -1) goto eopbreak;

                        /* this can be done quickly in assembly due to the quotient always being at most six bits */
                        for(k = 0; k < partitions_per_word; k++) {
                            char div = partword[i + k];
                            partword[i + k] = (char)temp / div;
                            temp -= partword[i + k] * div;
                        }
                    }

                    /* now we decode residual values for the partitions */
                    for(k = 0; k < partitions_per_word && i < partvals; k++, i++)
                        if(info->stagemasks[(int32_t)partword[i]] & (1 << s)) {
                            codebook_t *stagebook = s_codebooks + info->stagebooks[(partword[i] << 3) + s];
                            if(vorbis_book_decodevv_add(stagebook, in, i * samples_per_partition + beginoff, ch,
                                                        samples_per_partition, -8) == -1)
                                goto eopbreak;
                        }
                }
            }
        }
    }
eopbreak:

    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
/* decode vector / dim granularity guarding is done in the upper layer */
int32_t vorbis_book_decodev_add(codebook_t *book, int32_t *a, int32_t n, int32_t point) {
    if(book->used_entries > 0) {
        int32_t *v = (int32_t *)alloca(sizeof(*v) * book->dim);
        uint32_t i;

        for(i = 0; i < n;) {
            if(decode_map(book, v, point)) return -1;
            for(uint8_t j = 0; i < n && j < book->dim; j++) a[i++] += v[j];
        }
    }
    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
/* returns 0 on OK or -1 on eof */
/* decode vector / dim granularity guarding is done in the upper layer */
int32_t vorbis_book_decodevs_add(codebook_t *book, int32_t *a, int32_t n, int32_t point) {
    if(book->used_entries > 0) {
        int32_t      step = n / book->dim;
        int32_t *v = (int32_t *)alloca(sizeof(*v) * book->dim);
        int32_t      j;

        for(j = 0; j < step; j++) {
            if(decode_map(book, v, point)) return -1;
            for(uint8_t i = 0, o = j; i < book->dim; i++, o += step) a[o] += v[i];
        }
    }
    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
int32_t floor0_inverse2(vorbis_info_floor_t *i, int32_t *lsp, int32_t *out) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)i;


    if(lsp) {
        int32_t amp = lsp[info->order];

        /* take the coefficients back to a spectral envelope curve */
        vorbis_lsp_to_curve(out, s_blocksizes[s_dsp_state->W] / 2, info->barkmap, lsp, info->order, amp, info->ampdB,
                            info->rate >> 1);
        return (1);
    }
    memset(out, 0, sizeof(*out) * s_blocksizes[s_dsp_state->W] / 2);
    return (0);
}

//---------------------------------------------------------------------------------------------------------------------
int32_t floor1_inverse2(vorbis_info_floor_t *in, int32_t *fit_value, int32_t *out) {
    vorbis_info_floor_t *info = (vorbis_info_floor_t *)in;

    int32_t               n = s_blocksizes[s_dsp_state->W] / 2;
    int32_t               j;

    if(fit_value) {
        /* render the lines */
        int32_t hx = 0;
        int32_t lx = 0;
        int32_t ly = fit_value[0] * info->mult;

        for(j = 1; j < info->posts; j++) {
            int32_t current = info->forward_index[j];
            int32_t hy = fit_value[current] & 0x7fff;
            if(hy == fit_value[current]) {
                hy *= info->mult;
                hx = info->postlist[current];

                render_line(n, lx, hx, ly, hy, out);

                lx = hx;
                ly = hy;
            }
        }
        for(j = hx; j < n; j++) out[j] *= ly; /* be certain */
        return (1);
    }
    memset(out, 0, sizeof(*out) * n);
    return (0);
}
//---------------------------------------------------------------------------------------------------------------------
void render_line(int32_t n, int32_t x0, int32_t x1, int32_t y0, int32_t y1, int32_t *d) {
    int32_t dy = y1 - y0;
    int32_t adx = x1 - x0;
    int32_t ady = abs(dy);
    int32_t base = dy / adx;
    int32_t sy = (dy < 0 ? base - 1 : base + 1);
    int32_t x = x0;
    int32_t y = y0;
    int32_t err = 0;

    if(n > x1) n = x1;
    ady -= abs(base * adx);

    if(x < n){
        d[x] = MULT31_SHIFT15(d[x], FLOOR_fromdB_LOOKUP[y]);
    }

    while(++x < n) {
        err = err + ady;
        if(err >= adx) {
            err -= adx;
            y += sy;
        }
        else { y += base; }
        d[x] = MULT31_SHIFT15(d[x], FLOOR_fromdB_LOOKUP[y]);
    }
}
//---------------------------------------------------------------------------------------------------------------------
const uint16_t barklook[54] = {0,    51,    102,   154,   206,   258,   311,   365,   420,   477,  535,
                               594,  656,   719,   785,   854,   926,   1002,  1082,  1166,  1256, 1352,
                               1454, 1564,  1683,  1812,  1953,  2107,  2276,  2463,  2670,  2900, 3155,
                               3440, 3756,  4106,  4493,  4919,  5387,  5901,  6466,  7094,  7798, 8599,
                               9528, 10623, 11935, 13524, 15453, 17775, 20517, 23667, 27183, 31004};

const uint8_t MLOOP_1[64] = {
    0,  10, 11, 11, 12, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 13, 14, 14, 14, 14, 14, 14,
    14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
};


const uint8_t MLOOP_2[64] = {
    0, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
};

const uint8_t MLOOP_3[8] = {0, 1, 2, 2, 3, 3, 3, 3};

/* interpolated 1./sqrt(p) where .5 <= a < 1. (.100000... to .111111...) in 16.16 format returns in m.8 format */
int32_t ADJUST_SQRT2[2] = {8192, 5792};

//---------------------------------------------------------------------------------------------------------------------
void vorbis_lsp_to_curve(int32_t *curve, int32_t n, int32_t ln, int32_t *lsp, int32_t m, int32_t amp, int32_t ampoffset,
                         int32_t nyq) {
    /* 0 <= m < 256 */

    /* set up for using all int32_t later */
    int32_t      i;
    int32_t      ampoffseti = ampoffset * 4096;
    int32_t      ampi = amp;
    int32_t *ilsp = (int32_t *)alloca(m * sizeof(*ilsp));
    uint32_t imap = (1UL << 31) / ln;
    uint32_t tBnyq1 = toBARK(nyq) << 1;

    /* Besenham for frequency scale to avoid a division */
    int32_t f = 0;
    int32_t fdx = n;
    int32_t fbase = nyq / fdx;
    int32_t ferr = 0;
    int32_t fdy = nyq - fbase * fdx;
    int32_t map = 0;

    uint32_t nextbark = MULT31(imap >> 1, tBnyq1);

    int32_t nextf = barklook[nextbark >> 14] +
                (((nextbark & 0x3fff) * (barklook[(nextbark >> 14) + 1] - barklook[nextbark >> 14])) >> 14);

    /* lsp is in 8.24, range 0 to PI; coslook wants it in .16 0 to 1*/
    for(i = 0; i < m; i++) {
        int32_t val = MULT32(lsp[i], 0x517cc2);
        /* safeguard against a malicious stream */
        if(val < 0 || (val >> COS_LOOKUP_I_SHIFT) >= COS_LOOKUP_I_SZ) {
            memset(curve, 0, sizeof(*curve) * n);
            return;
        }

        ilsp[i] = vorbis_coslook_i(val);
    }

    i = 0;
    while(i < n) {
        int32_t      j;
        uint32_t pi = 46341; /* 2**-.5 in 0.16 */
        uint32_t qi = 46341;
        int32_t  qexp = 0, shift;
        int32_t  wi;

        wi = vorbis_coslook2_i((map * imap) >> 15);

        qi *= labs(ilsp[0] - wi);
        pi *= labs(ilsp[1] - wi);

        for(j = 3; j < m; j += 2) {
            if(!(shift = MLOOP_1[(pi | qi) >> 25]))
                if(!(shift = MLOOP_2[(pi | qi) >> 19])) shift = MLOOP_3[(pi | qi) >> 16];

            qi = (qi >> shift) * labs(ilsp[j - 1] - wi);
            pi = (pi >> shift) * labs(ilsp[j] - wi);
            qexp += shift;
        }
        if(!(shift = MLOOP_1[(pi | qi) >> 25]))
            if(!(shift = MLOOP_2[(pi | qi) >> 19])) shift = MLOOP_3[(pi | qi) >> 16];

        /* pi,qi normalized collectively, both tracked using qexp */

        if(m & 1) {
            /* odd order filter; slightly assymetric */
            /* the last coefficient */
            qi = (qi >> shift) * labs(ilsp[j - 1] - wi);
            pi = (pi >> shift) << 14;
            qexp += shift;

            if(!(shift = MLOOP_1[(pi | qi) >> 25]))
                if(!(shift = MLOOP_2[(pi | qi) >> 19])) shift = MLOOP_3[(pi | qi) >> 16];

            pi >>= shift;
            qi >>= shift;
            qexp += shift - 14 * ((m + 1) >> 1);

            pi = ((pi * pi) >> 16);
            qi = ((qi * qi) >> 16);
            qexp = qexp * 2 + m;

            pi *= (1 << 14) - ((wi * wi) >> 14);
            qi += pi >> 14;
        }
        else {
            /* even order filter; still symmetric */
            /* p*=p(1-w), q*=q(1+w), let normalization drift because it isn't     worth tracking step by step */

            pi >>= shift;
            qi >>= shift;
            qexp += shift - 7 * m;

            pi = ((pi * pi) >> 16);
            qi = ((qi * qi) >> 16);
            qexp = qexp * 2 + m;

            pi *= (1 << 14) - wi;
            qi *= (1 << 14) + wi;
            qi = (qi + pi) >> 14;
        }

        /* we've let the normalization drift because it wasn't important; however, for the lookup, things must be
     normalized again. We need at most one right shift or a number of left shifts */

        if(qi & 0xffff0000) { /* checks for 1.xxxxxxxxxxxxxxxx */
            qi >>= 1;
            qexp++;
        }
        else
            while(qi && !(qi & 0x8000)) { /* checks for 0.0xxxxxxxxxxxxxxx or less*/
                qi <<= 1;
                qexp--;
            }

        amp = vorbis_fromdBlook_i(ampi * /*  n.4         */
                                      vorbis_invsqlook_i(qi, qexp) -
                                  /*  m.8, m+n<=8 */
                                  ampoffseti); /*  8.12[0]     */

        curve[i] = MULT31_SHIFT15(curve[i], amp);

        while(++i < n) {
            /* line plot to get new f */
            ferr += fdy;
            if(ferr >= fdx) {
                ferr -= fdx;
                f++;
            }
            f += fbase;

            if(f >= nextf) break;

            curve[i] = MULT31_SHIFT15(curve[i], amp);
        }

        while(1) {
            map++;

            if(map + 1 < ln) {
                nextbark = MULT31((map + 1) * (imap >> 1), tBnyq1);

                nextf = barklook[nextbark >> 14] +
                        (((nextbark & 0x3fff) * (barklook[(nextbark >> 14) + 1] - barklook[nextbark >> 14])) >> 14);
                if(f <= nextf) break;
            }
            else {
                nextf = 9999999;
                break;
            }
        }
        if(map >= ln) {
            map = ln - 1; /* guard against the approximation */
            nextf = 9999999;
        }
    }
}
//---------------------------------------------------------------------------------------------------------------------
/* used in init only; interpolate the int32_t way */
int32_t toBARK(int32_t n) {
    int32_t i;
    for(i = 0; i < 54; i++)
        if(n >= barklook[i] && n < barklook[i + 1]) break;

    if(i == 54) { return 54 << 14; }
    else { return (i << 14) + (((n - barklook[i]) * ((1UL << 31) / (barklook[i + 1] - barklook[i]))) >> 17); }
}
//---------------------------------------------------------------------------------------------------------------------
/* interpolated lookup based cos function, domain 0 to PI only */
/* a is in 0.16 format, where 0==0, 2^^16-1==PI, return 0.14 */
int32_t vorbis_coslook_i(int32_t a) {
    int32_t i = a >> COS_LOOKUP_I_SHIFT;
    int32_t d = a & COS_LOOKUP_I_MASK;
    return COS_LOOKUP_I[i] - ((d * (COS_LOOKUP_I[i] - COS_LOOKUP_I[i + 1])) >> COS_LOOKUP_I_SHIFT);
}
//---------------------------------------------------------------------------------------------------------------------
/* interpolated half-wave lookup based cos function */
/* a is in 0.16 format, where 0==0, 2^^16==PI, return .LSP_FRACBITS */
int32_t vorbis_coslook2_i(int32_t a) {
    int32_t i = a >> COS_LOOKUP_I_SHIFT;
    int32_t d = a & COS_LOOKUP_I_MASK;
    return ((COS_LOOKUP_I[i] << COS_LOOKUP_I_SHIFT) - d * (COS_LOOKUP_I[i] - COS_LOOKUP_I[i + 1])) >>
           (COS_LOOKUP_I_SHIFT - LSP_FRACBITS + 14);
}
//---------------------------------------------------------------------------------------------------------------------
/* interpolated lookup based fromdB function, domain -140dB to 0dB only */
/* a is in n.12 format */

int32_t vorbis_fromdBlook_i(int32_t a) {
    if(a > 0) return 0x7fffffff;
    if(a < -573440) return 0;  // replacement for if(a < (-140 << 12)) return 0;
    return FLOOR_fromdB_LOOKUP[((a + (140 << 12)) * 467) >> 20];
}
//---------------------------------------------------------------------------------------------------------------------
int32_t vorbis_invsqlook_i(int32_t a, int32_t e) {
    int32_t i = (a & 0x7fff) >> (INVSQ_LOOKUP_I_SHIFT - 1);
    int32_t d = a & INVSQ_LOOKUP_I_MASK;                                /*  0.10 */
    int32_t val = INVSQ_LOOKUP_I[i] -                                   /*  1.16 */
                  ((INVSQ_LOOKUP_IDel[i] * d) >> INVSQ_LOOKUP_I_SHIFT); /* result 1.16 */
    val *= ADJUST_SQRT2[e & 1];
    e = (e >> 1) + 21;
    return (val >> e);
}
//---------------------------------------------------------------------------------------------------------------------
/* partial; doesn't perform last-step deinterleave/unrolling. That can be done more efficiently during pcm output */
void mdct_backward(int32_t n, int32_t *in) {
    int32_t shift;
    int32_t step;

    for(shift = 4; !(n & (1 << shift)); shift++)
        ;
    shift = 13 - shift;
    step = 2 << shift;

    presymmetry(in, n >> 1, step);
    mdct_butterflies(in, n >> 1, shift);
    mdct_bitreverse(in, n, shift);
    mdct_step7(in, n, step);
    mdct_step8(in, n, step);
}
//---------------------------------------------------------------------------------------------------------------------
void presymmetry(int32_t *in, int32_t n2, int32_t step) {
    int32_t       *aX;
    int32_t       *bX;
    const int32_t *T;
    int32_t            n4 = n2 >> 1;

    aX = in + n2 - 3;
    T = sincos_lookup0;

    do {
        int32_t r0 = aX[0];
        int32_t r2 = aX[2];
        XPROD31(r0, r2, T[0], T[1], &aX[0], &aX[2]);
        T += step;
        aX -= 4;
    } while(aX >= in + n4);
    do {
        int32_t r0 = aX[0];
        int32_t r2 = aX[2];
        XPROD31(r0, r2, T[1], T[0], &aX[0], &aX[2]);
        T -= step;
        aX -= 4;
    } while(aX >= in);

    aX = in + n2 - 4;
    bX = in;
    T = sincos_lookup0;
    do {
        int32_t ri0 = aX[0];
        int32_t ri2 = aX[2];
        int32_t ro0 = bX[0];
        int32_t ro2 = bX[2];

        XNPROD31(ro2, ro0, T[1], T[0], &aX[0], &aX[2]);
        T += step;
        XNPROD31(ri2, ri0, T[0], T[1], &bX[0], &bX[2]);

        aX -= 4;
        bX += 4;
    } while(aX >= in + n4);
}
//---------------------------------------------------------------------------------------------------------------------
void mdct_butterflies(int32_t *x, int32_t points, int32_t shift) {
    int32_t stages = 8 - shift;
    int32_t i, j;

    for(i = 0; --stages > 0; i++) {
        for(j = 0; j < (1 << i); j++) mdct_butterfly_generic(x + (points >> i) * j, points >> i, 4 << (i + shift));
    }

    for(j = 0; j < points; j += 32) mdct_butterfly_32(x + j);
}
//---------------------------------------------------------------------------------------------------------------------
/* N/stage point generic N stage butterfly (in place, 2 register) */
void mdct_butterfly_generic(int32_t *x, int32_t points, int32_t step) {
    const int32_t *T = sincos_lookup0;
    int32_t       *x1 = x + points - 4;
    int32_t       *x2 = x + (points >> 1) - 4;
    int32_t        r0, r1, r2, r3;

    do {
        r0 = x1[0] - x1[1];
        x1[0] += x1[1];
        r1 = x1[3] - x1[2];
        x1[2] += x1[3];
        r2 = x2[1] - x2[0];
        x1[1] = x2[1] + x2[0];
        r3 = x2[3] - x2[2];
        x1[3] = x2[3] + x2[2];
        XPROD31(r1, r0, T[0], T[1], &x2[0], &x2[2]);
        XPROD31(r2, r3, T[0], T[1], &x2[1], &x2[3]);
        T += step;
        x1 -= 4;
        x2 -= 4;
    } while(T < sincos_lookup0 + 1024);
    do {
        r0 = x1[0] - x1[1];
        x1[0] += x1[1];
        r1 = x1[2] - x1[3];
        x1[2] += x1[3];
        r2 = x2[0] - x2[1];
        x1[1] = x2[1] + x2[0];
        r3 = x2[3] - x2[2];
        x1[3] = x2[3] + x2[2];
        XNPROD31(r0, r1, T[0], T[1], &x2[0], &x2[2]);
        XNPROD31(r3, r2, T[0], T[1], &x2[1], &x2[3]);
        T -= step;
        x1 -= 4;
        x2 -= 4;
    } while(T > sincos_lookup0);
}
//---------------------------------------------------------------------------------------------------------------------
/* 32 point butterfly (in place, 4 register) */
void mdct_butterfly_32(int32_t *x) {
    int32_t r0, r1, r2, r3;

    r0 = x[16] - x[17];
    x[16] += x[17];
    r1 = x[18] - x[19];
    x[18] += x[19];
    r2 = x[1] - x[0];
    x[17] = x[1] + x[0];
    r3 = x[3] - x[2];
    x[19] = x[3] + x[2];
    XNPROD31(r0, r1, cPI3_8, cPI1_8, &x[0], &x[2]);
    XPROD31(r2, r3, cPI1_8, cPI3_8, &x[1], &x[3]);

    r0 = x[20] - x[21];
    x[20] += x[21];
    r1 = x[22] - x[23];
    x[22] += x[23];
    r2 = x[5] - x[4];
    x[21] = x[5] + x[4];
    r3 = x[7] - x[6];
    x[23] = x[7] + x[6];
    x[4] = MULT31((r0 - r1), cPI2_8);
    x[5] = MULT31((r3 + r2), cPI2_8);
    x[6] = MULT31((r0 + r1), cPI2_8);
    x[7] = MULT31((r3 - r2), cPI2_8);

    r0 = x[24] - x[25];
    x[24] += x[25];
    r1 = x[26] - x[27];
    x[26] += x[27];
    r2 = x[9] - x[8];
    x[25] = x[9] + x[8];
    r3 = x[11] - x[10];
    x[27] = x[11] + x[10];
    XNPROD31(r0, r1, cPI1_8, cPI3_8, &x[8], &x[10]);
    XPROD31(r2, r3, cPI3_8, cPI1_8, &x[9], &x[11]);

    r0 = x[28] - x[29];
    x[28] += x[29];
    r1 = x[30] - x[31];
    x[30] += x[31];
    r2 = x[12] - x[13];
    x[29] = x[13] + x[12];
    r3 = x[15] - x[14];
    x[31] = x[15] + x[14];
    x[12] = r0;
    x[13] = r3;
    x[14] = r1;
    x[15] = r2;

    mdct_butterfly_16(x);
    mdct_butterfly_16(x + 16);
}
//---------------------------------------------------------------------------------------------------------------------
/* 16 point butterfly (in place, 4 register) */
void mdct_butterfly_16(int32_t *x) {
    int32_t r0, r1, r2, r3;

    r0 = x[8] - x[9];
    x[8] += x[9];
    r1 = x[10] - x[11];
    x[10] += x[11];
    r2 = x[1] - x[0];
    x[9] = x[1] + x[0];
    r3 = x[3] - x[2];
    x[11] = x[3] + x[2];
    x[0] = MULT31((r0 - r1), cPI2_8);
    x[1] = MULT31((r2 + r3), cPI2_8);
    x[2] = MULT31((r0 + r1), cPI2_8);
    x[3] = MULT31((r3 - r2), cPI2_8);

    r2 = x[12] - x[13];
    x[12] += x[13];
    r3 = x[14] - x[15];
    x[14] += x[15];
    r0 = x[4] - x[5];
    x[13] = x[5] + x[4];
    r1 = x[7] - x[6];
    x[15] = x[7] + x[6];
    x[4] = r2;
    x[5] = r1;
    x[6] = r3;
    x[7] = r0;

    mdct_butterfly_8(x);
    mdct_butterfly_8(x + 8);
}
//---------------------------------------------------------------------------------------------------------------------
/* 8 point butterfly (in place) */
void mdct_butterfly_8(int32_t *x) {
    int32_t r0 = x[0] + x[1];
    int32_t r1 = x[0] - x[1];
    int32_t r2 = x[2] + x[3];
    int32_t r3 = x[2] - x[3];
    int32_t r4 = x[4] + x[5];
    int32_t r5 = x[4] - x[5];
    int32_t r6 = x[6] + x[7];
    int32_t r7 = x[6] - x[7];

    x[0] = r5 + r3;
    x[1] = r7 - r1;
    x[2] = r5 - r3;
    x[3] = r7 + r1;
    x[4] = r4 - r0;
    x[5] = r6 - r2;
    x[6] = r4 + r0;
    x[7] = r6 + r2;
}
//---------------------------------------------------------------------------------------------------------------------
void mdct_bitreverse(int32_t *x, int32_t n, int32_t shift) {
    int32_t      bit = 0;
    int32_t *w = x + (n >> 1);

    do {
        int32_t  b = bitrev12(bit++);
        int32_t *xx = x + (b >> shift);
        int32_t  r;

        w -= 2;

        if(w > xx) {
            r = xx[0];
            xx[0] = w[0];
            w[0] = r;

            r = xx[1];
            xx[1] = w[1];
            w[1] = r;
        }
    } while(w > x);
}
//---------------------------------------------------------------------------------------------------------------------
int32_t bitrev12(int32_t x) {
    uint8_t bitrev[16] = {0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15};
    return bitrev[x >> 8] | (bitrev[(x & 0x0f0) >> 4] << 4) | (((int32_t)bitrev[x & 0x00f]) << 8);
}
//---------------------------------------------------------------------------------------------------------------------
void mdct_step7(int32_t *x, int32_t n, int32_t step) {
    int32_t       *w0 = x;
    int32_t       *w1 = x + (n >> 1);
    const int32_t *T = (step >= 4) ? (sincos_lookup0 + (step >> 1)) : sincos_lookup1;
    const int32_t *Ttop = T + 1024;
    int32_t        r0, r1, r2, r3;

    do {
        w1 -= 2;

        r0 = w0[0] + w1[0];
        r1 = w1[1] - w0[1];
        r2 = MULT32(r0, T[1]) + MULT32(r1, T[0]);
        r3 = MULT32(r1, T[1]) - MULT32(r0, T[0]);
        T += step;

        r0 = (w0[1] + w1[1]) >> 1;
        r1 = (w0[0] - w1[0]) >> 1;
        w0[0] = r0 + r2;
        w0[1] = r1 + r3;
        w1[0] = r0 - r2;
        w1[1] = r3 - r1;

        w0 += 2;
    } while(T < Ttop);
    do {
        w1 -= 2;

        r0 = w0[0] + w1[0];
        r1 = w1[1] - w0[1];
        T -= step;
        r2 = MULT32(r0, T[0]) + MULT32(r1, T[1]);
        r3 = MULT32(r1, T[0]) - MULT32(r0, T[1]);

        r0 = (w0[1] + w1[1]) >> 1;
        r1 = (w0[0] - w1[0]) >> 1;
        w0[0] = r0 + r2;
        w0[1] = r1 + r3;
        w1[0] = r0 - r2;
        w1[1] = r3 - r1;

        w0 += 2;
    } while(w0 < w1);
}
//---------------------------------------------------------------------------------------------------------------------
void mdct_step8(int32_t *x, int32_t n, int32_t step) {
    const int32_t *T;
    const int32_t *V;
    int32_t       *iX = x + (n >> 1);
    step >>= 2;

    switch(step) {
        default:
            T = (step >= 4) ? (sincos_lookup0 + (step >> 1)) : sincos_lookup1;
            do {
                int32_t r0 = x[0];
                int32_t r1 = -x[1];
                XPROD31(r0, r1, T[0], T[1], x, x + 1);
                T += step;
                x += 2;
            } while(x < iX);
            break;

        case 1: {
            /* linear interpolation between table values: offset=0.5, step=1 */
            int32_t t0, t1, v0, v1, r0, r1;
            T = sincos_lookup0;
            V = sincos_lookup1;
            t0 = (*T++) >> 1;
            t1 = (*T++) >> 1;
            do {
                r0 = x[0];
                r1 = -x[1];
                t0 += (v0 = (*V++) >> 1);
                t1 += (v1 = (*V++) >> 1);
                XPROD31(r0, r1, t0, t1, x, x + 1);

                r0 = x[2];
                r1 = -x[3];
                v0 += (t0 = (*T++) >> 1);
                v1 += (t1 = (*T++) >> 1);
                XPROD31(r0, r1, v0, v1, x + 2, x + 3);

                x += 4;
            } while(x < iX);
            break;
        }

        case 0: {
            /* linear interpolation between table values: offset=0.25, step=0.5 */
            int32_t t0, t1, v0, v1, q0, q1, r0, r1;
            T = sincos_lookup0;
            V = sincos_lookup1;
            t0 = *T++;
            t1 = *T++;
            do {
                v0 = *V++;
                v1 = *V++;
                t0 += (q0 = (v0 - t0) >> 2);
                t1 += (q1 = (v1 - t1) >> 2);
                r0 = x[0];
                r1 = -x[1];
                XPROD31(r0, r1, t0, t1, x, x + 1);
                t0 = v0 - q0;
                t1 = v1 - q1;
                r0 = x[2];
                r1 = -x[3];
                XPROD31(r0, r1, t0, t1, x + 2, x + 3);

                t0 = *T++;
                t1 = *T++;
                v0 += (q0 = (t0 - v0) >> 2);
                v1 += (q1 = (t1 - v1) >> 2);
                r0 = x[4];
                r1 = -x[5];
                XPROD31(r0, r1, v0, v1, x + 4, x + 5);
                v0 = t0 - q0;
                v1 = t1 - q1;
                r0 = x[6];
                r1 = -x[7];
                XPROD31(r0, r1, v0, v1, x + 5, x + 6);

                x += 8;
            } while(x < iX);
            break;
        }
    }
}
//---------------------------------------------------------------------------------------------------------------------
/* decode vector / dim granularity guarding is done in the upper layer */
int32_t vorbis_book_decodevv_add(codebook_t *book, int32_t **a, int32_t offset, uint8_t ch, int32_t n, int32_t point) {
    if(book->used_entries > 0) {
        int32_t *v = (int32_t *)alloca(sizeof(*v) * book->dim);
        int32_t  i;
        uint8_t  chptr = 0;
        int32_t  m = offset + n;

        for(i = offset; i < m;) {
            if(decode_map(book, v, point)) return -1;
            for(uint8_t j = 0; i < m && j < book->dim; j++) {
                a[chptr++][i] += v[j];
                if(chptr == ch) {
                    chptr = 0;
                    i++;
                }
            }
        }
    }

    return 0;
}
//---------------------------------------------------------------------------------------------------------------------
/* pcm==0 indicates we just want the pending samples, no more */
int32_t vorbis_dsp_pcmout(int16_t *outBuff, int32_t outBuffSize) {
    if(s_dsp_state->out_begin > -1 && s_dsp_state->out_begin < s_dsp_state->out_end) {
        int32_t n = s_dsp_state->out_end - s_dsp_state->out_begin;

        if(outBuff) {
            int32_t i;
            if(n > outBuffSize) {
                n = outBuffSize;
                log_e("outBufferSize too small, must be min %i (int16_t) words", n);
            }
            for(i = 0; i < s_vorbisChannels; i++){
                mdct_unroll_lap(s_blocksizes[0], s_blocksizes[1],
                                s_dsp_state->lW, s_dsp_state->W, s_dsp_state->work[i],
                                s_dsp_state->mdctright[i], _vorbis_window(s_blocksizes[0] >> 1),
                                _vorbis_window(s_blocksizes[1] >> 1),
                                outBuff + i, s_vorbisChannels,
                                s_dsp_state->out_begin,
                                s_dsp_state->out_begin + n);
            }
        }
        return (n);
    }
    return (0);
}
//---------------------------------------------------------------------------------------------------------------------
int32_t *_vorbis_window(int32_t left) {
    switch(left) {
        case 32:
            return (int32_t *)vwin64;
        case 64:
            return (int32_t *)vwin128;
        case 128:
            return (int32_t *)vwin256;
        case 256:
            return (int32_t *)vwin512;
        case 512:
            return (int32_t *)vwin1024;
        case 1024:
            return (int32_t *)vwin2048;
        case 2048:
            return (int32_t *)vwin4096;
        case 4096:
            return (int32_t *)vwin8192;
        default:
            return (0);
    }
}
//---------------------------------------------------------------------------------------------------------------------
void mdct_unroll_lap(int32_t n0, int32_t n1, int32_t lW, int32_t W, int32_t *in, int32_t *right, const int32_t *w0, const int32_t *w1, int16_t *out,
                     int32_t step, int32_t start, /* samples, this frame */
                     int32_t end /* samples, this frame */) {
    int32_t       *l = in + (W && lW ? n1 >> 1 : n0 >> 1);
    int32_t       *r = right + (lW ? n1 >> 2 : n0 >> 2);
    int32_t       *post;
    const int32_t *wR = (W && lW ? w1 + (n1 >> 1) : w0 + (n0 >> 1));
    const int32_t *wL = (W && lW ? w1 : w0);

    int32_t preLap = (lW && !W ? (n1 >> 2) - (n0 >> 2) : 0);
    int32_t halfLap = (lW && W ? (n1 >> 2) : (n0 >> 2));
    int32_t postLap = (!lW && W ? (n1 >> 2) - (n0 >> 2) : 0);
    int32_t n, off;

    /* preceeding direct-copy lapping from previous frame, if any */
    if(preLap) {
        n = (end < preLap ? end : preLap);
        off = (start < preLap ? start : preLap);
        post = r - n;
        r -= off;
        start -= off;
        end -= n;
        while(r > post) {
            *out = CLIP_TO_15((*--r) >> 9);
            out += step;
        }
    }

    /* cross-lap; two halves due to wrap-around */
    n = (end < halfLap ? end : halfLap);
    off = (start < halfLap ? start : halfLap);
    post = r - n;
    r -= off;
    l -= off * 2;
    start -= off;
    wR -= off;
    wL += off;
    end -= n;
    while(r > post) {
        l -= 2;
        *out = CLIP_TO_15((MULT31(*--r, *--wR) + MULT31(*l, *wL++)) >> 9);
        out += step;
    }

    n = (end < halfLap ? end : halfLap);
    off = (start < halfLap ? start : halfLap);
    post = r + n;
    r += off;
    l += off * 2;
    start -= off;
    end -= n;
    wR -= off;
    wL += off;
    while(r < post) {
        *out = CLIP_TO_15((MULT31(*r++, *--wR) - MULT31(*l, *wL++)) >> 9);
        out += step;
        l += 2;
    }

    /* preceeding direct-copy lapping from previous frame, if any */
    if(postLap) {
        n = (end < postLap ? end : postLap);
        off = (start < postLap ? start : postLap);
        post = l + n * 2;
        l += off * 2;
        while(l < post) {
            *out = CLIP_TO_15((-*l) >> 9);
            out += step;
            l += 2;
        }
    }
}
//---------------------------------------------------------------------------------------------------------------------
