/* * Xing VBR tagging for LAME. * * Copyright (c) 1999 A.L. Faber * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ /* $Id: VbrTag.c,v 1.2 2006/02/09 16:56:23 kramm Exp $ */ #include #include "config_static.h" #include "machine.h" #if defined(__riscos__) && defined(FPA10) #include "ymath.h" #else #include #endif #include "bitstream.h" #include "lame.h" #include "VbrTag.h" #include "version.h" #include #include #include #ifdef WITH_DMALLOC #include #endif #ifdef _DEBUG /* #define DEBUG_VBRTAG */ #endif /* // 4 bytes for Header Tag // 4 bytes for Header Flags // 100 bytes for entry (NUMTOCENTRIES) // 4 bytes for FRAME SIZE // 4 bytes for STREAM_SIZE // 4 bytes for VBR SCALE. a VBR quality indicator: 0=best 100=worst // 20 bytes for LAME tag. for example, "LAME3.12 (beta 6)" // ___________ // 140 bytes */ #define VBRHEADERSIZE (NUMTOCENTRIES+4+4+4+4+4) #define LAMEHEADERSIZE (VBRHEADERSIZE + 9 + 1 + 1 + 8 + 1 + 1 + 3 + 1 + 1 + 2 + 4 + 2 + 2) /* the size of the Xing header (MPEG1 and MPEG2) in kbps */ #define XING_BITRATE1 128 #define XING_BITRATE2 64 #define XING_BITRATE25 32 const static char VBRTag[]={"Xing"}; const static char VBRTag2[]={"Info"}; /* Lookup table for fast CRC computation * See 'CRC_update_lookup' * Uses the polynomial x^16+x^15+x^2+1 */ unsigned int crc16_lookup[256] = { 0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440, 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, 0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40, 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, 0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641, 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, 0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441, 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, 0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41, 0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640, 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, 0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441, 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, 0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840, 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, 0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640, 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, 0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440, 0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841, 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, 0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641, 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040 }; /*********************************************************************** * Robert Hegemann 2001-01-17 ***********************************************************************/ static void addVbr(VBR_seek_info_t * v, int bitrate) { int i; v->sum += bitrate; v->seen ++; if (v->seen < v->want) { return; } if (v->pos < v->size) { v->bag[v->pos] = v->sum; v->pos ++; v->seen = 0; } if (v->pos == v->size) { for (i = 1; i < v->size; i += 2) { v->bag[i/2] = v->bag[i]; } v->want *= 2; v->pos /= 2; } } static void Xing_seek_table(VBR_seek_info_t * v, unsigned char *t) { int i, index; int seek_point; if (v->pos <= 0) return; for (i = 1; i < NUMTOCENTRIES; ++i) { float j = i/(float)NUMTOCENTRIES, act, sum; index = (int)(floor(j * v->pos)); if (index > v->pos-1) index = v->pos-1; act = v->bag[index]; sum = v->sum; seek_point = (int)(256. * act / sum); if (seek_point > 255) seek_point = 255; t[i] = seek_point; } } #if 0 void print_seeking(unsigned char *t) { int i; printf("seeking table "); for (i = 0; i < NUMTOCENTRIES; ++i) { printf(" %d ", t[i]); } printf("\n"); } #endif /**************************************************************************** * AddVbrFrame: Add VBR entry, used to fill the VBR the TOC entries * Paramters: * nStreamPos: how many bytes did we write to the bitstream so far * (in Bytes NOT Bits) **************************************************************************** */ void AddVbrFrame(lame_global_flags *gfp) { lame_internal_flags *gfc = gfp->internal_flags; int kbps = bitrate_table[gfp->version][gfc->bitrate_index]; if (gfc->VBR_seek_table.bag == NULL) { gfc->VBR_seek_table.sum = 0; gfc->VBR_seek_table.seen = 0; gfc->VBR_seek_table.want = 1; gfc->VBR_seek_table.pos = 0; gfc->VBR_seek_table.bag = malloc (400*sizeof(int)); if (gfc->VBR_seek_table.bag != NULL) { gfc->VBR_seek_table.size = 400; } else { gfc->VBR_seek_table.size = 0; ERRORF (gfc,"Error: can't allocate VbrFrames buffer\n"); return; } } addVbr(&gfc->VBR_seek_table, kbps); gfp->nVbrNumFrames++; } /*-------------------------------------------------------------*/ static int ExtractI4(unsigned char *buf) { int x; /* big endian extract */ x = buf[0]; x <<= 8; x |= buf[1]; x <<= 8; x |= buf[2]; x <<= 8; x |= buf[3]; return x; } static void CreateI4(unsigned char *buf, int nValue) { /* big endian create */ buf[0]=(nValue>>24)&0xff; buf[1]=(nValue>>16)&0xff; buf[2]=(nValue>> 8)&0xff; buf[3]=(nValue )&0xff; } static void CreateI2(unsigned char *buf, int nValue) { /* big endian create */ buf[0]=(nValue>> 8)&0xff; buf[1]=(nValue )&0xff; } /*-------------------------------------------------------------*/ /* Same as GetVbrTag below, but only checks for the Xing tag. requires buf to contain only 40 bytes */ /*-------------------------------------------------------------*/ int CheckVbrTag(unsigned char *buf) { int h_id, h_mode, h_sr_index; /* get selected MPEG header data */ h_id = (buf[1] >> 3) & 1; h_sr_index = (buf[2] >> 2) & 3; h_mode = (buf[3] >> 6) & 3; /* determine offset of header */ if( h_id ) { /* mpeg1 */ if( h_mode != 3 ) buf+=(32+4); else buf+=(17+4); } else { /* mpeg2 */ if( h_mode != 3 ) buf+=(17+4); else buf+=(9+4); } if( buf[0] != VBRTag[0] && buf[0] != VBRTag2[0] ) return 0; /* fail */ if( buf[1] != VBRTag[1] && buf[1] != VBRTag2[1]) return 0; /* header not found*/ if( buf[2] != VBRTag[2] && buf[2] != VBRTag2[2]) return 0; if( buf[3] != VBRTag[3] && buf[3] != VBRTag2[3]) return 0; return 1; } int GetVbrTag(VBRTAGDATA *pTagData, unsigned char *buf) { int i, head_flags; int h_bitrate,h_id, h_mode, h_sr_index; int enc_delay,enc_padding; /* get Vbr header data */ pTagData->flags = 0; /* get selected MPEG header data */ h_id = (buf[1] >> 3) & 1; h_sr_index = (buf[2] >> 2) & 3; h_mode = (buf[3] >> 6) & 3; h_bitrate = ((buf[2]>>4)&0xf); h_bitrate = bitrate_table[h_id][h_bitrate]; /* check for FFE syncword */ if ((buf[1]>>4)==0xE) pTagData->samprate = samplerate_table[2][h_sr_index]; else pTagData->samprate = samplerate_table[h_id][h_sr_index]; // if( h_id == 0 ) // pTagData->samprate >>= 1; /* determine offset of header */ if( h_id ) { /* mpeg1 */ if( h_mode != 3 ) buf+=(32+4); else buf+=(17+4); } else { /* mpeg2 */ if( h_mode != 3 ) buf+=(17+4); else buf+=(9+4); } if( buf[0] != VBRTag[0] && buf[0] != VBRTag2[0] ) return 0; /* fail */ if( buf[1] != VBRTag[1] && buf[1] != VBRTag2[1]) return 0; /* header not found*/ if( buf[2] != VBRTag[2] && buf[2] != VBRTag2[2]) return 0; if( buf[3] != VBRTag[3] && buf[3] != VBRTag2[3]) return 0; buf+=4; pTagData->h_id = h_id; head_flags = pTagData->flags = ExtractI4(buf); buf+=4; /* get flags */ if( head_flags & FRAMES_FLAG ) { pTagData->frames = ExtractI4(buf); buf+=4; } if( head_flags & BYTES_FLAG ) { pTagData->bytes = ExtractI4(buf); buf+=4; } if( head_flags & TOC_FLAG ) { if( pTagData->toc != NULL ) { for(i=0;itoc[i] = buf[i]; } buf+=NUMTOCENTRIES; } pTagData->vbr_scale = -1; if( head_flags & VBR_SCALE_FLAG ) { pTagData->vbr_scale = ExtractI4(buf); buf+=4; } pTagData->headersize = ((h_id+1)*72000*h_bitrate) / pTagData->samprate; buf+=21; enc_delay = buf[0] << 4; enc_delay += buf[1] >> 4; enc_padding= (buf[1] & 0x0F)<<8; enc_padding += buf[2]; // check for reasonable values (this may be an old Xing header, // not a INFO tag) if (enc_delay<0 || enc_delay > 3000) enc_delay=-1; if (enc_padding<0 || enc_padding > 3000) enc_padding=-1; pTagData->enc_delay=enc_delay; pTagData->enc_padding=enc_padding; #ifdef DEBUG_VBRTAG fprintf(stderr,"\n\n********************* VBR TAG INFO *****************\n"); fprintf(stderr,"tag :%s\n",VBRTag); fprintf(stderr,"head_flags :%d\n",head_flags); fprintf(stderr,"bytes :%d\n",pTagData->bytes); fprintf(stderr,"frames :%d\n",pTagData->frames); fprintf(stderr,"VBR Scale :%d\n",pTagData->vbr_scale); fprintf(stderr,"enc_delay = %i \n",enc_delay); fprintf(stderr,"enc_padding= %i \n",enc_padding); fprintf(stderr,"toc:\n"); if( pTagData->toc != NULL ) { for(i=0;itoc[i])); } } fprintf(stderr,"\n***************** END OF VBR TAG INFO ***************\n"); #endif return 1; /* success */ } /**************************************************************************** * InitVbrTag: Initializes the header, and write empty frame to stream * Paramters: * fpStream: pointer to output file stream * nMode : Channel Mode: 0=STEREO 1=JS 2=DS 3=MONO **************************************************************************** */ int InitVbrTag(lame_global_flags *gfp) { int nMode,SampIndex; lame_internal_flags *gfc = gfp->internal_flags; #define MAXFRAMESIZE 2880 // or 0xB40, the max freeformat 640 32kHz framesize // uint8_t pbtStreamBuffer[MAXFRAMESIZE]; nMode = gfp->mode; SampIndex = gfc->samplerate_index; /* Clear Frame position array variables */ //gfp->pVbrFrames=NULL; gfp->nVbrNumFrames=0; gfp->nVbrFrameBufferSize=0; /* Clear stream buffer */ // memset(pbtStreamBuffer,0x00,sizeof(pbtStreamBuffer)); /* // Xing VBR pretends to be a 48kbs layer III frame. (at 44.1kHz). // (at 48kHz they use 56kbs since 48kbs frame not big enough for // table of contents) // let's always embed Xing header inside a 64kbs layer III frame. // this gives us enough room for a LAME version string too. // size determined by sampling frequency (MPEG1) // 32kHz: 216 bytes@48kbs 288bytes@ 64kbs // 44.1kHz: 156 bytes 208bytes@64kbs (+1 if padding = 1) // 48kHz: 144 bytes 192 // // MPEG 2 values are the same since the framesize and samplerate // are each reduced by a factor of 2. */ { int i,bitrate,tot; if (1==gfp->version) { bitrate = XING_BITRATE1; } else { if (gfp->out_samplerate < 16000 ) bitrate = XING_BITRATE25; else bitrate = XING_BITRATE2; } if (gfp->VBR==vbr_off) bitrate = gfp->brate; gfp->TotalFrameSize= ((gfp->version+1)*72000*bitrate) / gfp->out_samplerate; tot = (gfc->sideinfo_len+LAMEHEADERSIZE); if (gfp->TotalFrameSize < tot || gfp->TotalFrameSize > MAXFRAMESIZE ) { // disable tag, it wont fit gfp->bWriteVbrTag = 0; return 0; } for (i=0; iTotalFrameSize; ++i) add_dummy_byte(gfp,0); } /* Success */ return 0; } /* fast CRC-16 computation - uses table crc16_lookup 8*/ int CRC_update_lookup(int value, int crc) { int tmp; tmp=crc^value; crc=(crc>>8)^crc16_lookup[tmp & 0xff]; return crc; } void UpdateMusicCRC(uint16_t *crc,unsigned char *buffer, int size){ int i; for (i=0; ibWriteVbrTag) return; if (nStart) MSGF( gfp->internal_flags, "Writing LAME Tag..."); else MSGF( gfp->internal_flags, "done\n"); } /**************************************************************************** * Jonathan Dee 2001/08/31 * * PutLameVBR: Write LAME info: mini version + info on various switches used * Paramters: * pbtStreamBuffer : pointer to output buffer * id3v2size : size of id3v2 tag in bytes * crc : computation of crc-16 of Lame Tag so far (starting at frame sync) * **************************************************************************** */ int PutLameVBR(lame_global_flags *gfp, FILE *fpStream, uint8_t *pbtStreamBuffer, uint32_t id3v2size, uint16_t crc) { lame_internal_flags *gfc = gfp->internal_flags; // FLOAT fVersion = LAME_MAJOR_VERSION + 0.01 * LAME_MINOR_VERSION; int nBytesWritten = 0; int nFilesize = 0; //size of fpStream. Will be equal to size after process finishes. int i; int enc_delay=lame_get_encoder_delay(gfp); // encoder delay int enc_padding=lame_get_encoder_padding(gfp); // encoder padding //recall: gfp->VBR_q is for example set by the switch -V // gfp->quality by -q, -h, -f, etc int nQuality = (100 - 10 * gfp->VBR_q - gfp->quality); const char *szVersion = get_lame_very_short_version(); uint8_t nVBR; uint8_t nRevision = 0x00; uint8_t nRevMethod; uint8_t vbr_type_translator[] = {1,5,3,2,4,0,3}; //numbering different in vbr_mode vs. Lame tag uint8_t nLowpass = ( ((gfp->lowpassfreq / 100.0)+.5) > 255 ? 255 : (gfp->lowpassfreq / 100.0)+.5 ); ieee754_float32_t fPeakSignalAmplitude = 0; //TODO... uint16_t nRadioReplayGain = 0; //TODO... uint16_t nAudioPhileReplayGain = 0; //TODO... uint8_t nNoiseShaping = gfp->internal_flags->noise_shaping; uint8_t nStereoMode = 0; int bNonOptimal = 0; uint8_t nSourceFreq = 0; uint8_t nMisc = 0; uint32_t nMusicLength = 0; int bId3v1Present = ((gfp->internal_flags->tag_spec.flags & CHANGED_FLAG) && !(gfp->internal_flags->tag_spec.flags & V2_ONLY_FLAG)); uint16_t nMusicCRC = 0; //psy model type: Gpsycho or NsPsytune unsigned char bExpNPsyTune = gfp->exp_nspsytune & 1; unsigned char bSafeJoint = (gfp->exp_nspsytune & 2)!=0; unsigned char bNoGapMore = 0; unsigned char bNoGapPrevious = 0; int nNoGapCount = gfp->internal_flags->nogap_total; int nNoGapCurr = gfp->internal_flags->nogap_current; uint8_t nAthType = gfp->ATHtype; //4 bits. uint8_t nFlags = 0; // if ABR, {store bitrate <=255} else { store "-b"} int nABRBitrate = (gfp->VBR==vbr_abr)?gfp->VBR_mean_bitrate_kbps:gfp->brate; //revision and vbr method if (gfp->VBR>=0 && gfp->VBR < sizeof(vbr_type_translator)) nVBR = vbr_type_translator[gfp->VBR]; else nVBR = 0x00; //unknown. nRevMethod = 0x10 * nRevision + nVBR; //nogap if (nNoGapCount != -1) { if (nNoGapCurr > 0) bNoGapPrevious = 1; if (nNoGapCurr < nNoGapCount-1) bNoGapMore = 1; } //flags nFlags = nAthType + (bExpNPsyTune << 4) + (bSafeJoint << 5) + (bNoGapMore << 6) + (bNoGapPrevious << 7); if (nQuality < 0) nQuality = 0; /*stereo mode field... a bit ugly.*/ switch(gfp->mode) { case MONO: nStereoMode = 0; break; case STEREO: nStereoMode = 1; break; case DUAL_CHANNEL: nStereoMode = 2; break; case JOINT_STEREO: if (gfp->force_ms) nStereoMode = 4; else nStereoMode = 3; break; case NOT_SET: /* FALLTHROUGH */ default: nStereoMode = 7; break; } if (gfp->mode_automs) nStereoMode = 5; /*Intensity stereo : nStereoMode = 6. IS is not implemented */ if (gfp->in_samplerate <= 32000) nSourceFreq = 0x00; else if (gfp->in_samplerate ==48000) nSourceFreq = 0x02; else if (gfp->in_samplerate > 48000) nSourceFreq = 0x03; else nSourceFreq = 0x01; //default is 44100Hz. //Check if the user overrided the default LAME behaviour with some nasty options if (gfp->short_blocks == short_block_forced || gfp->short_blocks == short_block_dispensed || ((gfp->lowpassfreq == -1) && (gfp->highpassfreq == -1)) || // "-k" (gfp->scale_left != gfp->scale_right) || gfp->disable_reservoir || gfp->noATH || gfp->ATHonly || (nAthType == 0) || gfp->in_samplerate <= 32000) bNonOptimal = 1; nMisc = nNoiseShaping + (nStereoMode << 2) + (bNonOptimal << 5) + (nSourceFreq << 6); //get filesize fseek(fpStream, 0, SEEK_END); nFilesize = ftell(fpStream); nMusicLength = nFilesize - id3v2size; //omit current frame if (bId3v1Present) nMusicLength-=128; //id3v1 present. nMusicCRC = gfc->nMusicCRC; /*Write all this information into the stream*/ CreateI4(&pbtStreamBuffer[nBytesWritten], nQuality); nBytesWritten+=4; strncpy(&pbtStreamBuffer[nBytesWritten], szVersion, 9); nBytesWritten+=9; pbtStreamBuffer[nBytesWritten] = nRevMethod ; nBytesWritten++; pbtStreamBuffer[nBytesWritten] = nLowpass; nBytesWritten++; memmove(&pbtStreamBuffer[nBytesWritten], &fPeakSignalAmplitude, 4); nBytesWritten+=4; CreateI2(&pbtStreamBuffer[nBytesWritten],nRadioReplayGain); nBytesWritten+=2; CreateI2(&pbtStreamBuffer[nBytesWritten],nAudioPhileReplayGain); nBytesWritten+=2; pbtStreamBuffer[nBytesWritten] = nFlags; nBytesWritten++; if (nABRBitrate >= 255) pbtStreamBuffer[nBytesWritten] = 0xFF; else pbtStreamBuffer[nBytesWritten] = nABRBitrate; nBytesWritten++; pbtStreamBuffer[nBytesWritten ] = enc_delay >> 4; // works for win32, does it for unix? pbtStreamBuffer[nBytesWritten +1] = (enc_delay << 4) + (enc_padding >> 8); pbtStreamBuffer[nBytesWritten +2] = enc_padding; nBytesWritten+=3; pbtStreamBuffer[nBytesWritten] = nMisc; nBytesWritten++; memset(pbtStreamBuffer+nBytesWritten,0, 3); //unused in rev0 nBytesWritten+=3; CreateI4(&pbtStreamBuffer[nBytesWritten], nMusicLength); nBytesWritten+=4; CreateI2(&pbtStreamBuffer[nBytesWritten], nMusicCRC); nBytesWritten+=2; /*Calculate tag CRC.... must be done here, since it includes *previous information*/ for (i = 0;iinternal_flags; long lFileSize; int nStreamIndex; char abyte,bbyte; uint8_t btToc[NUMTOCENTRIES]; uint8_t pbtStreamBuffer[MAXFRAMESIZE]; int i; uint16_t crc = 0x00; unsigned char id3v2Header[10]; size_t id3v2TagSize; if (gfc->VBR_seek_table.pos <= 0) return -1; /* Clear stream buffer */ memset(pbtStreamBuffer,0x00,sizeof(pbtStreamBuffer)); /* Seek to end of file*/ fseek(fpStream,0,SEEK_END); /* Get file size */ lFileSize=ftell(fpStream); /* Abort if file has zero length. Yes, it can happen :) */ if (lFileSize==0) return -1; /* * The VBR tag may NOT be located at the beginning of the stream. * If an ID3 version 2 tag was added, then it must be skipped to write * the VBR tag data. */ /* seek to the beginning of the stream */ fseek(fpStream,0,SEEK_SET); /* read 10 bytes in case there's an ID3 version 2 header here */ fread(id3v2Header,1,sizeof id3v2Header,fpStream); /* does the stream begin with the ID3 version 2 file identifier? */ if (!strncmp((char *)id3v2Header,"ID3",3)) { /* the tag size (minus the 10-byte header) is encoded into four * bytes where the most significant bit is clear in each byte */ id3v2TagSize=(((id3v2Header[6] & 0x7f)<<21) | ((id3v2Header[7] & 0x7f)<<14) | ((id3v2Header[8] & 0x7f)<<7) | (id3v2Header[9] & 0x7f)) + sizeof id3v2Header; } else { /* no ID3 version 2 tag in this stream */ id3v2TagSize=0; } /* Seek to first real frame */ fseek(fpStream,id3v2TagSize+gfp->TotalFrameSize,SEEK_SET); /* Read the header (first valid frame) */ fread(pbtStreamBuffer,4,1,fpStream); /* the default VBR header. 48 kbps layer III, no padding, no crc */ /* but sampling freq, mode andy copyright/copy protection taken */ /* from first valid frame */ pbtStreamBuffer[0]=(uint8_t) 0xff; abyte = (pbtStreamBuffer[1] & (char) 0xf1); { int bitrate; if (1==gfp->version) { bitrate = XING_BITRATE1; } else { if (gfp->out_samplerate < 16000 ) bitrate = XING_BITRATE25; else bitrate = XING_BITRATE2; } if (gfp->VBR==vbr_off) bitrate = gfp->brate; bbyte = 16*BitrateIndex(bitrate,gfp->version,gfp->out_samplerate); } /* Use as much of the info from the real frames in the * Xing header: samplerate, channels, crc, etc... */ if (gfp->version==1) { /* MPEG1 */ pbtStreamBuffer[1]=abyte | (char) 0x0a; /* was 0x0b; */ abyte = pbtStreamBuffer[2] & (char) 0x0d; /* AF keep also private bit */ pbtStreamBuffer[2]=(char) bbyte | abyte; /* 64kbs MPEG1 frame */ }else{ /* MPEG2 */ pbtStreamBuffer[1]=abyte | (char) 0x02; /* was 0x03; */ abyte = pbtStreamBuffer[2] & (char) 0x0d; /* AF keep also private bit */ pbtStreamBuffer[2]=(char) bbyte | abyte; /* 64kbs MPEG2 frame */ } /* Clear all TOC entries */ memset(btToc,0,sizeof(btToc)); Xing_seek_table (&gfc->VBR_seek_table, btToc); /* print_seeking (btToc); */ /* Start writing the tag after the zero frame */ nStreamIndex=gfc->sideinfo_len; /* note! Xing header specifies that Xing data goes in the * ancillary data with NO ERROR PROTECTION. If error protecton * in enabled, the Xing data still starts at the same offset, * and now it is in sideinfo data block, and thus will not * decode correctly by non-Xing tag aware players */ if (gfp->error_protection) nStreamIndex -= 2; /* Put Vbr tag */ if (gfp->VBR == vbr_off) { pbtStreamBuffer[nStreamIndex++]=VBRTag2[0]; pbtStreamBuffer[nStreamIndex++]=VBRTag2[1]; pbtStreamBuffer[nStreamIndex++]=VBRTag2[2]; pbtStreamBuffer[nStreamIndex++]=VBRTag2[3]; } else { pbtStreamBuffer[nStreamIndex++]=VBRTag[0]; pbtStreamBuffer[nStreamIndex++]=VBRTag[1]; pbtStreamBuffer[nStreamIndex++]=VBRTag[2]; pbtStreamBuffer[nStreamIndex++]=VBRTag[3]; } /* Put header flags */ CreateI4(&pbtStreamBuffer[nStreamIndex],FRAMES_FLAG+BYTES_FLAG+TOC_FLAG+VBR_SCALE_FLAG); nStreamIndex+=4; /* Put Total Number of frames */ CreateI4(&pbtStreamBuffer[nStreamIndex],gfp->nVbrNumFrames); nStreamIndex+=4; /* Put Total file size */ CreateI4(&pbtStreamBuffer[nStreamIndex],(int)lFileSize); nStreamIndex+=4; /* Put TOC */ memcpy(&pbtStreamBuffer[nStreamIndex],btToc,sizeof(btToc)); nStreamIndex+=sizeof(btToc); if (gfp->error_protection) { /* (jo) error_protection: add crc16 information to header */ CRC_writeheader(gfc, pbtStreamBuffer); } //work out CRC so far: initially crc = 0 for (i = 0;i< nStreamIndex ;i++) crc = CRC_update_lookup(pbtStreamBuffer[i], crc); /*Put LAME VBR info*/ nStreamIndex+=PutLameVBR(gfp, fpStream, pbtStreamBuffer + nStreamIndex, id3v2TagSize,crc); #ifdef DEBUG_VBRTAG { VBRTAGDATA TestHeader; GetVbrTag(&TestHeader,pbtStreamBuffer); } #endif /*Seek to the beginning of the stream */ fseek(fpStream,id3v2TagSize,SEEK_SET); /* Put it all to disk again */ if (fwrite(pbtStreamBuffer,(unsigned int)gfp->TotalFrameSize,1,fpStream)!=1) { return -1; } /* Save to delete the frame buffer */ //free(gfp->pVbrFrames); see HACKING for instructions on how //gfp->pVbrFrames=NULL; memory in 'gfp' is allocated/free'd return 0; /* success */ }