ref: 3bc7b61cb1c7c34b4f1ad39771febe6ea61b5094
dir: /id3v2.c/
/* * Have fun reading the following: * * http://id3.org/id3v2.4.0-structure * http://id3.org/id3v2.4.0-frames * http://id3.org/d3v2.3.0 * http://id3.org/id3v2-00 * http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm * http://wiki.hydrogenaud.io/index.php?title=MP3#VBRI.2C_XING.2C_and_LAME_headers * http://www.codeproject.com/Articles/8295/MPEG-Audio-Frame-Header#VBRIHeader */ #include "tagspriv.h" #define synchsafe(d) (uint)(((d)[0]&127)<<21 | ((d)[1]&127)<<14 | ((d)[2]&127)<<7 | ((d)[3]&127)<<0) static int v2cb(Tagctx *ctx, char *k, char *v) { k++; if(strcmp(k, "AL") == 0 || strcmp(k, "ALB") == 0) txtcb(ctx, Talbum, k-1, v); else if(strcmp(k, "PE1") == 0 || strcmp(k, "PE2") == 0 || strcmp(k, "P1") == 0 || strcmp(k, "P2") == 0) txtcb(ctx, Tartist, k-1, v); else if(strcmp(k, "IT2") == 0 || strcmp(k, "T2") == 0) txtcb(ctx, Ttitle, k-1, v); else if(strcmp(k, "YE") == 0 || strcmp(k, "YER") == 0 || strcmp(k, "DRC") == 0) txtcb(ctx, Tdate, k-1, v); else if(strcmp(k, "RK") == 0 || strcmp(k, "RCK") == 0) txtcb(ctx, Ttrack, k-1, v); else if(strcmp(k, "LEN") == 0) ctx->duration = atoi(v); else if(strcmp(k, "CM") == 0 || strcmp(k, "COM") == 0) txtcb(ctx, Tcomposer, k-1, v); else if(strcmp(k, "CO") == 0 || strcmp(k, "CON") == 0){ for(; v[0]; v++){ if(v[0] == '(' && v[1] <= '9' && v[1] >= '0'){ int i = atoi(&v[1]); if(i >= 0 && i < Numgenre) txtcb(ctx, Tgenre, k-1, id3genres[i]); for(v++; v[0] && v[0] != ')'; v++); v--; }else if(v[0] != '(' && v[0] != ')'){ txtcb(ctx, Tgenre, k-1, v); break; } } }else if(strcmp(k, "XXX") == 0 && strncmp(v, "REPLAYGAIN_", 11) == 0){ int type = -1; v += 11; if(strncmp(v, "TRACK_", 6) == 0){ v += 6; if(strcmp(v, "GAIN") == 0) type = Ttrackgain; else if(strcmp(v, "PEAK") == 0) type = Ttrackpeak; }else if(strncmp(v, "ALBUM_", 6) == 0){ v += 6; if(strcmp(v, "GAIN") == 0) type = Talbumgain; else if(strcmp(v, "PEAK") == 0) type = Talbumpeak; } if(type >= 0) txtcb(ctx, type, k-1, v+5); else return 0; }else if(strcmp(k-1, "COM") == 0 || strcmp(k-1, "COMM") == 0){ txtcb(ctx, Tcomment, k-1, v); }else{ txtcb(ctx, Tunknown, k-1, v); } return 1; } static int rva2(Tagctx *ctx, char *tag, int sz) { uint8_t *b, *end; if((b = memchr(tag, 0, sz)) == nil) return -1; b++; for(end = (uint8_t*)tag+sz; b+4 < end; b += 5){ int type = b[0]; float peak; float va = (float)(b[1]<<8 | b[2]) / 512.0f; if(b[3] == 24){ peak = (float)(b[4]<<16 | b[5]<<8 | b[6]) / 32768.0f; b += 2; }else if(b[3] == 16){ peak = (float)(b[4]<<8 | b[5]) / 32768.0f; b += 1; }else if(b[3] == 8){ peak = (float)b[4] / 32768.0f; }else return -1; if(type == 1){ /* master volume */ char vas[16], peaks[8]; snprintf(vas, sizeof(vas), "%+.5f dB", va); snprintf(peaks, sizeof(peaks), "%.5f", peak); vas[sizeof(vas)-1] = 0; peaks[sizeof(peaks)-1] = 0; if(strcmp((char*)tag, "track") == 0){ txtcb(ctx, Ttrackgain, "RVA2", vas); txtcb(ctx, Ttrackpeak, "RVA2", peaks); }else if(strcmp((char*)tag, "album") == 0){ txtcb(ctx, Talbumgain, "RVA2", vas); txtcb(ctx, Talbumpeak, "RVA2", peaks); } break; } } return 0; } static int resync(uint8_t *b, int sz) { int i; if(sz < 4) return sz; for(i = 0; i < sz-2; i++){ if(b[i] == 0xff && b[i+1] == 0x00 && (b[i+2] & 0xe0) == 0xe0){ memmove(&b[i+1], &b[i+2], sz-i-2); sz--; } } return sz; } static int unsyncread(void *buf, int *sz) { int i; uint8_t *b; b = buf; for(i = 0; i < *sz; i++){ if(b[i] == 0xff){ if(i+1 >= *sz || (b[i+1] == 0x00 && i+2 >= *sz)) break; if(b[i+1] == 0x00 && (b[i+2] & 0xe0) == 0xe0){ memmove(&b[i+1], &b[i+2], *sz-i-2); (*sz)--; } } } return i; } static int nontext(Tagctx *ctx, uint8_t *d, int tsz, int unsync) { int n, offset; char *b, *tag; Tagread f; tag = ctx->buf; n = 0; f = unsync ? unsyncread : nil; if(strcmp((char*)d, "APIC") == 0){ offset = ctx->seek(ctx, 0, 1); if((n = ctx->read(ctx, tag, 256)) == 256){ /* APIC mime and description should fit */ b = tag + 1; /* mime type */ for(n = 1 + strlen(b) + 2; n < 253; n++){ if(tag[0] == 0 || tag[0] == 3){ /* one zero byte */ if(tag[n] == 0){ n++; break; } }else if(tag[n] == 0 && tag[n+1] == 0 && tag[n+2] == 0){ n += 3; break; } } tagscallcb(ctx, Timage, "APIC", b, offset+n, tsz-n, f); n = 256; } }else if(strcmp((char*)d, "PIC") == 0){ offset = ctx->seek(ctx, 0, 1); if((n = ctx->read(ctx, tag, 256)) == 256){ /* PIC description should fit */ b = tag + 1; /* mime type */ for(n = 5; n < 253; n++){ if(tag[0] == 0 || tag[0] == 3){ /* one zero byte */ if(tag[n] == 0){ n++; break; } }else if(tag[n] == 0 && tag[n+1] == 0 && tag[n+2] == 0){ n += 3; break; } } if(tsz > n) tagscallcb(ctx, Timage, "PIC", strcmp(b, "JPG") == 0 ? "image/jpeg" : "image/png", offset+n, tsz-n, f); n = 256; } }else if(strcmp((char*)d, "RVA2") == 0 && tsz >= 6+5){ /* replay gain. 6 = "track\0", 5 = other */ if(ctx->bufsz >= tsz && (n = ctx->read(ctx, tag, tsz)) == tsz) rva2(ctx, tag, unsync ? resync((uint8_t*)tag, n) : n); } return ctx->seek(ctx, tsz-n, 1) < 0 ? -1 : 0; } static int text(Tagctx *ctx, uint8_t *d, int tsz, int unsync) { char *b, *tag; if(ctx->bufsz >= tsz+1){ /* place the data at the end to make best effort at charset conversion */ tag = &ctx->buf[ctx->bufsz - tsz - 1]; if(ctx->read(ctx, tag, tsz) != tsz) return -1; }else{ ctx->seek(ctx, tsz, 1); return 0; } if(unsync) tsz = resync((uint8_t*)tag, tsz); tag[tsz] = 0; b = &tag[1]; switch(tag[0]){ case 0: /* iso-8859-1 */ if(iso88591toutf8((uint8_t*)ctx->buf, ctx->bufsz, (uint8_t*)b, tsz) > 0) v2cb(ctx, (char*)d, ctx->buf); break; case 1: /* utf-16 */ case 2: if(utf16to8((uint8_t*)ctx->buf, ctx->bufsz, (uint8_t*)b, tsz) > 0) v2cb(ctx, (char*)d, ctx->buf); break; case 3: /* utf-8 */ if(*b) v2cb(ctx, (char*)d, b); break; } return 0; } static int isid3(uint8_t *d) { /* "ID3" version[2] flags[1] size[4] */ return ( d[0] == 'I' && d[1] == 'D' && d[2] == '3' && d[3] < 0xff && d[4] < 0xff && d[6] < 0x80 && d[7] < 0x80 && d[8] < 0x80 && d[9] < 0x80 ); } static const uint8_t bitrates[4][4][16] = { { {0}, {0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80, 0}, /* v2.5 III */ {0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80, 0}, /* v2.5 II */ {0, 16, 24, 28, 32, 40, 48, 56, 64, 72, 80, 88, 96, 112, 128, 0}, /* v2.5 I */ }, { {0}, {0}, {0}, {0} }, { {0}, {0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80, 0}, /* v2 III */ {0, 4, 8, 12, 16, 20, 24, 28, 32, 40, 48, 56, 64, 72, 80, 0}, /* v2 II */ {0, 16, 24, 28, 32, 40, 48, 56, 64, 72, 80, 88, 96, 112, 128, 0}, /* v2 I */ }, { {0}, {0, 16, 20, 24, 28, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 0}, /* v1 III */ {0, 16, 24, 28, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 0}, /* v1 II */ {0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 0}, /* v1 I */ } }; static const uint samplerates[4][4] = { {11025, 12000, 8000, 0}, { 0, 0, 0, 0}, {22050, 24000, 16000, 0}, {44100, 48000, 32000, 0}, }; static const int chans[] = {2, 2, 2, 1}; static const int samplesframe[4][4] = { {0, 0, 0, 0}, {0, 576, 1152, 384}, {0, 576, 1152, 384}, {0, 1152, 1152, 384}, }; static void getduration(Tagctx *ctx, int offset) { uint64_t n, framelen, samplespf, toc; uint8_t *b; uint x; int xversion, xlayer, xbitrate, i; if(ctx->read(ctx, ctx->buf, 256) != 256) return; x = beuint((uint8_t*)ctx->buf); xversion = x >> 19 & 3; xlayer = x >> 17 & 3; xbitrate = x >> 12 & 0xf; ctx->bitrate = 2000*(int)bitrates[xversion][xlayer][xbitrate]; samplespf = samplesframe[xversion][xlayer]; ctx->samplerate = samplerates[xversion][x >> 10 & 3]; ctx->channels = chans[x >> 6 & 3]; if(ctx->samplerate > 0){ framelen = (uint64_t)144*ctx->bitrate / ctx->samplerate; if((x & (1<<9)) != 0) /* padding */ framelen += xlayer == 3 ? 4 : 1; /* for I it's 4 bytes */ if(memcmp(&ctx->buf[0x24], "Info", 4) == 0 || memcmp(&ctx->buf[0x24], "Xing", 4) == 0){ b = (uint8_t*)ctx->buf + 0x28; x = beuint(b); b += 4; if((x & 1) != 0){ /* number of frames is set */ n = beuint(b); b += 4; ctx->duration = n * samplespf * 1000 / ctx->samplerate; } if((x & 2) != 0){ /* file size is set */ n = beuint(b); b += 4; if(ctx->duration == 0 && framelen > 0) ctx->duration = n * samplespf * 1000 / framelen / ctx->samplerate; if((x & 4) != 0 && ctx->toc != nil){ /* TOC is set */ toc = offset + 100 + (char*)b - ctx->buf; if((x & 8) != 0) /* VBR scale */ toc += 4; for(i = 0; i < 100; i++){ /* * offset = n * b[i] / 256 * ms = i * duration / 100 */ ctx->toc(ctx, i * ctx->duration / 100, toc + (n * b[i]) / 256); } b += 100; if((x & 8) != 0) /* VBR scale */ b += 4; } } offset += (char*)b - ctx->buf; }else if(memcmp(&ctx->buf[0x24], "VBRI", 4) == 0){ n = beuint((uint8_t*)&ctx->buf[0x32]); ctx->duration = n * samplespf * 1000 / ctx->samplerate; if(ctx->duration == 0 && framelen > 0){ n = beuint((uint8_t*)&ctx->buf[0x28]); /* file size */ ctx->duration = n * samplespf * 1000 / framelen / ctx->samplerate; } } } if(ctx->bitrate > 0 && ctx->duration == 0) /* worst case -- use real file size instead */ ctx->duration = (ctx->seek(ctx, 0, 2) - offset)/(ctx->bitrate / 1000) * 8; } int tagid3v2(Tagctx *ctx) { int sz, exsz, framesz; int ver, unsync, offset; int newpos, oldpos; uint8_t d[10], *b; if(ctx->read(ctx, d, sizeof(d)) != sizeof(d)) return -1; if(!isid3(d)){ /* no tags, but the stream information is there */ if(d[0] != 0xff || (d[1] & 0xfe) != 0xfa) return -1; ctx->seek(ctx, -(int)sizeof(d), 1); getduration(ctx, 0); return 0; } oldpos = 0; header: ver = d[3]; unsync = d[5] & (1<<7); sz = synchsafe(&d[6]); if(ver == 2 && (d[5] & (1<<6)) != 0) /* compression */ return -1; ctx->restart = sizeof(d)+sz; if(ver > 2){ if((d[5] & (1<<4)) != 0) /* footer */ sz -= 10; if((d[5] & (1<<6)) != 0){ /* skip extended header */ if(ctx->read(ctx, d, 4) != 4) return -1; exsz = (ver >= 3) ? beuint(d) : synchsafe(d); if(exsz < 6 || ctx->seek(ctx, exsz-4, 1) < 0) return -1; sz -= exsz; } } framesz = (ver >= 3) ? 10 : 6; for(; sz > framesz;){ int tsz, frameunsync; if(ctx->read(ctx, d, framesz) != framesz) return -1; sz -= framesz; /* return on padding */ if(memcmp(d, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", framesz) == 0) break; if(ver >= 3){ tsz = (ver == 3) ? beuint(&d[4]) : synchsafe(&d[4]); if(tsz < 0 || tsz > sz) break; frameunsync = d[9] & (1<<1); d[4] = 0; if((d[9] & 0x0c) != 0){ /* compression & encryption */ ctx->seek(ctx, tsz, 1); sz -= tsz; continue; } if(ver == 4 && (d[9] & 1<<0) != 0){ /* skip data length indicator */ ctx->seek(ctx, 4, 1); sz -= 4; tsz -= 4; } }else{ tsz = beuint(&d[3]) >> 8; if(tsz > sz) return -1; frameunsync = 0; d[3] = 0; } sz -= tsz; if(d[0] == 'T' && text(ctx, d, tsz, unsync || frameunsync) != 0) return -1; else if(d[0] != 'T' && nontext(ctx, d, tsz, unsync || frameunsync) != 0) return -1; } offset = ctx->seek(ctx, sz, 1); sz = ctx->bufsz <= 2048 ? ctx->bufsz : 2048; b = nil; for(exsz = 0; exsz < 2048; exsz += sz){ if(ctx->read(ctx, ctx->buf, sz) != sz) break; for(b = (uint8_t*)ctx->buf; (b = memchr(b, 'I', sz - 1 - ((char*)b - ctx->buf))) != nil; b++){ newpos = ctx->seek(ctx, (char*)b - ctx->buf + offset + exsz, 0); if(ctx->read(ctx, d, sizeof(d)) != sizeof(d)) return 0; if(isid3(d) && newpos != oldpos){ oldpos = newpos; goto header; } } for(b = (uint8_t*)ctx->buf; (b = memchr(b, 0xff, sz-3)) != nil; b++){ if((b[1] & 0xe0) == 0xe0){ offset = ctx->seek(ctx, (char*)b - ctx->buf + offset + exsz, 0); exsz = 2048; break; } } } if(b != nil) getduration(ctx, offset); return 0; }