1 /* 2 parse: spawned from common; clustering around stream/frame parsing 3 4 copyright ?-2014 by the mpg123 project - free software under the terms of the LGPL 2.1 5 see COPYING and AUTHORS files in distribution or http://mpg123.org 6 initially written by Michael Hipp & Thomas Orgis 7 */ 8 9 #include "mpg123lib_intern.h" 10 11 #include <sys/stat.h> 12 #include <fcntl.h> 13 14 #include "getbits.h" 15 16 #if defined (WANT_WIN32_SOCKETS) 17 #include <winsock2.h> 18 #include <ws2tcpip.h> 19 #endif 20 21 /* a limit for number of frames in a track; beyond that unsigned long may not be enough to hold byte addresses */ 22 #ifdef HAVE_LIMITS_H 23 #include <limits.h> 24 #endif 25 #ifndef ULONG_MAX 26 /* hm, is this portable across preprocessors? */ 27 #define ULONG_MAX ((unsigned long)-1) 28 #endif 29 #define TRACK_MAX_FRAMES ULONG_MAX/4/1152 30 31 #include "mpeghead.h" 32 33 #include "debug.h" 34 35 #define bsbufid(fr) (fr)->bsbuf==(fr)->bsspace[0] ? 0 : ((fr)->bsbuf==fr->bsspace[1] ? 1 : ( (fr)->bsbuf==(fr)->bsspace[0]+512 ? 2 : ((fr)->bsbuf==fr->bsspace[1]+512 ? 3 : -1) ) ) 36 37 /* PARSE_GOOD and PARSE_BAD have to be 1 and 0 (TRUE and FALSE), others can vary. */ 38 enum parse_codes 39 { 40 PARSE_MORE = MPG123_NEED_MORE 41 ,PARSE_ERR = MPG123_ERR 42 ,PARSE_END = 10 /* No more audio data to find. */ 43 ,PARSE_GOOD = 1 /* Everything's fine. */ 44 ,PARSE_BAD = 0 /* Not fine (invalid data). */ 45 ,PARSE_RESYNC = 2 /* Header not good, go into resync. */ 46 ,PARSE_AGAIN = 3 /* Really start over, throw away and read a new header, again. */ 47 }; 48 49 /* bitrates for [mpeg1/2][layer] */ 50 static const int tabsel_123[2][3][16] = 51 { 52 { 53 {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,}, 54 {0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,}, 55 {0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} 56 }, 57 { 58 {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,}, 59 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,}, 60 {0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} 61 } 62 }; 63 64 static const long freqs[9] = { 44100, 48000, 32000, 22050, 24000, 16000 , 11025 , 12000 , 8000 }; 65 66 static int decode_header(mpg123_handle *fr,unsigned long newhead, int *freeformat_count); 67 static int skip_junk(mpg123_handle *fr, unsigned long *newheadp, long *headcount); 68 static int do_readahead(mpg123_handle *fr, unsigned long newhead); 69 static int wetwork(mpg123_handle *fr, unsigned long *newheadp); 70 71 /* These two are to be replaced by one function that gives all the frame parameters (for outsiders).*/ 72 /* Those functions are unsafe regarding bad arguments (inside the mpg123_handle), but just returning anything would also be unsafe, the caller code has to be trusted. */ 73 74 int frame_bitrate(mpg123_handle *fr) 75 { 76 return tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index]; 77 } 78 79 long frame_freq(mpg123_handle *fr) 80 { 81 return freqs[fr->sampling_frequency]; 82 } 83 84 /* compiler is smart enought to inline this one or should I really do it as macro...? */ 85 static int head_check(unsigned long head) 86 { 87 if 88 ( 89 ((head & HDR_SYNC) != HDR_SYNC) 90 || 91 /* layer: 01,10,11 is 1,2,3; 00 is reserved */ 92 (!(HDR_LAYER_VAL(head))) 93 || 94 /* 1111 means bad bitrate */ 95 (HDR_BITRATE_VAL(head) == 0xf) 96 || 97 /* sampling freq: 11 is reserved */ 98 (HDR_SAMPLERATE_VAL(head) == 0x3) 99 /* here used to be a mpeg 2.5 check... re-enabled 2.5 decoding due to lack of evidence that it is really not good */ 100 ) 101 { 102 return FALSE; 103 } 104 /* if no check failed, the header is valid (hopefully)*/ 105 else 106 { 107 return TRUE; 108 } 109 } 110 111 /* This is moderately sized buffers. Int offset is enough. */ 112 static unsigned long bit_read_long(unsigned char *buf, int *offset) 113 { 114 unsigned long val = /* 32 bit value */ 115 (((unsigned long) buf[*offset]) << 24) 116 | (((unsigned long) buf[*offset+1]) << 16) 117 | (((unsigned long) buf[*offset+2]) << 8) 118 | ((unsigned long) buf[*offset+3]); 119 *offset += 4; 120 return val; 121 } 122 123 static unsigned short bit_read_short(unsigned char *buf, int *offset) 124 { 125 unsigned short val = /* 16 bit value */ 126 (((unsigned short) buf[*offset] ) << 8) 127 | ((unsigned short) buf[*offset+1]); 128 *offset += 2; 129 return val; 130 } 131 132 static int check_lame_tag(mpg123_handle *fr) 133 { 134 int i; 135 unsigned long xing_flags; 136 unsigned long long_tmp; 137 /* 138 going to look for Xing or Info at some position after the header 139 MPEG 1 MPEG 2/2.5 (LSF) 140 Stereo, Joint Stereo, Dual Channel 32 17 141 Mono 17 9 142 */ 143 int lame_offset = (fr->stereo == 2) 144 ? (fr->lsf ? 17 : 32) 145 : (fr->lsf ? 9 : 17); 146 147 if(fr->p.flags & MPG123_IGNORE_INFOFRAME) goto check_lame_tag_no; 148 149 debug("do we have lame tag?"); 150 /* 151 Note: CRC or not, that does not matter here. 152 But, there is any combination of Xing flags in the wild. There are headers 153 without the search index table! I cannot assume a reasonable minimal size 154 for the actual data, have to check if each byte of information is present. 155 But: 4 B Info/Xing + 4 B flags is bare minimum. 156 */ 157 if(fr->framesize < lame_offset+8) goto check_lame_tag_no; 158 159 /* only search for tag when all zero before it (apart from checksum) */ 160 for(i=2; i < lame_offset; ++i) if(fr->bsbuf[i] != 0) goto check_lame_tag_no; 161 162 debug("possibly..."); 163 if 164 ( 165 (fr->bsbuf[lame_offset] == 'I') 166 && (fr->bsbuf[lame_offset+1] == 'n') 167 && (fr->bsbuf[lame_offset+2] == 'f') 168 && (fr->bsbuf[lame_offset+3] == 'o') 169 ) 170 { 171 /* We still have to see what there is */ 172 } 173 else if 174 ( 175 (fr->bsbuf[lame_offset] == 'X') 176 && (fr->bsbuf[lame_offset+1] == 'i') 177 && (fr->bsbuf[lame_offset+2] == 'n') 178 && (fr->bsbuf[lame_offset+3] == 'g') 179 ) 180 { 181 fr->vbr = MPG123_VBR; /* Xing header means always VBR */ 182 } 183 else goto check_lame_tag_no; 184 185 /* we have one of these headers... */ 186 if(VERBOSE2) fprintf(stderr, "Note: Xing/Lame/Info header detected\n"); 187 lame_offset += 4; 188 xing_flags = bit_read_long(fr->bsbuf, &lame_offset); 189 debug1("Xing: flags 0x%08lx", xing_flags); 190 191 /* From now on, I have to carefully check if the announced data is actually 192 there! I'm always returning 'yes', though. */ 193 #define check_bytes_left(n) if(fr->framesize < lame_offset+n) \ 194 goto check_lame_tag_yes 195 if(xing_flags & 1) /* total bitstream frames */ 196 { 197 check_bytes_left(4); long_tmp = bit_read_long(fr->bsbuf, &lame_offset); 198 if(fr->p.flags & MPG123_IGNORE_STREAMLENGTH) 199 { 200 if(VERBOSE3) fprintf(stderr 201 , "Note: Ignoring Xing frames because of MPG123_IGNORE_STREAMLENGTH\n"); 202 } 203 else 204 { 205 /* Check for endless stream, but: TRACK_MAX_FRAMES sensible at all? */ 206 fr->track_frames = long_tmp > TRACK_MAX_FRAMES ? 0 : (off_t) long_tmp; 207 #ifdef GAPLESS 208 /* All or nothing: Only if encoder delay/padding is known, we'll cut 209 samples for gapless. */ 210 if(fr->p.flags & MPG123_GAPLESS) 211 frame_gapless_init(fr, fr->track_frames, 0, 0); 212 #endif 213 if(VERBOSE3) fprintf(stderr, "Note: Xing: %lu frames\n", long_tmp); 214 } 215 } 216 if(xing_flags & 0x2) /* total bitstream bytes */ 217 { 218 check_bytes_left(4); long_tmp = bit_read_long(fr->bsbuf, &lame_offset); 219 if(fr->p.flags & MPG123_IGNORE_STREAMLENGTH) 220 { 221 if(VERBOSE3) fprintf(stderr 222 , "Note: Ignoring Xing bytes because of MPG123_IGNORE_STREAMLENGTH\n"); 223 } 224 else 225 { 226 /* The Xing bitstream length, at least as interpreted by the Lame 227 encoder, encompasses all data from the Xing header frame on, 228 ignoring leading ID3v2 data. Trailing tags (ID3v1) seem to be 229 included, though. */ 230 if(fr->rdat.filelen < 1) 231 fr->rdat.filelen = (off_t) long_tmp + fr->audio_start; /* Overflow? */ 232 else 233 { 234 if((off_t)long_tmp != fr->rdat.filelen - fr->audio_start && NOQUIET) 235 { /* 1/filelen instead of 1/(filelen-start), my decision */ 236 double diff = 100.0/fr->rdat.filelen 237 * ( fr->rdat.filelen - fr->audio_start 238 - (off_t)long_tmp ); 239 if(diff < 0.) diff = -diff; 240 241 if(VERBOSE3) fprintf(stderr 242 , "Note: Xing stream size %lu differs by %f%% from determined/given file size!\n" 243 , long_tmp, diff); 244 245 if(diff > 1. && NOQUIET) fprintf(stderr 246 , "Warning: Xing stream size off by more than 1%%, fuzzy seeking may be even more fuzzy than by design!\n"); 247 } 248 } 249 250 if(VERBOSE3) fprintf(stderr, "Note: Xing: %lu bytes\n", long_tmp); 251 } 252 } 253 if(xing_flags & 0x4) /* TOC */ 254 { 255 check_bytes_left(100); 256 frame_fill_toc(fr, fr->bsbuf+lame_offset); 257 lame_offset += 100; 258 } 259 if(xing_flags & 0x8) /* VBR quality */ 260 { 261 check_bytes_left(4); long_tmp = bit_read_long(fr->bsbuf, &lame_offset); 262 if(VERBOSE3) fprintf(stderr, "Note: Xing: quality = %lu\n", long_tmp); 263 } 264 /* 265 Either zeros/nothing, or: 266 0-8: LAME3.90a 267 9: revision/VBR method 268 10: lowpass 269 11-18: ReplayGain 270 19: encoder flags 271 20: ABR 272 21-23: encoder delays 273 */ 274 check_bytes_left(24); /* I'm interested in 24 B of extra info. */ 275 if(fr->bsbuf[lame_offset] != 0) 276 { 277 unsigned char lame_vbr; 278 float replay_gain[2] = {0,0}; 279 float peak = 0; 280 float gain_offset = 0; /* going to be +6 for old lame that used 83dB */ 281 char nb[10]; 282 off_t pad_in; 283 off_t pad_out; 284 memcpy(nb, fr->bsbuf+lame_offset, 9); 285 nb[9] = 0; 286 if(VERBOSE3) fprintf(stderr, "Note: Info: Encoder: %s\n", nb); 287 if(!strncmp("LAME", nb, 4)) 288 { 289 /* Lame versions before 3.95.1 used 83 dB reference level, later 290 versions 89 dB. We stick with 89 dB as being "normal", adding 291 6 dB. */ 292 unsigned int major, minor; 293 char rest[6]; 294 rest[0] = 0; 295 if(sscanf(nb+4, "%u.%u%s", &major, &minor, rest) >= 2) 296 { 297 debug3("LAME: %u/%u/%s", major, minor, rest); 298 /* We cannot detect LAME 3.95 reliably (same version string as 299 3.95.1), so this is a blind spot. Everything < 3.95 is safe, 300 though. */ 301 if(major < 3 || (major == 3 && minor < 95)) 302 { 303 gain_offset = 6; 304 if(VERBOSE3) fprintf(stderr 305 , "Note: Info: Old LAME detected, using ReplayGain preamp of %f dB.\n" 306 , gain_offset); 307 } 308 } 309 else if(VERBOSE3) fprintf(stderr 310 , "Note: Info: Cannot determine LAME version.\n"); 311 } 312 lame_offset += 9; /* 9 in */ 313 314 /* The 4 big bits are tag revision, the small bits vbr method. */ 315 lame_vbr = fr->bsbuf[lame_offset] & 15; 316 lame_offset += 1; /* 10 in */ 317 if(VERBOSE3) 318 { 319 fprintf(stderr, "Note: Info: rev %u\n", fr->bsbuf[lame_offset] >> 4); 320 fprintf(stderr, "Note: Info: vbr mode %u\n", lame_vbr); 321 } 322 switch(lame_vbr) 323 { 324 /* from rev1 proposal... not sure if all good in practice */ 325 case 1: 326 case 8: fr->vbr = MPG123_CBR; break; 327 case 2: 328 case 9: fr->vbr = MPG123_ABR; break; 329 default: fr->vbr = MPG123_VBR; /* 00==unknown is taken as VBR */ 330 } 331 lame_offset += 1; /* 11 in, skipping lowpass filter value */ 332 333 /* ReplayGain peak ampitude, 32 bit float -- why did I parse it as int 334 before?? Ah, yes, Lame seems to store it as int since some day in 2003; 335 I've only seen zeros anyway until now, bah! */ 336 if 337 ( 338 (fr->bsbuf[lame_offset] != 0) 339 || (fr->bsbuf[lame_offset+1] != 0) 340 || (fr->bsbuf[lame_offset+2] != 0) 341 || (fr->bsbuf[lame_offset+3] != 0) 342 ) 343 { 344 debug("Wow! Is there _really_ a non-zero peak value? Now is it stored as float or int - how should I know?"); 345 /* byte*peak_bytes = (byte*) &peak; 346 ... endianess ... just copy bytes to avoid floating point operation on unaligned memory? 347 peak_bytes[0] = ... 348 peak = *(float*) (fr->bsbuf+lame_offset); */ 349 } 350 if(VERBOSE3) fprintf(stderr 351 , "Note: Info: peak = %f (I won't use this)\n", peak); 352 peak = 0; /* until better times arrived */ 353 lame_offset += 4; /* 15 in */ 354 355 /* ReplayGain values - lame only writes radio mode gain... 356 16bit gain, 3 bits name, 3 bits originator, sign (1=-, 0=+), 357 dB value*10 in 9 bits (fixed point) ignore the setting if name or 358 originator == 000! 359 radio 0 0 1 0 1 1 1 0 0 1 1 1 1 1 0 1 360 audiophile 0 1 0 0 1 0 0 0 0 0 0 1 0 1 0 0 */ 361 for(i =0; i < 2; ++i) 362 { 363 unsigned char gt = fr->bsbuf[lame_offset] >> 5; 364 unsigned char origin = (fr->bsbuf[lame_offset] >> 2) & 0x7; 365 float factor = (fr->bsbuf[lame_offset] & 0x2) ? -0.1f : 0.1f; 366 unsigned short gain = bit_read_short(fr->bsbuf, &lame_offset) & 0x1ff; /* 19 in (2 cycles) */ 367 if(origin == 0 || gt < 1 || gt > 2) continue; 368 369 --gt; 370 replay_gain[gt] = factor * (float) gain; 371 /* Apply gain offset for automatic origin. */ 372 if(origin == 3) replay_gain[gt] += gain_offset; 373 } 374 if(VERBOSE3) 375 { 376 fprintf(stderr, "Note: Info: Radio Gain = %03.1fdB\n" 377 , replay_gain[0]); 378 fprintf(stderr, "Note: Info: Audiophile Gain = %03.1fdB\n" 379 , replay_gain[1]); 380 } 381 for(i=0; i < 2; ++i) 382 { 383 if(fr->rva.level[i] <= 0) 384 { 385 fr->rva.peak[i] = 0; /* TODO: use parsed peak? */ 386 fr->rva.gain[i] = replay_gain[i]; 387 fr->rva.level[i] = 0; 388 } 389 } 390 391 lame_offset += 1; /* 20 in, skipping encoding flags byte */ 392 393 /* ABR rate */ 394 if(fr->vbr == MPG123_ABR) 395 { 396 fr->abr_rate = fr->bsbuf[lame_offset]; 397 if(VERBOSE3) fprintf(stderr, "Note: Info: ABR rate = %u\n" 398 , fr->abr_rate); 399 } 400 lame_offset += 1; /* 21 in */ 401 402 /* Encoder delay and padding, two 12 bit values 403 ... lame does write them from int. */ 404 pad_in = ( (((int) fr->bsbuf[lame_offset]) << 4) 405 | (((int) fr->bsbuf[lame_offset+1]) >> 4) ); 406 pad_out = ( (((int) fr->bsbuf[lame_offset+1]) << 8) 407 | ((int) fr->bsbuf[lame_offset+2]) ) & 0xfff; 408 lame_offset += 3; /* 24 in */ 409 if(VERBOSE3) fprintf(stderr, "Note: Encoder delay = %i; padding = %i\n" 410 , (int)pad_in, (int)pad_out); 411 #ifdef GAPLESS 412 if(fr->p.flags & MPG123_GAPLESS) 413 frame_gapless_init(fr, fr->track_frames, pad_in, pad_out); 414 #endif 415 /* final: 24 B LAME data */ 416 } 417 418 check_lame_tag_yes: 419 /* switch buffer back ... */ 420 fr->bsbuf = fr->bsspace[fr->bsnum]+512; 421 fr->bsnum = (fr->bsnum + 1) & 1; 422 return 1; 423 check_lame_tag_no: 424 return 0; 425 } 426 427 /* Just tell if the header is some mono. */ 428 static int header_mono(unsigned long newhead) 429 { 430 return HDR_CHANNEL_VAL(newhead) == MPG_MD_MONO ? TRUE : FALSE; 431 } 432 433 /* true if the two headers will work with the same decoding routines */ 434 static int head_compatible(unsigned long fred, unsigned long bret) 435 { 436 return ( (fred & HDR_CMPMASK) == (bret & HDR_CMPMASK) 437 && header_mono(fred) == header_mono(bret) ); 438 } 439 440 static void halfspeed_prepare(mpg123_handle *fr) 441 { 442 /* save for repetition */ 443 if(fr->p.halfspeed && fr->lay == 3) 444 { 445 debug("halfspeed - reusing old bsbuf "); 446 memcpy (fr->ssave, fr->bsbuf, fr->ssize); 447 } 448 } 449 450 /* If this returns 1, the next frame is the repetition. */ 451 static int halfspeed_do(mpg123_handle *fr) 452 { 453 /* Speed-down hack: Play it again, Sam (the frame, I mean). */ 454 if (fr->p.halfspeed) 455 { 456 if(fr->halfphase) /* repeat last frame */ 457 { 458 debug("repeat!"); 459 fr->to_decode = fr->to_ignore = TRUE; 460 --fr->halfphase; 461 fr->bitindex = 0; 462 fr->wordpointer = (unsigned char *) fr->bsbuf; 463 if(fr->lay == 3) memcpy (fr->bsbuf, fr->ssave, fr->ssize); 464 if(fr->error_protection) fr->crc = getbits(fr, 16); /* skip crc */ 465 return 1; 466 } 467 else 468 { 469 fr->halfphase = fr->p.halfspeed - 1; 470 } 471 } 472 return 0; 473 } 474 475 /* 476 Temporary macro until we got this worked out. 477 Idea is to filter out special return values that shall trigger direct jumps to end / resync / read again. 478 Particularily, the generic ret==PARSE_BAD==0 and ret==PARSE_GOOD==1 are not affected. 479 */ 480 #define JUMP_CONCLUSION(ret) \ 481 { \ 482 if(ret < 0){ debug1("%s", ret == MPG123_NEED_MORE ? "need more" : "read error"); goto read_frame_bad; } \ 483 else if(ret == PARSE_AGAIN) goto read_again; \ 484 else if(ret == PARSE_RESYNC) goto init_resync; \ 485 else if(ret == PARSE_END){ ret=0; goto read_frame_bad; } \ 486 } 487 488 /* 489 That's a big one: read the next frame. 1 is success, <= 0 is some error 490 Special error READER_MORE means: Please feed more data and try again. 491 */ 492 int read_frame(mpg123_handle *fr) 493 { 494 /* TODO: rework this thing */ 495 int freeformat_count = 0; 496 unsigned long newhead; 497 off_t framepos; 498 int ret; 499 /* stuff that needs resetting if complete frame reading fails */ 500 int oldsize = fr->framesize; 501 int oldphase = fr->halfphase; 502 503 /* The counter for the search-first-header loop. 504 It is persistent outside the loop to prevent seemingly endless loops 505 when repeatedly headers are found that do not have valid followup headers. */ 506 long headcount = 0; 507 508 fr->fsizeold=fr->framesize; /* for Layer3 */ 509 510 if(halfspeed_do(fr) == 1) return 1; 511 512 read_again: 513 /* In case we are looping to find a valid frame, discard any buffered data before the current position. 514 This is essential to prevent endless looping, always going back to the beginning when feeder buffer is exhausted. */ 515 if(fr->rd->forget != NULL) fr->rd->forget(fr); 516 517 debug2("trying to get frame %"OFF_P" at %"OFF_P, (off_p)fr->num+1, (off_p)fr->rd->tell(fr)); 518 if((ret = fr->rd->head_read(fr,&newhead)) <= 0){ debug1("need more? (%i)", ret); goto read_frame_bad;} 519 520 init_resync: 521 522 #ifdef SKIP_JUNK 523 if(!fr->firsthead && !head_check(newhead)) 524 { 525 ret = skip_junk(fr, &newhead, &headcount); 526 JUMP_CONCLUSION(ret); 527 } 528 #endif 529 530 ret = head_check(newhead); 531 if(ret) ret = decode_header(fr, newhead, &freeformat_count); 532 533 JUMP_CONCLUSION(ret); /* That only continues for ret == PARSE_BAD or PARSE_GOOD. */ 534 if(ret == PARSE_BAD) 535 { /* Header was not good. */ 536 ret = wetwork(fr, &newhead); /* Messy stuff, handle junk, resync ... */ 537 JUMP_CONCLUSION(ret); 538 /* Normally, we jumped already. If for some reason everything's fine to continue, do continue. */ 539 if(ret != PARSE_GOOD) goto read_frame_bad; 540 } 541 542 if(!fr->firsthead) 543 { 544 ret = do_readahead(fr, newhead); 545 /* readahead can fail mit NEED_MORE, in which case we must also make the just read header available again for next go */ 546 if(ret < 0) fr->rd->back_bytes(fr, 4); 547 JUMP_CONCLUSION(ret); 548 } 549 550 /* Now we should have our valid header and proceed to reading the frame. */ 551 552 /* if filepos is invalid, so is framepos */ 553 framepos = fr->rd->tell(fr) - 4; 554 /* flip/init buffer for Layer 3 */ 555 { 556 unsigned char *newbuf = fr->bsspace[fr->bsnum]+512; 557 /* read main data into memory */ 558 if((ret=fr->rd->read_frame_body(fr,newbuf,fr->framesize))<0) 559 { 560 /* if failed: flip back */ 561 debug("need more?"); 562 goto read_frame_bad; 563 } 564 fr->bsbufold = fr->bsbuf; 565 fr->bsbuf = newbuf; 566 } 567 fr->bsnum = (fr->bsnum + 1) & 1; 568 569 if(!fr->firsthead) 570 { 571 fr->firsthead = newhead; /* _now_ it's time to store it... the first real header */ 572 /* This is the first header of our current stream segment. 573 It is only the actual first header of the whole stream when fr->num is still below zero! 574 Think of resyncs where firsthead has been reset for format flexibility. */ 575 if(fr->num < 0) 576 { 577 fr->audio_start = framepos; 578 /* Only check for LAME tag at beginning of whole stream 579 ... when there indeed is one in between, it's the user's problem. */ 580 if(fr->lay == 3 && check_lame_tag(fr) == 1) 581 { /* ...in practice, Xing/LAME tags are layer 3 only. */ 582 if(fr->rd->forget != NULL) fr->rd->forget(fr); 583 584 fr->oldhead = 0; 585 goto read_again; 586 } 587 /* now adjust volume */ 588 do_rva(fr); 589 } 590 591 debug2("fr->firsthead: %08lx, audio_start: %li", fr->firsthead, (long int)fr->audio_start); 592 } 593 594 fr->bitindex = 0; 595 fr->wordpointer = (unsigned char *) fr->bsbuf; 596 /* Question: How bad does the floating point value get with repeated recomputation? 597 Also, considering that we can play the file or parts of many times. */ 598 if(++fr->mean_frames != 0) 599 { 600 fr->mean_framesize = ((fr->mean_frames-1)*fr->mean_framesize+compute_bpf(fr)) / fr->mean_frames ; 601 } 602 ++fr->num; /* 0 for first frame! */ 603 debug4("Frame %"OFF_P" %08lx %i, next filepos=%"OFF_P, 604 (off_p)fr->num, newhead, fr->framesize, (off_p)fr->rd->tell(fr)); 605 if(!(fr->state_flags & FRAME_FRANKENSTEIN) && ( 606 (fr->track_frames > 0 && fr->num >= fr->track_frames) 607 #ifdef GAPLESS 608 || (fr->gapless_frames > 0 && fr->num >= fr->gapless_frames) 609 #endif 610 )) 611 { 612 fr->state_flags |= FRAME_FRANKENSTEIN; 613 if(NOQUIET) fprintf(stderr, "\nWarning: Encountered more data after announced end of track (frame %"OFF_P"/%"OFF_P"). Frankenstein!\n", (off_p)fr->num, 614 #ifdef GAPLESS 615 fr->gapless_frames > 0 ? (off_p)fr->gapless_frames : 616 #endif 617 (off_p)fr->track_frames); 618 } 619 620 halfspeed_prepare(fr); 621 622 /* index the position */ 623 fr->input_offset = framepos; 624 #ifdef FRAME_INDEX 625 /* Keep track of true frame positions in our frame index. 626 but only do so when we are sure that the frame number is accurate... */ 627 if((fr->state_flags & FRAME_ACCURATE) && FI_NEXT(fr->index, fr->num)) 628 fi_add(&fr->index, framepos); 629 #endif 630 631 if(fr->silent_resync > 0) --fr->silent_resync; 632 633 if(fr->rd->forget != NULL) fr->rd->forget(fr); 634 635 fr->to_decode = fr->to_ignore = TRUE; 636 if(fr->error_protection) fr->crc = getbits(fr, 16); /* skip crc */ 637 638 /* 639 Let's check for header change after deciding that the new one is good 640 and actually having read a frame. 641 642 header_change > 1: decoder structure has to be updated 643 Preserve header_change value from previous runs if it is serious. 644 If we still have a big change pending, it should be dealt with outside, 645 fr->header_change set to zero afterwards. 646 */ 647 if(fr->header_change < 2) 648 { 649 fr->header_change = 2; /* output format change is possible... */ 650 if(fr->oldhead) /* check a following header for change */ 651 { 652 if(fr->oldhead == newhead) fr->header_change = 0; 653 else 654 /* Headers that match in this test behave the same for the outside world. 655 namely: same decoding routines, same amount of decoded data. */ 656 if(head_compatible(fr->oldhead, newhead)) 657 fr->header_change = 1; 658 else 659 { 660 fr->state_flags |= FRAME_FRANKENSTEIN; 661 if(NOQUIET) 662 fprintf(stderr, "\nWarning: Big change (MPEG version, layer, rate). Frankenstein stream?\n"); 663 } 664 } 665 else if(fr->firsthead && !head_compatible(fr->firsthead, newhead)) 666 { 667 fr->state_flags |= FRAME_FRANKENSTEIN; 668 if(NOQUIET) 669 fprintf(stderr, "\nWarning: Big change from first (MPEG version, layer, rate). Frankenstein stream?\n"); 670 } 671 } 672 673 fr->oldhead = newhead; 674 675 return 1; 676 read_frame_bad: 677 /* Also if we searched for valid data in vein, we can forget skipped data. 678 Otherwise, the feeder would hold every dead old byte in memory until the first valid frame! */ 679 if(fr->rd->forget != NULL) fr->rd->forget(fr); 680 681 fr->silent_resync = 0; 682 if(fr->err == MPG123_OK) fr->err = MPG123_ERR_READER; 683 fr->framesize = oldsize; 684 fr->halfphase = oldphase; 685 /* That return code might be inherited from some feeder action, or reader error. */ 686 return ret; 687 } 688 689 690 /* 691 * read ahead and find the next MPEG header, to guess framesize 692 * return value: success code 693 * PARSE_GOOD: found a valid frame size (stored in the handle). 694 * <0: error codes, possibly from feeder buffer (NEED_MORE) 695 * PARSE_BAD: cannot get the framesize for some reason and shall silentry try the next possible header (if this is no free format stream after all...) 696 */ 697 static int guess_freeformat_framesize(mpg123_handle *fr, unsigned long oldhead) 698 { 699 long i; 700 int ret; 701 unsigned long head; 702 if(!(fr->rdat.flags & (READER_SEEKABLE|READER_BUFFERED))) 703 { 704 if(NOQUIET) error("Cannot look for freeformat frame size with non-seekable and non-buffered stream!"); 705 706 return PARSE_BAD; 707 } 708 if((ret=fr->rd->head_read(fr,&head))<=0) 709 return ret; 710 711 /* We are already 4 bytes into it */ 712 for(i=4;i<MAXFRAMESIZE+4;i++) 713 { 714 if((ret=fr->rd->head_shift(fr,&head))<=0) return ret; 715 716 /* No head_check needed, the mask contains all relevant bits. */ 717 if((head & HDR_SAMEMASK) == (oldhead & HDR_SAMEMASK)) 718 { 719 fr->rd->back_bytes(fr,i+1); 720 fr->framesize = i-3; 721 return PARSE_GOOD; /* Success! */ 722 } 723 } 724 fr->rd->back_bytes(fr,i); 725 return PARSE_BAD; 726 } 727 728 729 /* 730 * decode a header and write the information 731 * into the frame structure 732 * Return values are compatible with those of read_frame, namely: 733 * 1: success 734 * 0: no valid header 735 * <0: some error 736 * You are required to do a head_check() before calling! 737 */ 738 static int decode_header(mpg123_handle *fr,unsigned long newhead, int *freeformat_count) 739 { 740 #ifdef DEBUG /* Do not waste cycles checking the header twice all the time. */ 741 if(!head_check(newhead)) 742 { 743 error1("trying to decode obviously invalid header 0x%08lx", newhead); 744 } 745 #endif 746 /* For some reason, the layer and sampling freq settings used to be wrapped 747 in a weird conditional including MPG123_NO_RESYNC. What was I thinking? 748 This information has to be consistent. */ 749 fr->lay = 4 - HDR_LAYER_VAL(newhead); 750 751 if(HDR_VERSION_VAL(newhead) & 0x2) 752 { 753 fr->lsf = (HDR_VERSION_VAL(newhead) & 0x1) ? 0 : 1; 754 fr->mpeg25 = 0; 755 fr->sampling_frequency = HDR_SAMPLERATE_VAL(newhead) + (fr->lsf*3); 756 } 757 else 758 { 759 fr->lsf = 1; 760 fr->mpeg25 = 1; 761 fr->sampling_frequency = 6 + HDR_SAMPLERATE_VAL(newhead); 762 } 763 764 #ifdef DEBUG 765 /* seen a file where this varies (old lame tag without crc, track with crc) */ 766 if((HDR_CRC_VAL(newhead)^0x1) != fr->error_protection) debug("changed crc bit!"); 767 #endif 768 fr->error_protection = HDR_CRC_VAL(newhead)^0x1; 769 fr->bitrate_index = HDR_BITRATE_VAL(newhead); 770 fr->padding = HDR_PADDING_VAL(newhead); 771 fr->extension = HDR_PRIVATE_VAL(newhead); 772 fr->mode = HDR_CHANNEL_VAL(newhead); 773 fr->mode_ext = HDR_CHANEX_VAL(newhead); 774 fr->copyright = HDR_COPYRIGHT_VAL(newhead); 775 fr->original = HDR_ORIGINAL_VAL(newhead); 776 fr->emphasis = HDR_EMPHASIS_VAL(newhead); 777 fr->freeformat = !(newhead & HDR_BITRATE); 778 779 fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2; 780 781 /* we can't use tabsel_123 for freeformat, so trying to guess framesize... */ 782 if(fr->freeformat) 783 { 784 /* when we first encounter the frame with freeformat, guess framesize */ 785 if(fr->freeformat_framesize < 0) 786 { 787 int ret; 788 *freeformat_count += 1; 789 if(*freeformat_count > 5) 790 { 791 if(VERBOSE3) error("You fooled me too often. Refusing to guess free format frame size _again_."); 792 return PARSE_BAD; 793 } 794 ret = guess_freeformat_framesize(fr, newhead); 795 if(ret == PARSE_GOOD) 796 { 797 fr->freeformat_framesize = fr->framesize - fr->padding; 798 if(VERBOSE2) 799 fprintf(stderr, "Note: free format frame size %li\n", fr->freeformat_framesize); 800 } 801 else 802 { 803 if(ret == MPG123_NEED_MORE) 804 debug("Need more data to guess free format frame size."); 805 else if(VERBOSE3) 806 error("Encountered free format header, but failed to guess frame size."); 807 808 return ret; 809 } 810 } 811 /* freeformat should be CBR, so the same framesize can be used at the 2nd reading or later */ 812 else 813 { 814 fr->framesize = fr->freeformat_framesize + fr->padding; 815 } 816 } 817 818 switch(fr->lay) 819 { 820 #ifndef NO_LAYER1 821 case 1: 822 fr->spf = 384; 823 fr->do_layer = do_layer1; 824 if(!fr->freeformat) 825 { 826 fr->framesize = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000; 827 fr->framesize /= freqs[fr->sampling_frequency]; 828 fr->framesize = ((fr->framesize+fr->padding)<<2)-4; 829 } 830 break; 831 #endif 832 #ifndef NO_LAYER2 833 case 2: 834 fr->spf = 1152; 835 fr->do_layer = do_layer2; 836 if(!fr->freeformat) 837 { 838 debug2("bitrate index: %i (%i)", fr->bitrate_index, tabsel_123[fr->lsf][1][fr->bitrate_index] ); 839 fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000; 840 fr->framesize /= freqs[fr->sampling_frequency]; 841 fr->framesize += fr->padding - 4; 842 } 843 break; 844 #endif 845 #ifndef NO_LAYER3 846 case 3: 847 fr->spf = fr->lsf ? 576 : 1152; /* MPEG 2.5 implies LSF.*/ 848 fr->do_layer = do_layer3; 849 if(fr->lsf) 850 fr->ssize = (fr->stereo == 1) ? 9 : 17; 851 else 852 fr->ssize = (fr->stereo == 1) ? 17 : 32; 853 854 if(fr->error_protection) 855 fr->ssize += 2; 856 857 if(!fr->freeformat) 858 { 859 fr->framesize = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000; 860 fr->framesize /= freqs[fr->sampling_frequency]<<(fr->lsf); 861 fr->framesize = fr->framesize + fr->padding - 4; 862 } 863 break; 864 #endif 865 default: 866 if(NOQUIET) error1("Layer type %i not supported in this build!", fr->lay); 867 868 return PARSE_BAD; 869 } 870 if (fr->framesize > MAXFRAMESIZE) 871 { 872 if(NOQUIET) error1("Frame size too big: %d", fr->framesize+4-fr->padding); 873 874 return PARSE_BAD; 875 } 876 return PARSE_GOOD; 877 } 878 879 void set_pointer(mpg123_handle *fr, long backstep) 880 { 881 fr->wordpointer = fr->bsbuf + fr->ssize - backstep; 882 if (backstep) 883 memcpy(fr->wordpointer,fr->bsbufold+fr->fsizeold-backstep,backstep); 884 885 fr->bitindex = 0; 886 } 887 888 /********************************/ 889 890 double compute_bpf(mpg123_handle *fr) 891 { 892 return (fr->framesize > 0) ? fr->framesize + 4.0 : 1.0; 893 } 894 895 int attribute_align_arg mpg123_spf(mpg123_handle *mh) 896 { 897 if(mh == NULL) return MPG123_ERR; 898 899 return mh->firsthead ? mh->spf : MPG123_ERR; 900 } 901 902 double attribute_align_arg mpg123_tpf(mpg123_handle *fr) 903 { 904 static int bs[4] = { 0,384,1152,1152 }; 905 double tpf; 906 if(fr == NULL || !fr->firsthead) return MPG123_ERR; 907 908 tpf = (double) bs[fr->lay]; 909 tpf /= freqs[fr->sampling_frequency] << (fr->lsf); 910 return tpf; 911 } 912 913 int attribute_align_arg mpg123_position(mpg123_handle *fr, off_t no, off_t buffsize, 914 off_t *current_frame, off_t *frames_left, 915 double *current_seconds, double *seconds_left) 916 { 917 double tpf; 918 double dt = 0.0; 919 off_t cur, left; 920 double curs, lefts; 921 922 if(!fr || !fr->rd) return MPG123_ERR; 923 924 no += fr->num; /* no starts out as offset */ 925 cur = no; 926 tpf = mpg123_tpf(fr); 927 if(buffsize > 0 && fr->af.rate > 0 && fr->af.channels > 0) 928 { 929 dt = (double) buffsize / fr->af.rate / fr->af.channels; 930 if(fr->af.encoding & MPG123_ENC_16) dt *= 0.5; 931 } 932 933 left = 0; 934 935 if((fr->track_frames != 0) && (fr->track_frames >= fr->num)) left = no < fr->track_frames ? fr->track_frames - no : 0; 936 else 937 if(fr->rdat.filelen >= 0) 938 { 939 double bpf; 940 off_t t = fr->rd->tell(fr); 941 bpf = fr->mean_framesize ? fr->mean_framesize : compute_bpf(fr); 942 left = (off_t)((double)(fr->rdat.filelen-t)/bpf); 943 /* no can be different for prophetic purposes, file pointer is always associated with fr->num! */ 944 if(fr->num != no) 945 { 946 if(fr->num > no) left += fr->num - no; 947 else 948 { 949 if(left >= (no - fr->num)) left -= no - fr->num; 950 else left = 0; /* uh, oh! */ 951 } 952 } 953 /* I totally don't understand why we should re-estimate the given correct(?) value */ 954 /* fr->num = (unsigned long)((double)t/bpf); */ 955 } 956 957 /* beginning with 0 or 1?*/ 958 curs = (double) no*tpf-dt; 959 lefts = (double)left*tpf+dt; 960 #if 0 961 curs = curs < 0 ? 0.0 : curs; 962 #endif 963 if(left < 0 || lefts < 0) 964 { /* That is the case for non-seekable streams. */ 965 left = 0; 966 lefts = 0.0; 967 } 968 if(current_frame != NULL) *current_frame = cur; 969 if(frames_left != NULL) *frames_left = left; 970 if(current_seconds != NULL) *current_seconds = curs; 971 if(seconds_left != NULL) *seconds_left = lefts; 972 return MPG123_OK; 973 } 974 975 int get_songlen(mpg123_handle *fr,int no) 976 { 977 double tpf; 978 979 if(!fr) 980 return 0; 981 982 if(no < 0) { 983 if(!fr->rd || fr->rdat.filelen < 0) 984 return 0; 985 no = (int) ((double) fr->rdat.filelen / compute_bpf(fr)); 986 } 987 988 tpf = mpg123_tpf(fr); 989 return (int) (no*tpf); 990 } 991 992 /* first attempt of read ahead check to find the real first header; cannot believe what junk is out there! */ 993 static int do_readahead(mpg123_handle *fr, unsigned long newhead) 994 { 995 unsigned long nexthead = 0; 996 int hd = 0; 997 off_t start, oret; 998 int ret; 999 1000 if( ! (!fr->firsthead && fr->rdat.flags & (READER_SEEKABLE|READER_BUFFERED)) ) 1001 return PARSE_GOOD; 1002 1003 start = fr->rd->tell(fr); 1004 1005 debug2("doing ahead check with BPF %d at %"OFF_P, fr->framesize+4, (off_p)start); 1006 /* step framesize bytes forward and read next possible header*/ 1007 if((oret=fr->rd->skip_bytes(fr, fr->framesize))<0) 1008 { 1009 if(oret==READER_ERROR && NOQUIET) error("cannot seek!"); 1010 1011 return oret == MPG123_NEED_MORE ? PARSE_MORE : PARSE_ERR; 1012 } 1013 1014 /* Read header, seek back. */ 1015 hd = fr->rd->head_read(fr,&nexthead); 1016 if( fr->rd->back_bytes(fr, fr->rd->tell(fr)-start) < 0 ) 1017 { 1018 if(NOQUIET) error("Cannot seek back!"); 1019 1020 return PARSE_ERR; 1021 } 1022 if(hd == MPG123_NEED_MORE) return PARSE_MORE; 1023 1024 debug1("After fetching next header, at %"OFF_P, (off_p)fr->rd->tell(fr)); 1025 if(!hd) 1026 { 1027 if(NOQUIET) warning("Cannot read next header, a one-frame stream? Duh..."); 1028 return PARSE_END; 1029 } 1030 1031 debug2("does next header 0x%08lx match first 0x%08lx?", nexthead, newhead); 1032 if(!head_check(nexthead) || !head_compatible(newhead, nexthead)) 1033 { 1034 debug("No, the header was not valid, start from beginning..."); 1035 fr->oldhead = 0; /* start over */ 1036 /* try next byte for valid header */ 1037 if((ret=fr->rd->back_bytes(fr, 3))<0) 1038 { 1039 if(NOQUIET) error("Cannot seek 3 bytes back!"); 1040 1041 return PARSE_ERR; 1042 } 1043 return PARSE_AGAIN; 1044 } 1045 else return PARSE_GOOD; 1046 } 1047 1048 static int handle_id3v2(mpg123_handle *fr, unsigned long newhead) 1049 { 1050 int ret; 1051 fr->oldhead = 0; /* Think about that. Used to be present only for skipping of junk, not resync-style wetwork. */ 1052 ret = parse_new_id3(fr, newhead); 1053 if (ret < 0) return ret; 1054 #ifndef NO_ID3V2 1055 else if(ret > 0){ debug("got ID3v2"); fr->metaflags |= MPG123_NEW_ID3|MPG123_ID3; } 1056 else debug("no useful ID3v2"); 1057 #endif 1058 return PARSE_AGAIN; 1059 } 1060 1061 static int handle_apetag(mpg123_handle *fr, unsigned long newhead) 1062 { 1063 unsigned char apebuf[28]; 1064 unsigned long val; 1065 int i, ret; 1066 1067 fr->oldhead = 0; 1068 1069 /* Apetag headers are 32 bytes, newhead contains 4, read the rest */ 1070 if((ret=fr->rd->fullread(fr,apebuf,28)) < 0) return ret; 1071 1072 /* Apetags start with "APETAGEX", "APET" is already tested. */ 1073 if(strncmp((char *)apebuf,"AGEX",4) != 0) 1074 goto apetag_bad; 1075 1076 /* Version must be 2.000 / 2000 */ 1077 val = (apebuf[7]<<24)|(apebuf[6]<<16)|(apebuf[5]<<8)|apebuf[4]; 1078 if(val != 2000) 1079 goto apetag_bad; 1080 1081 /* Last 8 bytes must be 0 */ 1082 for(i=20; i<28; i++) 1083 if(apebuf[i]) 1084 goto apetag_bad; 1085 1086 /* Looks good, skip the rest. */ 1087 val = (apebuf[11]<<24)|(apebuf[10]<<16)|(apebuf[9]<<8)|apebuf[8]; 1088 if((ret=fr->rd->skip_bytes(fr,val)) < 0) return ret; 1089 1090 return PARSE_AGAIN; 1091 1092 apetag_bad: 1093 if(fr->rd->back_bytes(fr,31) < 0 && NOQUIET) 1094 error("Cannot seek 31 bytes back!"); 1095 1096 return PARSE_AGAIN; /* Give the resync code a chance to fix things */ 1097 } 1098 1099 /* Advance a byte in stream to get next possible header and forget 1100 buffered data if possible (for feed reader). */ 1101 #define FORGET_INTERVAL 1024 /* Used by callers to set forget flag each <n> bytes. */ 1102 static int forget_head_shift(mpg123_handle *fr, unsigned long *newheadp, int forget) 1103 { 1104 int ret; 1105 if((ret=fr->rd->head_shift(fr,newheadp))<=0) return ret; 1106 /* Try to forget buffered data as early as possible to speed up parsing where 1107 new data needs to be added for resync (and things would be re-parsed again 1108 and again because of the start from beginning after hitting end). */ 1109 if(forget && fr->rd->forget != NULL) 1110 { 1111 /* Ensure that the last 4 bytes stay in buffers for reading the header 1112 anew. */ 1113 if(!fr->rd->back_bytes(fr, 4)) 1114 { 1115 fr->rd->forget(fr); 1116 fr->rd->back_bytes(fr, -4); 1117 } 1118 } 1119 return ret; /* No surprise here, error already triggered early return. */ 1120 } 1121 1122 /* watch out for junk/tags on beginning of stream by invalid header */ 1123 static int skip_junk(mpg123_handle *fr, unsigned long *newheadp, long *headcount) 1124 { 1125 int ret; 1126 int freeformat_count = 0; 1127 long limit = 65536; 1128 unsigned long newhead = *newheadp; 1129 unsigned int forgetcount = 0; 1130 /* check for id3v2; first three bytes (of 4) are "ID3" */ 1131 if((newhead & (unsigned long) 0xffffff00) == (unsigned long) 0x49443300) 1132 { 1133 return handle_id3v2(fr, newhead); 1134 } 1135 else if(VERBOSE2 && fr->silent_resync == 0) fprintf(stderr,"Note: Junk at the beginning (0x%08lx)\n",newhead); 1136 1137 /* I even saw RIFF headers at the beginning of MPEG streams ;( */ 1138 if(newhead == ('R'<<24)+('I'<<16)+('F'<<8)+'F') 1139 { 1140 if(VERBOSE2 && fr->silent_resync == 0) fprintf(stderr, "Note: Looks like a RIFF header.\n"); 1141 1142 if((ret=fr->rd->head_read(fr,&newhead))<=0) return ret; 1143 1144 while(newhead != ('d'<<24)+('a'<<16)+('t'<<8)+'a') 1145 { 1146 if(++forgetcount > FORGET_INTERVAL) forgetcount = 0; 1147 if((ret=forget_head_shift(fr,&newhead,!forgetcount))<=0) return ret; 1148 } 1149 if((ret=fr->rd->head_read(fr,&newhead))<=0) return ret; 1150 1151 if(VERBOSE2 && fr->silent_resync == 0) fprintf(stderr,"Note: Skipped RIFF header!\n"); 1152 1153 fr->oldhead = 0; 1154 *newheadp = newhead; 1155 return PARSE_AGAIN; 1156 } 1157 1158 /* 1159 Unhandled junk... just continue search for a header, stepping in single bytes through next 64K. 1160 This is rather identical to the resync loop. 1161 */ 1162 debug("searching for header..."); 1163 *newheadp = 0; /* Invalidate the external value. */ 1164 ret = 0; /* We will check the value after the loop. */ 1165 1166 /* We prepare for at least the 64K bytes as usual, unless 1167 user explicitly wanted more (even infinity). Never less. */ 1168 if(fr->p.resync_limit < 0 || fr->p.resync_limit > limit) 1169 limit = fr->p.resync_limit; 1170 1171 do 1172 { 1173 ++(*headcount); 1174 if(limit >= 0 && *headcount >= limit) break; 1175 1176 if(++forgetcount > FORGET_INTERVAL) forgetcount = 0; 1177 if((ret=forget_head_shift(fr, &newhead, !forgetcount))<=0) return ret; 1178 1179 if(head_check(newhead) && (ret=decode_header(fr, newhead, &freeformat_count))) break; 1180 } while(1); 1181 if(ret<0) return ret; 1182 1183 if(limit >= 0 && *headcount >= limit) 1184 { 1185 if(NOQUIET) error1("Giving up searching valid MPEG header after %li bytes of junk.", *headcount); 1186 return PARSE_END; 1187 } 1188 else debug1("hopefully found one at %"OFF_P, (off_p)fr->rd->tell(fr)); 1189 1190 /* If the new header ist good, it is already decoded. */ 1191 *newheadp = newhead; 1192 return PARSE_GOOD; 1193 } 1194 1195 /* The newhead is bad, so let's check if it is something special, otherwise just resync. */ 1196 static int wetwork(mpg123_handle *fr, unsigned long *newheadp) 1197 { 1198 int ret = PARSE_ERR; 1199 unsigned long newhead = *newheadp; 1200 *newheadp = 0; 1201 1202 /* Classic ID3 tags. Read, then start parsing again. */ 1203 if((newhead & 0xffffff00) == ('T'<<24)+('A'<<16)+('G'<<8)) 1204 { 1205 fr->id3buf[0] = (unsigned char) ((newhead >> 24) & 0xff); 1206 fr->id3buf[1] = (unsigned char) ((newhead >> 16) & 0xff); 1207 fr->id3buf[2] = (unsigned char) ((newhead >> 8) & 0xff); 1208 fr->id3buf[3] = (unsigned char) ( newhead & 0xff); 1209 1210 if((ret=fr->rd->fullread(fr,fr->id3buf+4,124)) < 0) return ret; 1211 1212 fr->metaflags |= MPG123_NEW_ID3|MPG123_ID3; 1213 fr->rdat.flags |= READER_ID3TAG; /* that marks id3v1 */ 1214 if(VERBOSE3) fprintf(stderr,"Note: Skipped ID3v1 tag.\n"); 1215 1216 return PARSE_AGAIN; 1217 } 1218 /* This is similar to initial junk skipping code... */ 1219 /* Check for id3v2; first three bytes (of 4) are "ID3" */ 1220 if((newhead & (unsigned long) 0xffffff00) == (unsigned long) 0x49443300) 1221 { 1222 return handle_id3v2(fr, newhead); 1223 } 1224 /* Check for an apetag header */ 1225 if(newhead == ('A'<<24)+('P'<<16)+('E'<<8)+'T') 1226 { 1227 return handle_apetag(fr, newhead); 1228 } 1229 else if(NOQUIET && fr->silent_resync == 0) 1230 { 1231 fprintf(stderr,"Note: Illegal Audio-MPEG-Header 0x%08lx at offset %"OFF_P".\n", 1232 newhead, (off_p)fr->rd->tell(fr)-4); 1233 } 1234 1235 /* Now we got something bad at hand, try to recover. */ 1236 1237 if(NOQUIET && (newhead & 0xffffff00) == ('b'<<24)+('m'<<16)+('p'<<8)) fprintf(stderr,"Note: Could be a BMP album art.\n"); 1238 1239 if( !(fr->p.flags & MPG123_NO_RESYNC) ) 1240 { 1241 long try = 0; 1242 long limit = fr->p.resync_limit; 1243 unsigned int forgetcount = 0; 1244 1245 /* If a resync is needed the bitreservoir of previous frames is no longer valid */ 1246 fr->bitreservoir = 0; 1247 1248 if(NOQUIET && fr->silent_resync == 0) fprintf(stderr, "Note: Trying to resync...\n"); 1249 1250 do /* ... shift the header with additional single bytes until be found something that could be a header. */ 1251 { 1252 ++try; 1253 if(limit >= 0 && try >= limit) break; 1254 1255 if(++forgetcount > FORGET_INTERVAL) forgetcount = 0; 1256 if((ret=forget_head_shift(fr,&newhead,!forgetcount)) <= 0) 1257 { 1258 *newheadp = newhead; 1259 if(NOQUIET) fprintf (stderr, "Note: Hit end of (available) data during resync.\n"); 1260 1261 return ret ? ret : PARSE_END; 1262 } 1263 if(VERBOSE3) debug3("resync try %li at %"OFF_P", got newhead 0x%08lx", try, (off_p)fr->rd->tell(fr), newhead); 1264 } while(!head_check(newhead)); 1265 1266 *newheadp = newhead; 1267 if(NOQUIET && fr->silent_resync == 0) fprintf (stderr, "Note: Skipped %li bytes in input.\n", try); 1268 1269 /* Now we either got something that could be a header, or we gave up. */ 1270 if(limit >= 0 && try >= limit) 1271 { 1272 if(NOQUIET) 1273 error1("Giving up resync after %li bytes - your stream is not nice... (maybe increasing resync limit could help).", try); 1274 1275 fr->err = MPG123_RESYNC_FAIL; 1276 return PARSE_ERR; 1277 } 1278 else 1279 { 1280 debug1("Found possibly valid header 0x%lx... unsetting oldhead to reinit stream.", newhead); 1281 fr->oldhead = 0; 1282 return PARSE_RESYNC; 1283 } 1284 } 1285 else 1286 { 1287 if(NOQUIET) error("not attempting to resync..."); 1288 1289 fr->err = MPG123_OUT_OF_SYNC; 1290 return PARSE_ERR; 1291 } 1292 /* Control never goes here... we return before that. */ 1293 } 1294