apps/codecs/libmad/decoder.c

   1 /*
   2  * libmad - MPEG audio decoder library
   3  * Copyright (C) 2000-2004 Underbit Technologies, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  * $Id$
  20  */
  21
  22 # ifdef HAVE_CONFIG_H
  23 #  include "config.h"
  24 # endif
  25
  26 # include "global.h"
  27
  28 # ifdef HAVE_SYS_TYPES_H
  29 #  include <sys/types.h>
  30 # endif
  31
  32 # ifdef HAVE_SYS_WAIT_H
  33 #  include <sys/wait.h>
  34 # endif
  35
  36 # ifdef HAVE_UNISTD_H
  37 #  include <unistd.h>
  38 # endif
  39
  40 # ifdef HAVE_FCNTL_H
  41 #  include <fcntl.h>
  42 # endif
  43
  44 # ifdef HAVE_ERRNO_H
  45 #  include <errno.h>
  46 # endif
  47
  48 # include "stream.h"
  49 # include "frame.h"
  50 # include "synth.h"
  51 # include "decoder.h"
  52
  53 /*
  54  * NAME:        decoder->init()
  55  * DESCRIPTION: initialize a decoder object with callback routines
  56  */
  57 void mad_decoder_init(struct mad_decoder *decoder, void *data,
  58                       enum mad_flow (*input_func)(void *,
  59                                                   struct mad_stream *),
  60                       enum mad_flow (*header_func)(void *,
  61                                                    struct mad_header const *),
  62                       enum mad_flow (*filter_func)(void *,
  63                                                    struct mad_stream const *,
  64                                                    struct mad_frame *),
  65                       enum mad_flow (*output_func)(void *,
  66                                                    struct mad_header const *,
  67                                                    struct mad_pcm *),
  68                       enum mad_flow (*error_func)(void *,
  69                                                   struct mad_stream *,
  70                                                   struct mad_frame *),
  71                       enum mad_flow (*message_func)(void *,
  72                                                     void *, unsigned int *))
  73 {
  74   decoder->mode         = -1;
  75
  76   decoder->options      = 0;
  77
  78   decoder->async.pid    = 0;
  79   decoder->async.in     = -1;
  80   decoder->async.out    = -1;
  81
  82   decoder->sync         = 0;
  83
  84   decoder->cb_data      = data;
  85
  86   decoder->input_func   = input_func;
  87   decoder->header_func  = header_func;
  88   decoder->filter_func  = filter_func;
  89   decoder->output_func  = output_func;
  90   decoder->error_func   = error_func;
  91   decoder->message_func = message_func;
  92 }
  93
  94 int mad_decoder_finish(struct mad_decoder *decoder)
  95 {
  96 # if defined(USE_ASYNC)
  97   if (decoder->mode == MAD_DECODER_MODE_ASYNC && decoder->async.pid) {
  98     pid_t pid;
  99     int status;
 100
 101     close(decoder->async.in);
 102
 103     do
 104       pid = waitpid(decoder->async.pid, &status, 0);
 105     while (pid == -1 && errno == EINTR);
 106
 107     decoder->mode = -1;
 108
 109     close(decoder->async.out);
 110
 111     decoder->async.pid = 0;
 112     decoder->async.in  = -1;
 113     decoder->async.out = -1;
 114
 115     if (pid == -1)
 116       return -1;
 117
 118     return (!WIFEXITED(status) || WEXITSTATUS(status)) ? -1 : 0;
 119   }
 120 # else
 121   /* Avoid compiler warning */
 122   (void)decoder;
 123 # endif
 124
 125   return 0;
 126 }
 127
 128 # if defined(USE_ASYNC)
 129 static
 130 enum mad_flow send_io(int fd, void const *data, size_t len)
 131 {
 132   char const *ptr = data;
 133   ssize_t count;
 134
 135   while (len) {
 136     do
 137       count = write(fd, ptr, len);
 138     while (count == -1 && errno == EINTR);
 139
 140     if (count == -1)
 141       return MAD_FLOW_BREAK;
 142
 143     len -= count;
 144     ptr += count;
 145   }
 146
 147   return MAD_FLOW_CONTINUE;
 148 }
 149
 150 static
 151 enum mad_flow receive_io(int fd, void *buffer, size_t len)
 152 {
 153   char *ptr = buffer;
 154   ssize_t count;
 155
 156   while (len) {
 157     do
 158       count = read(fd, ptr, len);
 159     while (count == -1 && errno == EINTR);
 160
 161     if (count == -1)
 162       return (errno == EAGAIN) ? MAD_FLOW_IGNORE : MAD_FLOW_BREAK;
 163     else if (count == 0)
 164       return MAD_FLOW_STOP;
 165
 166     len -= count;
 167     ptr += count;
 168   }
 169
 170   return MAD_FLOW_CONTINUE;
 171 }
 172
 173 static
 174 enum mad_flow receive_io_blocking(int fd, void *buffer, size_t len)
 175 {
 176   int flags, blocking;
 177   enum mad_flow result;
 178
 179   flags = fcntl(fd, F_GETFL);
 180   if (flags == -1)
 181     return MAD_FLOW_BREAK;
 182
 183   blocking = flags & ~O_NONBLOCK;
 184
 185   if (blocking != flags &&
 186       fcntl(fd, F_SETFL, blocking) == -1)
 187     return MAD_FLOW_BREAK;
 188
 189   result = receive_io(fd, buffer, len);
 190
 191   if (flags != blocking &&
 192       fcntl(fd, F_SETFL, flags) == -1)
 193     return MAD_FLOW_BREAK;
 194
 195   return result;
 196 }
 197
 198 static
 199 enum mad_flow send(int fd, void const *message, unsigned int size)
 200 {
 201   enum mad_flow result;
 202
 203   /* send size */
 204
 205   result = send_io(fd, &size, sizeof(size));
 206
 207   /* send message */
 208
 209   if (result == MAD_FLOW_CONTINUE)
 210     result = send_io(fd, message, size);
 211
 212   return result;
 213 }
 214
 215 static
 216 enum mad_flow receive(int fd, void **message, unsigned int *size)
 217 {
 218   enum mad_flow result;
 219   unsigned int actual;
 220
 221   if (*message == 0)
 222     *size = 0;
 223
 224   /* receive size */
 225
 226   result = receive_io(fd, &actual, sizeof(actual));
 227
 228   /* receive message */
 229
 230   if (result == MAD_FLOW_CONTINUE) {
 231     if (actual > *size)
 232       actual -= *size;
 233     else {
 234       *size  = actual;
 235       actual = 0;
 236     }
 237
 238     if (*size > 0) {
 239       if (*message == 0) {
 240         *message = malloc(*size);
 241         if (*message == 0)
 242           return MAD_FLOW_BREAK;
 243       }
 244
 245       result = receive_io_blocking(fd, *message, *size);
 246     }
 247
 248     /* throw away remainder of message */
 249
 250     while (actual && result == MAD_FLOW_CONTINUE) {
 251       char sink[256];
 252       unsigned int len;
 253
 254       len = actual > sizeof(sink) ? sizeof(sink) : actual;
 255
 256       result = receive_io_blocking(fd, sink, len);
 257
 258       actual -= len;
 259     }
 260   }
 261
 262   return result;
 263 }
 264
 265 static
 266 enum mad_flow check_message(struct mad_decoder *decoder)
 267 {
 268   enum mad_flow result;
 269   void *message = 0;
 270   unsigned int size;
 271
 272   result = receive(decoder->async.in, &message, &size);
 273
 274   if (result == MAD_FLOW_CONTINUE) {
 275     if (decoder->message_func == 0)
 276       size = 0;
 277     else {
 278       result = decoder->message_func(decoder->cb_data, message, &size);
 279
 280       if (result == MAD_FLOW_IGNORE ||
 281           result == MAD_FLOW_BREAK)
 282         size = 0;
 283     }
 284
 285     if (send(decoder->async.out, message, size) != MAD_FLOW_CONTINUE)
 286       result = MAD_FLOW_BREAK;
 287   }
 288
 289   if (message)
 290     free(message);
 291
 292   return result;
 293 }
 294 # endif
 295
 296 static
 297 enum mad_flow error_default(void *data, struct mad_stream *stream,
 298                             struct mad_frame *frame)
 299 {
 300   int *bad_last_frame = data;
 301
 302   switch (stream->error) {
 303   case MAD_ERROR_BADCRC:
 304     if (*bad_last_frame)
 305       mad_frame_mute(frame);
 306     else
 307       *bad_last_frame = 1;
 308
 309     return MAD_FLOW_IGNORE;
 310
 311   default:
 312     return MAD_FLOW_CONTINUE;
 313   }
 314 }
 315
 316 static
 317 int run_sync(struct mad_decoder *decoder)
 318 {
 319   enum mad_flow (*error_func)(void *, struct mad_stream *, struct mad_frame *);
 320   void *error_data;
 321   int bad_last_frame = 0;
 322   struct mad_stream *stream;
 323   struct mad_frame *frame;
 324   struct mad_synth *synth;
 325   int result = 0;
 326
 327   if (decoder->input_func == 0)
 328     return 0;
 329
 330   if (decoder->error_func) {
 331     error_func = decoder->error_func;
 332     error_data = decoder->cb_data;
 333   }
 334   else {
 335     error_func = error_default;
 336     error_data = &bad_last_frame;
 337   }
 338
 339   stream = &decoder->sync->stream;
 340   frame  = &decoder->sync->frame;
 341   synth  = &decoder->sync->synth;
 342
 343   mad_stream_init(stream);
 344   mad_frame_init(frame);
 345   mad_synth_init(synth);
 346
 347   mad_stream_options(stream, decoder->options);
 348
 349   do {
 350     switch (decoder->input_func(decoder->cb_data, stream)) {
 351     case MAD_FLOW_STOP:
 352       goto done;
 353     case MAD_FLOW_BREAK:
 354       goto fail;
 355     case MAD_FLOW_IGNORE:
 356       continue;
 357     case MAD_FLOW_CONTINUE:
 358       break;
 359     }
 360
 361     while (1) {
 362 # if defined(USE_ASYNC)
 363       if (decoder->mode == MAD_DECODER_MODE_ASYNC) {
 364         switch (check_message(decoder)) {
 365         case MAD_FLOW_IGNORE:
 366         case MAD_FLOW_CONTINUE:
 367           break;
 368         case MAD_FLOW_BREAK:
 369           goto fail;
 370         case MAD_FLOW_STOP:
 371           goto done;
 372         }
 373       }
 374 # endif
 375
 376       if (decoder->header_func) {
 377         if (mad_header_decode(&frame->header, stream) == -1) {
 378           if (!MAD_RECOVERABLE(stream->error))
 379             break;
 380
 381           switch (error_func(error_data, stream, frame)) {
 382           case MAD_FLOW_STOP:
 383             goto done;
 384           case MAD_FLOW_BREAK:
 385             goto fail;
 386           case MAD_FLOW_IGNORE:
 387           case MAD_FLOW_CONTINUE:
 388           default:
 389             continue;
 390           }
 391         }
 392
 393         switch (decoder->header_func(decoder->cb_data, &frame->header)) {
 394         case MAD_FLOW_STOP:
 395           goto done;
 396         case MAD_FLOW_BREAK:
 397           goto fail;
 398         case MAD_FLOW_IGNORE:
 399           continue;
 400         case MAD_FLOW_CONTINUE:
 401           break;
 402         }
 403       }
 404
 405       if (mad_frame_decode(frame, stream) == -1) {
 406         if (!MAD_RECOVERABLE(stream->error))
 407           break;
 408
 409         switch (error_func(error_data, stream, frame)) {
 410         case MAD_FLOW_STOP:
 411           goto done;
 412         case MAD_FLOW_BREAK:
 413           goto fail;
 414         case MAD_FLOW_IGNORE:
 415           break;
 416         case MAD_FLOW_CONTINUE:
 417         default:
 418           continue;
 419         }
 420       }
 421       else
 422         bad_last_frame = 0;
 423
 424       if (decoder->filter_func) {
 425         switch (decoder->filter_func(decoder->cb_data, stream, frame)) {
 426         case MAD_FLOW_STOP:
 427           goto done;
 428         case MAD_FLOW_BREAK:
 429           goto fail;
 430         case MAD_FLOW_IGNORE:
 431           continue;
 432         case MAD_FLOW_CONTINUE:
 433           break;
 434         }
 435       }
 436
 437       mad_synth_frame(synth, frame);
 438
 439       if (decoder->output_func) {
 440         switch (decoder->output_func(decoder->cb_data,
 441                                      &frame->header, &synth->pcm)) {
 442         case MAD_FLOW_STOP:
 443           goto done;
 444         case MAD_FLOW_BREAK:
 445           goto fail;
 446         case MAD_FLOW_IGNORE:
 447         case MAD_FLOW_CONTINUE:
 448           break;
 449         }
 450       }
 451     }
 452   }
 453   while (stream->error == MAD_ERROR_BUFLEN);
 454
 455  fail:
 456   result = -1;
 457
 458  done:
 459   mad_synth_finish(synth);
 460   mad_frame_finish(frame);
 461   mad_stream_finish(stream);
 462
 463   return result;
 464 }
 465
 466 # if defined(USE_ASYNC)
 467 static
 468 int run_async(struct mad_decoder *decoder)
 469 {
 470   pid_t pid;
 471   int ptoc[2], ctop[2], flags;
 472
 473   if (pipe(ptoc) == -1)
 474     return -1;
 475
 476   if (pipe(ctop) == -1) {
 477     close(ptoc[0]);
 478     close(ptoc[1]);
 479     return -1;
 480   }
 481
 482   flags = fcntl(ptoc[0], F_GETFL);
 483   if (flags == -1 ||
 484       fcntl(ptoc[0], F_SETFL, flags | O_NONBLOCK) == -1) {
 485     close(ctop[0]);
 486     close(ctop[1]);
 487     close(ptoc[0]);
 488     close(ptoc[1]);
 489     return -1;
 490   }
 491
 492   pid = fork();
 493   if (pid == -1) {
 494     close(ctop[0]);
 495     close(ctop[1]);
 496     close(ptoc[0]);
 497     close(ptoc[1]);
 498     return -1;
 499   }
 500
 501   decoder->async.pid = pid;
 502
 503   if (pid) {
 504     /* parent */
 505
 506     close(ptoc[0]);
 507     close(ctop[1]);
 508
 509     decoder->async.in  = ctop[0];
 510     decoder->async.out = ptoc[1];
 511
 512     return 0;
 513   }
 514
 515   /* child */
 516
 517   close(ptoc[1]);
 518   close(ctop[0]);
 519
 520   decoder->async.in  = ptoc[0];
 521   decoder->async.out = ctop[1];
 522
 523   _exit(run_sync(decoder));
 524
 525   /* not reached */
 526   return -1;
 527 }
 528 # endif
 529
 530 /*
 531  * NAME:        decoder->run()
 532  * DESCRIPTION: run the decoder thread either synchronously or asynchronously
 533  */
 534 int mad_decoder_run(struct mad_decoder *decoder, enum mad_decoder_mode mode)
 535 {
 536   int result;
 537   int (*run)(struct mad_decoder *) = 0;
 538
 539   switch (decoder->mode = mode) {
 540   case MAD_DECODER_MODE_SYNC:
 541     run = run_sync;
 542     break;
 543
 544   case MAD_DECODER_MODE_ASYNC:
 545 # if defined(USE_ASYNC)
 546     run = run_async;
 547 # endif
 548     break;
 549   }
 550
 551   if (run == 0)
 552     return -1;
 553
 554   decoder->sync = malloc(sizeof(*decoder->sync));
 555   if (decoder->sync == 0)
 556     return -1;
 557
 558   result = run(decoder);
 559
 560   free(decoder->sync);
 561   decoder->sync = 0;
 562
 563   return result;
 564 }
 565
 566 /*
 567  * NAME:        decoder->message()
 568  * DESCRIPTION: send a message to and receive a reply from the decoder process
 569  */
 570 int mad_decoder_message(struct mad_decoder *decoder,
 571                         void *message, unsigned int *len)
 572 {
 573 # if defined(USE_ASYNC)
 574   if (decoder->mode != MAD_DECODER_MODE_ASYNC ||
 575       send(decoder->async.out, message, *len) != MAD_FLOW_CONTINUE ||
 576       receive(decoder->async.in, &message, len) != MAD_FLOW_CONTINUE)
 577     return -1;
 578
 579   return 0;
 580 # else
 581   /* Avoid compiler warnings */
 582   (void)decoder;
 583   (void)message;
 584   (void)len;
 585   return -1;
 586 # endif
 587 }