libmpdemux/demux_audio.c

   1 /*
   2  * This file is part of MPlayer.
   3  *
   4  * MPlayer is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * MPlayer is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #include "config.h"
  20 #include "mp_msg.h"
  21 #include "help_mp.h"
  22
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include "stream/stream.h"
  26 #include "demuxer.h"
  27 #include "stheader.h"
  28 #include "genres.h"
  29 #include "mp3_hdr.h"
  30 #include "ffmpeg_files/intreadwrite.h"
  31
  32 #include <string.h>
  33
  34 #define MP3 1
  35 #define WAV 2
  36 #define fLaC 3
  37
  38
  39 #define HDR_SIZE 4
  40
  41 typedef struct da_priv {
  42   int frmt;
  43   double next_pts;
  44 } da_priv_t;
  45
  46 //! rather arbitrary value for maximum length of wav-format headers
  47 #define MAX_WAVHDR_LEN (1 * 1024 * 1024)
  48
  49 //! how many valid frames in a row we need before accepting as valid MP3
  50 #define MIN_MP3_HDRS 12
  51
  52 //! Used to describe a potential (chain of) MP3 headers we found
  53 typedef struct mp3_hdr {
  54   off_t frame_pos; // start of first frame in this "chain" of headers
  55   off_t next_frame_pos; // here we expect the next header with same parameters
  56   int mp3_chans;
  57   int mp3_freq;
  58   int mpa_spf;
  59   int mpa_layer;
  60   int mpa_br;
  61   int cons_hdrs; // if this reaches MIN_MP3_HDRS we accept as MP3 file
  62   struct mp3_hdr *next;
  63 } mp3_hdr_t;
  64
  65 void print_wave_header(WAVEFORMATEX *h, int verbose_level);
  66
  67 int hr_mp3_seek = 0;
  68
  69 /**
  70  * \brief free a list of MP3 header descriptions
  71  * \param list pointer to the head-of-list pointer
  72  */
  73 static void free_mp3_hdrs(mp3_hdr_t **list) {
  74   mp3_hdr_t *tmp;
  75   while (*list) {
  76     tmp = (*list)->next;
  77     free(*list);
  78     *list = tmp;
  79   }
  80 }
  81
  82 /**
  83  * \brief add another potential MP3 header to our list
  84  * If it fits into an existing chain this one is expanded otherwise
  85  * a new one is created.
  86  * All entries that expected a MP3 header before the current position
  87  * are discarded.
  88  * The list is expected to be and will be kept sorted by next_frame_pos
  89  * and when those are equal by frame_pos.
  90  * \param list pointer to the head-of-list pointer
  91  * \param st_pos stream position where the described header starts
  92  * \param mp3_chans number of channels as specified by the header (*)
  93  * \param mp3_freq sampling frequency as specified by the header (*)
  94  * \param mpa_spf frame size as specified by the header
  95  * \param mpa_layer layer type ("version") as specified by the header (*)
  96  * \param mpa_br bitrate as specified by the header
  97  * \param mp3_flen length of the frame as specified by the header
  98  * \return If non-null the current file is accepted as MP3 and the
  99  * mp3_hdr struct describing the valid chain is returned. Must be
 100  * freed independent of the list.
 101  *
 102  * parameters marked by (*) must be the same for all headers in the same chain
 103  */
 104 static mp3_hdr_t *add_mp3_hdr(mp3_hdr_t **list, off_t st_pos,
 105                                int mp3_chans, int mp3_freq, int mpa_spf,
 106                                int mpa_layer, int mpa_br, int mp3_flen) {
 107   mp3_hdr_t *tmp;
 108   int in_list = 0;
 109   while (*list && (*list)->next_frame_pos <= st_pos) {
 110     if (((*list)->next_frame_pos < st_pos) || ((*list)->mp3_chans != mp3_chans)
 111          || ((*list)->mp3_freq != mp3_freq) || ((*list)->mpa_layer != mpa_layer) ) {
 112       // wasn't valid!
 113       tmp = (*list)->next;
 114       free(*list);
 115       *list = tmp;
 116     } else {
 117       (*list)->cons_hdrs++;
 118       (*list)->next_frame_pos = st_pos + mp3_flen;
 119       (*list)->mpa_spf = mpa_spf;
 120       (*list)->mpa_br = mpa_br;
 121       if ((*list)->cons_hdrs >= MIN_MP3_HDRS) {
 122         // copy the valid entry, so that the list can be easily freed
 123         tmp = malloc(sizeof(mp3_hdr_t));
 124         memcpy(tmp, *list, sizeof(mp3_hdr_t));
 125         tmp->next = NULL;
 126         return tmp;
 127       }
 128       in_list = 1;
 129       list = &((*list)->next);
 130     }
 131   }
 132   if (!in_list) { // does not belong into an existing chain, insert
 133     // find right position to insert to keep sorting
 134     while (*list && (*list)->next_frame_pos <= st_pos + mp3_flen)
 135       list = &((*list)->next);
 136     tmp = malloc(sizeof(mp3_hdr_t));
 137     tmp->frame_pos = st_pos;
 138     tmp->next_frame_pos = st_pos + mp3_flen;
 139     tmp->mp3_chans = mp3_chans;
 140     tmp->mp3_freq = mp3_freq;
 141     tmp->mpa_spf = mpa_spf;
 142     tmp->mpa_layer = mpa_layer;
 143     tmp->mpa_br = mpa_br;
 144     tmp->cons_hdrs = 1;
 145     tmp->next = *list;
 146     *list = tmp;
 147   }
 148   return NULL;
 149 }
 150
 151 #if 0 /* this code is a mess, clean it up before reenabling */
 152 #define FLAC_SIGNATURE_SIZE 4
 153 #define FLAC_STREAMINFO_SIZE 34
 154 #define FLAC_SEEKPOINT_SIZE 18
 155
 156 enum {
 157   FLAC_STREAMINFO = 0,
 158   FLAC_PADDING,
 159   FLAC_APPLICATION,
 160   FLAC_SEEKTABLE,
 161   FLAC_VORBIS_COMMENT,
 162   FLAC_CUESHEET
 163 } flac_preamble_t;
 164
 165 static void
 166 get_flac_metadata (demuxer_t* demuxer)
 167 {
 168   uint8_t preamble[4];
 169   unsigned int blk_len;
 170   stream_t *s = demuxer->stream;
 171
 172   /* file is qualified; skip over the signature bytes in the stream */
 173   stream_seek (s, 4);
 174
 175   /* loop through the metadata blocks; use a do-while construct since there
 176    * will always be 1 metadata block */
 177   do {
 178     int r;
 179
 180     r = stream_read (s, (char *) preamble, FLAC_SIGNATURE_SIZE);
 181     if (r != FLAC_SIGNATURE_SIZE)
 182       return;
 183
 184     blk_len = AV_RB24(preamble + 1);
 185
 186     switch (preamble[0] & 0x7F)
 187     {
 188     case FLAC_VORBIS_COMMENT:
 189     {
 190       /* For a description of the format please have a look at */
 191       /* http://www.xiph.org/vorbis/doc/v-comment.html */
 192
 193       uint32_t length, comment_list_len;
 194       char comments[blk_len];
 195       uint8_t *ptr = comments;
 196       char *comment;
 197       int cn;
 198       char c;
 199
 200       if (stream_read (s, comments, blk_len) == blk_len)
 201       {
 202         length = AV_RL32(ptr);
 203         ptr += 4 + length;
 204
 205         comment_list_len = AV_RL32(ptr);
 206         ptr += 4;
 207
 208         cn = 0;
 209         for (; cn < comment_list_len; cn++)
 210         {
 211           length = AV_RL32(ptr);
 212           ptr += 4;
 213
 214           comment = ptr;
 215           if (&comment[length] < comments || &comment[length] >= &comments[blk_len])
 216             return;
 217           c = comment[length];
 218           comment[length] = 0;
 219
 220           if (!strncasecmp ("TITLE=", comment, 6) && (length - 6 > 0))
 221             demux_info_add (demuxer, "Title", comment + 6);
 222           else if (!strncasecmp ("ARTIST=", comment, 7) && (length - 7 > 0))
 223             demux_info_add (demuxer, "Artist", comment + 7);
 224           else if (!strncasecmp ("ALBUM=", comment, 6) && (length - 6 > 0))
 225             demux_info_add (demuxer, "Album", comment + 6);
 226           else if (!strncasecmp ("DATE=", comment, 5) && (length - 5 > 0))
 227             demux_info_add (demuxer, "Year", comment + 5);
 228           else if (!strncasecmp ("GENRE=", comment, 6) && (length - 6 > 0))
 229             demux_info_add (demuxer, "Genre", comment + 6);
 230           else if (!strncasecmp ("Comment=", comment, 8) && (length - 8 > 0))
 231             demux_info_add (demuxer, "Comment", comment + 8);
 232           else if (!strncasecmp ("TRACKNUMBER=", comment, 12)
 233                    && (length - 12 > 0))
 234           {
 235             char buf[31];
 236             buf[30] = '\0';
 237             sprintf (buf, "%d", atoi (comment + 12));
 238             demux_info_add(demuxer, "Track", buf);
 239           }
 240           comment[length] = c;
 241
 242           ptr += length;
 243         }
 244       }
 245       break;
 246     }
 247
 248     case FLAC_STREAMINFO:
 249     case FLAC_PADDING:
 250     case FLAC_APPLICATION:
 251     case FLAC_SEEKTABLE:
 252     case FLAC_CUESHEET:
 253     default:
 254       /* 6-127 are presently reserved */
 255       stream_skip (s, blk_len);
 256       break;
 257     }
 258   } while ((preamble[0] & 0x80) == 0);
 259 }
 260 #endif
 261
 262 static int demux_audio_open(demuxer_t* demuxer) {
 263   stream_t *s;
 264   sh_audio_t* sh_audio;
 265   uint8_t hdr[HDR_SIZE];
 266   int frmt = 0, n = 0, step;
 267   off_t st_pos = 0, next_frame_pos = 0;
 268   // mp3_hdrs list is sorted first by next_frame_pos and then by frame_pos
 269   mp3_hdr_t *mp3_hdrs = NULL, *mp3_found = NULL;
 270   da_priv_t* priv;
 271
 272   s = demuxer->stream;
 273
 274   stream_read(s, hdr, HDR_SIZE);
 275   while(n < 30000 && !s->eof) {
 276     int mp3_freq, mp3_chans, mp3_flen, mpa_layer, mpa_spf, mpa_br;
 277     st_pos = stream_tell(s) - HDR_SIZE;
 278     step = 1;
 279
 280     if( hdr[0] == 'R' && hdr[1] == 'I' && hdr[2] == 'F' && hdr[3] == 'F' ) {
 281       stream_skip(s,4);
 282       if(s->eof)
 283         break;
 284       stream_read(s,hdr,4);
 285       if(s->eof)
 286         break;
 287       if(hdr[0] != 'W' || hdr[1] != 'A' || hdr[2] != 'V'  || hdr[3] != 'E' )
 288         stream_skip(s,-8);
 289       else
 290       // We found wav header. Now we can have 'fmt ' or a mp3 header
 291       // empty the buffer
 292         step = 4;
 293     } else if( hdr[0] == 'I' && hdr[1] == 'D' && hdr[2] == '3' && (hdr[3] >= 2)) {
 294       int len;
 295       stream_skip(s,2);
 296       stream_read(s,hdr,4);
 297       len = (hdr[0]<<21) | (hdr[1]<<14) | (hdr[2]<<7) | hdr[3];
 298       stream_skip(s,len);
 299       step = 4;
 300     } else if( hdr[0] == 'f' && hdr[1] == 'm' && hdr[2] == 't' && hdr[3] == ' ' ) {
 301       frmt = WAV;
 302       break;
 303     } else if((mp3_flen = mp_get_mp3_header(hdr, &mp3_chans, &mp3_freq,
 304                                 &mpa_spf, &mpa_layer, &mpa_br)) > 0) {
 305       mp3_found = add_mp3_hdr(&mp3_hdrs, st_pos, mp3_chans, mp3_freq,
 306                               mpa_spf, mpa_layer, mpa_br, mp3_flen);
 307       if (mp3_found) {
 308         frmt = MP3;
 309         break;
 310       }
 311     } else if( hdr[0] == 'f' && hdr[1] == 'L' && hdr[2] == 'a' && hdr[3] == 'C' ) {
 312       frmt = fLaC;
 313       if (!mp3_hdrs || mp3_hdrs->cons_hdrs < 3)
 314         break;
 315     }
 316     // Add here some other audio format detection
 317     if(step < HDR_SIZE)
 318       memmove(hdr,&hdr[step],HDR_SIZE-step);
 319     stream_read(s, &hdr[HDR_SIZE - step], step);
 320     n++;
 321   }
 322
 323   free_mp3_hdrs(&mp3_hdrs);
 324
 325   if(!frmt)
 326     return 0;
 327
 328   sh_audio = new_sh_audio(demuxer,0);
 329
 330   switch(frmt) {
 331   case MP3:
 332     sh_audio->format = (mp3_found->mpa_layer < 3 ? 0x50 : 0x55);
 333     demuxer->movi_start = mp3_found->frame_pos;
 334     next_frame_pos = mp3_found->next_frame_pos;
 335     sh_audio->audio.dwSampleSize= 0;
 336     sh_audio->audio.dwScale = mp3_found->mpa_spf;
 337     sh_audio->audio.dwRate = mp3_found->mp3_freq;
 338     sh_audio->wf = malloc(sizeof(WAVEFORMATEX));
 339     sh_audio->wf->wFormatTag = sh_audio->format;
 340     sh_audio->wf->nChannels = mp3_found->mp3_chans;
 341     sh_audio->wf->nSamplesPerSec = mp3_found->mp3_freq;
 342     sh_audio->wf->nAvgBytesPerSec = mp3_found->mpa_br * (1000 / 8);
 343     sh_audio->wf->nBlockAlign = mp3_found->mpa_spf;
 344     sh_audio->wf->wBitsPerSample = 16;
 345     sh_audio->wf->cbSize = 0;
 346     sh_audio->i_bps = sh_audio->wf->nAvgBytesPerSec;
 347     free(mp3_found);
 348     mp3_found = NULL;
 349     if(s->end_pos && (s->flags & MP_STREAM_SEEK) == MP_STREAM_SEEK) {
 350       char tag[4];
 351       stream_seek(s,s->end_pos-128);
 352       stream_read(s,tag,3);
 353       tag[3] = '\0';
 354       if(strcmp(tag,"TAG"))
 355         demuxer->movi_end = s->end_pos;
 356       else {
 357         char buf[31];
 358         uint8_t g;
 359         demuxer->movi_end = stream_tell(s)-3;
 360         stream_read(s,buf,30);
 361         buf[30] = '\0';
 362         demux_info_add(demuxer,"Title",buf);
 363         stream_read(s,buf,30);
 364         buf[30] = '\0';
 365         demux_info_add(demuxer,"Artist",buf);
 366         stream_read(s,buf,30);
 367         buf[30] = '\0';
 368         demux_info_add(demuxer,"Album",buf);
 369         stream_read(s,buf,4);
 370         buf[4] = '\0';
 371         demux_info_add(demuxer,"Year",buf);
 372         stream_read(s,buf,30);
 373         buf[30] = '\0';
 374         demux_info_add(demuxer,"Comment",buf);
 375         if(buf[28] == 0 && buf[29] != 0) {
 376           uint8_t trk = (uint8_t)buf[29];
 377           sprintf(buf,"%d",trk);
 378           demux_info_add(demuxer,"Track",buf);
 379         }
 380         g = stream_read_char(s);
 381         demux_info_add(demuxer,"Genre",genres[g]);
 382       }
 383     }
 384     break;
 385   case WAV: {
 386     unsigned int chunk_type;
 387     unsigned int chunk_size;
 388     WAVEFORMATEX* w;
 389     int l;
 390     l = stream_read_dword_le(s);
 391     if(l < 16) {
 392       mp_msg(MSGT_DEMUX,MSGL_ERR,"[demux_audio] Bad wav header length: too short (%d)!!!\n",l);
 393       l = 16;
 394     }
 395     if(l > MAX_WAVHDR_LEN) {
 396       mp_msg(MSGT_DEMUX,MSGL_ERR,"[demux_audio] Bad wav header length: too long (%d)!!!\n",l);
 397       l = 16;
 398     }
 399     sh_audio->wf = w = malloc(l > sizeof(WAVEFORMATEX) ? l : sizeof(WAVEFORMATEX));
 400     w->wFormatTag = sh_audio->format = stream_read_word_le(s);
 401     w->nChannels = sh_audio->channels = stream_read_word_le(s);
 402     w->nSamplesPerSec = sh_audio->samplerate = stream_read_dword_le(s);
 403     w->nAvgBytesPerSec = stream_read_dword_le(s);
 404     w->nBlockAlign = stream_read_word_le(s);
 405     w->wBitsPerSample = stream_read_word_le(s);
 406     sh_audio->samplesize = (w->wBitsPerSample + 7) / 8;
 407     w->cbSize = 0;
 408     sh_audio->i_bps = sh_audio->wf->nAvgBytesPerSec;
 409     l -= 16;
 410     if (l >= 2) {
 411       w->cbSize = stream_read_word_le(s);
 412       l -= 2;
 413       if (l < w->cbSize) {
 414         mp_msg(MSGT_DEMUX,MSGL_ERR,"[demux_audio] truncated extradata (%d < %d)\n",
 415                l,w->cbSize);
 416         w->cbSize = l;
 417       }
 418       stream_read(s,(char*)((char*)(w)+sizeof(WAVEFORMATEX)),w->cbSize);
 419       l -= w->cbSize;
 420     }
 421
 422     if( mp_msg_test(MSGT_DEMUX,MSGL_V) ) print_wave_header(w, MSGL_V);
 423     if(l)
 424       stream_skip(s,l);
 425     do
 426     {
 427       chunk_type = stream_read_fourcc(demuxer->stream);
 428       chunk_size = stream_read_dword_le(demuxer->stream);
 429       if (chunk_type != mmioFOURCC('d', 'a', 't', 'a'))
 430         stream_skip(demuxer->stream, chunk_size);
 431     } while (!s->eof && chunk_type != mmioFOURCC('d', 'a', 't', 'a'));
 432     demuxer->movi_start = stream_tell(s);
 433     demuxer->movi_end = chunk_size ? demuxer->movi_start + chunk_size : s->end_pos;
 434 //    printf("wav: %X .. %X\n",(int)demuxer->movi_start,(int)demuxer->movi_end);
 435     // Check if it contains dts audio
 436     if((w->wFormatTag == 0x01) && (w->nChannels == 2) && (w->nSamplesPerSec == 44100)) {
 437         unsigned char buf[16384]; // vlc uses 16384*4 (4 dts frames)
 438         unsigned int i;
 439         memset(buf, 0, sizeof(buf));
 440         stream_read(s, buf, sizeof(buf));
 441         for (i = 0; i < sizeof(buf) - 5; i += 2) {
 442             // DTS, 14 bit, LE
 443             if((buf[i] == 0xff) && (buf[i+1] == 0x1f) && (buf[i+2] == 0x00) &&
 444                (buf[i+3] == 0xe8) && ((buf[i+4] & 0xfe) == 0xf0) && (buf[i+5] == 0x07)) {
 445                 sh_audio->format = 0x2001;
 446                 mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 14 bit, LE\n");
 447                 break;
 448             }
 449             // DTS, 14 bit, BE
 450             if((buf[i] == 0x1f) && (buf[i+1] == 0xff) && (buf[i+2] == 0xe8) &&
 451                (buf[i+3] == 0x00) && (buf[i+4] == 0x07) && ((buf[i+5] & 0xfe) == 0xf0)) {
 452                 sh_audio->format = 0x2001;
 453                 mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 14 bit, BE\n");
 454                 break;
 455             }
 456             // DTS, 16 bit, BE
 457             if((buf[i] == 0x7f) && (buf[i+1] == 0xfe) && (buf[i+2] == 0x80) &&
 458                (buf[i+3] == 0x01)) {
 459                 sh_audio->format = 0x2001;
 460                 mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 16 bit, BE\n");
 461                 break;
 462             }
 463             // DTS, 16 bit, LE
 464             if((buf[i] == 0xfe) && (buf[i+1] == 0x7f) && (buf[i+2] == 0x01) &&
 465                (buf[i+3] == 0x80)) {
 466                 sh_audio->format = 0x2001;
 467                 mp_msg(MSGT_DEMUX,MSGL_V,"[demux_audio] DTS audio in wav, 16 bit, LE\n");
 468                 break;
 469             }
 470         }
 471         if (sh_audio->format == 0x2001)
 472             mp_msg(MSGT_DEMUX,MSGL_DBG2,"[demux_audio] DTS sync offset = %u\n", i);
 473
 474     }
 475     stream_seek(s,demuxer->movi_start);
 476   } break;
 477   case fLaC:
 478             sh_audio->format = mmioFOURCC('f', 'L', 'a', 'C');
 479             demuxer->movi_start = stream_tell(s) - 4;
 480             demuxer->movi_end = s->end_pos;
 481             if (demuxer->movi_end > demuxer->movi_start) {
 482               // try to find out approx. bitrate
 483               int64_t size = demuxer->movi_end - demuxer->movi_start;
 484               int64_t num_samples = 0;
 485               int32_t srate = 0;
 486               stream_skip(s, 14);
 487               stream_read(s, (char *)&srate, 3);
 488               srate = be2me_32(srate) >> 12;
 489               stream_read(s, (char *)&num_samples, 5);
 490               num_samples = (be2me_64(num_samples) >> 24) & 0xfffffffffULL;
 491               if (num_samples && srate)
 492                 sh_audio->i_bps = size * srate / num_samples;
 493             }
 494             if (sh_audio->i_bps < 1) // guess value to prevent crash
 495               sh_audio->i_bps = 64 * 1024;
 496 //          get_flac_metadata (demuxer);
 497             break;
 498   }
 499
 500   priv = malloc(sizeof(da_priv_t));
 501   priv->frmt = frmt;
 502   priv->next_pts = 0;
 503   demuxer->priv = priv;
 504   demuxer->audio->id = 0;
 505   demuxer->audio->sh = sh_audio;
 506   sh_audio->ds = demuxer->audio;
 507   sh_audio->samplerate = sh_audio->audio.dwRate;
 508
 509   if(stream_tell(s) != demuxer->movi_start)
 510   {
 511     mp_msg(MSGT_DEMUX, MSGL_V, "demux_audio: seeking from 0x%X to start pos 0x%X\n",
 512             (int)stream_tell(s), (int)demuxer->movi_start);
 513     stream_seek(s,demuxer->movi_start);
 514     if (stream_tell(s) != demuxer->movi_start) {
 515       mp_msg(MSGT_DEMUX, MSGL_V, "demux_audio: seeking failed, now at 0x%X!\n",
 516               (int)stream_tell(s));
 517       if (next_frame_pos) {
 518         mp_msg(MSGT_DEMUX, MSGL_V, "demux_audio: seeking to 0x%X instead\n",
 519                 (int)next_frame_pos);
 520         stream_seek(s, next_frame_pos);
 521       }
 522     }
 523   }
 524
 525   mp_msg(MSGT_DEMUX,MSGL_V,"demux_audio: audio data 0x%X - 0x%X  \n",(int)demuxer->movi_start,(int)demuxer->movi_end);
 526
 527   return DEMUXER_TYPE_AUDIO;
 528 }
 529
 530
 531 static int demux_audio_fill_buffer(demuxer_t *demux, demux_stream_t *ds) {
 532   int l;
 533   demux_packet_t* dp;
 534   sh_audio_t* sh_audio = ds->sh;
 535   da_priv_t* priv = demux->priv;
 536   double this_pts = priv->next_pts;
 537   stream_t* s = demux->stream;
 538
 539   if(s->eof)
 540     return 0;
 541
 542   switch(priv->frmt) {
 543   case MP3 :
 544     while(1) {
 545       uint8_t hdr[4];
 546       stream_read(s,hdr,4);
 547       if (s->eof)
 548         return 0;
 549       l = mp_decode_mp3_header(hdr);
 550       if(l < 0) {
 551         if (demux->movi_end && stream_tell(s) >= demux->movi_end)
 552           return 0; // might be ID3 tag, i.e. EOF
 553         stream_skip(s,-3);
 554       } else {
 555         dp = new_demux_packet(l);
 556         memcpy(dp->buffer,hdr,4);
 557         if (stream_read(s,dp->buffer + 4,l-4) != l-4)
 558         {
 559           free_demux_packet(dp);
 560           return 0;
 561         }
 562         priv->next_pts += sh_audio->audio.dwScale/(double)sh_audio->samplerate;
 563         break;
 564       }
 565     } break;
 566   case WAV : {
 567     unsigned align = sh_audio->wf->nBlockAlign;
 568     l = sh_audio->wf->nAvgBytesPerSec;
 569     if (l <= 0) l = 65536;
 570     if (demux->movi_end && l > demux->movi_end - stream_tell(s)) {
 571       // do not read beyond end, there might be junk after data chunk
 572       l = demux->movi_end - stream_tell(s);
 573       if (l <= 0) return 0;
 574     }
 575     if (align)
 576       l = (l + align - 1) / align * align;
 577     dp = new_demux_packet(l);
 578     l = stream_read(s,dp->buffer,l);
 579     priv->next_pts += l/(double)sh_audio->i_bps;
 580     break;
 581   }
 582   case fLaC: {
 583     l = 65535;
 584     dp = new_demux_packet(l);
 585     l = stream_read(s,dp->buffer,l);
 586     /* FLAC is not a constant-bitrate codec. These values will be wrong. */
 587     priv->next_pts += l/(double)sh_audio->i_bps;
 588     break;
 589   }
 590   default:
 591     mp_tmsg(MSGT_DEMUXER,MSGL_WARN,"Audio demuxer: unknown format %d.\n",priv->frmt);
 592     return 0;
 593   }
 594
 595   resize_demux_packet(dp, l);
 596   dp->pts = this_pts;
 597   ds_add_packet(ds, dp);
 598   return 1;
 599 }
 600
 601 static void high_res_mp3_seek(demuxer_t *demuxer,float time) {
 602   uint8_t hdr[4];
 603   int len,nf;
 604   da_priv_t* priv = demuxer->priv;
 605   sh_audio_t* sh = (sh_audio_t*)demuxer->audio->sh;
 606
 607   nf = time*sh->samplerate/sh->audio.dwScale;
 608   while(nf > 0) {
 609     stream_read(demuxer->stream,hdr,4);
 610     len = mp_decode_mp3_header(hdr);
 611     if(len < 0) {
 612       stream_skip(demuxer->stream,-3);
 613       continue;
 614     }
 615     stream_skip(demuxer->stream,len-4);
 616     priv->next_pts += sh->audio.dwScale/(double)sh->samplerate;
 617     nf--;
 618   }
 619 }
 620
 621 static void demux_audio_seek(demuxer_t *demuxer,float rel_seek_secs,float audio_delay,int flags){
 622   sh_audio_t* sh_audio;
 623   stream_t* s;
 624   int64_t base,pos;
 625   float len;
 626   da_priv_t* priv;
 627
 628   if(!(sh_audio = demuxer->audio->sh))
 629     return;
 630   s = demuxer->stream;
 631   priv = demuxer->priv;
 632
 633   if(priv->frmt == MP3 && hr_mp3_seek && !(flags & SEEK_FACTOR)) {
 634     len = (flags & SEEK_ABSOLUTE) ? rel_seek_secs - priv->next_pts : rel_seek_secs;
 635     if(len < 0) {
 636       stream_seek(s,demuxer->movi_start);
 637       len = priv->next_pts + len;
 638       priv->next_pts = 0;
 639     }
 640     if(len > 0)
 641       high_res_mp3_seek(demuxer,len);
 642     return;
 643   }
 644
 645   base = flags&SEEK_ABSOLUTE ? demuxer->movi_start : stream_tell(s);
 646   if(flags&SEEK_FACTOR)
 647     pos = base + ((demuxer->movi_end - demuxer->movi_start)*rel_seek_secs);
 648   else
 649     pos = base + (rel_seek_secs*sh_audio->i_bps);
 650
 651   if(demuxer->movi_end && pos >= demuxer->movi_end) {
 652      pos = demuxer->movi_end;
 653   } else if(pos < demuxer->movi_start)
 654     pos = demuxer->movi_start;
 655
 656   priv->next_pts = (pos-demuxer->movi_start)/(double)sh_audio->i_bps;
 657
 658   switch(priv->frmt) {
 659   case WAV:
 660     pos -= (pos - demuxer->movi_start) %
 661             (sh_audio->wf->nBlockAlign ? sh_audio->wf->nBlockAlign :
 662              (sh_audio->channels * sh_audio->samplesize));
 663     break;
 664   }
 665
 666   stream_seek(s,pos);
 667 }
 668
 669 static void demux_close_audio(demuxer_t* demuxer) {
 670   da_priv_t* priv = demuxer->priv;
 671
 672   if(!priv)
 673     return;
 674   free(priv);
 675 }
 676
 677 static int demux_audio_control(demuxer_t *demuxer,int cmd, void *arg){
 678     sh_audio_t *sh_audio=demuxer->audio->sh;
 679     int audio_length = sh_audio->i_bps ? demuxer->movi_end / sh_audio->i_bps : 0;
 680     da_priv_t* priv = demuxer->priv;
 681
 682     switch(cmd) {
 683         case DEMUXER_CTRL_GET_TIME_LENGTH:
 684             if (audio_length<=0) return DEMUXER_CTRL_DONTKNOW;
 685             *((double *)arg)=(double)audio_length;
 686             return DEMUXER_CTRL_GUESS;
 687
 688         case DEMUXER_CTRL_GET_PERCENT_POS:
 689             if (audio_length<=0)
 690                 return DEMUXER_CTRL_DONTKNOW;
 691             *((int *)arg)=(int)( (priv->next_pts*100)  / audio_length);
 692             return DEMUXER_CTRL_OK;
 693
 694         default:
 695             return DEMUXER_CTRL_NOTIMPL;
 696     }
 697 }
 698
 699
 700 const demuxer_desc_t demuxer_desc_audio = {
 701   "Audio demuxer",
 702   "audio",
 703   "Audio only",
 704   "?",
 705   "Audio only files",
 706   DEMUXER_TYPE_AUDIO,
 707   0, // unsafe autodetect
 708   demux_audio_open,
 709   demux_audio_fill_buffer,
 710   NULL,
 711   demux_close_audio,
 712   demux_audio_seek,
 713   demux_audio_control
 714 };