Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * LOAS AudioSyncStream demuxer
  3.  * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
  4.  *
  5.  * This file is part of FFmpeg.
  6.  *
  7.  * FFmpeg is free software; you can redistribute it and/or
  8.  * modify it under the terms of the GNU Lesser General Public
  9.  * License as published by the Free Software Foundation; either
  10.  * version 2.1 of the License, or (at your option) any later version.
  11.  *
  12.  * FFmpeg is distributed in the hope that it will be useful,
  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15.  * Lesser General Public License for more details.
  16.  *
  17.  * You should have received a copy of the GNU Lesser General Public
  18.  * License along with FFmpeg; if not, write to the Free Software
  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20.  */
  21.  
  22. #include "libavutil/intreadwrite.h"
  23. #include "libavutil/internal.h"
  24. #include "avformat.h"
  25. #include "internal.h"
  26. #include "rawdec.h"
  27.  
  28. static int loas_probe(AVProbeData *p)
  29. {
  30.     int max_frames = 0, first_frames = 0;
  31.     int fsize, frames;
  32.     const uint8_t *buf0 = p->buf;
  33.     const uint8_t *buf2;
  34.     const uint8_t *buf;
  35.     const uint8_t *end = buf0 + p->buf_size - 3;
  36.     buf = buf0;
  37.  
  38.     for(; buf < end; buf= buf2+1) {
  39.         buf2 = buf;
  40.  
  41.         for(frames = 0; buf2 < end; frames++) {
  42.             uint32_t header = AV_RB24(buf2);
  43.             if((header >> 13) != 0x2B7)
  44.                 break;
  45.             fsize = (header & 0x1FFF) + 3;
  46.             if(fsize < 7)
  47.                 break;
  48.             fsize = FFMIN(fsize, end - buf2);
  49.             buf2 += fsize;
  50.         }
  51.         max_frames = FFMAX(max_frames, frames);
  52.         if(buf == buf0)
  53.             first_frames= frames;
  54.     }
  55.     if   (first_frames>=3) return AVPROBE_SCORE_EXTENSION+1;
  56.     else if(max_frames>100)return AVPROBE_SCORE_EXTENSION;
  57.     else if(max_frames>=3) return AVPROBE_SCORE_EXTENSION / 2;
  58.     else                   return 0;
  59. }
  60.  
  61. static int loas_read_header(AVFormatContext *s)
  62. {
  63.     AVStream *st;
  64.  
  65.     st = avformat_new_stream(s, NULL);
  66.     if (!st)
  67.         return AVERROR(ENOMEM);
  68.  
  69.     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
  70.     st->codec->codec_id = s->iformat->raw_codec_id;
  71.     st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
  72.  
  73.     //LCM of all possible AAC sample rates
  74.     avpriv_set_pts_info(st, 64, 1, 28224000);
  75.  
  76.     return 0;
  77. }
  78.  
  79. AVInputFormat ff_loas_demuxer = {
  80.     .name           = "loas",
  81.     .long_name      = NULL_IF_CONFIG_SMALL("LOAS AudioSyncStream"),
  82.     .read_probe     = loas_probe,
  83.     .read_header    = loas_read_header,
  84.     .read_packet    = ff_raw_read_partial_packet,
  85.     .flags= AVFMT_GENERIC_INDEX,
  86.     .raw_codec_id = AV_CODEC_ID_AAC_LATM,
  87. };
  88.