libavformat/voc_packet.c

   1 /*
   2  * This file is part of Libav.
   3  *
   4  * Libav is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * Libav 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 GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with Libav; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #include "avformat.h"
  20 #include "internal.h"
  21 #include "voc.h"
  22
  23 int
  24 ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
  25 {
  26     VocDecContext *voc = s->priv_data;
  27     AVCodecParameters *par = st->codecpar;
  28     AVIOContext *pb = s->pb;
  29     VocType type;
  30     int size, tmp_codec=-1;
  31     int sample_rate = 0;
  32     int channels = 1;
  33
  34     while (!voc->remaining_size) {
  35         type = avio_r8(pb);
  36         if (type == VOC_TYPE_EOF)
  37             return AVERROR(EIO);
  38         voc->remaining_size = avio_rl24(pb);
  39         if (!voc->remaining_size) {
  40             if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL))
  41                 return AVERROR(EIO);
  42             voc->remaining_size = avio_size(pb) - avio_tell(pb);
  43         }
  44         max_size -= 4;
  45
  46         switch (type) {
  47         case VOC_TYPE_VOICE_DATA:
  48             if (!par->sample_rate) {
  49                 par->sample_rate = 1000000 / (256 - avio_r8(pb));
  50                 if (sample_rate)
  51                     par->sample_rate = sample_rate;
  52                 avpriv_set_pts_info(st, 64, 1, par->sample_rate);
  53                 par->channels = channels;
  54                 par->bits_per_coded_sample = av_get_bits_per_sample(par->codec_id);
  55             } else
  56                 avio_skip(pb, 1);
  57             tmp_codec = avio_r8(pb);
  58             voc->remaining_size -= 2;
  59             max_size -= 2;
  60             channels = 1;
  61             break;
  62
  63         case VOC_TYPE_VOICE_DATA_CONT:
  64             break;
  65
  66         case VOC_TYPE_EXTENDED:
  67             sample_rate = avio_rl16(pb);
  68             avio_r8(pb);
  69             channels = avio_r8(pb) + 1;
  70             sample_rate = 256000000 / (channels * (65536 - sample_rate));
  71             voc->remaining_size = 0;
  72             max_size -= 4;
  73             break;
  74
  75         case VOC_TYPE_NEW_VOICE_DATA:
  76             if (!par->sample_rate) {
  77                 par->sample_rate = avio_rl32(pb);
  78                 avpriv_set_pts_info(st, 64, 1, par->sample_rate);
  79                 par->bits_per_coded_sample = avio_r8(pb);
  80                 par->channels = avio_r8(pb);
  81             } else
  82                 avio_skip(pb, 6);
  83             tmp_codec = avio_rl16(pb);
  84             avio_skip(pb, 4);
  85             voc->remaining_size -= 12;
  86             max_size -= 12;
  87             break;
  88
  89         default:
  90             avio_skip(pb, voc->remaining_size);
  91             max_size -= voc->remaining_size;
  92             voc->remaining_size = 0;
  93             break;
  94         }
  95     }
  96
  97     if (tmp_codec >= 0) {
  98         tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
  99         if (par->codec_id == AV_CODEC_ID_NONE)
 100             par->codec_id = tmp_codec;
 101         else if (par->codec_id != tmp_codec)
 102             av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
 103         if (par->codec_id == AV_CODEC_ID_NONE) {
 104             if (s->audio_codec_id == AV_CODEC_ID_NONE) {
 105                 av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
 106                 return AVERROR(EINVAL);
 107             }
 108             av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
 109         }
 110     }
 111
 112     par->bit_rate = par->sample_rate * par->bits_per_coded_sample;
 113
 114     if (max_size <= 0)
 115         max_size = 2048;
 116     size = FFMIN(voc->remaining_size, max_size);
 117     voc->remaining_size -= size;
 118     return av_get_packet(pb, pkt, size);
 119 }