libavformat/g728dec.c

   1 /*
   2  * G.728 raw demuxer
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "avformat.h"
  22 #include "demux.h"
  23 #include "internal.h"
  24
  25 static int g728_read_header(AVFormatContext *s)
  26 {
  27     AVStream *st = avformat_new_stream(s, NULL);
  28     if (!st)
  29         return AVERROR(ENOMEM);
  30
  31     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
  32     st->codecpar->codec_id    = ffifmt(s->iformat)->raw_codec_id;
  33     st->codecpar->sample_rate = 8000;
  34     st->codecpar->bit_rate    = 16000;
  35     st->codecpar->block_align = 5;
  36     st->codecpar->ch_layout   = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
  37     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  38
  39     return 0;
  40 }
  41
  42 static int g728_read_packet(AVFormatContext *s, AVPacket *pkt)
  43 {
  44     int ret = av_get_packet(s->pb, pkt, 1020); // a size similar to RAW_PACKET_SIZE divisible by 5
  45     pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
  46     pkt->duration = (pkt->size / 5) * 20;
  47     return ret;
  48 }
  49
  50 const FFInputFormat ff_g728_demuxer = {
  51     .p.name         = "g728",
  52     .p.long_name    = NULL_IF_CONFIG_SMALL("raw G.728"),
  53     .p.extensions   = "g728",
  54     .p.flags        = AVFMT_GENERIC_INDEX,
  55     .read_header    = g728_read_header,
  56     .read_packet    = g728_read_packet,
  57     .raw_codec_id   = AV_CODEC_ID_G728,
  58 };