libavformat/afc.c

   1 /*
   2  * AFC demuxer
   3  * Copyright (c) 2012 Paul B Mahol
   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/channel_layout.h"
  23 #include "avformat.h"
  24 #include "demux.h"
  25 #include "internal.h"
  26
  27 typedef struct AFCDemuxContext {
  28     int64_t    data_end;
  29 } AFCDemuxContext;
  30
  31 static int afc_read_header(AVFormatContext *s)
  32 {
  33     AFCDemuxContext *c = s->priv_data;
  34     AVStream *st;
  35     int ret;
  36
  37     st = avformat_new_stream(s, NULL);
  38     if (!st)
  39         return AVERROR(ENOMEM);
  40     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  41     st->codecpar->codec_id   = AV_CODEC_ID_ADPCM_AFC;
  42     st->codecpar->ch_layout  = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
  43
  44     if ((ret = ff_alloc_extradata(st->codecpar, 1)) < 0)
  45         return ret;
  46     st->codecpar->extradata[0] = 8 * st->codecpar->ch_layout.nb_channels;
  47
  48     c->data_end = avio_rb32(s->pb) + 32LL;
  49     st->duration = avio_rb32(s->pb);
  50     st->codecpar->sample_rate = avio_rb16(s->pb);
  51     avio_skip(s->pb, 22);
  52     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  53
  54     return 0;
  55 }
  56
  57 static int afc_read_packet(AVFormatContext *s, AVPacket *pkt)
  58 {
  59     AFCDemuxContext *c = s->priv_data;
  60     int64_t size = c->data_end - avio_tell(s->pb);
  61     int ret;
  62
  63     size = FFMIN(size, 18 * 128);
  64     if (size <= 0)
  65         return AVERROR_EOF;
  66
  67     ret = av_get_packet(s->pb, pkt, size);
  68     pkt->stream_index = 0;
  69     return ret;
  70 }
  71
  72 const FFInputFormat ff_afc_demuxer = {
  73     .p.name         = "afc",
  74     .p.long_name    = NULL_IF_CONFIG_SMALL("AFC"),
  75     .p.extensions   = "afc",
  76     .p.flags        = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK,
  77     .priv_data_size = sizeof(AFCDemuxContext),
  78     .read_header    = afc_read_header,
  79     .read_packet    = afc_read_packet,
  80 };