libavformat/ilbc.c

   1 /*
   2  * iLBC storage file format
   3  * Copyright (c) 2012 Martin Storsjo
   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 "config_components.h"
  23
  24 #include "avformat.h"
  25 #include "avio_internal.h"
  26 #include "demux.h"
  27 #include "internal.h"
  28 #include "mux.h"
  29 #include "rawenc.h"
  30
  31 static const char mode20_header[] = "#!iLBC20\n";
  32 static const char mode30_header[] = "#!iLBC30\n";
  33
  34 static int ilbc_write_header(AVFormatContext *s)
  35 {
  36     AVIOContext *pb = s->pb;
  37     AVCodecParameters *par = s->streams[0]->codecpar;
  38
  39     if (par->block_align == 50) {
  40         avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
  41     } else if (par->block_align == 38) {
  42         avio_write(pb, mode20_header, sizeof(mode20_header) - 1);
  43     } else {
  44         av_log(s, AV_LOG_ERROR, "Unsupported mode\n");
  45         return AVERROR(EINVAL);
  46     }
  47     return 0;
  48 }
  49
  50 static int ilbc_probe(const AVProbeData *p)
  51 {
  52     // Only check for "#!iLBC" which matches both formats
  53     if (!memcmp(p->buf, mode20_header, 6))
  54         return AVPROBE_SCORE_MAX;
  55     else
  56         return 0;
  57 }
  58
  59 static int ilbc_read_header(AVFormatContext *s)
  60 {
  61     AVIOContext *pb = s->pb;
  62     AVStream *st;
  63     uint8_t header[9];
  64     int ret;
  65
  66     ret = ffio_read_size(pb, header, 9);
  67     if (ret < 0)
  68         return ret;
  69
  70     st = avformat_new_stream(s, NULL);
  71     if (!st)
  72         return AVERROR(ENOMEM);
  73     st->codecpar->codec_id = AV_CODEC_ID_ILBC;
  74     st->codecpar->sample_rate = 8000;
  75     st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
  76     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  77     st->start_time = 0;
  78     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  79     if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
  80         st->codecpar->block_align = 38;
  81         st->codecpar->bit_rate = 15200;
  82     } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
  83         st->codecpar->block_align = 50;
  84         st->codecpar->bit_rate = 13333;
  85     } else {
  86         av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
  87         return AVERROR_INVALIDDATA;
  88     }
  89
  90     return 0;
  91 }
  92
  93 static int ilbc_read_packet(AVFormatContext *s,
  94                           AVPacket *pkt)
  95 {
  96     AVCodecParameters *par = s->streams[0]->codecpar;
  97     int ret;
  98
  99     if ((ret = av_get_packet(s->pb, pkt, par->block_align)) != par->block_align)
 100         return ret < 0 ? ret : AVERROR_INVALIDDATA;
 101
 102     pkt->stream_index = 0;
 103     pkt->duration = par->block_align == 38 ? 160 : 240;
 104
 105     return 0;
 106 }
 107
 108 const FFInputFormat ff_ilbc_demuxer = {
 109     .p.name       = "ilbc",
 110     .p.long_name  = NULL_IF_CONFIG_SMALL("iLBC storage"),
 111     .p.flags      = AVFMT_GENERIC_INDEX,
 112     .read_probe   = ilbc_probe,
 113     .read_header  = ilbc_read_header,
 114     .read_packet  = ilbc_read_packet,
 115 };
 116
 117 #if CONFIG_ILBC_MUXER
 118 const FFOutputFormat ff_ilbc_muxer = {
 119     .p.name         = "ilbc",
 120     .p.long_name    = NULL_IF_CONFIG_SMALL("iLBC storage"),
 121     .p.mime_type    = "audio/iLBC",
 122     .p.extensions   = "lbc",
 123     .p.video_codec    = AV_CODEC_ID_NONE,
 124     .p.audio_codec  = AV_CODEC_ID_ILBC,
 125     .p.subtitle_codec = AV_CODEC_ID_NONE,
 126     .p.flags        = AVFMT_NOTIMESTAMPS,
 127     .flags_internal   = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
 128                         FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
 129     .write_header = ilbc_write_header,
 130     .write_packet = ff_raw_write_packet,
 131 };
 132 #endif