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 "avformat.h"
  23 #include "internal.h"
  24 #include "rawenc.h"
  25
  26 static const char mode20_header[] = "#!iLBC20\n";
  27 static const char mode30_header[] = "#!iLBC30\n";
  28
  29 static int ilbc_write_header(AVFormatContext *s)
  30 {
  31     AVIOContext *pb = s->pb;
  32     AVCodecParameters *par;
  33
  34     if (s->nb_streams != 1) {
  35         av_log(s, AV_LOG_ERROR, "Unsupported number of streams\n");
  36         return AVERROR(EINVAL);
  37     }
  38     par = s->streams[0]->codecpar;
  39
  40     if (par->codec_id != AV_CODEC_ID_ILBC) {
  41         av_log(s, AV_LOG_ERROR, "Unsupported codec\n");
  42         return AVERROR(EINVAL);
  43     }
  44
  45     if (par->block_align == 50) {
  46         avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
  47     } else if (par->block_align == 38) {
  48         avio_write(pb, mode20_header, sizeof(mode20_header) - 1);
  49     } else {
  50         av_log(s, AV_LOG_ERROR, "Unsupported mode\n");
  51         return AVERROR(EINVAL);
  52     }
  53     return 0;
  54 }
  55
  56 static int ilbc_probe(const AVProbeData *p)
  57 {
  58     // Only check for "#!iLBC" which matches both formats
  59     if (!memcmp(p->buf, mode20_header, 6))
  60         return AVPROBE_SCORE_MAX;
  61     else
  62         return 0;
  63 }
  64
  65 static int ilbc_read_header(AVFormatContext *s)
  66 {
  67     AVIOContext *pb = s->pb;
  68     AVStream *st;
  69     uint8_t header[9];
  70
  71     if (avio_read(pb, header, 9) != 9)
  72         return AVERROR_INVALIDDATA;
  73
  74     st = avformat_new_stream(s, NULL);
  75     if (!st)
  76         return AVERROR(ENOMEM);
  77     st->codecpar->codec_id = AV_CODEC_ID_ILBC;
  78     st->codecpar->sample_rate = 8000;
  79     st->codecpar->channels = 1;
  80     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
  81     st->start_time = 0;
  82     avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
  83     if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
  84         st->codecpar->block_align = 38;
  85         st->codecpar->bit_rate = 15200;
  86     } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
  87         st->codecpar->block_align = 50;
  88         st->codecpar->bit_rate = 13333;
  89     } else {
  90         av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
  91         return AVERROR_INVALIDDATA;
  92     }
  93
  94     return 0;
  95 }
  96
  97 static int ilbc_read_packet(AVFormatContext *s,
  98                           AVPacket *pkt)
  99 {
 100     AVCodecParameters *par = s->streams[0]->codecpar;
 101     int ret;
 102
 103     if ((ret = av_new_packet(pkt, par->block_align)) < 0)
 104         return ret;
 105
 106     pkt->stream_index = 0;
 107     pkt->pos = avio_tell(s->pb);
 108     pkt->duration = par->block_align == 38 ? 160 : 240;
 109     if ((ret = avio_read(s->pb, pkt->data, par->block_align)) != par->block_align) {
 110         return ret < 0 ? ret : AVERROR(EIO);
 111     }
 112
 113     return 0;
 114 }
 115
 116 AVInputFormat ff_ilbc_demuxer = {
 117     .name         = "ilbc",
 118     .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage"),
 119     .read_probe   = ilbc_probe,
 120     .read_header  = ilbc_read_header,
 121     .read_packet  = ilbc_read_packet,
 122     .flags        = AVFMT_GENERIC_INDEX,
 123 };
 124
 125 #if CONFIG_ILBC_MUXER
 126 AVOutputFormat ff_ilbc_muxer = {
 127     .name         = "ilbc",
 128     .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage"),
 129     .mime_type    = "audio/iLBC",
 130     .extensions   = "lbc",
 131     .audio_codec  = AV_CODEC_ID_ILBC,
 132     .write_header = ilbc_write_header,
 133     .write_packet = ff_raw_write_packet,
 134     .flags        = AVFMT_NOTIMESTAMPS,
 135 };
 136 #endif