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/*
* amr file format
* Copyright (c) 2001 ffmpeg project
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.txt?number=3267
Only mono files are supported.
*/
#include "avformat.h"
static const char AMR_header [] = "#!AMR\n";
static const char AMRWB_header [] = "#!AMR-WB\n";
#if CONFIG_AMR_MUXER
static int amr_write_header(AVFormatContext *s)
{
ByteIOContext *pb = s->pb;
AVCodecContext *enc = s->streams[0]->codec;
s->priv_data = NULL;
if (enc->codec_id == CODEC_ID_AMR_NB)
{
put_tag(pb, AMR_header); /* magic number */
}
else if(enc->codec_id == CODEC_ID_AMR_WB)
{
put_tag(pb, AMRWB_header); /* magic number */
}
else
{
return -1;
}
put_flush_packet(pb);
return 0;
}
static int amr_write_packet(AVFormatContext *s, AVPacket *pkt)
{
put_buffer(s->pb, pkt->data, pkt->size);
put_flush_packet(s->pb);
return 0;
}
#endif /* CONFIG_AMR_MUXER */
static int amr_probe(AVProbeData *p)
{
//Only check for "#!AMR" which could be amr-wb, amr-nb.
//This will also trigger multichannel files: "#!AMR_MC1.0\n" and
//"#!AMR-WB_MC1.0\n" (not supported)
if(memcmp(p->buf,AMR_header,5)==0)
return AVPROBE_SCORE_MAX;
else
return 0;
}
/* amr input */
static int amr_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
ByteIOContext *pb = s->pb;
AVStream *st;
uint8_t header[9];
get_buffer(pb, header, 6);
st = av_new_stream(s, 0);
if (!st)
{
return AVERROR(ENOMEM);
}
if(memcmp(header,AMR_header,6)!=0)
{
get_buffer(pb, header+6, 3);
if(memcmp(header,AMRWB_header,9)!=0)
{
return -1;
}
st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b');
st->codec->codec_id = CODEC_ID_AMR_WB;
st->codec->sample_rate = 16000;
}
else
{
st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r');
st->codec->codec_id = CODEC_ID_AMR_NB;
st->codec->sample_rate = 8000;
}
st->codec->channels = 1;
st->codec->codec_type = CODEC_TYPE_AUDIO;
av_set_pts_info(st, 64, 1, st->codec->sample_rate);
return 0;
}
static int amr_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
AVCodecContext *enc = s->streams[0]->codec;
int read, size = 0, toc, mode;
if (url_feof(s->pb))
{
return AVERROR(EIO);
}
//FIXME this is wrong, this should rather be in a AVParset
toc=get_byte(s->pb);
mode = (toc >> 3) & 0x0F;
if (enc->codec_id == CODEC_ID_AMR_NB)
{
static const uint8_t packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};
size=packed_size[mode]+1;
}
else if(enc->codec_id == CODEC_ID_AMR_WB)
{
static uint8_t packed_size[16] = {18, 24, 33, 37, 41, 47, 51, 59, 61, 6, 6, 0, 0, 0, 1, 1};
size=packed_size[mode];
}
else
{
assert(0);
}
if ( (size==0) || av_new_packet(pkt, size))
{
return AVERROR(EIO);
}
pkt->stream_index = 0;
pkt->pos= url_ftell(s->pb);
pkt->data[0]=toc;
pkt->duration= enc->codec_id == CODEC_ID_AMR_NB ? 160 : 320;
read = get_buffer(s->pb, pkt->data+1, size-1);
if (read != size-1)
{
av_free_packet(pkt);
return AVERROR(EIO);
}
return 0;
}
#if CONFIG_AMR_DEMUXER
AVInputFormat amr_demuxer = {
"amr",
NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
0, /*priv_data_size*/
amr_probe,
amr_read_header,
amr_read_packet,
NULL,
};
#endif
#if CONFIG_AMR_MUXER
AVOutputFormat amr_muxer = {
"amr",
NULL_IF_CONFIG_SMALL("3GPP AMR file format"),
"audio/amr",
"amr",
0,
CODEC_ID_AMR_NB,
CODEC_ID_NONE,
amr_write_header,
amr_write_packet,
};
#endif
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