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/*
* amr file format
* Copyright (c) 2001 ffmpeg project
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 unsigned char AMR_header [] = "#!AMR\n";
static const unsigned char AMRWB_header [] = "#!AMR-WB\n";
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
{
//This is an error!
}
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;
}
static int amr_write_trailer(AVFormatContext *s)
{
return 0;
}
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 (p->buf_size < 5)
return 0;
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);
if(memcmp(header,AMR_header,6)!=0)
{
get_buffer(pb, header+6, 3);
if(memcmp(header,AMRWB_header,9)!=0)
{
return -1;
}
st = av_new_stream(s, 0);
if (!st)
{
return AVERROR_NOMEM;
}
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_tag = MKTAG('s', 'a', 'w', 'b');
st->codec->codec_id = CODEC_ID_AMR_WB;
st->codec->channels = 1;
st->codec->sample_rate = 16000;
}
else
{
st = av_new_stream(s, 0);
if (!st)
{
return AVERROR_NOMEM;
}
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_tag = MKTAG('s', 'a', 'm', 'r');
st->codec->codec_id = CODEC_ID_AMR_NB;
st->codec->channels = 1;
st->codec->sample_rate = 8000;
}
return 0;
}
#define MAX_SIZE 32
static int amr_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
AVCodecContext *enc = s->streams[0]->codec;
if (enc->codec_id == CODEC_ID_AMR_NB)
{
const static uint8_t packed_size[16] = {12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0};
uint8_t toc, q, ft;
int read;
int size;
if (url_feof(&s->pb))
{
return AVERROR_IO;
}
toc=get_byte(&s->pb);
q = (toc >> 2) & 0x01;
ft = (toc >> 3) & 0x0F;
size=packed_size[ft];
if (av_new_packet(pkt, size+1))
{
return AVERROR_IO;
}
pkt->stream_index = 0;
pkt->pos= url_ftell(&s->pb);
pkt->data[0]=toc;
read = get_buffer(&s->pb, pkt->data+1, size);
if (read != size)
{
av_free_packet(pkt);
return AVERROR_IO;
}
return 0;
}
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};
uint8_t toc, mode;
int read;
int size;
if (url_feof(&s->pb))
{
return AVERROR_IO;
}
toc=get_byte(&s->pb);
mode = (uint8_t)((toc >> 3) & 0x0F);
size = packed_size[mode];
if ( (size==0) || av_new_packet(pkt, size))
{
return AVERROR_IO;
}
pkt->stream_index = 0;
pkt->pos= url_ftell(&s->pb);
pkt->data[0]=toc;
read = get_buffer(&s->pb, pkt->data+1, size-1);
if (read != (size-1))
{
av_free_packet(pkt);
return AVERROR_IO;
}
return 0;
}
else
{
return AVERROR_IO;
}
}
static int amr_read_close(AVFormatContext *s)
{
return 0;
}
static AVInputFormat amr_iformat = {
"amr",
"3gpp amr file format",
0, /*priv_data_size*/
amr_probe,
amr_read_header,
amr_read_packet,
amr_read_close,
};
static AVOutputFormat amr_oformat = {
"amr",
"3gpp amr file format",
"audio/amr",
"amr",
0,
CODEC_ID_AMR_NB,
CODEC_ID_NONE,
amr_write_header,
amr_write_packet,
amr_write_trailer,
};
int amr_init(void)
{
av_register_input_format(&amr_iformat);
av_register_output_format(&amr_oformat);
return 0;
}
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