ffmpeg/libavformat/amr.c

179 lines
3.8 KiB
C
Raw Normal View History

/*
* 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 amr narrowband (not amr-wb) is supported for now.
*/
#include "avformat.h"
#include "avi.h"
static const unsigned char AMR_header [] = "#!AMR\n";
/* AMR_FILE header */
static int put_amr_header(ByteIOContext *pb, AVCodecContext *enc)
{
put_tag(pb, AMR_header); /* magic number */
return 0;
}
static int amr_write_header(AVFormatContext *s)
{
ByteIOContext *pb = &s->pb;
s->priv_data = NULL;
/* format header */
if (put_amr_header(pb, &s->streams[0]->codec) < 0) {
return -1;
}
put_flush_packet(pb);
return 0;
}
static int amr_write_packet(AVFormatContext *s, int stream_index_ptr,
uint8_t *buf, int size, int force_pts)
{
put_buffer(&s->pb, buf, size);
put_flush_packet(&s->pb);
return 0;
}
static int amr_write_trailer(AVFormatContext *s)
{
return 0;
}
static int amr_probe(AVProbeData *p)
{
/* check file header */
if (p->buf_size < 6)
return 0;
if(memcmp(p->buf,AMR_header,6)==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[6];
get_buffer(pb, header, 6);
if(memcmp(header,AMR_header,6)!=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 = CODEC_ID_AMR_NB;
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)
{
static uint16_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 -EIO;
toc=0;
toc=get_byte(&s->pb);
q = (toc >> 2) & 0x01;
ft = (toc >> 3) & 0x0F;
size=packed_size[ft];
//printf("amr_read_packet size=%d\n",size);
if (av_new_packet(pkt, size+1))
return -EIO;
pkt->stream_index = 0;
pkt->data[0]=toc;
read = get_buffer(&s->pb, pkt->data+1, size);
if (read != size)
{
av_free_packet(pkt);
return -EIO;
}
return 0;
}
static int amr_read_close(AVFormatContext *s)
{
return 0;
}
static AVInputFormat amr_iformat = {
"amr",
"3gpp amr file format",
0,
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;
}