FFmpeg/libavformat/ilbc.c
Clément Bœsch 7308439158 lavf: Don't explicitly flush after each written packet in muxers
Since 596e5d4783, this is not necessary anymore. It also allows to
actually disable the flushing, improving write performance (but
possibly giving worse latency in real-time streaming).

Signed-off-by: Martin Storsjö <martin@martin.st>
2013-09-16 22:17:33 +03:00

141 lines
4.0 KiB
C

/*
* iLBC storage file format
* Copyright (c) 2012 Martin Storsjo
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "internal.h"
static const char mode20_header[] = "#!iLBC20\n";
static const char mode30_header[] = "#!iLBC30\n";
static int ilbc_write_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
AVCodecContext *enc;
if (s->nb_streams != 1) {
av_log(s, AV_LOG_ERROR, "Unsupported number of streams\n");
return AVERROR(EINVAL);
}
enc = s->streams[0]->codec;
if (enc->codec_id != AV_CODEC_ID_ILBC) {
av_log(s, AV_LOG_ERROR, "Unsupported codec\n");
return AVERROR(EINVAL);
}
if (enc->block_align == 50) {
avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
} else if (enc->block_align == 38) {
avio_write(pb, mode20_header, sizeof(mode20_header) - 1);
} else {
av_log(s, AV_LOG_ERROR, "Unsupported mode\n");
return AVERROR(EINVAL);
}
avio_flush(pb);
return 0;
}
static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
{
avio_write(s->pb, pkt->data, pkt->size);
return 0;
}
static int ilbc_probe(AVProbeData *p)
{
// Only check for "#!iLBC" which matches both formats
if (!memcmp(p->buf, mode20_header, 6))
return AVPROBE_SCORE_MAX;
else
return 0;
}
static int ilbc_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
AVStream *st;
uint8_t header[9];
avio_read(pb, header, 9);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_id = AV_CODEC_ID_ILBC;
st->codec->sample_rate = 8000;
st->codec->channels = 1;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->start_time = 0;
avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
st->codec->block_align = 38;
st->codec->bit_rate = 15200;
} else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
st->codec->block_align = 50;
st->codec->bit_rate = 13333;
} else {
av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
static int ilbc_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
AVCodecContext *enc = s->streams[0]->codec;
int ret;
if ((ret = av_new_packet(pkt, enc->block_align)) < 0)
return ret;
pkt->stream_index = 0;
pkt->pos = avio_tell(s->pb);
pkt->duration = enc->block_align == 38 ? 160 : 240;
if ((ret = avio_read(s->pb, pkt->data, enc->block_align)) != enc->block_align) {
av_free_packet(pkt);
return ret < 0 ? ret : AVERROR(EIO);
}
return 0;
}
AVInputFormat ff_ilbc_demuxer = {
.name = "ilbc",
.long_name = NULL_IF_CONFIG_SMALL("iLBC storage"),
.read_probe = ilbc_probe,
.read_header = ilbc_read_header,
.read_packet = ilbc_read_packet,
.flags = AVFMT_GENERIC_INDEX,
};
AVOutputFormat ff_ilbc_muxer = {
.name = "ilbc",
.long_name = NULL_IF_CONFIG_SMALL("iLBC storage"),
.mime_type = "audio/iLBC",
.extensions = "lbc",
.audio_codec = AV_CODEC_ID_ILBC,
.write_header = ilbc_write_header,
.write_packet = ilbc_write_packet,
.flags = AVFMT_NOTIMESTAMPS,
};