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/*
* G.726 raw demuxer
* Copyright 2017 Carl Eugen Hoyos
*
* 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
*/
#include "config_components.h"
#include "avformat.h"
#include "internal.h"
#include "libavutil/opt.h"
typedef struct G726Context {
AVClass *class;
int code_size;
int sample_rate;
} G726Context;
static int g726_read_header(AVFormatContext *s)
{
G726Context *c = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = s->iformat->raw_codec_id;
st->codecpar->sample_rate = c->sample_rate;
st->codecpar->bits_per_coded_sample = c->code_size;
st->codecpar->bit_rate = ((int[]){ 16000, 24000, 32000, 40000 })[c->code_size - 2];
st->codecpar->ch_layout.nb_channels = 1;
return 0;
}
static int g726_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int res;
res = av_get_packet(s->pb, pkt, 1020); // a size similar to RAW_PACKET_SIZE divisible by all code_size values
if (res < 0)
return res;
return 0;
}
#define OFFSET(x) offsetof(G726Context, x)
static const AVOption options[] = {
{ "code_size", "Bits per G.726 code",
OFFSET(code_size), AV_OPT_TYPE_INT, {.i64 = 4}, 2, 5, AV_OPT_FLAG_DECODING_PARAM },
{ "sample_rate", "",
OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 8000}, 0, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
{ NULL },
};
static const AVClass g726_demuxer_class = {
.class_name = "G.726 demuxer",
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
#if CONFIG_G726_DEMUXER
const AVInputFormat ff_g726_demuxer = {
.name = "g726",
.long_name = NULL_IF_CONFIG_SMALL("raw big-endian G.726 (\"left aligned\")"),
.read_header = g726_read_header,
.read_packet = g726_read_packet,
.priv_data_size = sizeof(G726Context),
.priv_class = &g726_demuxer_class,
.raw_codec_id = AV_CODEC_ID_ADPCM_G726,
};
#endif
#if CONFIG_G726LE_DEMUXER
const AVInputFormat ff_g726le_demuxer = {
.name = "g726le",
.long_name = NULL_IF_CONFIG_SMALL("raw little-endian G.726 (\"right aligned\")"),
.read_header = g726_read_header,
.read_packet = g726_read_packet,
.priv_data_size = sizeof(G726Context),
.priv_class = &g726_demuxer_class,
.raw_codec_id = AV_CODEC_ID_ADPCM_G726LE,
};
#endif
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