ffmpeg/libavformat/oggparseopus.c

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/*
* Opus parser for Ogg
* Copyright (c) 2012 Nicolas George
*
* 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 <string.h>
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
#include "oggdec.h"
struct oggopus_private {
int need_comments;
unsigned pre_skip;
int64_t cur_dts;
};
#define OPUS_HEAD_SIZE 19
static int opus_header(AVFormatContext *avf, int idx)
{
struct ogg *ogg = avf->priv_data;
struct ogg_stream *os = &ogg->streams[idx];
AVStream *st = avf->streams[idx];
struct oggopus_private *priv = os->private;
uint8_t *packet = os->buf + os->pstart;
uint8_t *extradata;
if (!priv) {
priv = os->private = av_mallocz(sizeof(*priv));
if (!priv)
return AVERROR(ENOMEM);
}
if (os->flags & OGG_FLAG_BOS) {
if (os->psize < OPUS_HEAD_SIZE || (AV_RL8(packet + 8) & 0xF0) != 0)
return AVERROR_INVALIDDATA;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_CODEC_ID_OPUS;
st->codec->channels = AV_RL8(packet + 9);
priv->pre_skip = AV_RL16(packet + 10);
extradata = av_malloc(os->psize + FF_INPUT_BUFFER_PADDING_SIZE);
if (!extradata)
return AVERROR(ENOMEM);
memcpy(extradata, packet, os->psize);
st->codec->extradata = extradata;
st->codec->extradata_size = os->psize;
st->codec->sample_rate = 48000;
avpriv_set_pts_info(st, 64, 1, 48000);
priv->need_comments = 1;
return 1;
}
if (priv->need_comments) {
if (os->psize < 8 || memcmp(packet, "OpusTags", 8))
return AVERROR_INVALIDDATA;
ff_vorbis_stream_comment(avf, st, packet + 8, os->psize - 8);
priv->need_comments--;
return 1;
}
return 0;
}
static int opus_packet(AVFormatContext *avf, int idx)
{
struct ogg *ogg = avf->priv_data;
struct ogg_stream *os = &ogg->streams[idx];
AVStream *st = avf->streams[idx];
struct oggopus_private *priv = os->private;
uint8_t *packet = os->buf + os->pstart;
unsigned toc, toc_config, toc_count, frame_size, nb_frames = 1;
if (!os->psize)
return AVERROR_INVALIDDATA;
toc = *packet;
toc_config = toc >> 3;
toc_count = toc & 3;
frame_size = toc_config < 12 ? FFMAX(480, 960 * (toc_config & 3)) :
toc_config < 16 ? 480 << (toc_config & 1) :
120 << (toc_config & 3);
if (toc_count == 3) {
if (os->psize < 2)
return AVERROR_INVALIDDATA;
nb_frames = packet[1] & 0x3F;
} else if (toc_count) {
nb_frames = 2;
}
os->pduration = frame_size * nb_frames;
if (os->lastpts != AV_NOPTS_VALUE) {
if (st->start_time == AV_NOPTS_VALUE)
st->start_time = os->lastpts;
priv->cur_dts = os->lastdts = os->lastpts -= priv->pre_skip;
}
priv->cur_dts += os->pduration;
if ((os->flags & OGG_FLAG_EOS)) {
int64_t skip = priv->cur_dts - os->granule + priv->pre_skip;
skip = FFMIN(skip, os->pduration);
if (skip > 0) {
os->pduration = skip < os->pduration ? os->pduration - skip : 1;
av_log(avf, AV_LOG_WARNING,
"Last packet is truncated to %d (because of unimplemented end trim support).\n",
os->pduration);
return AVERROR_PATCHWELCOME;
}
}
return 0;
}
const struct ogg_codec ff_opus_codec = {
.name = "Opus",
.magic = "OpusHead",
.magicsize = 8,
.header = opus_header,
.packet = opus_packet,
.granule_is_start = 1,
.nb_header = 1,
};