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FFmpeg/libavformat/ivfdec.c
Dai, Jianhui J 3b358f151d avformat/ivfenc: Set the "number of frames" in IVF header
Should set "number of frames" to bytes 24-27 of IVF header, not
duration.
It is described by [1], and confirmed by parsing all IVF files in [2].

This commit also updates the md5sum of refs to pass fate-cbs.

[1] Duck IVF - MultimediaWiki
https://wiki.multimedia.cx/index.php/Duck_IVF

[2] webm/vp8-test-vectors
https://chromium.googlesource.com/webm/vp8-test-vectors

Signed-off-by: Jianhui Dai <jianhui.j.dai@intel.com>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
2023-07-09 16:56:58 -04:00

100 lines
3.1 KiB
C

/*
* Copyright (c) 2010 David Conrad
*
* 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 "avformat.h"
#include "internal.h"
#include "riff.h"
#include "libavutil/intreadwrite.h"
static int probe(const AVProbeData *p)
{
if (AV_RL32(p->buf) == MKTAG('D','K','I','F')
&& !AV_RL16(p->buf+4) && AV_RL16(p->buf+6) == 32)
return AVPROBE_SCORE_MAX-2;
return 0;
}
static int read_header(AVFormatContext *s)
{
AVStream *st;
AVRational time_base;
avio_rl32(s->pb); // DKIF
avio_rl16(s->pb); // version
avio_rl16(s->pb); // header size
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_tag = avio_rl32(s->pb);
st->codecpar->codec_id = ff_codec_get_id(ff_codec_bmp_tags, st->codecpar->codec_tag);
st->codecpar->width = avio_rl16(s->pb);
st->codecpar->height = avio_rl16(s->pb);
time_base.den = avio_rl32(s->pb);
time_base.num = avio_rl32(s->pb);
st->nb_frames = avio_rl32(s->pb);
avio_skip(s->pb, 4); // unused
// Infer duration from nb_frames, in order to be backward compatible with
// previous IVF demuxer.
// It is popular to configure time_base to 1/frame_rate by IVF muxer, that
// the duration happens to be the same with nb_frames. See
// `https://chromium.googlesource.com/webm/vp8-test-vectors/+/refs/heads/main`
st->duration = st->nb_frames;
ffstream(st)->need_parsing = AVSTREAM_PARSE_HEADERS;
if (!time_base.den || !time_base.num) {
av_log(s, AV_LOG_ERROR, "Invalid frame rate\n");
return AVERROR_INVALIDDATA;
}
avpriv_set_pts_info(st, 64, time_base.num, time_base.den);
return 0;
}
static int read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret, size = avio_rl32(s->pb);
int64_t pts = avio_rl64(s->pb);
ret = av_get_packet(s->pb, pkt, size);
pkt->stream_index = 0;
pkt->pts = pts;
pkt->pos -= 12;
return ret;
}
const AVInputFormat ff_ivf_demuxer = {
.name = "ivf",
.long_name = NULL_IF_CONFIG_SMALL("On2 IVF"),
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
.flags = AVFMT_GENERIC_INDEX,
.codec_tag = (const AVCodecTag* const []){ ff_codec_bmp_tags, 0 },
};