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FFmpeg/libavformat/ivfdec.c
Andreas Rheinhardt b800327f4c avformat/avformat: Add FFInputFormat, hide internals of AVInputFormat
This commit does for AVInputFormat what commit
59c9dc82f4 did for AVOutputFormat:
It adds a new type FFInputFormat, moves all the internals
of AVInputFormat to it and adds a now reduced AVInputFormat
as first member.

This does not affect/improve extensibility of both public
or private fields for demuxers (it is still a mess due to lavd).

This is possible since 50f34172e0
(which removed the last usage of an internal field of AVInputFormat
in fftools).

(Hint: tools/probetest.c accesses the internals of FFInputFormat
as well, but given that it is a testing tool this is not considered
a problem.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-07 08:53:31 -03:00

101 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 "demux.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 FFInputFormat ff_ivf_demuxer = {
.p.name = "ivf",
.p.long_name = NULL_IF_CONFIG_SMALL("On2 IVF"),
.p.flags = AVFMT_GENERIC_INDEX,
.p.codec_tag = (const AVCodecTag* const []){ ff_codec_bmp_tags, 0 },
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
};