ffmpeg/libavformat/mods.c

101 lines
2.6 KiB
C

/*
* MODS demuxer
* Copyright (c) 2020 Paul B Mahol
*
* 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
static int mods_probe(const AVProbeData *p)
{
if (memcmp(p->buf, "MODSN3\x0a\x00", 8))
return 0;
if (AV_RB32(p->buf + 8) == 0)
return 0;
if (AV_RB32(p->buf + 12) == 0)
return 0;
if (AV_RB32(p->buf + 16) == 0)
return 0;
return AVPROBE_SCORE_MAX;
}
static int mods_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
AVRational fps;
int64_t pos;
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avio_skip(pb, 8);
st->nb_frames = avio_rl32(pb);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_MOBICLIP;
st->codecpar->width = avio_rl32(pb);
st->codecpar->height = avio_rl32(pb);
fps.num = avio_rl32(pb);
fps.den = 0x1000000;
avpriv_set_pts_info(st, 64, fps.den, fps.num);
avio_skip(pb, 16);
pos = avio_rl32(pb) + 4;
avio_seek(pb, pos, SEEK_SET);
pos = avio_rl32(pb);
avio_seek(pb, pos, SEEK_SET);
return 0;
}
static int mods_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
unsigned size;
int64_t pos;
int ret;
if (avio_feof(pb))
return AVERROR_EOF;
pos = avio_tell(pb);
size = avio_rl32(pb) >> 14;
ret = av_get_packet(pb, pkt, size);
pkt->pos = pos;
pkt->stream_index = 0;
pkt->flags |= AV_PKT_FLAG_KEY;
return ret;
}
AVInputFormat ff_mods_demuxer = {
.name = "mods",
.long_name = NULL_IF_CONFIG_SMALL("MobiClip MODS"),
.read_probe = mods_probe,
.read_header = mods_read_header,
.read_packet = mods_read_packet,
.extensions = "mods",
.flags = AVFMT_GENERIC_INDEX,
};