ffmpeg/libavformat/dfa.c

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/*
* Chronomaster DFA Format Demuxer
* Copyright (c) 2011 Konstantin Shishkov
*
* 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 dfa_probe(AVProbeData *p)
{
if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('D', 'F', 'I', 'A'))
return 0;
return AVPROBE_SCORE_MAX;
}
static int dfa_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
AVStream *st;
int frames;
int version;
uint32_t mspf;
if (avio_rl32(pb) != MKTAG('D', 'F', 'I', 'A')) {
av_log(s, AV_LOG_ERROR, "Invalid magic for DFA\n");
return AVERROR_INVALIDDATA;
}
version = avio_rl16(pb);
frames = avio_rl16(pb);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
st->codec->codec_id = AV_CODEC_ID_DFA;
st->codec->width = avio_rl16(pb);
st->codec->height = avio_rl16(pb);
mspf = avio_rl32(pb);
if (!mspf) {
av_log(s, AV_LOG_WARNING, "Zero FPS reported, defaulting to 10\n");
mspf = 100;
}
avpriv_set_pts_info(st, 24, mspf, 1000);
avio_skip(pb, 128 - 16); // padding
st->duration = frames;
if (ff_alloc_extradata(st->codec, 2))
return AVERROR(ENOMEM);
AV_WL16(st->codec->extradata, version);
if (version == 0x100)
st->sample_aspect_ratio = (AVRational){2, 1};
return 0;
}
static int dfa_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
uint32_t frame_size;
int ret, first = 1;
if (pb->eof_reached)
return AVERROR_EOF;
if (av_get_packet(pb, pkt, 12) != 12)
return AVERROR(EIO);
while (!pb->eof_reached) {
if (!first) {
ret = av_append_packet(pb, pkt, 12);
if (ret < 0) {
av_free_packet(pkt);
return ret;
}
} else
first = 0;
frame_size = AV_RL32(pkt->data + pkt->size - 8);
if (frame_size > INT_MAX - 4) {
av_log(s, AV_LOG_ERROR, "Too large chunk size: %d\n", frame_size);
return AVERROR(EIO);
}
if (AV_RL32(pkt->data + pkt->size - 12) == MKTAG('E', 'O', 'F', 'R')) {
if (frame_size) {
av_log(s, AV_LOG_WARNING, "skipping %d bytes of end-of-frame marker chunk\n",
frame_size);
avio_skip(pb, frame_size);
}
return 0;
}
ret = av_append_packet(pb, pkt, frame_size);
if (ret < 0) {
av_free_packet(pkt);
return ret;
}
}
return 0;
}
AVInputFormat ff_dfa_demuxer = {
.name = "dfa",
.long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
.read_probe = dfa_probe,
.read_header = dfa_read_header,
.read_packet = dfa_read_packet,
.flags = AVFMT_GENERIC_INDEX,
};