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/*
* On2 VP8 parser for Ogg
* Copyright (C) 2013 James Almer
*
* 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"
#include "oggdec.h"
#define VP8_HEADER_SIZE 26
static int vp8_header(AVFormatContext *s, int idx)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + idx;
uint8_t *p = os->buf + os->pstart;
AVStream *st = s->streams[idx];
AVRational framerate;
if (os->psize < 7 || p[0] != 0x4f)
return 0;
switch (p[5]){
case 0x01:
if (os->psize < VP8_HEADER_SIZE) {
av_log(s, AV_LOG_ERROR, "Invalid OggVP8 header packet");
return AVERROR_INVALIDDATA;
}
if (p[6] != 1) {
av_log(s, AV_LOG_WARNING,
"Unknown OggVP8 version %d.%d\n", p[6], p[7]);
return AVERROR_INVALIDDATA;
}
st->codecpar->width = AV_RB16(p + 8);
st->codecpar->height = AV_RB16(p + 10);
st->sample_aspect_ratio.num = AV_RB24(p + 12);
st->sample_aspect_ratio.den = AV_RB24(p + 15);
framerate.num = AV_RB32(p + 18);
framerate.den = AV_RB32(p + 22);
avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_VP8;
st->internal->need_parsing = AVSTREAM_PARSE_HEADERS;
break;
case 0x02:
if (p[6] != 0x20)
return AVERROR_INVALIDDATA;
ff_vorbis_stream_comment(s, st, p + 7, os->psize - 7);
break;
default:
av_log(s, AV_LOG_ERROR, "Unknown VP8 header type 0x%02X\n", p[5]);
return AVERROR_INVALIDDATA;
}
return 1;
}
static uint64_t vp8_gptopts(AVFormatContext *s, int idx,
uint64_t granule, int64_t *dts)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + idx;
int invcnt = !((granule >> 30) & 3);
// If page granule is that of an invisible vp8 frame, its pts will be
// that of the end of the next visible frame. We subtract 1 for those
// to prevent messing up pts calculations.
uint64_t pts = (granule >> 32) - invcnt;
uint32_t dist = (granule >> 3) & 0x07ffffff;
if (!dist)
os->pflags |= AV_PKT_FLAG_KEY;
if (dts)
*dts = pts;
return pts;
}
static int vp8_packet(AVFormatContext *s, int idx)
{
struct ogg *ogg = s->priv_data;
struct ogg_stream *os = ogg->streams + idx;
uint8_t *p = os->buf + os->pstart;
if ((!os->lastpts || os->lastpts == AV_NOPTS_VALUE) &&
!(os->flags & OGG_FLAG_EOS)) {
int seg;
int duration;
uint8_t *last_pkt = p;
uint8_t *next_pkt;
seg = os->segp;
duration = (last_pkt[0] >> 4) & 1;
next_pkt = last_pkt += os->psize;
for (; seg < os->nsegs; seg++) {
if (os->segments[seg] < 255) {
duration += (last_pkt[0] >> 4) & 1;
last_pkt = next_pkt + os->segments[seg];
}
next_pkt += os->segments[seg];
}
os->lastpts =
os->lastdts = vp8_gptopts(s, idx, os->granule, NULL) - duration;
if(s->streams[idx]->start_time == AV_NOPTS_VALUE) {
s->streams[idx]->start_time = os->lastpts;
if (s->streams[idx]->duration && s->streams[idx]->duration != AV_NOPTS_VALUE)
s->streams[idx]->duration -= s->streams[idx]->start_time;
}
}
if (os->psize > 0)
os->pduration = (p[0] >> 4) & 1;
return 0;
}
const struct ogg_codec ff_vp8_codec = {
.magic = "OVP80",
.magicsize = 5,
.header = vp8_header,
.packet = vp8_packet,
.gptopts = vp8_gptopts,
.nb_header = 1,
};
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