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/*
* webp muxer
* Copyright (c) 2014 Michael Niedermayer
*
* 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 "libavutil/opt.h"
#include "avformat.h"
#include "internal.h"
typedef struct WebpContext{
AVClass *class;
int frame_count;
AVPacket last_pkt;
int loop;
} WebpContext;
static int webp_write_header(AVFormatContext *s)
{
AVStream *st;
if (s->nb_streams != 1) {
av_log(s, AV_LOG_ERROR, "Only exactly 1 stream is supported\n");
return AVERROR(EINVAL);
}
st = s->streams[0];
if (st->codec->codec_id != AV_CODEC_ID_WEBP) {
av_log(s, AV_LOG_ERROR, "Only WebP is supported\n");
return AVERROR(EINVAL);
}
avpriv_set_pts_info(st, 24, 1, 1000);
avio_write(s->pb, "RIFF\0\0\0\0WEBP", 12);
return 0;
}
static int flush(AVFormatContext *s, int trailer, int64_t pts)
{
WebpContext *w = s->priv_data;
AVStream *st = s->streams[0];
if (w->last_pkt.size) {
int skip = 0;
if (AV_RL32(w->last_pkt.data) == AV_RL32("RIFF"))
skip = 12;
if (AV_RL32(w->last_pkt.data + skip) == AV_RL32("VP8X"))
skip += AV_RL32(w->last_pkt.data + skip + 4) + 8;
w->frame_count ++;
if (w->frame_count == 1 && !trailer) {
avio_write(s->pb, "VP8X", 4);
avio_wl32(s->pb, 10);
avio_w8(s->pb, 2+16);
avio_wl24(s->pb, 0);
avio_wl24(s->pb, st->codec->width - 1);
avio_wl24(s->pb, st->codec->height - 1);
avio_write(s->pb, "ANIM", 4);
avio_wl32(s->pb, 6);
avio_wl32(s->pb, 0xFFFFFFFF);
avio_wl16(s->pb, w->loop);
}
if (w->frame_count > trailer) {
avio_write(s->pb, "ANMF", 4);
avio_wl32(s->pb, 16 + w->last_pkt.size - skip);
avio_wl24(s->pb, 0);
avio_wl24(s->pb, 0);
avio_wl24(s->pb, st->codec->width - 1);
avio_wl24(s->pb, st->codec->height - 1);
if (w->last_pkt.pts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE) {
avio_wl24(s->pb, pts - w->last_pkt.pts);
} else
avio_wl24(s->pb, w->last_pkt.duration);
avio_w8(s->pb, 0);
}
avio_write(s->pb, w->last_pkt.data + skip, w->last_pkt.size - skip);
av_free_packet(&w->last_pkt);
}
return 0;
}
static int webp_write_packet(AVFormatContext *s, AVPacket *pkt)
{
WebpContext *w = s->priv_data;
int ret;
if ((ret = flush(s, 0, pkt->pts)) < 0)
return ret;
av_copy_packet(&w->last_pkt, pkt);
return 0;
}
static int webp_write_trailer(AVFormatContext *s)
{
unsigned filesize;
int ret;
if ((ret = flush(s, 1, AV_NOPTS_VALUE)) < 0)
return ret;
filesize = avio_tell(s->pb);
avio_seek(s->pb, 4, SEEK_SET);
avio_wl32(s->pb, filesize - 8);
return 0;
}
#define OFFSET(x) offsetof(WebpContext, x)
#define ENC AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "loop", "Number of times to loop the output: 0 - infinite loop", OFFSET(loop),
AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 65535, ENC },
{ NULL },
};
static const AVClass webp_muxer_class = {
.class_name = "WebP muxer",
.item_name = av_default_item_name,
.version = LIBAVUTIL_VERSION_INT,
.option = options,
};
AVOutputFormat ff_webp_muxer = {
.name = "webp",
.long_name = NULL_IF_CONFIG_SMALL("WebP"),
.extensions = "webp",
.priv_data_size = sizeof(WebpContext),
.video_codec = AV_CODEC_ID_WEBP,
.write_header = webp_write_header,
.write_packet = webp_write_packet,
.write_trailer = webp_write_trailer,
.priv_class = &webp_muxer_class,
.flags = AVFMT_VARIABLE_FPS,
};
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