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/*
* Copyright (c) 2013 Matthew Heaney
*
* 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
*/
/**
* @file
* WebVTT subtitle muxer
* @see http://dev.w3.org/html5/webvtt/
*/
#include "avformat.h"
#include "internal.h"
#include "mux.h"
static void webvtt_write_time(AVIOContext *pb, int64_t millisec)
{
int64_t sec, min, hour;
sec = millisec / 1000;
millisec -= 1000 * sec;
min = sec / 60;
sec -= 60 * min;
hour = min / 60;
min -= 60 * hour;
if (hour > 0)
avio_printf(pb, "%02"PRId64":", hour);
avio_printf(pb, "%02"PRId64":%02"PRId64".%03"PRId64"", min, sec, millisec);
}
static int webvtt_write_header(AVFormatContext *ctx)
{
AVStream *s = ctx->streams[0];
AVCodecParameters *par = ctx->streams[0]->codecpar;
AVIOContext *pb = ctx->pb;
if (par->codec_id != AV_CODEC_ID_WEBVTT) {
av_log(ctx, AV_LOG_ERROR, "Exactly one WebVTT stream is needed.\n");
return AVERROR(EINVAL);
}
avpriv_set_pts_info(s, 64, 1, 1000);
avio_printf(pb, "WEBVTT\n");
return 0;
}
static int webvtt_write_packet(AVFormatContext *ctx, AVPacket *pkt)
{
AVIOContext *pb = ctx->pb;
size_t id_size, settings_size;
int id_size_int, settings_size_int;
uint8_t *id, *settings;
avio_printf(pb, "\n");
id = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_IDENTIFIER,
&id_size);
if (id_size > INT_MAX)
return AVERROR(EINVAL);
id_size_int = id_size;
if (id && id_size_int > 0)
avio_printf(pb, "%.*s\n", id_size_int, id);
webvtt_write_time(pb, pkt->pts);
avio_printf(pb, " --> ");
webvtt_write_time(pb, pkt->pts + pkt->duration);
settings = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_SETTINGS,
&settings_size);
if (settings_size > INT_MAX)
return AVERROR(EINVAL);
settings_size_int = settings_size;
if (settings && settings_size_int > 0)
avio_printf(pb, " %.*s", settings_size_int, settings);
avio_printf(pb, "\n");
avio_write(pb, pkt->data, pkt->size);
avio_printf(pb, "\n");
return 0;
}
const FFOutputFormat ff_webvtt_muxer = {
.p.name = "webvtt",
.p.long_name = NULL_IF_CONFIG_SMALL("WebVTT subtitle"),
.p.extensions = "vtt",
.p.mime_type = "text/vtt",
.p.flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
.p.video_codec = AV_CODEC_ID_NONE,
.p.audio_codec = AV_CODEC_ID_NONE,
.p.subtitle_codec = AV_CODEC_ID_WEBVTT,
.write_header = webvtt_write_header,
.write_packet = webvtt_write_packet,
.flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH,
};
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