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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"
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, "%"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];
AVCodecContext *avctx = ctx->streams[0]->codec;
AVIOContext *pb = ctx->pb;
if (ctx->nb_streams != 1 || avctx->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");
avio_flush(pb);
return 0;
}
static int webvtt_write_packet(AVFormatContext *ctx, AVPacket *pkt)
{
AVIOContext *pb = ctx->pb;
int id_size, settings_size;
uint8_t *id, *settings;
avio_printf(pb, "\n");
id = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_IDENTIFIER,
&id_size);
if (id && id_size > 0)
avio_printf(pb, "%.*s\n", id_size, 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 && settings_size > 0)
avio_printf(pb, " %.*s", settings_size, settings);
avio_printf(pb, "\n");
avio_write(pb, pkt->data, pkt->size);
avio_printf(pb, "\n");
return 0;
}
AVOutputFormat ff_webvtt_muxer = {
.name = "webvtt",
.long_name = NULL_IF_CONFIG_SMALL("WebVTT subtitle"),
.extensions = "vtt",
.mime_type = "text/vtt",
.flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
.subtitle_codec = AV_CODEC_ID_WEBVTT,
.write_header = webvtt_write_header,
.write_packet = webvtt_write_packet,
};
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