/*
  * 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, "%ld:", hour);
 
     avio_printf(pb, "%02ld:%02ld.%03ld", min, sec, millisec);
 }
 
 static int webvtt_write_header(AVFormatContext *ctx)
 {
     AVStream     *s = ctx->streams[0];
     AVIOContext *pb = ctx->pb;
 
     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",
     .subtitle_codec    = AV_CODEC_ID_WEBVTT,
     .write_header      = webvtt_write_header,
     .write_packet      = webvtt_write_packet,
 };