yading@11: /*
yading@11:  * SubRip subtitle muxer
yading@11:  * Copyright (c) 2012  Nicolas George <nicolas.george@normalesup.org>
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "libavutil/log.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: 
yading@11: /* TODO: add options for:
yading@11:    - character encoding;
yading@11:    - LF / CRLF;
yading@11:    - byte order mark.
yading@11:  */
yading@11: 
yading@11: typedef struct SRTContext{
yading@11:     unsigned index;
yading@11: } SRTContext;
yading@11: 
yading@11: static int srt_write_header(AVFormatContext *avf)
yading@11: {
yading@11:     SRTContext *srt = avf->priv_data;
yading@11: 
yading@11:     if (avf->nb_streams != 1 ||
yading@11:         avf->streams[0]->codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
yading@11:         av_log(avf, AV_LOG_ERROR,
yading@11:                "SRT supports only a single subtitles stream.\n");
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11:     if (avf->streams[0]->codec->codec_id != AV_CODEC_ID_TEXT &&
yading@11:         avf->streams[0]->codec->codec_id != AV_CODEC_ID_SUBRIP &&
yading@11:         avf->streams[0]->codec->codec_id != AV_CODEC_ID_SRT) {
yading@11:         av_log(avf, AV_LOG_ERROR,
yading@11:                "Unsupported subtitles codec: %s\n",
yading@11:                avcodec_get_name(avf->streams[0]->codec->codec_id));
yading@11:         return AVERROR(EINVAL);
yading@11:     }
yading@11:     avpriv_set_pts_info(avf->streams[0], 64, 1, 1000);
yading@11:     srt->index = 1;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int srt_write_packet(AVFormatContext *avf, AVPacket *pkt)
yading@11: {
yading@11:     SRTContext *srt = avf->priv_data;
yading@11:     int write_ts = avf->streams[0]->codec->codec_id != AV_CODEC_ID_SRT;
yading@11: 
yading@11:     if (write_ts) {
yading@11:         int64_t s = pkt->pts, e, d = pkt->duration;
yading@11:         int size, x1 = -1, y1 = -1, x2 = -1, y2 = -1;
yading@11:         const uint8_t *p;
yading@11: 
yading@11:         p = av_packet_get_side_data(pkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);
yading@11:         if (p && size == 16) {
yading@11:             x1 = AV_RL32(p     );
yading@11:             y1 = AV_RL32(p +  4);
yading@11:             x2 = AV_RL32(p +  8);
yading@11:             y2 = AV_RL32(p + 12);
yading@11:         }
yading@11: 
yading@11:         if (d <= 0)
yading@11:             /* For backward compatibility, fallback to convergence_duration. */
yading@11:             d = pkt->convergence_duration;
yading@11:         if (s == AV_NOPTS_VALUE || d < 0) {
yading@11:             av_log(avf, AV_LOG_WARNING,
yading@11:                    "Insufficient timestamps in event number %d.\n", srt->index);
yading@11:             return 0;
yading@11:         }
yading@11:         e = s + d;
yading@11:         avio_printf(avf->pb, "%d\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d",
yading@11:                        srt->index,
yading@11:                        (int)(s / 3600000),      (int)(s / 60000) % 60,
yading@11:                        (int)(s /    1000) % 60, (int)(s %  1000),
yading@11:                        (int)(e / 3600000),      (int)(e / 60000) % 60,
yading@11:                        (int)(e /    1000) % 60, (int)(e %  1000));
yading@11:         if (p)
yading@11:             avio_printf(avf->pb, "  X1:%03d X2:%03d Y1:%03d Y2:%03d",
yading@11:                         x1, x2, y1, y2);
yading@11:         avio_printf(avf->pb, "\n");
yading@11:     }
yading@11:     avio_write(avf->pb, pkt->data, pkt->size);
yading@11:     if (write_ts)
yading@11:         avio_write(avf->pb, "\n\n", 2);
yading@11:     srt->index++;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVOutputFormat ff_srt_muxer = {
yading@11:     .name           = "srt",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
yading@11:     .mime_type      = "application/x-subrip",
yading@11:     .extensions     = "srt",
yading@11:     .priv_data_size = sizeof(SRTContext),
yading@11:     .write_header   = srt_write_header,
yading@11:     .write_packet   = srt_write_packet,
yading@11:     .flags          = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
yading@11:     .subtitle_codec = AV_CODEC_ID_SUBRIP,
yading@11: };