diff options
Diffstat (limited to 'libavformat/srtenc.c')
| -rw-r--r-- | libavformat/srtenc.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/libavformat/srtenc.c b/libavformat/srtenc.c new file mode 100644 index 0000000..b43504b --- /dev/null +++ b/libavformat/srtenc.c @@ -0,0 +1,115 @@ +/* + * SubRip subtitle muxer + * Copyright (c) 2012 Nicolas George <nicolas.george@normalesup.org> + * + * 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 "avformat.h" +#include "internal.h" +#include "libavutil/log.h" +#include "libavutil/intreadwrite.h" + +/* TODO: add options for: + - character encoding; + - LF / CRLF; + - byte order mark. + */ + +typedef struct SRTContext{ + unsigned index; +} SRTContext; + +static int srt_write_header(AVFormatContext *avf) +{ + SRTContext *srt = avf->priv_data; + + if (avf->nb_streams != 1 || + avf->streams[0]->codec->codec_type != AVMEDIA_TYPE_SUBTITLE) { + av_log(avf, AV_LOG_ERROR, + "SRT supports only a single subtitles stream.\n"); + return AVERROR(EINVAL); + } + if (avf->streams[0]->codec->codec_id != AV_CODEC_ID_TEXT && + avf->streams[0]->codec->codec_id != AV_CODEC_ID_SUBRIP && + avf->streams[0]->codec->codec_id != AV_CODEC_ID_SRT) { + av_log(avf, AV_LOG_ERROR, + "Unsupported subtitles codec: %s\n", + avcodec_get_name(avf->streams[0]->codec->codec_id)); + return AVERROR(EINVAL); + } + avpriv_set_pts_info(avf->streams[0], 64, 1, 1000); + srt->index = 1; + return 0; +} + +static int srt_write_packet(AVFormatContext *avf, AVPacket *pkt) +{ + SRTContext *srt = avf->priv_data; + int write_ts = avf->streams[0]->codec->codec_id != AV_CODEC_ID_SRT; + + if (write_ts) { + int64_t s = pkt->pts, e, d = pkt->duration; + int size, x1 = -1, y1 = -1, x2 = -1, y2 = -1; + const uint8_t *p; + + p = av_packet_get_side_data(pkt, AV_PKT_DATA_SUBTITLE_POSITION, &size); + if (p && size == 16) { + x1 = AV_RL32(p ); + y1 = AV_RL32(p + 4); + x2 = AV_RL32(p + 8); + y2 = AV_RL32(p + 12); + } + + if (d <= 0) + /* For backward compatibility, fallback to convergence_duration. */ + d = pkt->convergence_duration; + if (s == AV_NOPTS_VALUE || d < 0) { + av_log(avf, AV_LOG_WARNING, + "Insufficient timestamps in event number %d.\n", srt->index); + return 0; + } + e = s + d; + avio_printf(avf->pb, "%d\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d", + srt->index, + (int)(s / 3600000), (int)(s / 60000) % 60, + (int)(s / 1000) % 60, (int)(s % 1000), + (int)(e / 3600000), (int)(e / 60000) % 60, + (int)(e / 1000) % 60, (int)(e % 1000)); + if (p) + avio_printf(avf->pb, " X1:%03d X2:%03d Y1:%03d Y2:%03d", + x1, x2, y1, y2); + avio_printf(avf->pb, "\n"); + } + avio_write(avf->pb, pkt->data, pkt->size); + if (write_ts) + avio_write(avf->pb, "\n\n", 2); + srt->index++; + return 0; +} + +AVOutputFormat ff_srt_muxer = { + .name = "srt", + .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"), + .mime_type = "application/x-subrip", + .extensions = "srt", + .priv_data_size = sizeof(SRTContext), + .write_header = srt_write_header, + .write_packet = srt_write_packet, + .flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT, + .subtitle_codec = AV_CODEC_ID_SUBRIP, +}; |
