| 1 | /* |
| 2 | * SubRip subtitle muxer |
| 3 | * Copyright (c) 2012 Nicolas George <nicolas.george@normalesup.org> |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | #include "avformat.h" |
| 23 | #include "internal.h" |
| 24 | #include "libavutil/log.h" |
| 25 | #include "libavutil/intreadwrite.h" |
| 26 | |
| 27 | /* TODO: add options for: |
| 28 | - character encoding; |
| 29 | - LF / CRLF; |
| 30 | - byte order mark. |
| 31 | */ |
| 32 | |
| 33 | typedef struct SRTContext{ |
| 34 | unsigned index; |
| 35 | } SRTContext; |
| 36 | |
| 37 | static int srt_write_header(AVFormatContext *avf) |
| 38 | { |
| 39 | SRTContext *srt = avf->priv_data; |
| 40 | |
| 41 | if (avf->nb_streams != 1 || |
| 42 | avf->streams[0]->codec->codec_type != AVMEDIA_TYPE_SUBTITLE) { |
| 43 | av_log(avf, AV_LOG_ERROR, |
| 44 | "SRT supports only a single subtitles stream.\n"); |
| 45 | return AVERROR(EINVAL); |
| 46 | } |
| 47 | if (avf->streams[0]->codec->codec_id != AV_CODEC_ID_TEXT && |
| 48 | avf->streams[0]->codec->codec_id != AV_CODEC_ID_SUBRIP) { |
| 49 | av_log(avf, AV_LOG_ERROR, |
| 50 | "Unsupported subtitles codec: %s\n", |
| 51 | avcodec_get_name(avf->streams[0]->codec->codec_id)); |
| 52 | return AVERROR(EINVAL); |
| 53 | } |
| 54 | avpriv_set_pts_info(avf->streams[0], 64, 1, 1000); |
| 55 | srt->index = 1; |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | static int srt_write_packet(AVFormatContext *avf, AVPacket *pkt) |
| 60 | { |
| 61 | SRTContext *srt = avf->priv_data; |
| 62 | |
| 63 | // TODO: reindent |
| 64 | int64_t s = pkt->pts, e, d = pkt->duration; |
| 65 | int size, x1 = -1, y1 = -1, x2 = -1, y2 = -1; |
| 66 | const uint8_t *p; |
| 67 | |
| 68 | p = av_packet_get_side_data(pkt, AV_PKT_DATA_SUBTITLE_POSITION, &size); |
| 69 | if (p && size == 16) { |
| 70 | x1 = AV_RL32(p ); |
| 71 | y1 = AV_RL32(p + 4); |
| 72 | x2 = AV_RL32(p + 8); |
| 73 | y2 = AV_RL32(p + 12); |
| 74 | } |
| 75 | |
| 76 | if (d <= 0) |
| 77 | /* For backward compatibility, fallback to convergence_duration. */ |
| 78 | d = pkt->convergence_duration; |
| 79 | if (s == AV_NOPTS_VALUE || d < 0) { |
| 80 | av_log(avf, AV_LOG_WARNING, |
| 81 | "Insufficient timestamps in event number %d.\n", srt->index); |
| 82 | return 0; |
| 83 | } |
| 84 | e = s + d; |
| 85 | avio_printf(avf->pb, "%d\n%02d:%02d:%02d,%03d --> %02d:%02d:%02d,%03d", |
| 86 | srt->index, |
| 87 | (int)(s / 3600000), (int)(s / 60000) % 60, |
| 88 | (int)(s / 1000) % 60, (int)(s % 1000), |
| 89 | (int)(e / 3600000), (int)(e / 60000) % 60, |
| 90 | (int)(e / 1000) % 60, (int)(e % 1000)); |
| 91 | if (p) |
| 92 | avio_printf(avf->pb, " X1:%03d X2:%03d Y1:%03d Y2:%03d", |
| 93 | x1, x2, y1, y2); |
| 94 | avio_printf(avf->pb, "\n"); |
| 95 | |
| 96 | avio_write(avf->pb, pkt->data, pkt->size); |
| 97 | avio_write(avf->pb, "\n\n", 2); |
| 98 | srt->index++; |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | AVOutputFormat ff_srt_muxer = { |
| 103 | .name = "srt", |
| 104 | .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"), |
| 105 | .mime_type = "application/x-subrip", |
| 106 | .extensions = "srt", |
| 107 | .priv_data_size = sizeof(SRTContext), |
| 108 | .write_header = srt_write_header, |
| 109 | .write_packet = srt_write_packet, |
| 110 | .flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT, |
| 111 | .subtitle_codec = AV_CODEC_ID_SUBRIP, |
| 112 | }; |