1/*
2 * SSA/ASS muxer
3 * Copyright (c) 2008 Michael Niedermayer
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
25typedef struct ASSContext{
26    unsigned int extra_index;
27    int write_ts; // 0: ssa (timing in payload), 1: ass (matroska like)
28}ASSContext;
29
30static int write_header(AVFormatContext *s)
31{
32    ASSContext *ass = s->priv_data;
33    AVCodecContext *avctx= s->streams[0]->codec;
34    uint8_t *last= NULL;
35
36    if (s->nb_streams != 1 || (avctx->codec_id != AV_CODEC_ID_SSA &&
37                               avctx->codec_id != AV_CODEC_ID_ASS)) {
38        av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
39        return -1;
40    }
41    ass->write_ts = avctx->codec_id == AV_CODEC_ID_ASS;
42    avpriv_set_pts_info(s->streams[0], 64, 1, 100);
43
44    while(ass->extra_index < avctx->extradata_size){
45        uint8_t *p  = avctx->extradata + ass->extra_index;
46        uint8_t *end= strchr(p, '\n');
47        if(!end) end= avctx->extradata + avctx->extradata_size;
48        else     end++;
49
50        avio_write(s->pb, p, end-p);
51        ass->extra_index += end-p;
52
53        if(last && !memcmp(last, "[Events]", 8))
54            break;
55        last=p;
56    }
57
58    avio_flush(s->pb);
59
60    return 0;
61}
62
63static int write_packet(AVFormatContext *s, AVPacket *pkt)
64{
65    ASSContext *ass = s->priv_data;
66
67    if (ass->write_ts) {
68        long int layer;
69        char *p;
70        int64_t start = pkt->pts;
71        int64_t end   = start + pkt->duration;
72        int hh1, mm1, ss1, ms1;
73        int hh2, mm2, ss2, ms2;
74
75        p = pkt->data + strcspn(pkt->data, ",") + 1; // skip ReadOrder
76        layer = strtol(p, &p, 10);
77        if (*p == ',')
78            p++;
79        hh1 = (int)(start / 360000);    mm1 = (int)(start / 6000) % 60;
80        hh2 = (int)(end   / 360000);    mm2 = (int)(end   / 6000) % 60;
81        ss1 = (int)(start / 100) % 60;  ms1 = (int)(start % 100);
82        ss2 = (int)(end   / 100) % 60;  ms2 = (int)(end   % 100);
83        if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99;
84        if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99;
85        avio_printf(s->pb, "Dialogue: %ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s\r\n",
86                    layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, p);
87    } else {
88        avio_write(s->pb, pkt->data, pkt->size);
89    }
90
91    return 0;
92}
93
94static int write_trailer(AVFormatContext *s)
95{
96    ASSContext *ass = s->priv_data;
97    AVCodecContext *avctx= s->streams[0]->codec;
98
99    avio_write(s->pb, avctx->extradata      + ass->extra_index,
100                      avctx->extradata_size - ass->extra_index);
101
102    return 0;
103}
104
105AVOutputFormat ff_ass_muxer = {
106    .name           = "ass",
107    .long_name      = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
108    .mime_type      = "text/x-ssa",
109    .extensions     = "ass,ssa",
110    .priv_data_size = sizeof(ASSContext),
111    .subtitle_codec = AV_CODEC_ID_SSA,
112    .write_header   = write_header,
113    .write_packet   = write_packet,
114    .write_trailer  = write_trailer,
115    .flags          = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS | AVFMT_TS_NONSTRICT,
116};
117