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assenc.c
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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 
25 typedef struct ASSContext{
26  unsigned int extra_index;
27  int write_ts; // 0: ssa (timing in payload), 1: ass (matroska like)
28 }ASSContext;
29 
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 
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 
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 
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,
116 };