assenc.c
Go to the documentation of this file.
1 /*
2  * SSA/ASS encoder
3  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "avcodec.h"
23 #include "libavutil/avstring.h"
24 
26 {
27  avctx->extradata = av_malloc(avctx->subtitle_header_size);
28  if (!avctx->extradata)
29  return AVERROR(ENOMEM);
30  memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size);
31  avctx->extradata_size = avctx->subtitle_header_size;
32  return 0;
33 }
34 
35 static int ass_encode_frame(AVCodecContext *avctx,
36  unsigned char *buf, int bufsize, void *data)
37 {
38  AVSubtitle *sub = data;
39  int i, len, total_len = 0;
40 
41  for (i=0; i<sub->num_rects; i++) {
42  if (sub->rects[i]->type != SUBTITLE_ASS) {
43  av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
44  return -1;
45  }
46 
47  len = av_strlcpy(buf+total_len, sub->rects[i]->ass, bufsize-total_len);
48 
49  if (len > bufsize-total_len-1) {
50  av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
51  return -1;
52  }
53 
54  total_len += len;
55  }
56 
57  return total_len;
58 }
59 
61  .name = "ass",
62  .long_name = NULL_IF_CONFIG_SMALL("Advanced SubStation Alpha subtitle"),
63  .type = AVMEDIA_TYPE_SUBTITLE,
64  .id = CODEC_ID_SSA,
65  .init = ass_encode_init,
66  .encode = ass_encode_frame,
67 };