assdec.c
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1 /*
2  * SSA/ASS decoder
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 "ass.h"
24 
26 {
27  avctx->subtitle_header = av_malloc(avctx->extradata_size);
28  if (!avctx->extradata)
29  return AVERROR(ENOMEM);
30  memcpy(avctx->subtitle_header, avctx->extradata, avctx->extradata_size);
31  avctx->subtitle_header_size = avctx->extradata_size;
32  return 0;
33 }
34 
35 static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr,
36  AVPacket *avpkt)
37 {
38  const char *ptr = avpkt->data;
39  int len, size = avpkt->size;
40 
41  ff_ass_init(data);
42 
43  while (size > 0) {
44  len = ff_ass_add_rect(data, ptr, 0, 0/* FIXME: duration */, 1);
45  if (len < 0)
46  return len;
47  ptr += len;
48  size -= len;
49  }
50 
51  *got_sub_ptr = avpkt->size > 0;
52  return avpkt->size;
53 }
54 
56  .name = "ass",
57  .long_name = NULL_IF_CONFIG_SMALL("Advanced SubStation Alpha subtitle"),
58  .type = AVMEDIA_TYPE_SUBTITLE,
59  .id = CODEC_ID_SSA,
60  .init = ass_decode_init,
61  .decode = ass_decode_frame,
62 };