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 };
int size
int size
Definition: avcodec.h:909
AVCodec.
Definition: avcodec.h:3189
static av_cold int ass_decode_init(AVCodecContext *avctx)
Definition: assdec.c:25
#define av_cold
Definition: attributes.h:71
int subtitle_header_size
Definition: avcodec.h:3075
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1387
const char data[16]
Definition: mxf.c:60
uint8_t * data
Definition: avcodec.h:908
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
void ff_ass_init(AVSubtitle *sub)
Initialize an AVSubtitle structure for use with ff_ass_add_rect().
Definition: ass.c:81
const char * name
Name of the codec implementation.
Definition: avcodec.h:3196
AVCodec ff_ass_decoder
Definition: assdec.c:55
static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *avpkt)
Definition: assdec.c:35
external API header
main external API structure.
Definition: avcodec.h:1329
int extradata_size
Definition: avcodec.h:1388
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:64
int len
int ff_ass_add_rect(AVSubtitle *sub, const char *dialog, int ts_start, int ts_end, int raw)
Add an ASS dialog line to an AVSubtitle as a new AVSubtitleRect.
Definition: ass.c:95
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:3074