FFmpeg  4.0
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 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 <string.h>
23 
24 #include "avcodec.h"
25 #include "ass.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/mem.h"
28 
30 {
31  avctx->subtitle_header = av_malloc(avctx->extradata_size + 1);
32  if (!avctx->subtitle_header)
33  return AVERROR(ENOMEM);
34  memcpy(avctx->subtitle_header, avctx->extradata, avctx->extradata_size);
35  avctx->subtitle_header[avctx->extradata_size] = 0;
36  avctx->subtitle_header_size = avctx->extradata_size;
37  return 0;
38 }
39 
40 static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr,
41  AVPacket *avpkt)
42 {
43  AVSubtitle *sub = data;
44 
45  if (avpkt->size <= 0)
46  return avpkt->size;
47 
48  sub->rects = av_malloc(sizeof(*sub->rects));
49  if (!sub->rects)
50  return AVERROR(ENOMEM);
51  sub->rects[0] = av_mallocz(sizeof(*sub->rects[0]));
52  if (!sub->rects[0])
53  return AVERROR(ENOMEM);
54  sub->num_rects = 1;
55  sub->rects[0]->type = SUBTITLE_ASS;
56  sub->rects[0]->ass = av_strdup(avpkt->data);
57  if (!sub->rects[0]->ass)
58  return AVERROR(ENOMEM);
59  *got_sub_ptr = 1;
60  return avpkt->size;
61 }
62 
63 #if CONFIG_SSA_DECODER
65  .name = "ssa",
66  .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
67  .type = AVMEDIA_TYPE_SUBTITLE,
68  .id = AV_CODEC_ID_ASS,
69  .init = ass_decode_init,
70  .decode = ass_decode_frame,
71 };
72 #endif
73 
74 #if CONFIG_ASS_DECODER
76  .name = "ass",
77  .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
78  .type = AVMEDIA_TYPE_SUBTITLE,
79  .id = AV_CODEC_ID_ASS,
80  .init = ass_decode_init,
81  .decode = ass_decode_frame,
82 };
83 #endif
Memory handling functions.
int size
Definition: avcodec.h:1431
unsigned num_rects
Definition: avcodec.h:3864
AVCodec.
Definition: avcodec.h:3408
AVSubtitleRect ** rects
Definition: avcodec.h:3865
static av_cold int ass_decode_init(AVCodecContext *avctx)
Definition: assdec.c:29
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
int subtitle_header_size
Definition: avcodec.h:2986
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1618
const char data[16]
Definition: mxf.c:90
uint8_t * data
Definition: avcodec.h:1430
#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:186
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
const char * name
Name of the codec implementation.
Definition: avcodec.h:3415
common internal API header
static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *avpkt)
Definition: assdec.c:40
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:251
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1518
int extradata_size
Definition: avcodec.h:1619
AVCodec ff_ssa_decoder
AVCodec ff_ass_decoder
Formatted text, the ass field must be set by the decoder and is authoritative.
Definition: avcodec.h:3820
char * ass
0 terminated ASS/SSA compatible event line.
Definition: avcodec.h:3855
enum AVSubtitleType type
Definition: avcodec.h:3846
This structure stores compressed data.
Definition: avcodec.h:1407
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:2985