Libav
assenc.c
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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 <string.h>
23 
24 #include "avcodec.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/internal.h"
27 #include "libavutil/mem.h"
28 
30 {
31  avctx->extradata = av_malloc(avctx->subtitle_header_size);
32  if (!avctx->extradata)
33  return AVERROR(ENOMEM);
34  memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size);
35  avctx->extradata_size = avctx->subtitle_header_size;
36  return 0;
37 }
38 
39 static int ass_encode_frame(AVCodecContext *avctx,
40  unsigned char *buf, int bufsize,
41  const AVSubtitle *sub)
42 {
43  int i, len, total_len = 0;
44 
45  for (i=0; i<sub->num_rects; i++) {
46  if (sub->rects[i]->type != SUBTITLE_ASS) {
47  av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");
48  return -1;
49  }
50 
51  len = av_strlcpy(buf+total_len, sub->rects[i]->ass, bufsize-total_len);
52 
53  if (len > bufsize-total_len-1) {
54  av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");
55  return -1;
56  }
57 
58  total_len += len;
59  }
60 
61  return total_len;
62 }
63 
65  .name = "ass",
66  .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
67  .type = AVMEDIA_TYPE_SUBTITLE,
68  .id = AV_CODEC_ID_SSA,
69  .init = ass_encode_init,
70  .encode_sub = ass_encode_frame,
71 };
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:62
memory handling functions
static int ass_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub)
Definition: assenc.c:39
unsigned num_rects
Definition: avcodec.h:3081
AVCodec.
Definition: avcodec.h:2790
AVSubtitleRect ** rects
Definition: avcodec.h:3082
#define av_cold
Definition: attributes.h:66
int subtitle_header_size
Definition: avcodec.h:2732
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1158
static av_cold int ass_encode_init(AVCodecContext *avctx)
Definition: assenc.c:29
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#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:150
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:168
const char * name
Name of the codec implementation.
Definition: avcodec.h:2797
size_t av_strlcpy(char *dst, const char *src, size_t size)
Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.
Definition: avstring.c:81
common internal API header
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1044
int extradata_size
Definition: avcodec.h:1159
Formatted text, the ass field must be set by the decoder and is authoritative.
Definition: avcodec.h:3047
int len
char * ass
0 terminated ASS/SSA compatible event line.
Definition: avcodec.h:3073
enum AVSubtitleType type
Definition: avcodec.h:3064
AVCodec ff_ass_encoder
Definition: assenc.c:64
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:2731