FFmpeg  4.4
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  if (avctx->extradata_size)
35  memcpy(avctx->subtitle_header, avctx->extradata, avctx->extradata_size);
36  avctx->subtitle_header[avctx->extradata_size] = 0;
37  avctx->subtitle_header_size = avctx->extradata_size;
38  return 0;
39 }
40 
41 static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr,
42  AVPacket *avpkt)
43 {
44  AVSubtitle *sub = data;
45 
46  if (avpkt->size <= 0)
47  return avpkt->size;
48 
49  sub->rects = av_malloc(sizeof(*sub->rects));
50  if (!sub->rects)
51  return AVERROR(ENOMEM);
52  sub->rects[0] = av_mallocz(sizeof(*sub->rects[0]));
53  if (!sub->rects[0])
54  return AVERROR(ENOMEM);
55  sub->num_rects = 1;
56  sub->rects[0]->type = SUBTITLE_ASS;
57  sub->rects[0]->ass = av_strdup(avpkt->data);
58  if (!sub->rects[0]->ass)
59  return AVERROR(ENOMEM);
60  *got_sub_ptr = 1;
61  return avpkt->size;
62 }
63 
64 #if CONFIG_SSA_DECODER
66  .name = "ssa",
67  .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
68  .type = AVMEDIA_TYPE_SUBTITLE,
69  .id = AV_CODEC_ID_ASS,
70  .init = ass_decode_init,
71  .decode = ass_decode_frame,
72 };
73 #endif
74 
75 #if CONFIG_ASS_DECODER
77  .name = "ass",
78  .long_name = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
79  .type = AVMEDIA_TYPE_SUBTITLE,
80  .id = AV_CODEC_ID_ASS,
81  .init = ass_decode_init,
82  .decode = ass_decode_frame,
83 };
84 #endif
AVCodec ff_ass_decoder
AVCodec ff_ssa_decoder
#define av_cold
Definition: attributes.h:88
Libavcodec external API header.
static float sub(float src0, float src1)
@ SUBTITLE_ASS
Formatted text, the ass field must be set by the decoder and is authoritative.
Definition: avcodec.h:2682
@ AV_CODEC_ID_ASS
Definition: codec_id.h:546
#define AVERROR(e)
Definition: error.h:43
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:237
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:253
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
static av_cold int ass_decode_init(AVCodecContext *avctx)
Definition: assdec.c:29
static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr, AVPacket *avpkt)
Definition: assdec.c:41
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
Memory handling functions.
const char data[16]
Definition: mxf.c:142
main external API structure.
Definition: avcodec.h:536
int subtitle_header_size
Definition: avcodec.h:2017
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:2016
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:637
int extradata_size
Definition: avcodec.h:638
AVCodec.
Definition: codec.h:197
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
#define av_malloc(s)