xref: /third_party/ffmpeg/libavcodec/assdec.c (revision cabdff1a)
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 "codec_internal.h"
27#include "config_components.h"
28#include "libavutil/internal.h"
29#include "libavutil/mem.h"
30
31static av_cold int ass_decode_init(AVCodecContext *avctx)
32{
33    avctx->subtitle_header = av_malloc(avctx->extradata_size + 1);
34    if (!avctx->subtitle_header)
35        return AVERROR(ENOMEM);
36    if (avctx->extradata_size)
37        memcpy(avctx->subtitle_header, avctx->extradata, avctx->extradata_size);
38    avctx->subtitle_header[avctx->extradata_size] = 0;
39    avctx->subtitle_header_size = avctx->extradata_size;
40    return 0;
41}
42
43static int ass_decode_frame(AVCodecContext *avctx, AVSubtitle *sub,
44                            int *got_sub_ptr, const AVPacket *avpkt)
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
65const FFCodec ff_ssa_decoder = {
66    .p.name       = "ssa",
67    .p.long_name  = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
68    .p.type       = AVMEDIA_TYPE_SUBTITLE,
69    .p.id         = AV_CODEC_ID_ASS,
70    .init         = ass_decode_init,
71    FF_CODEC_DECODE_SUB_CB(ass_decode_frame),
72    .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
73};
74#endif
75
76#if CONFIG_ASS_DECODER
77const FFCodec ff_ass_decoder = {
78    .p.name       = "ass",
79    .p.long_name  = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
80    .p.type       = AVMEDIA_TYPE_SUBTITLE,
81    .p.id         = AV_CODEC_ID_ASS,
82    .init         = ass_decode_init,
83    FF_CODEC_DECODE_SUB_CB(ass_decode_frame),
84    .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
85};
86#endif
87