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 "ass_split.h"
27#include "libavutil/internal.h"
28#include "libavutil/mem.h"
29
30static av_cold int ass_decode_init(AVCodecContext *avctx)
31{
32    avctx->subtitle_header = av_malloc(avctx->extradata_size + 1);
33    if (!avctx->subtitle_header)
34        return AVERROR(ENOMEM);
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    avctx->priv_data = ff_ass_split(avctx->extradata);
39    if(!avctx->priv_data)
40        return -1;
41    return 0;
42}
43
44static int ass_decode_close(AVCodecContext *avctx)
45{
46    ff_ass_split_free(avctx->priv_data);
47    avctx->priv_data = NULL;
48    return 0;
49}
50
51#if CONFIG_SSA_DECODER
52static int ssa_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr,
53                            AVPacket *avpkt)
54{
55    const char *ptr = avpkt->data;
56    int len, size = avpkt->size;
57
58    while (size > 0) {
59        int duration;
60        ASSDialog *dialog = ff_ass_split_dialog(avctx->priv_data, ptr, 0, NULL);
61        if (!dialog)
62            return AVERROR_INVALIDDATA;
63        duration = dialog->end - dialog->start;
64        len = ff_ass_add_rect(data, ptr, 0, duration, 1);
65        if (len < 0)
66            return len;
67        ptr  += len;
68        size -= len;
69    }
70
71    *got_sub_ptr = avpkt->size > 0;
72    return avpkt->size;
73}
74
75AVCodec ff_ssa_decoder = {
76    .name         = "ssa",
77    .long_name    = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
78    .type         = AVMEDIA_TYPE_SUBTITLE,
79    .id           = AV_CODEC_ID_SSA,
80    .init         = ass_decode_init,
81    .decode       = ssa_decode_frame,
82    .close        = ass_decode_close,
83};
84#endif
85
86#if CONFIG_ASS_DECODER
87static int ass_decode_frame(AVCodecContext *avctx, void *data, int *got_sub_ptr,
88                            AVPacket *avpkt)
89{
90    int ret;
91    AVSubtitle *sub = data;
92    const char *ptr = avpkt->data;
93    static const AVRational ass_tb = {1, 100};
94    const int ts_start    = av_rescale_q(avpkt->pts,      avctx->time_base, ass_tb);
95    const int ts_duration = av_rescale_q(avpkt->duration, avctx->time_base, ass_tb);
96
97    if (avpkt->size <= 0)
98        return avpkt->size;
99
100    ret = ff_ass_add_rect(sub, ptr, ts_start, ts_duration, 2);
101    if (ret < 0) {
102        if (ret == AVERROR_INVALIDDATA)
103            av_log(avctx, AV_LOG_ERROR, "Invalid ASS packet\n");
104        return ret;
105    }
106
107    *got_sub_ptr = avpkt->size > 0;
108    return avpkt->size;
109}
110
111AVCodec ff_ass_decoder = {
112    .name         = "ass",
113    .long_name    = NULL_IF_CONFIG_SMALL("ASS (Advanced SubStation Alpha) subtitle"),
114    .type         = AVMEDIA_TYPE_SUBTITLE,
115    .id           = AV_CODEC_ID_ASS,
116    .init         = ass_decode_init,
117    .decode       = ass_decode_frame,
118    .close        = ass_decode_close,
119};
120#endif
121