1 /*
2 * SubRip subtitle 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 "libavutil/avstring.h"
23 #include "libavutil/common.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/parseutils.h"
26 #include "avcodec.h"
27 #include "ass.h"
28 #include "htmlsubtitles.h"
29
srt_to_ass(AVCodecContext * avctx,AVBPrint * dst,const char * in,int x1,int y1,int x2,int y2)30 static int srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,
31 const char *in, int x1, int y1, int x2, int y2)
32 {
33 if (x1 >= 0 && y1 >= 0) {
34 /* XXX: here we rescale coordinate assuming they are in DVD resolution
35 * (720x480) since we don't have anything better */
36
37 if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1) && x2 >= x1 && y2 >= y1) {
38 /* text rectangle defined, write the text at the center of the rectangle */
39 const int cx = x1 + (x2 - x1)/2;
40 const int cy = y1 + (y2 - y1)/2;
41 const int scaled_x = cx * (int64_t)ASS_DEFAULT_PLAYRESX / 720;
42 const int scaled_y = cy * (int64_t)ASS_DEFAULT_PLAYRESY / 480;
43 av_bprintf(dst, "{\\an5}{\\pos(%d,%d)}", scaled_x, scaled_y);
44 } else {
45 /* only the top left corner, assume the text starts in that corner */
46 const int scaled_x = x1 * (int64_t)ASS_DEFAULT_PLAYRESX / 720;
47 const int scaled_y = y1 * (int64_t)ASS_DEFAULT_PLAYRESY / 480;
48 av_bprintf(dst, "{\\an1}{\\pos(%d,%d)}", scaled_x, scaled_y);
49 }
50 }
51
52 return ff_htmlmarkup_to_ass(avctx, dst, in);
53 }
54
srt_decode_frame(AVCodecContext * avctx,void * data,int * got_sub_ptr,AVPacket * avpkt)55 static int srt_decode_frame(AVCodecContext *avctx,
56 void *data, int *got_sub_ptr, AVPacket *avpkt)
57 {
58 AVSubtitle *sub = data;
59 AVBPrint buffer;
60 int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
61 int ret;
62 buffer_size_t size;
63 const uint8_t *p = av_packet_get_side_data(avpkt, AV_PKT_DATA_SUBTITLE_POSITION, &size);
64 FFASSDecoderContext *s = avctx->priv_data;
65
66 if (p && size == 16) {
67 x1 = AV_RL32(p );
68 y1 = AV_RL32(p + 4);
69 x2 = AV_RL32(p + 8);
70 y2 = AV_RL32(p + 12);
71 }
72
73 if (avpkt->size <= 0)
74 return avpkt->size;
75
76 av_bprint_init(&buffer, 0, AV_BPRINT_SIZE_UNLIMITED);
77
78 ret = srt_to_ass(avctx, &buffer, avpkt->data, x1, y1, x2, y2);
79 if (ret >= 0)
80 ret = ff_ass_add_rect(sub, buffer.str, s->readorder++, 0, NULL, NULL);
81 av_bprint_finalize(&buffer, NULL);
82 if (ret < 0)
83 return ret;
84
85 *got_sub_ptr = sub->num_rects > 0;
86 return avpkt->size;
87 }
88
89 #if CONFIG_SRT_DECODER
90 /* deprecated decoder */
91 AVCodec ff_srt_decoder = {
92 .name = "srt",
93 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
94 .type = AVMEDIA_TYPE_SUBTITLE,
95 .id = AV_CODEC_ID_SUBRIP,
96 .init = ff_ass_subtitle_header_default,
97 .decode = srt_decode_frame,
98 .flush = ff_ass_decoder_flush,
99 .priv_data_size = sizeof(FFASSDecoderContext),
100 };
101 #endif
102
103 #if CONFIG_SUBRIP_DECODER
104 AVCodec ff_subrip_decoder = {
105 .name = "subrip",
106 .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
107 .type = AVMEDIA_TYPE_SUBTITLE,
108 .id = AV_CODEC_ID_SUBRIP,
109 .init = ff_ass_subtitle_header_default,
110 .decode = srt_decode_frame,
111 .flush = ff_ass_decoder_flush,
112 .priv_data_size = sizeof(FFASSDecoderContext),
113 };
114 #endif
115