Replace AVSubtitleRect.rgba_palette and bitmap by AVPicture.
[libav.git] / libavcodec / xsubdec.c
1 /*
2 * XSUB subtitle decoder
3 * Copyright (c) 2007 Reimar Döffinger
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 #include "avcodec.h"
22 #include "bitstream.h"
23 #include "bytestream.h"
24
25 static av_cold int decode_init(AVCodecContext *avctx) {
26 avctx->pix_fmt = PIX_FMT_PAL8;
27 return 0;
28 }
29
30 static const uint8_t tc_offsets[9] = { 0, 1, 3, 4, 6, 7, 9, 10, 11 };
31 static const uint8_t tc_muls[9] = { 10, 6, 10, 6, 10, 6, 10, 10, 1 };
32
33 static uint64_t parse_timecode(const uint8_t *buf) {
34 int i;
35 int64_t ms = 0;
36 if (buf[2] != ':' || buf[5] != ':' || buf[8] != '.')
37 return AV_NOPTS_VALUE;
38 for (i = 0; i < sizeof(tc_offsets); i++) {
39 uint8_t c = buf[tc_offsets[i]] - '0';
40 if (c > 9) return AV_NOPTS_VALUE;
41 ms = (ms + c) * tc_muls[i];
42 }
43 return ms;
44 }
45
46 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
47 const uint8_t *buf, int buf_size) {
48 AVSubtitle *sub = data;
49 const uint8_t *buf_end = buf + buf_size;
50 uint8_t *bitmap;
51 int w, h, x, y, rlelen, i;
52 GetBitContext gb;
53
54 // check that at least header fits
55 if (buf_size < 27 + 7 * 2 + 4 * 3) {
56 av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
57 return -1;
58 }
59
60 // read start and end time
61 if (buf[0] != '[' || buf[13] != '-' || buf[26] != ']') {
62 av_log(avctx, AV_LOG_ERROR, "invalid time code\n");
63 return -1;
64 }
65 sub->start_display_time = parse_timecode(buf + 1);
66 sub->end_display_time = parse_timecode(buf + 14);
67 buf += 27;
68
69 // read header
70 w = bytestream_get_le16(&buf);
71 h = bytestream_get_le16(&buf);
72 if (avcodec_check_dimensions(avctx, w, h) < 0)
73 return -1;
74 x = bytestream_get_le16(&buf);
75 y = bytestream_get_le16(&buf);
76 // skip bottom right position, it gives no new information
77 bytestream_get_le16(&buf);
78 bytestream_get_le16(&buf);
79 rlelen = bytestream_get_le16(&buf);
80
81 // allocate sub and set values
82 if (!sub->rects) {
83 sub->rects = av_mallocz(sizeof(*sub->rects));
84 sub->rects[0] = av_mallocz(sizeof(*sub->rects[0]));
85 sub->num_rects = 1;
86 }
87 av_freep(&sub->rects[0]->pict.data[0]);
88 sub->rects[0]->x = x; sub->rects[0]->y = y;
89 sub->rects[0]->w = w; sub->rects[0]->h = h;
90 sub->rects[0]->pict.linesize[0] = w;
91 sub->rects[0]->pict.data[0] = av_malloc(w * h);
92 sub->rects[0]->nb_colors = 4;
93 sub->rects[0]->pict.data[1] = av_malloc(sub->rects[0]->nb_colors * 4);
94
95 // read palette
96 for (i = 0; i < sub->rects[0]->nb_colors; i++)
97 ((uint32_t*)sub->rects[0]->pict.data[1])[i] = bytestream_get_be24(&buf);
98 // make all except background (first entry) non-transparent
99 for (i = 1; i < sub->rects[0]->nb_colors; i++)
100 ((uint32_t*)sub->rects[0]->pict.data[1])[i] |= 0xff000000;
101
102 // process RLE-compressed data
103 rlelen = FFMIN(rlelen, buf_end - buf);
104 init_get_bits(&gb, buf, rlelen * 8);
105 bitmap = sub->rects[0]->pict.data[0];
106 for (y = 0; y < h; y++) {
107 // interlaced: do odd lines
108 if (y == (h + 1) / 2) bitmap = sub->rects[0]->pict.data[0] + w;
109 for (x = 0; x < w; ) {
110 int log2 = ff_log2_tab[show_bits(&gb, 8)];
111 int run = get_bits(&gb, 14 - 4 * (log2 >> 1));
112 int color = get_bits(&gb, 2);
113 run = FFMIN(run, w - x);
114 // run length 0 means till end of row
115 if (!run) run = w - x;
116 memset(bitmap, color, run);
117 bitmap += run;
118 x += run;
119 }
120 // interlaced, skip every second line
121 bitmap += w;
122 align_get_bits(&gb);
123 }
124 *data_size = 1;
125 return buf_size;
126 }
127
128 AVCodec xsub_decoder = {
129 "xsub",
130 CODEC_TYPE_SUBTITLE,
131 CODEC_ID_XSUB,
132 0,
133 decode_init,
134 NULL,
135 NULL,
136 decode_frame,
137 .long_name = NULL_IF_CONFIG_SMALL("XSUB"),
138 };