2 * DVD subtitle decoding for ffmpeg
3 * Copyright (c) 2005 Fabrice Bellard.
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "bitstream.h"
23 #include "colorspace.h"
28 static void yuv_a_to_rgba(const uint8_t *ycbcr, const uint8_t *alpha, uint32_t *rgba, int num_values)
30 uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
33 int r_add, g_add, b_add;
35 for (i = num_values; i > 0; i--) {
39 YUV_TO_RGB1_CCIR(cb, cr);
40 YUV_TO_RGB2_CCIR(r, g, b, y);
41 *rgba++ = (*alpha++ << 24) | (r << 16) | (g << 8) | b;
45 static int dvdsub_init_decoder(AVCodecContext *avctx)
50 static int decode_run_2bit(GetBitContext *gb, int *color)
55 for (t = 1; v < t && t <= 0x40; t <<= 2)
56 v = (v << 4) | get_bits(gb, 4);
58 if (v < 4) { /* Code for fill rest of line */
64 static int decode_run_8bit(GetBitContext *gb, int *color)
67 int has_run = get_bits1(gb);
69 *color = get_bits(gb, 8);
71 *color = get_bits(gb, 2);
74 len = get_bits(gb, 7);
80 len = get_bits(gb, 3) + 2;
86 static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
87 const uint8_t *buf, int start, int buf_size, int is_8bit)
94 bit_len = (buf_size - start) * 8;
95 init_get_bits(&gb, buf + start, bit_len);
101 if (get_bits_count(&gb) > bit_len)
104 len = decode_run_8bit(&gb, &color);
106 len = decode_run_2bit(&gb, &color);
107 len = FFMIN(len, w - x);
108 memset(d + x, color, len);
123 static void guess_palette(uint32_t *rgba_palette,
126 uint32_t subtitle_color)
128 uint8_t color_used[16];
129 int nb_opaque_colors, i, level, j, r, g, b;
131 for(i = 0; i < 4; i++)
134 memset(color_used, 0, 16);
135 nb_opaque_colors = 0;
136 for(i = 0; i < 4; i++) {
137 if (alpha[i] != 0 && !color_used[colormap[i]]) {
138 color_used[colormap[i]] = 1;
143 if (nb_opaque_colors == 0)
146 j = nb_opaque_colors;
147 memset(color_used, 0, 16);
148 for(i = 0; i < 4; i++) {
150 if (!color_used[colormap[i]]) {
151 level = (0xff * j) / nb_opaque_colors;
152 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
153 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
154 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
155 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
156 color_used[colormap[i]] = (i + 1);
159 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
160 ((alpha[i] * 17) << 24);
166 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
168 static int decode_dvd_subtitles(AVSubtitle *sub_header,
169 const uint8_t *buf, int buf_size)
171 int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
172 int big_offsets, offset_size, is_8bit = 0;
173 const uint8_t *yuv_palette = 0;
174 uint8_t colormap[4], alpha[256];
181 sub_header->rects = NULL;
182 sub_header->num_rects = 0;
183 sub_header->start_display_time = 0;
184 sub_header->end_display_time = 0;
186 if (AV_RB16(buf) == 0) { /* HD subpicture with 4-byte offsets */
196 cmd_pos = READ_OFFSET(buf + cmd_pos);
198 while ((cmd_pos + 2 + offset_size) < buf_size) {
199 date = AV_RB16(buf + cmd_pos);
200 next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
202 av_log(NULL, AV_LOG_INFO, "cmd_pos=0x%04x next=0x%04x date=%d\n",
203 cmd_pos, next_cmd_pos, date);
205 pos = cmd_pos + 2 + offset_size;
208 x1 = y1 = x2 = y2 = 0;
209 while (pos < buf_size) {
212 av_log(NULL, AV_LOG_INFO, "cmd=%02x\n", cmd);
216 /* menu subpicture */
221 sub_header->start_display_time = (date << 10) / 90;
225 sub_header->end_display_time = (date << 10) / 90;
229 if ((buf_size - pos) < 2)
231 colormap[3] = buf[pos] >> 4;
232 colormap[2] = buf[pos] & 0x0f;
233 colormap[1] = buf[pos + 1] >> 4;
234 colormap[0] = buf[pos + 1] & 0x0f;
239 if ((buf_size - pos) < 2)
241 alpha[3] = buf[pos] >> 4;
242 alpha[2] = buf[pos] & 0x0f;
243 alpha[1] = buf[pos + 1] >> 4;
244 alpha[0] = buf[pos + 1] & 0x0f;
247 av_log(NULL, AV_LOG_INFO, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
252 if ((buf_size - pos) < 6)
254 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
255 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
256 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
257 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
261 av_log(NULL, AV_LOG_INFO, "x1=%d x2=%d y1=%d y2=%d\n",
267 if ((buf_size - pos) < 4)
269 offset1 = AV_RB16(buf + pos);
270 offset2 = AV_RB16(buf + pos + 2);
272 av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
277 if ((buf_size - pos) < 8)
279 offset1 = AV_RB32(buf + pos);
280 offset2 = AV_RB32(buf + pos + 4);
282 av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
289 if ((buf_size - pos) < 768)
291 yuv_palette = buf + pos;
295 /* HD set contrast (alpha) */
296 if ((buf_size - pos) < 256)
298 for (i = 0; i < 256; i++)
299 alpha[i] = 0xFF - buf[pos+i];
307 av_log(NULL, AV_LOG_INFO, "unrecognised subpicture command 0x%x\n", cmd);
317 /* decode the bitmap */
324 if (w > 0 && h > 0) {
325 if (sub_header->rects != NULL) {
326 for (i = 0; i < sub_header->num_rects; i++) {
327 av_free(sub_header->rects[i].bitmap);
328 av_free(sub_header->rects[i].rgba_palette);
330 av_freep(&sub_header->rects);
331 sub_header->num_rects = 0;
334 bitmap = av_malloc(w * h);
335 sub_header->rects = av_mallocz(sizeof(AVSubtitleRect));
336 sub_header->num_rects = 1;
337 sub_header->rects[0].bitmap = bitmap;
338 decode_rle(bitmap, w * 2, w, (h + 1) / 2,
339 buf, offset1, buf_size, is_8bit);
340 decode_rle(bitmap + w, w * 2, w, h / 2,
341 buf, offset2, buf_size, is_8bit);
343 if (yuv_palette == 0)
345 sub_header->rects[0].rgba_palette = av_malloc(256 * 4);
346 sub_header->rects[0].nb_colors = 256;
347 yuv_a_to_rgba(yuv_palette, alpha, sub_header->rects[0].rgba_palette, 256);
349 sub_header->rects[0].rgba_palette = av_malloc(4 * 4);
350 sub_header->rects[0].nb_colors = 4;
351 guess_palette(sub_header->rects[0].rgba_palette,
352 colormap, alpha, 0xffff00);
354 sub_header->rects[0].x = x1;
355 sub_header->rects[0].y = y1;
356 sub_header->rects[0].w = w;
357 sub_header->rects[0].h = h;
358 sub_header->rects[0].linesize = w;
361 if (next_cmd_pos == cmd_pos)
363 cmd_pos = next_cmd_pos;
365 if (sub_header->num_rects > 0)
368 if (sub_header->rects != NULL) {
369 for (i = 0; i < sub_header->num_rects; i++) {
370 av_free(sub_header->rects[i].bitmap);
371 av_free(sub_header->rects[i].rgba_palette);
373 av_freep(&sub_header->rects);
374 sub_header->num_rects = 0;
379 static int is_transp(const uint8_t *buf, int pitch, int n,
380 const uint8_t *transp_color)
383 for(i = 0; i < n; i++) {
384 if (!transp_color[*buf])
391 /* return 0 if empty rectangle, 1 if non empty */
392 static int find_smallest_bounding_rectangle(AVSubtitle *s)
394 uint8_t transp_color[256];
395 int y1, y2, x1, x2, y, w, h, i;
398 if (s->num_rects == 0 || s->rects == NULL || s->rects[0].w <= 0 || s->rects[0].h <= 0)
401 memset(transp_color, 0, 256);
402 for(i = 0; i < s->rects[0].nb_colors; i++) {
403 if ((s->rects[0].rgba_palette[i] >> 24) == 0)
407 while (y1 < s->rects[0].h && is_transp(s->rects[0].bitmap + y1 * s->rects[0].linesize,
408 1, s->rects[0].w, transp_color))
410 if (y1 == s->rects[0].h) {
411 av_freep(&s->rects[0].bitmap);
412 s->rects[0].w = s->rects[0].h = 0;
416 y2 = s->rects[0].h - 1;
417 while (y2 > 0 && is_transp(s->rects[0].bitmap + y2 * s->rects[0].linesize, 1,
418 s->rects[0].w, transp_color))
421 while (x1 < (s->rects[0].w - 1) && is_transp(s->rects[0].bitmap + x1, s->rects[0].linesize,
422 s->rects[0].h, transp_color))
424 x2 = s->rects[0].w - 1;
425 while (x2 > 0 && is_transp(s->rects[0].bitmap + x2, s->rects[0].linesize, s->rects[0].h,
430 bitmap = av_malloc(w * h);
433 for(y = 0; y < h; y++) {
434 memcpy(bitmap + w * y, s->rects[0].bitmap + x1 + (y1 + y) * s->rects[0].linesize, w);
436 av_freep(&s->rects[0].bitmap);
437 s->rects[0].bitmap = bitmap;
438 s->rects[0].linesize = w;
446 static int dvdsub_close_decoder(AVCodecContext *avctx)
453 static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
454 uint32_t *rgba_palette)
459 f = fopen(filename, "w");
468 for(y = 0; y < h; y++) {
469 for(x = 0; x < w; x++) {
470 v = rgba_palette[bitmap[y * w + x]];
471 putc((v >> 16) & 0xff, f);
472 putc((v >> 8) & 0xff, f);
473 putc((v >> 0) & 0xff, f);
480 static int dvdsub_decode(AVCodecContext *avctx,
481 void *data, int *data_size,
482 uint8_t *buf, int buf_size)
484 AVSubtitle *sub = (void *)data;
487 is_menu = decode_dvd_subtitles(sub, buf, buf_size);
495 if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)
499 av_log(NULL, AV_LOG_INFO, "start=%d ms end =%d ms\n",
500 sub->start_display_time,
501 sub->end_display_time);
502 ppm_save("/tmp/a.ppm", sub->rects[0].bitmap,
503 sub->rects[0].w, sub->rects[0].h, sub->rects[0].rgba_palette);
510 AVCodec dvdsub_decoder = {
513 CODEC_ID_DVD_SUBTITLE,
517 dvdsub_close_decoder,