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
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 decode_run_2bit(GetBitContext *gb, int *color)
50 for (t = 1; v < t && t <= 0x40; t <<= 2)
51 v = (v << 4) | get_bits(gb, 4);
53 if (v < 4) { /* Code for fill rest of line */
59 static int decode_run_8bit(GetBitContext *gb, int *color)
62 int has_run = get_bits1(gb);
64 *color = get_bits(gb, 8);
66 *color = get_bits(gb, 2);
69 len = get_bits(gb, 7);
75 len = get_bits(gb, 3) + 2;
81 static int decode_rle(uint8_t *bitmap, int linesize, int w, int h,
82 const uint8_t *buf, int start, int buf_size, int is_8bit)
89 bit_len = (buf_size - start) * 8;
90 init_get_bits(&gb, buf + start, bit_len);
96 if (get_bits_count(&gb) > bit_len)
99 len = decode_run_8bit(&gb, &color);
101 len = decode_run_2bit(&gb, &color);
102 len = FFMIN(len, w - x);
103 memset(d + x, color, len);
118 static void guess_palette(uint32_t *rgba_palette,
121 uint32_t subtitle_color)
123 uint8_t color_used[16];
124 int nb_opaque_colors, i, level, j, r, g, b;
126 for(i = 0; i < 4; i++)
129 memset(color_used, 0, 16);
130 nb_opaque_colors = 0;
131 for(i = 0; i < 4; i++) {
132 if (alpha[i] != 0 && !color_used[colormap[i]]) {
133 color_used[colormap[i]] = 1;
138 if (nb_opaque_colors == 0)
141 j = nb_opaque_colors;
142 memset(color_used, 0, 16);
143 for(i = 0; i < 4; i++) {
145 if (!color_used[colormap[i]]) {
146 level = (0xff * j) / nb_opaque_colors;
147 r = (((subtitle_color >> 16) & 0xff) * level) >> 8;
148 g = (((subtitle_color >> 8) & 0xff) * level) >> 8;
149 b = (((subtitle_color >> 0) & 0xff) * level) >> 8;
150 rgba_palette[i] = b | (g << 8) | (r << 16) | ((alpha[i] * 17) << 24);
151 color_used[colormap[i]] = (i + 1);
154 rgba_palette[i] = (rgba_palette[color_used[colormap[i]] - 1] & 0x00ffffff) |
155 ((alpha[i] * 17) << 24);
161 #define READ_OFFSET(a) (big_offsets ? AV_RB32(a) : AV_RB16(a))
163 static int decode_dvd_subtitles(AVSubtitle *sub_header,
164 const uint8_t *buf, int buf_size)
166 int cmd_pos, pos, cmd, x1, y1, x2, y2, offset1, offset2, next_cmd_pos;
167 int big_offsets, offset_size, is_8bit = 0;
168 const uint8_t *yuv_palette = 0;
169 uint8_t colormap[4], alpha[256];
176 sub_header->rects = NULL;
177 sub_header->num_rects = 0;
178 sub_header->format = 0;
179 sub_header->start_display_time = 0;
180 sub_header->end_display_time = 0;
182 if (AV_RB16(buf) == 0) { /* HD subpicture with 4-byte offsets */
192 cmd_pos = READ_OFFSET(buf + cmd_pos);
194 while ((cmd_pos + 2 + offset_size) < buf_size) {
195 date = AV_RB16(buf + cmd_pos);
196 next_cmd_pos = READ_OFFSET(buf + cmd_pos + 2);
198 av_log(NULL, AV_LOG_INFO, "cmd_pos=0x%04x next=0x%04x date=%d\n",
199 cmd_pos, next_cmd_pos, date);
201 pos = cmd_pos + 2 + offset_size;
204 x1 = y1 = x2 = y2 = 0;
205 while (pos < buf_size) {
208 av_log(NULL, AV_LOG_INFO, "cmd=%02x\n", cmd);
212 /* menu subpicture */
217 sub_header->start_display_time = (date << 10) / 90;
221 sub_header->end_display_time = (date << 10) / 90;
225 if ((buf_size - pos) < 2)
227 colormap[3] = buf[pos] >> 4;
228 colormap[2] = buf[pos] & 0x0f;
229 colormap[1] = buf[pos + 1] >> 4;
230 colormap[0] = buf[pos + 1] & 0x0f;
235 if ((buf_size - pos) < 2)
237 alpha[3] = buf[pos] >> 4;
238 alpha[2] = buf[pos] & 0x0f;
239 alpha[1] = buf[pos + 1] >> 4;
240 alpha[0] = buf[pos + 1] & 0x0f;
243 av_log(NULL, AV_LOG_INFO, "alpha=%x%x%x%x\n", alpha[0],alpha[1],alpha[2],alpha[3]);
248 if ((buf_size - pos) < 6)
250 x1 = (buf[pos] << 4) | (buf[pos + 1] >> 4);
251 x2 = ((buf[pos + 1] & 0x0f) << 8) | buf[pos + 2];
252 y1 = (buf[pos + 3] << 4) | (buf[pos + 4] >> 4);
253 y2 = ((buf[pos + 4] & 0x0f) << 8) | buf[pos + 5];
257 av_log(NULL, AV_LOG_INFO, "x1=%d x2=%d y1=%d y2=%d\n",
263 if ((buf_size - pos) < 4)
265 offset1 = AV_RB16(buf + pos);
266 offset2 = AV_RB16(buf + pos + 2);
268 av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
273 if ((buf_size - pos) < 8)
275 offset1 = AV_RB32(buf + pos);
276 offset2 = AV_RB32(buf + pos + 4);
278 av_log(NULL, AV_LOG_INFO, "offset1=0x%04x offset2=0x%04x\n", offset1, offset2);
285 if ((buf_size - pos) < 768)
287 yuv_palette = buf + pos;
291 /* HD set contrast (alpha) */
292 if ((buf_size - pos) < 256)
294 for (i = 0; i < 256; i++)
295 alpha[i] = 0xFF - buf[pos+i];
303 av_log(NULL, AV_LOG_INFO, "unrecognised subpicture command 0x%x\n", cmd);
313 /* decode the bitmap */
320 if (w > 0 && h > 0) {
321 if (sub_header->rects != NULL) {
322 for (i = 0; i < sub_header->num_rects; i++) {
323 av_freep(&sub_header->rects[i]->pict.data[0]);
324 av_freep(&sub_header->rects[i]->pict.data[1]);
325 av_freep(&sub_header->rects[i]);
327 av_freep(&sub_header->rects);
328 sub_header->num_rects = 0;
331 bitmap = av_malloc(w * h);
332 sub_header->rects = av_mallocz(sizeof(*sub_header->rects));
333 sub_header->rects[0] = av_mallocz(sizeof(AVSubtitleRect));
334 sub_header->num_rects = 1;
335 sub_header->rects[0]->pict.data[0] = bitmap;
336 decode_rle(bitmap, w * 2, w, (h + 1) / 2,
337 buf, offset1, buf_size, is_8bit);
338 decode_rle(bitmap + w, w * 2, w, h / 2,
339 buf, offset2, buf_size, is_8bit);
341 if (yuv_palette == 0)
343 sub_header->rects[0]->pict.data[1] = av_malloc(256 * 4);
344 sub_header->rects[0]->nb_colors = 256;
345 yuv_a_to_rgba(yuv_palette, alpha, (uint32_t*)sub_header->rects[0]->pict.data[1], 256);
347 sub_header->rects[0]->pict.data[1] = av_malloc(4 * 4);
348 sub_header->rects[0]->nb_colors = 4;
349 guess_palette((uint32_t*)sub_header->rects[0]->pict.data[1],
350 colormap, alpha, 0xffff00);
352 sub_header->rects[0]->x = x1;
353 sub_header->rects[0]->y = y1;
354 sub_header->rects[0]->w = w;
355 sub_header->rects[0]->h = h;
356 sub_header->rects[0]->pict.linesize[0] = w;
359 if (next_cmd_pos == cmd_pos)
361 cmd_pos = next_cmd_pos;
363 if (sub_header->num_rects > 0)
366 if (sub_header->rects != NULL) {
367 for (i = 0; i < sub_header->num_rects; i++) {
368 av_freep(&sub_header->rects[i]->pict.data[0]);
369 av_freep(&sub_header->rects[i]->pict.data[1]);
370 av_freep(&sub_header->rects[i]);
372 av_freep(&sub_header->rects);
373 sub_header->num_rects = 0;
378 static int is_transp(const uint8_t *buf, int pitch, int n,
379 const uint8_t *transp_color)
382 for(i = 0; i < n; i++) {
383 if (!transp_color[*buf])
390 /* return 0 if empty rectangle, 1 if non empty */
391 static int find_smallest_bounding_rectangle(AVSubtitle *s)
393 uint8_t transp_color[256];
394 int y1, y2, x1, x2, y, w, h, i;
397 if (s->num_rects == 0 || s->rects == NULL || s->rects[0]->w <= 0 || s->rects[0]->h <= 0)
400 memset(transp_color, 0, 256);
401 for(i = 0; i < s->rects[0]->nb_colors; i++) {
402 if ((((uint32_t*)s->rects[0]->pict.data[1])[i] >> 24) == 0)
406 while (y1 < s->rects[0]->h && is_transp(s->rects[0]->pict.data[0] + y1 * s->rects[0]->pict.linesize[0],
407 1, s->rects[0]->w, transp_color))
409 if (y1 == s->rects[0]->h) {
410 av_freep(&s->rects[0]->pict.data[0]);
411 s->rects[0]->w = s->rects[0]->h = 0;
415 y2 = s->rects[0]->h - 1;
416 while (y2 > 0 && is_transp(s->rects[0]->pict.data[0] + y2 * s->rects[0]->pict.linesize[0], 1,
417 s->rects[0]->w, transp_color))
420 while (x1 < (s->rects[0]->w - 1) && is_transp(s->rects[0]->pict.data[0] + x1, s->rects[0]->pict.linesize[0],
421 s->rects[0]->h, transp_color))
423 x2 = s->rects[0]->w - 1;
424 while (x2 > 0 && is_transp(s->rects[0]->pict.data[0] + x2, s->rects[0]->pict.linesize[0], s->rects[0]->h,
429 bitmap = av_malloc(w * h);
432 for(y = 0; y < h; y++) {
433 memcpy(bitmap + w * y, s->rects[0]->pict.data[0] + x1 + (y1 + y) * s->rects[0]->pict.linesize[0], w);
435 av_freep(&s->rects[0]->pict.data[0]);
436 s->rects[0]->pict.data[0] = bitmap;
437 s->rects[0]->pict.linesize[0] = w;
440 s->rects[0]->x += x1;
441 s->rects[0]->y += y1;
449 static void ppm_save(const char *filename, uint8_t *bitmap, int w, int h,
450 uint32_t *rgba_palette)
455 f = fopen(filename, "w");
464 for(y = 0; y < h; y++) {
465 for(x = 0; x < w; x++) {
466 v = rgba_palette[bitmap[y * w + x]];
467 putc((v >> 16) & 0xff, f);
468 putc((v >> 8) & 0xff, f);
469 putc((v >> 0) & 0xff, f);
476 static int dvdsub_decode(AVCodecContext *avctx,
477 void *data, int *data_size,
480 const uint8_t *buf = avpkt->data;
481 int buf_size = avpkt->size;
482 AVSubtitle *sub = (void *)data;
485 is_menu = decode_dvd_subtitles(sub, buf, buf_size);
493 if (!is_menu && find_smallest_bounding_rectangle(sub) == 0)
497 av_log(NULL, AV_LOG_INFO, "start=%d ms end =%d ms\n",
498 sub->start_display_time,
499 sub->end_display_time);
500 ppm_save("/tmp/a.ppm", sub->rects[0]->pict.data[0],
501 sub->rects[0]->w, sub->rects[0]->h, sub->rects[0]->pict.data[1]);
508 AVCodec dvdsub_decoder = {
511 CODEC_ID_DVD_SUBTITLE,
517 .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),