Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / dvdsubenc.c
1 /*
2 * DVD subtitle encoding
3 * Copyright (c) 2005 Wolfram Gloger
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 "bytestream.h"
23 #include "internal.h"
24 #include "libavutil/avassert.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/imgutils.h"
27 #include "libavutil/opt.h"
28
29 typedef struct {
30 AVClass *class;
31 uint32_t global_palette[16];
32 int even_rows_fix;
33 } DVDSubtitleContext;
34
35 // ncnt is the nibble counter
36 #define PUTNIBBLE(val)\
37 do {\
38 if (ncnt++ & 1)\
39 *q++ = bitbuf | ((val) & 0x0f);\
40 else\
41 bitbuf = (val) << 4;\
42 } while(0)
43
44 static void dvd_encode_rle(uint8_t **pq,
45 const uint8_t *bitmap, int linesize,
46 int w, int h,
47 const int cmap[256])
48 {
49 uint8_t *q;
50 unsigned int bitbuf = 0;
51 int ncnt;
52 int x, y, len, color;
53
54 q = *pq;
55
56 for (y = 0; y < h; ++y) {
57 ncnt = 0;
58 for(x = 0; x < w; x += len) {
59 color = bitmap[x];
60 for (len=1; x+len < w; ++len)
61 if (bitmap[x+len] != color)
62 break;
63 color = cmap[color];
64 av_assert0(color < 4);
65 if (len < 0x04) {
66 PUTNIBBLE((len << 2)|color);
67 } else if (len < 0x10) {
68 PUTNIBBLE(len >> 2);
69 PUTNIBBLE((len << 2)|color);
70 } else if (len < 0x40) {
71 PUTNIBBLE(0);
72 PUTNIBBLE(len >> 2);
73 PUTNIBBLE((len << 2)|color);
74 } else if (x+len == w) {
75 PUTNIBBLE(0);
76 PUTNIBBLE(0);
77 PUTNIBBLE(0);
78 PUTNIBBLE(color);
79 } else {
80 if (len > 0xff)
81 len = 0xff;
82 PUTNIBBLE(0);
83 PUTNIBBLE(len >> 6);
84 PUTNIBBLE(len >> 2);
85 PUTNIBBLE((len << 2)|color);
86 }
87 }
88 /* end of line */
89 if (ncnt & 1)
90 PUTNIBBLE(0);
91 bitmap += linesize;
92 }
93
94 *pq = q;
95 }
96
97 static int color_distance(uint32_t a, uint32_t b)
98 {
99 int r = 0, d, i;
100 int alpha_a = 8, alpha_b = 8;
101
102 for (i = 24; i >= 0; i -= 8) {
103 d = alpha_a * (int)((a >> i) & 0xFF) -
104 alpha_b * (int)((b >> i) & 0xFF);
105 r += d * d;
106 alpha_a = a >> 28;
107 alpha_b = b >> 28;
108 }
109 return r;
110 }
111
112 /**
113 * Count colors used in a rectangle, quantizing alpha and grouping by
114 * nearest global palette entry.
115 */
116 static void count_colors(AVCodecContext *avctx, unsigned hits[33],
117 const AVSubtitleRect *r)
118 {
119 DVDSubtitleContext *dvdc = avctx->priv_data;
120 unsigned count[256] = { 0 };
121 uint32_t *palette = (uint32_t *)r->pict.data[1];
122 uint32_t color;
123 int x, y, i, j, match, d, best_d, av_uninit(best_j);
124 uint8_t *p = r->pict.data[0];
125
126 for (y = 0; y < r->h; y++) {
127 for (x = 0; x < r->w; x++)
128 count[*(p++)]++;
129 p += r->pict.linesize[0] - r->w;
130 }
131 for (i = 0; i < 256; i++) {
132 if (!count[i]) /* avoid useless search */
133 continue;
134 color = palette[i];
135 /* 0: transparent, 1-16: semi-transparent, 17-33 opaque */
136 match = color < 0x33000000 ? 0 : color < 0xCC000000 ? 1 : 17;
137 if (match) {
138 best_d = INT_MAX;
139 for (j = 0; j < 16; j++) {
140 d = color_distance(0xFF000000 | color,
141 0xFF000000 | dvdc->global_palette[j]);
142 if (d < best_d) {
143 best_d = d;
144 best_j = j;
145 }
146 }
147 match += best_j;
148 }
149 hits[match] += count[i];
150 }
151 }
152
153 static void select_palette(AVCodecContext *avctx, int out_palette[4],
154 int out_alpha[4], unsigned hits[33])
155 {
156 DVDSubtitleContext *dvdc = avctx->priv_data;
157 int i, j, bright, mult;
158 uint32_t color;
159 int selected[4] = { 0 };
160 uint32_t pseudopal[33] = { 0 };
161 uint32_t refcolor[3] = { 0x00000000, 0xFFFFFFFF, 0xFF000000 };
162
163 /* Bonus for transparent: if the rectangle fits tightly the text, the
164 background color can be quite rare, but it would be ugly without it */
165 hits[0] *= 16;
166 /* Bonus for bright colors */
167 for (i = 0; i < 16; i++) {
168 if (!(hits[1 + i] + hits[17 + i]))
169 continue; /* skip unused colors to gain time */
170 color = dvdc->global_palette[i];
171 bright = 0;
172 for (j = 0; j < 3; j++, color >>= 8)
173 bright += (color & 0xFF) < 0x40 || (color & 0xFF) >= 0xC0;
174 mult = 2 + FFMIN(bright, 2);
175 hits[ 1 + i] *= mult;
176 hits[17 + i] *= mult;
177 }
178
179 /* Select four most frequent colors */
180 for (i = 0; i < 4; i++) {
181 for (j = 0; j < 33; j++)
182 if (hits[j] > hits[selected[i]])
183 selected[i] = j;
184 hits[selected[i]] = 0;
185 }
186
187 /* Order the colors like in most DVDs:
188 0: background, 1: foreground, 2: outline */
189 for (i = 0; i < 16; i++) {
190 pseudopal[ 1 + i] = 0x80000000 | dvdc->global_palette[i];
191 pseudopal[17 + i] = 0xFF000000 | dvdc->global_palette[i];
192 }
193 for (i = 0; i < 3; i++) {
194 int best_d = color_distance(refcolor[i], pseudopal[selected[i]]);
195 for (j = i + 1; j < 4; j++) {
196 int d = color_distance(refcolor[i], pseudopal[selected[j]]);
197 if (d < best_d) {
198 FFSWAP(int, selected[i], selected[j]);
199 best_d = d;
200 }
201 }
202 }
203
204 /* Output */
205 for (i = 0; i < 4; i++) {
206 out_palette[i] = selected[i] ? (selected[i] - 1) & 0xF : 0;
207 out_alpha [i] = !selected[i] ? 0 : selected[i] < 17 ? 0x80 : 0xFF;
208 }
209 }
210
211 static void build_color_map(AVCodecContext *avctx, int cmap[],
212 const uint32_t palette[],
213 const int out_palette[], unsigned int const out_alpha[])
214 {
215 DVDSubtitleContext *dvdc = avctx->priv_data;
216 int i, j, d, best_d;
217 uint32_t pseudopal[4];
218
219 for (i = 0; i < 4; i++)
220 pseudopal[i] = (out_alpha[i] << 24) |
221 dvdc->global_palette[out_palette[i]];
222 for (i = 0; i < 256; i++) {
223 best_d = INT_MAX;
224 for (j = 0; j < 4; j++) {
225 d = color_distance(pseudopal[j], palette[i]);
226 if (d < best_d) {
227 cmap[i] = j;
228 best_d = d;
229 }
230 }
231 }
232 }
233
234 static void copy_rectangle(AVSubtitleRect *dst, AVSubtitleRect *src, int cmap[])
235 {
236 int x, y;
237 uint8_t *p, *q;
238
239 p = src->pict.data[0];
240 q = dst->pict.data[0] + (src->x - dst->x) +
241 (src->y - dst->y) * dst->pict.linesize[0];
242 for (y = 0; y < src->h; y++) {
243 for (x = 0; x < src->w; x++)
244 *(q++) = cmap[*(p++)];
245 p += src->pict.linesize[0] - src->w;
246 q += dst->pict.linesize[0] - src->w;
247 }
248 }
249
250 static int encode_dvd_subtitles(AVCodecContext *avctx,
251 uint8_t *outbuf, int outbuf_size,
252 const AVSubtitle *h)
253 {
254 DVDSubtitleContext *dvdc = avctx->priv_data;
255 uint8_t *q, *qq;
256 int offset1, offset2;
257 int i, rects = h->num_rects, ret;
258 unsigned global_palette_hits[33] = { 0 };
259 int cmap[256];
260 int out_palette[4];
261 int out_alpha[4];
262 AVSubtitleRect vrect;
263 uint8_t *vrect_data = NULL;
264 int x2, y2;
265 int forced = 0;
266
267 if (rects == 0 || !h->rects)
268 return AVERROR(EINVAL);
269 for (i = 0; i < rects; i++)
270 if (h->rects[i]->type != SUBTITLE_BITMAP) {
271 av_log(avctx, AV_LOG_ERROR, "Bitmap subtitle required\n");
272 return AVERROR(EINVAL);
273 }
274 /* Mark this subtitle forced if any of the rectangles is forced. */
275 for (i = 0; i < rects; i++)
276 if ((h->rects[i]->flags & AV_SUBTITLE_FLAG_FORCED) != 0) {
277 forced = 1;
278 break;
279 }
280 vrect = *h->rects[0];
281
282 if (rects > 1) {
283 /* DVD subtitles can have only one rectangle: build a virtual
284 rectangle containing all actual rectangles.
285 The data of the rectangles will be copied later, when the palette
286 is decided, because the rectangles may have different palettes. */
287 int xmin = h->rects[0]->x, xmax = xmin + h->rects[0]->w;
288 int ymin = h->rects[0]->y, ymax = ymin + h->rects[0]->h;
289 for (i = 1; i < rects; i++) {
290 xmin = FFMIN(xmin, h->rects[i]->x);
291 ymin = FFMIN(ymin, h->rects[i]->y);
292 xmax = FFMAX(xmax, h->rects[i]->x + h->rects[i]->w);
293 ymax = FFMAX(ymax, h->rects[i]->y + h->rects[i]->h);
294 }
295 vrect.x = xmin;
296 vrect.y = ymin;
297 vrect.w = xmax - xmin;
298 vrect.h = ymax - ymin;
299 if ((ret = av_image_check_size(vrect.w, vrect.h, 0, avctx)) < 0)
300 return ret;
301
302 /* Count pixels outside the virtual rectangle as transparent */
303 global_palette_hits[0] = vrect.w * vrect.h;
304 for (i = 0; i < rects; i++)
305 global_palette_hits[0] -= h->rects[i]->w * h->rects[i]->h;
306 }
307
308 for (i = 0; i < rects; i++)
309 count_colors(avctx, global_palette_hits, h->rects[i]);
310 select_palette(avctx, out_palette, out_alpha, global_palette_hits);
311
312 if (rects > 1) {
313 if (!(vrect_data = av_calloc(vrect.w, vrect.h)))
314 return AVERROR(ENOMEM);
315 vrect.pict.data [0] = vrect_data;
316 vrect.pict.linesize[0] = vrect.w;
317 for (i = 0; i < rects; i++) {
318 build_color_map(avctx, cmap, (uint32_t *)h->rects[i]->pict.data[1],
319 out_palette, out_alpha);
320 copy_rectangle(&vrect, h->rects[i], cmap);
321 }
322 for (i = 0; i < 4; i++)
323 cmap[i] = i;
324 } else {
325 build_color_map(avctx, cmap, (uint32_t *)h->rects[0]->pict.data[1],
326 out_palette, out_alpha);
327 }
328
329 av_log(avctx, AV_LOG_DEBUG, "Selected palette:");
330 for (i = 0; i < 4; i++)
331 av_log(avctx, AV_LOG_DEBUG, " 0x%06x@@%02x (0x%x,0x%x)",
332 dvdc->global_palette[out_palette[i]], out_alpha[i],
333 out_palette[i], out_alpha[i] >> 4);
334 av_log(avctx, AV_LOG_DEBUG, "\n");
335
336 // encode data block
337 q = outbuf + 4;
338 offset1 = q - outbuf;
339 // worst case memory requirement: 1 nibble per pixel..
340 if ((q - outbuf) + vrect.w * vrect.h / 2 + 17 + 21 > outbuf_size) {
341 av_log(NULL, AV_LOG_ERROR, "dvd_subtitle too big\n");
342 ret = AVERROR_BUFFER_TOO_SMALL;
343 goto fail;
344 }
345 dvd_encode_rle(&q, vrect.pict.data[0], vrect.w * 2,
346 vrect.w, (vrect.h + 1) >> 1, cmap);
347 offset2 = q - outbuf;
348 dvd_encode_rle(&q, vrect.pict.data[0] + vrect.w, vrect.w * 2,
349 vrect.w, vrect.h >> 1, cmap);
350
351 if (dvdc->even_rows_fix && (vrect.h & 1)) {
352 // Work-around for some players that want the height to be even.
353 vrect.h++;
354 *q++ = 0x00; // 0x00 0x00 == empty row, i.e. fully transparent
355 *q++ = 0x00;
356 }
357
358 // set data packet size
359 qq = outbuf + 2;
360 bytestream_put_be16(&qq, q - outbuf);
361
362 // send start display command
363 bytestream_put_be16(&q, (h->start_display_time*90) >> 10);
364 bytestream_put_be16(&q, (q - outbuf) /*- 2 */ + 8 + 12 + 2);
365 *q++ = 0x03; // palette - 4 nibbles
366 *q++ = (out_palette[3] << 4) | out_palette[2];
367 *q++ = (out_palette[1] << 4) | out_palette[0];
368 *q++ = 0x04; // alpha - 4 nibbles
369 *q++ = (out_alpha[3] & 0xF0) | (out_alpha[2] >> 4);
370 *q++ = (out_alpha[1] & 0xF0) | (out_alpha[0] >> 4);
371
372 // 12 bytes per rect
373 x2 = vrect.x + vrect.w - 1;
374 y2 = vrect.y + vrect.h - 1;
375
376 *q++ = 0x05;
377 // x1 x2 -> 6 nibbles
378 *q++ = vrect.x >> 4;
379 *q++ = (vrect.x << 4) | ((x2 >> 8) & 0xf);
380 *q++ = x2;
381 // y1 y2 -> 6 nibbles
382 *q++ = vrect.y >> 4;
383 *q++ = (vrect.y << 4) | ((y2 >> 8) & 0xf);
384 *q++ = y2;
385
386 *q++ = 0x06;
387 // offset1, offset2
388 bytestream_put_be16(&q, offset1);
389 bytestream_put_be16(&q, offset2);
390
391 *q++ = forced ? 0x00 : 0x01; // start command
392 *q++ = 0xff; // terminating command
393
394 // send stop display command last
395 bytestream_put_be16(&q, (h->end_display_time*90) >> 10);
396 bytestream_put_be16(&q, (q - outbuf) - 2 /*+ 4*/);
397 *q++ = 0x02; // set end
398 *q++ = 0xff; // terminating command
399
400 qq = outbuf;
401 bytestream_put_be16(&qq, q - outbuf);
402
403 av_log(NULL, AV_LOG_DEBUG, "subtitle_packet size=%"PTRDIFF_SPECIFIER"\n", q - outbuf);
404 ret = q - outbuf;
405
406 fail:
407 av_free(vrect_data);
408 return ret;
409 }
410
411 static int dvdsub_init(AVCodecContext *avctx)
412 {
413 DVDSubtitleContext *dvdc = avctx->priv_data;
414 static const uint32_t default_palette[16] = {
415 0x000000, 0x0000FF, 0x00FF00, 0xFF0000,
416 0xFFFF00, 0xFF00FF, 0x00FFFF, 0xFFFFFF,
417 0x808000, 0x8080FF, 0x800080, 0x80FF80,
418 0x008080, 0xFF8080, 0x555555, 0xAAAAAA,
419 };
420 AVBPrint extradata;
421 int i, ret;
422
423 av_assert0(sizeof(dvdc->global_palette) == sizeof(default_palette));
424 memcpy(dvdc->global_palette, default_palette, sizeof(dvdc->global_palette));
425
426 av_bprint_init(&extradata, 0, 1);
427 if (avctx->width && avctx->height)
428 av_bprintf(&extradata, "size: %dx%d\n", avctx->width, avctx->height);
429 av_bprintf(&extradata, "palette:");
430 for (i = 0; i < 16; i++)
431 av_bprintf(&extradata, " %06"PRIx32"%c",
432 dvdc->global_palette[i] & 0xFFFFFF, i < 15 ? ',' : '\n');
433
434 ret = avpriv_bprint_to_extradata(avctx, &extradata);
435 if (ret < 0)
436 return ret;
437
438 return 0;
439 }
440
441 static int dvdsub_encode(AVCodecContext *avctx,
442 unsigned char *buf, int buf_size,
443 const AVSubtitle *sub)
444 {
445 //DVDSubtitleContext *s = avctx->priv_data;
446 int ret;
447
448 ret = encode_dvd_subtitles(avctx, buf, buf_size, sub);
449 return ret;
450 }
451
452 #define OFFSET(x) offsetof(DVDSubtitleContext, x)
453 #define SE AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM
454 static const AVOption options[] = {
455 {"even_rows_fix", "Make number of rows even (workaround for some players)", OFFSET(even_rows_fix), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SE},
456 { NULL },
457 };
458
459 static const AVClass dvdsubenc_class = {
460 .class_name = "VOBSUB subtitle encoder",
461 .item_name = av_default_item_name,
462 .option = options,
463 .version = LIBAVUTIL_VERSION_INT,
464 };
465
466 AVCodec ff_dvdsub_encoder = {
467 .name = "dvdsub",
468 .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),
469 .type = AVMEDIA_TYPE_SUBTITLE,
470 .id = AV_CODEC_ID_DVD_SUBTITLE,
471 .init = dvdsub_init,
472 .encode_sub = dvdsub_encode,
473 .priv_class = &dvdsubenc_class,
474 .priv_data_size = sizeof(DVDSubtitleContext),
475 };