2 * DVB subtitle encoding
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 "bytestream.h"
23 #include "libavutil/colorspace.h"
25 typedef struct DVBSubtitleContext {
29 #define PUTBITS2(val)\
31 bitbuf |= (val) << bitcnt;\
40 static int dvb_encode_rle2(uint8_t **pq, int buf_size,
41 const uint8_t *bitmap, int linesize,
44 uint8_t *q, *line_begin;
47 int x, y, len, x1, v, color;
51 for(y = 0; y < h; y++) {
52 // Worst case line is 3 bits per value + 4 bytes overhead
53 if (buf_size * 8 < w * 3 + 32)
54 return AVERROR_BUFFER_TOO_SMALL;
64 while (x1 < w && bitmap[x1] == color)
67 if (color == 0 && len == 2) {
71 } else if (len >= 3 && len <= 10) {
74 PUTBITS2((v >> 2) | 2);
77 } else if (len >= 12 && len <= 27) {
85 } else if (len >= 29) {
86 /* length = 29 ... 284 */
94 PUTBITS2((v >> 4) & 3);
95 PUTBITS2((v >> 2) & 3);
116 buf_size -= q - line_begin;
123 #define PUTBITS4(val)\
125 bitbuf |= (val) << bitcnt;\
134 /* some DVB decoders only implement 4 bits/pixel */
135 static int dvb_encode_rle4(uint8_t **pq, int buf_size,
136 const uint8_t *bitmap, int linesize,
139 uint8_t *q, *line_begin;
142 int x, y, len, x1, v, color;
146 for(y = 0; y < h; y++) {
147 // Worst case line is 6 bits per value, + 4 bytes overhead
148 if (buf_size * 8 < w * 6 + 32)
149 return AVERROR_BUFFER_TOO_SMALL;
158 color = bitmap[x1++];
159 while (x1 < w && bitmap[x1] == color)
162 if (color == 0 && len == 2) {
165 } else if (color == 0 && (len >= 3 && len <= 9)) {
168 } else if (len >= 4 && len <= 7) {
170 PUTBITS4(8 + len - 4);
172 } else if (len >= 9 && len <= 24) {
177 } else if (len >= 25) {
203 buf_size -= q - line_begin;
210 static int dvb_encode_rle8(uint8_t **pq, int buf_size,
211 const uint8_t *bitmap, int linesize,
214 uint8_t *q, *line_begin;
215 int x, y, len, x1, color;
219 for (y = 0; y < h; y++) {
220 // Worst case line is 12 bits per value, + 3 bytes overhead
221 if (buf_size * 8 < w * 12 + 24)
222 return AVERROR_BUFFER_TOO_SMALL;
229 color = bitmap[x1++];
230 while (x1 < w && bitmap[x1] == color)
233 if (len == 1 && color) {
234 // 00000001 to 11111111 1 pixel in colour x
238 // 00000000 0LLLLLLL L pixels (1-127) in colour 0 (L > 0)
239 len = FFMIN(len, 127);
242 } else if (len > 2) {
243 // 00000000 1LLLLLLL CCCCCCCC L pixels (3-127) in colour C (L > 2)
244 len = FFMIN(len, 127);
260 // 00000000 end of 8-bit/pixel_code_string
264 buf_size -= q - line_begin;
271 static int dvbsub_encode(AVCodecContext *avctx, uint8_t *outbuf, int buf_size,
274 DVBSubtitleContext *s = avctx->priv_data;
275 uint8_t *q, *pseg_len;
276 int page_id, region_id, clut_id, object_id, i, bpp_index, page_state;
283 if (h->num_rects && !h->rects)
284 return AVERROR(EINVAL);
286 if (avctx->width > 0 && avctx->height > 0) {
288 return AVERROR_BUFFER_TOO_SMALL;
289 /* display definition segment */
290 *q++ = 0x0f; /* sync_byte */
291 *q++ = 0x14; /* segment_type */
292 bytestream_put_be16(&q, page_id);
294 q += 2; /* segment length */
295 *q++ = 0x00; /* dds version number & display window flag */
296 bytestream_put_be16(&q, avctx->width - 1); /* display width */
297 bytestream_put_be16(&q, avctx->height - 1); /* display height */
298 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
302 /* page composition segment */
304 if (buf_size < 8 + h->num_rects * 6)
305 return AVERROR_BUFFER_TOO_SMALL;
306 *q++ = 0x0f; /* sync_byte */
307 *q++ = 0x10; /* segment_type */
308 bytestream_put_be16(&q, page_id);
310 q += 2; /* segment length */
311 *q++ = 30; /* page_timeout (seconds) */
312 page_state = 2; /* mode change */
313 /* page_version = 0 + page_state */
314 *q++ = (s->object_version << 4) | (page_state << 2) | 3;
316 for (region_id = 0; region_id < h->num_rects; region_id++) {
318 *q++ = 0xff; /* reserved */
319 bytestream_put_be16(&q, h->rects[region_id]->x); /* left pos */
320 bytestream_put_be16(&q, h->rects[region_id]->y); /* top pos */
323 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
324 buf_size -= 8 + h->num_rects * 6;
327 for (clut_id = 0; clut_id < h->num_rects; clut_id++) {
328 if (buf_size < 6 + h->rects[clut_id]->nb_colors * 6)
329 return AVERROR_BUFFER_TOO_SMALL;
333 if (h->rects[clut_id]->nb_colors <= 4) {
334 /* 2 bpp, some decoders do not support it correctly */
336 } else if (h->rects[clut_id]->nb_colors <= 16) {
337 /* 4 bpp, standard encoding */
339 } else if (h->rects[clut_id]->nb_colors <= 256) {
340 /* 8 bpp, standard encoding */
343 return AVERROR(EINVAL);
348 *q++ = 0x0f; /* sync byte */
349 *q++ = 0x12; /* CLUT definition segment */
350 bytestream_put_be16(&q, page_id);
352 q += 2; /* segment length */
354 *q++ = (0 << 4) | 0xf; /* version = 0 */
356 for(i = 0; i < h->rects[clut_id]->nb_colors; i++) {
357 *q++ = i; /* clut_entry_id */
358 *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */
361 uint32_t x= ((uint32_t*)h->rects[clut_id]->data[1])[i];
362 a = (x >> 24) & 0xff;
363 r = (x >> 16) & 0xff;
367 *q++ = RGB_TO_Y_CCIR(r, g, b);
368 *q++ = RGB_TO_V_CCIR(r, g, b, 0);
369 *q++ = RGB_TO_U_CCIR(r, g, b, 0);
374 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
375 buf_size -= 6 + h->rects[clut_id]->nb_colors * 6;
378 if (buf_size < h->num_rects * 22)
379 return AVERROR_BUFFER_TOO_SMALL;
380 for (region_id = 0; region_id < h->num_rects; region_id++) {
382 /* region composition segment */
384 if (h->rects[region_id]->nb_colors <= 4) {
385 /* 2 bpp, some decoders do not support it correctly */
387 } else if (h->rects[region_id]->nb_colors <= 16) {
388 /* 4 bpp, standard encoding */
390 } else if (h->rects[region_id]->nb_colors <= 256) {
391 /* 8 bpp, standard encoding */
394 return AVERROR(EINVAL);
397 *q++ = 0x0f; /* sync_byte */
398 *q++ = 0x11; /* segment_type */
399 bytestream_put_be16(&q, page_id);
401 q += 2; /* segment length */
403 *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */
404 bytestream_put_be16(&q, h->rects[region_id]->w); /* region width */
405 bytestream_put_be16(&q, h->rects[region_id]->h); /* region height */
406 *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03;
407 *q++ = region_id; /* clut_id == region_id */
408 *q++ = 0; /* 8 bit fill colors */
409 *q++ = 0x03; /* 4 bit and 2 bit fill colors */
411 bytestream_put_be16(&q, region_id); /* object_id == region_id */
412 *q++ = (0 << 6) | (0 << 4);
417 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
419 buf_size -= h->num_rects * 22;
421 for (object_id = 0; object_id < h->num_rects; object_id++) {
422 int (*dvb_encode_rle)(uint8_t **pq, int buf_size,
423 const uint8_t *bitmap, int linesize,
427 return AVERROR_BUFFER_TOO_SMALL;
429 /* bpp_index maths */
430 if (h->rects[object_id]->nb_colors <= 4) {
431 /* 2 bpp, some decoders do not support it correctly */
432 dvb_encode_rle = dvb_encode_rle2;
433 } else if (h->rects[object_id]->nb_colors <= 16) {
434 /* 4 bpp, standard encoding */
435 dvb_encode_rle = dvb_encode_rle4;
436 } else if (h->rects[object_id]->nb_colors <= 256) {
437 /* 8 bpp, standard encoding */
438 dvb_encode_rle = dvb_encode_rle8;
440 return AVERROR(EINVAL);
443 /* Object Data segment */
444 *q++ = 0x0f; /* sync byte */
446 bytestream_put_be16(&q, page_id);
448 q += 2; /* segment length */
450 bytestream_put_be16(&q, object_id);
451 *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0,
452 object_coding_method,
453 non_modifying_color_flag */
455 uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr;
460 pbottom_field_len = q;
465 ret = dvb_encode_rle(&q, buf_size,
466 h->rects[object_id]->data[0],
467 h->rects[object_id]->w * 2,
468 h->rects[object_id]->w,
469 h->rects[object_id]->h >> 1);
474 ret = dvb_encode_rle(&q, buf_size,
475 h->rects[object_id]->data[0] + h->rects[object_id]->w,
476 h->rects[object_id]->w * 2,
477 h->rects[object_id]->w,
478 h->rects[object_id]->h >> 1);
483 bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr);
484 bytestream_put_be16(&pbottom_field_len, q - bottom_ptr);
487 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
491 /* end of display set segment */
494 return AVERROR_BUFFER_TOO_SMALL;
495 *q++ = 0x0f; /* sync_byte */
496 *q++ = 0x80; /* segment_type */
497 bytestream_put_be16(&q, page_id);
499 q += 2; /* segment length */
501 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
504 s->object_version = (s->object_version + 1) & 0xf;
508 AVCodec ff_dvbsub_encoder = {
510 .long_name = NULL_IF_CONFIG_SMALL("DVB subtitles"),
511 .type = AVMEDIA_TYPE_SUBTITLE,
512 .id = AV_CODEC_ID_DVB_SUBTITLE,
513 .priv_data_size = sizeof(DVBSubtitleContext),
514 .encode_sub = dvbsub_encode,