2 * DVB subtitle encoding 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 "bytestream.h"
23 #include "colorspace.h"
25 typedef struct DVBSubtitleContext {
30 #define PUTBITS2(val)\
32 bitbuf |= (val) << bitcnt;\
41 static void dvb_encode_rle2(uint8_t **pq,
42 const uint8_t *bitmap, int linesize,
48 int x, y, len, x1, v, color;
52 for(y = 0; y < h; y++) {
61 while (x1 < w && bitmap[x1] == color)
64 if (color == 0 && len == 2) {
68 } else if (len >= 3 && len <= 10) {
71 PUTBITS2((v >> 2) | 2);
74 } else if (len >= 12 && len <= 27) {
82 } else if (len >= 29) {
83 /* length = 29 ... 284 */
91 PUTBITS2((v >> 4) & 3);
92 PUTBITS2((v >> 2) & 3);
117 #define PUTBITS4(val)\
119 bitbuf |= (val) << bitcnt;\
128 /* some DVB decoders only implement 4 bits/pixel */
129 static void dvb_encode_rle4(uint8_t **pq,
130 const uint8_t *bitmap, int linesize,
136 int x, y, len, x1, v, color;
140 for(y = 0; y < h; y++) {
148 color = bitmap[x1++];
149 while (x1 < w && bitmap[x1] == color)
152 if (color == 0 && len == 2) {
155 } else if (color == 0 && (len >= 3 && len <= 9)) {
158 } else if (len >= 4 && len <= 7) {
160 PUTBITS4(8 + len - 4);
162 } else if (len >= 9 && len <= 24) {
167 } else if (len >= 25) {
197 static int encode_dvb_subtitles(DVBSubtitleContext *s,
198 uint8_t *outbuf, AVSubtitle *h)
200 uint8_t *q, *pseg_len;
201 int page_id, region_id, clut_id, object_id, i, bpp_index, page_state;
208 if (h->num_rects == 0 || h->rects == NULL)
211 *q++ = 0x00; /* subtitle_stream_id */
213 /* page composition segment */
215 *q++ = 0x0f; /* sync_byte */
216 *q++ = 0x10; /* segment_type */
217 bytestream_put_be16(&q, page_id);
219 q += 2; /* segment length */
220 *q++ = 30; /* page_timeout (seconds) */
222 page_state = 0; /* normal case */
224 page_state = 2; /* mode change */
225 /* page_version = 0 + page_state */
226 *q++ = s->object_version | (page_state << 2) | 3;
228 for (region_id = 0; region_id < h->num_rects; region_id++) {
230 *q++ = 0xff; /* reserved */
231 bytestream_put_be16(&q, h->rects[region_id].x); /* left pos */
232 bytestream_put_be16(&q, h->rects[region_id].y); /* top pos */
235 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
237 if (!s->hide_state) {
238 for (clut_id = 0; clut_id < h->num_rects; clut_id++) {
242 if (h->rects[clut_id].nb_colors <= 4) {
243 /* 2 bpp, some decoders do not support it correctly */
245 } else if (h->rects[clut_id].nb_colors <= 16) {
246 /* 4 bpp, standard encoding */
252 *q++ = 0x0f; /* sync byte */
253 *q++ = 0x12; /* CLUT definition segment */
254 bytestream_put_be16(&q, page_id);
256 q += 2; /* segment length */
258 *q++ = (0 << 4) | 0xf; /* version = 0 */
260 for(i = 0; i < h->rects[clut_id].nb_colors; i++) {
261 *q++ = i; /* clut_entry_id */
262 *q++ = (1 << (7 - bpp_index)) | (0xf << 1) | 1; /* 2 bits/pixel full range */
265 a = (h->rects[clut_id].rgba_palette[i] >> 24) & 0xff;
266 r = (h->rects[clut_id].rgba_palette[i] >> 16) & 0xff;
267 g = (h->rects[clut_id].rgba_palette[i] >> 8) & 0xff;
268 b = (h->rects[clut_id].rgba_palette[i] >> 0) & 0xff;
270 *q++ = RGB_TO_Y_CCIR(r, g, b);
271 *q++ = RGB_TO_V_CCIR(r, g, b, 0);
272 *q++ = RGB_TO_U_CCIR(r, g, b, 0);
277 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
281 for (region_id = 0; region_id < h->num_rects; region_id++) {
283 /* region composition segment */
285 if (h->rects[region_id].nb_colors <= 4) {
286 /* 2 bpp, some decoders do not support it correctly */
288 } else if (h->rects[region_id].nb_colors <= 16) {
289 /* 4 bpp, standard encoding */
295 *q++ = 0x0f; /* sync_byte */
296 *q++ = 0x11; /* segment_type */
297 bytestream_put_be16(&q, page_id);
299 q += 2; /* segment length */
301 *q++ = (s->object_version << 4) | (0 << 3) | 0x07; /* version , no fill */
302 bytestream_put_be16(&q, h->rects[region_id].w); /* region width */
303 bytestream_put_be16(&q, h->rects[region_id].h); /* region height */
304 *q++ = ((1 + bpp_index) << 5) | ((1 + bpp_index) << 2) | 0x03;
305 *q++ = region_id; /* clut_id == region_id */
306 *q++ = 0; /* 8 bit fill colors */
307 *q++ = 0x03; /* 4 bit and 2 bit fill colors */
309 if (!s->hide_state) {
310 bytestream_put_be16(&q, region_id); /* object_id == region_id */
311 *q++ = (0 << 6) | (0 << 4);
317 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
320 if (!s->hide_state) {
322 for (object_id = 0; object_id < h->num_rects; object_id++) {
323 /* Object Data segment */
325 if (h->rects[object_id].nb_colors <= 4) {
326 /* 2 bpp, some decoders do not support it correctly */
328 } else if (h->rects[object_id].nb_colors <= 16) {
329 /* 4 bpp, standard encoding */
335 *q++ = 0x0f; /* sync byte */
337 bytestream_put_be16(&q, page_id);
339 q += 2; /* segment length */
341 bytestream_put_be16(&q, object_id);
342 *q++ = (s->object_version << 4) | (0 << 2) | (0 << 1) | 1; /* version = 0,
343 onject_coding_method,
344 non_modifying_color_flag */
346 uint8_t *ptop_field_len, *pbottom_field_len, *top_ptr, *bottom_ptr;
347 void (*dvb_encode_rle)(uint8_t **pq,
348 const uint8_t *bitmap, int linesize,
352 pbottom_field_len = q;
356 dvb_encode_rle = dvb_encode_rle2;
358 dvb_encode_rle = dvb_encode_rle4;
361 dvb_encode_rle(&q, h->rects[object_id].bitmap, h->rects[object_id].w * 2,
362 h->rects[object_id].w, h->rects[object_id].h >> 1);
364 dvb_encode_rle(&q, h->rects[object_id].bitmap + h->rects[object_id].w,
365 h->rects[object_id].w * 2, h->rects[object_id].w,
366 h->rects[object_id].h >> 1);
368 bytestream_put_be16(&ptop_field_len, bottom_ptr - top_ptr);
369 bytestream_put_be16(&pbottom_field_len, q - bottom_ptr);
372 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
376 /* end of display set segment */
378 *q++ = 0x0f; /* sync_byte */
379 *q++ = 0x80; /* segment_type */
380 bytestream_put_be16(&q, page_id);
382 q += 2; /* segment length */
384 bytestream_put_be16(&pseg_len, q - pseg_len - 2);
386 *q++ = 0xff; /* end of PES data */
388 s->object_version = (s->object_version + 1) & 0xf;
389 s->hide_state = !s->hide_state;
393 static int dvbsub_encode(AVCodecContext *avctx,
394 unsigned char *buf, int buf_size, void *data)
396 DVBSubtitleContext *s = avctx->priv_data;
397 AVSubtitle *sub = data;
400 ret = encode_dvb_subtitles(s, buf, sub);
404 AVCodec dvbsub_encoder = {
407 CODEC_ID_DVB_SUBTITLE,
408 sizeof(DVBSubtitleContext),
411 .long_name = "DVB subtitles",