FFmpeg
dvdsubenc.c
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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  char *palette_str;
35 
36 // ncnt is the nibble counter
37 #define PUTNIBBLE(val)\
38 do {\
39  if (ncnt++ & 1)\
40  *q++ = bitbuf | ((val) & 0x0f);\
41  else\
42  bitbuf = (val) << 4;\
43 } while(0)
44 
45 static void dvd_encode_rle(uint8_t **pq,
46  const uint8_t *bitmap, int linesize,
47  int w, int h,
48  const int cmap[256])
49 {
50  uint8_t *q;
51  unsigned int bitbuf = 0;
52  int ncnt;
53  int x, y, len, color;
54 
55  q = *pq;
56 
57  for (y = 0; y < h; ++y) {
58  ncnt = 0;
59  for(x = 0; x < w; x += len) {
60  color = bitmap[x];
61  for (len=1; x+len < w; ++len)
62  if (bitmap[x+len] != color)
63  break;
64  color = cmap[color];
65  av_assert0(color < 4);
66  if (len < 0x04) {
67  PUTNIBBLE((len << 2)|color);
68  } else if (len < 0x10) {
69  PUTNIBBLE(len >> 2);
70  PUTNIBBLE((len << 2)|color);
71  } else if (len < 0x40) {
72  PUTNIBBLE(0);
73  PUTNIBBLE(len >> 2);
74  PUTNIBBLE((len << 2)|color);
75  } else if (x+len == w) {
76  PUTNIBBLE(0);
77  PUTNIBBLE(0);
78  PUTNIBBLE(0);
79  PUTNIBBLE(color);
80  } else {
81  if (len > 0xff)
82  len = 0xff;
83  PUTNIBBLE(0);
84  PUTNIBBLE(len >> 6);
85  PUTNIBBLE(len >> 2);
86  PUTNIBBLE((len << 2)|color);
87  }
88  }
89  /* end of line */
90  if (ncnt & 1)
91  PUTNIBBLE(0);
92  bitmap += linesize;
93  }
94 
95  *pq = q;
96 }
97 
98 static int color_distance(uint32_t a, uint32_t b)
99 {
100  int r = 0, d, i;
101  int alpha_a = 8, alpha_b = 8;
102 
103  for (i = 24; i >= 0; i -= 8) {
104  d = alpha_a * (int)((a >> i) & 0xFF) -
105  alpha_b * (int)((b >> i) & 0xFF);
106  r += d * d;
107  alpha_a = a >> 28;
108  alpha_b = b >> 28;
109  }
110  return r;
111 }
112 
113 /**
114  * Count colors used in a rectangle, quantizing alpha and grouping by
115  * nearest global palette entry.
116  */
117 static void count_colors(AVCodecContext *avctx, unsigned hits[33],
118  const AVSubtitleRect *r)
119 {
120  DVDSubtitleContext *dvdc = avctx->priv_data;
121  unsigned count[256] = { 0 };
122  uint32_t *palette = (uint32_t *)r->data[1];
123  uint32_t color;
124  int x, y, i, j, match, d, best_d, av_uninit(best_j);
125  uint8_t *p = r->data[0];
126 
127  for (y = 0; y < r->h; y++) {
128  for (x = 0; x < r->w; x++)
129  count[*(p++)]++;
130  p += r->linesize[0] - r->w;
131  }
132  for (i = 0; i < 256; i++) {
133  if (!count[i]) /* avoid useless search */
134  continue;
135  color = palette[i];
136  /* 0: transparent, 1-16: semi-transparent, 17-33 opaque */
137  match = color < 0x33000000 ? 0 : color < 0xCC000000 ? 1 : 17;
138  if (match) {
139  best_d = INT_MAX;
140  for (j = 0; j < 16; j++) {
141  d = color_distance(0xFF000000 | color,
142  0xFF000000 | dvdc->global_palette[j]);
143  if (d < best_d) {
144  best_d = d;
145  best_j = j;
146  }
147  }
148  match += best_j;
149  }
150  hits[match] += count[i];
151  }
152 }
153 
154 static void select_palette(AVCodecContext *avctx, int out_palette[4],
155  int out_alpha[4], unsigned hits[33])
156 {
157  DVDSubtitleContext *dvdc = avctx->priv_data;
158  int i, j, bright, mult;
159  uint32_t color;
160  int selected[4] = { 0 };
161  uint32_t pseudopal[33] = { 0 };
162  uint32_t refcolor[3] = { 0x00000000, 0xFFFFFFFF, 0xFF000000 };
163 
164  /* Bonus for transparent: if the rectangle fits tightly the text, the
165  background color can be quite rare, but it would be ugly without it */
166  hits[0] *= 16;
167  /* Bonus for bright colors */
168  for (i = 0; i < 16; i++) {
169  if (!(hits[1 + i] + hits[17 + i]))
170  continue; /* skip unused colors to gain time */
171  color = dvdc->global_palette[i];
172  bright = 0;
173  for (j = 0; j < 3; j++, color >>= 8)
174  bright += (color & 0xFF) < 0x40 || (color & 0xFF) >= 0xC0;
175  mult = 2 + FFMIN(bright, 2);
176  hits[ 1 + i] *= mult;
177  hits[17 + i] *= mult;
178  }
179 
180  /* Select four most frequent colors */
181  for (i = 0; i < 4; i++) {
182  for (j = 0; j < 33; j++)
183  if (hits[j] > hits[selected[i]])
184  selected[i] = j;
185  hits[selected[i]] = 0;
186  }
187 
188  /* Order the colors like in most DVDs:
189  0: background, 1: foreground, 2: outline */
190  for (i = 0; i < 16; i++) {
191  pseudopal[ 1 + i] = 0x80000000 | dvdc->global_palette[i];
192  pseudopal[17 + i] = 0xFF000000 | dvdc->global_palette[i];
193  }
194  for (i = 0; i < 3; i++) {
195  int best_d = color_distance(refcolor[i], pseudopal[selected[i]]);
196  for (j = i + 1; j < 4; j++) {
197  int d = color_distance(refcolor[i], pseudopal[selected[j]]);
198  if (d < best_d) {
199  FFSWAP(int, selected[i], selected[j]);
200  best_d = d;
201  }
202  }
203  }
204 
205  /* Output */
206  for (i = 0; i < 4; i++) {
207  out_palette[i] = selected[i] ? (selected[i] - 1) & 0xF : 0;
208  out_alpha [i] = !selected[i] ? 0 : selected[i] < 17 ? 0x80 : 0xFF;
209  }
210 }
211 
212 static void build_color_map(AVCodecContext *avctx, int cmap[],
213  const uint32_t palette[],
214  const int out_palette[], unsigned int const out_alpha[])
215 {
216  DVDSubtitleContext *dvdc = avctx->priv_data;
217  int i, j, d, best_d;
218  uint32_t pseudopal[4];
219 
220  for (i = 0; i < 4; i++)
221  pseudopal[i] = (out_alpha[i] << 24) |
222  dvdc->global_palette[out_palette[i]];
223  for (i = 0; i < 256; i++) {
224  best_d = INT_MAX;
225  for (j = 0; j < 4; j++) {
226  d = color_distance(pseudopal[j], palette[i]);
227  if (d < best_d) {
228  cmap[i] = j;
229  best_d = d;
230  }
231  }
232  }
233 }
234 
235 static void copy_rectangle(AVSubtitleRect *dst, AVSubtitleRect *src, int cmap[])
236 {
237  int x, y;
238  uint8_t *p, *q;
239 
240  p = src->data[0];
241  q = dst->data[0] + (src->x - dst->x) +
242  (src->y - dst->y) * dst->linesize[0];
243  for (y = 0; y < src->h; y++) {
244  for (x = 0; x < src->w; x++)
245  *(q++) = cmap[*(p++)];
246  p += src->linesize[0] - src->w;
247  q += dst->linesize[0] - src->w;
248  }
249 }
250 
252  uint8_t *outbuf, int outbuf_size,
253  const AVSubtitle *h)
254 {
255  DVDSubtitleContext *dvdc = avctx->priv_data;
256  uint8_t *q, *qq;
257  int offset1, offset2;
258  int i, rects = h->num_rects, ret;
259  unsigned global_palette_hits[33] = { 0 };
260  int cmap[256];
261  int out_palette[4];
262  int out_alpha[4];
263  AVSubtitleRect vrect;
264  uint8_t *vrect_data = NULL;
265  int x2, y2;
266  int forced = 0;
267 
268  if (rects == 0 || !h->rects)
269  return AVERROR(EINVAL);
270  for (i = 0; i < rects; i++)
271  if (h->rects[i]->type != SUBTITLE_BITMAP) {
272  av_log(avctx, AV_LOG_ERROR, "Bitmap subtitle required\n");
273  return AVERROR(EINVAL);
274  }
275  /* Mark this subtitle forced if any of the rectangles is forced. */
276  for (i = 0; i < rects; i++)
277  if ((h->rects[i]->flags & AV_SUBTITLE_FLAG_FORCED) != 0) {
278  forced = 1;
279  break;
280  }
281 
282 #if FF_API_AVPICTURE
284  for (i = 0; i < rects; i++)
285  if (!h->rects[i]->data[0]) {
286  AVSubtitleRect *rect = h->rects[i];
287  int j;
288  for (j = 0; j < 4; j++) {
289  rect->data[j] = rect->pict.data[j];
290  rect->linesize[j] = rect->pict.linesize[j];
291  }
292  }
294 #endif
295 
296  vrect = *h->rects[0];
297 
298  if (rects > 1) {
299  /* DVD subtitles can have only one rectangle: build a virtual
300  rectangle containing all actual rectangles.
301  The data of the rectangles will be copied later, when the palette
302  is decided, because the rectangles may have different palettes. */
303  int xmin = h->rects[0]->x, xmax = xmin + h->rects[0]->w;
304  int ymin = h->rects[0]->y, ymax = ymin + h->rects[0]->h;
305  for (i = 1; i < rects; i++) {
306  xmin = FFMIN(xmin, h->rects[i]->x);
307  ymin = FFMIN(ymin, h->rects[i]->y);
308  xmax = FFMAX(xmax, h->rects[i]->x + h->rects[i]->w);
309  ymax = FFMAX(ymax, h->rects[i]->y + h->rects[i]->h);
310  }
311  vrect.x = xmin;
312  vrect.y = ymin;
313  vrect.w = xmax - xmin;
314  vrect.h = ymax - ymin;
315  if ((ret = av_image_check_size(vrect.w, vrect.h, 0, avctx)) < 0)
316  return ret;
317 
318  /* Count pixels outside the virtual rectangle as transparent */
319  global_palette_hits[0] = vrect.w * vrect.h;
320  for (i = 0; i < rects; i++)
321  global_palette_hits[0] -= h->rects[i]->w * h->rects[i]->h;
322  }
323 
324  for (i = 0; i < rects; i++)
325  count_colors(avctx, global_palette_hits, h->rects[i]);
326  select_palette(avctx, out_palette, out_alpha, global_palette_hits);
327 
328  if (rects > 1) {
329  if (!(vrect_data = av_calloc(vrect.w, vrect.h)))
330  return AVERROR(ENOMEM);
331  vrect.data [0] = vrect_data;
332  vrect.linesize[0] = vrect.w;
333  for (i = 0; i < rects; i++) {
334  build_color_map(avctx, cmap, (uint32_t *)h->rects[i]->data[1],
335  out_palette, out_alpha);
336  copy_rectangle(&vrect, h->rects[i], cmap);
337  }
338  for (i = 0; i < 4; i++)
339  cmap[i] = i;
340  } else {
341  build_color_map(avctx, cmap, (uint32_t *)h->rects[0]->data[1],
342  out_palette, out_alpha);
343  }
344 
345  av_log(avctx, AV_LOG_DEBUG, "Selected palette:");
346  for (i = 0; i < 4; i++)
347  av_log(avctx, AV_LOG_DEBUG, " 0x%06"PRIx32"@@%02x (0x%x,0x%x)",
348  dvdc->global_palette[out_palette[i]], out_alpha[i],
349  out_palette[i], out_alpha[i] >> 4);
350  av_log(avctx, AV_LOG_DEBUG, "\n");
351 
352  // encode data block
353  q = outbuf + 4;
354  offset1 = q - outbuf;
355  // worst case memory requirement: 1 nibble per pixel..
356  if ((q - outbuf) + vrect.w * vrect.h / 2 + 17 + 21 > outbuf_size) {
357  av_log(NULL, AV_LOG_ERROR, "dvd_subtitle too big\n");
359  goto fail;
360  }
361  dvd_encode_rle(&q, vrect.data[0], vrect.w * 2,
362  vrect.w, (vrect.h + 1) >> 1, cmap);
363  offset2 = q - outbuf;
364  dvd_encode_rle(&q, vrect.data[0] + vrect.w, vrect.w * 2,
365  vrect.w, vrect.h >> 1, cmap);
366 
367  if (dvdc->even_rows_fix && (vrect.h & 1)) {
368  // Work-around for some players that want the height to be even.
369  vrect.h++;
370  *q++ = 0x00; // 0x00 0x00 == empty row, i.e. fully transparent
371  *q++ = 0x00;
372  }
373 
374  // set data packet size
375  qq = outbuf + 2;
376  bytestream_put_be16(&qq, q - outbuf);
377 
378  // send start display command
379  bytestream_put_be16(&q, (h->start_display_time*90) >> 10);
380  bytestream_put_be16(&q, (q - outbuf) /*- 2 */ + 8 + 12 + 2);
381  *q++ = 0x03; // palette - 4 nibbles
382  *q++ = (out_palette[3] << 4) | out_palette[2];
383  *q++ = (out_palette[1] << 4) | out_palette[0];
384  *q++ = 0x04; // alpha - 4 nibbles
385  *q++ = (out_alpha[3] & 0xF0) | (out_alpha[2] >> 4);
386  *q++ = (out_alpha[1] & 0xF0) | (out_alpha[0] >> 4);
387 
388  // 12 bytes per rect
389  x2 = vrect.x + vrect.w - 1;
390  y2 = vrect.y + vrect.h - 1;
391 
392  *q++ = 0x05;
393  // x1 x2 -> 6 nibbles
394  *q++ = vrect.x >> 4;
395  *q++ = (vrect.x << 4) | ((x2 >> 8) & 0xf);
396  *q++ = x2;
397  // y1 y2 -> 6 nibbles
398  *q++ = vrect.y >> 4;
399  *q++ = (vrect.y << 4) | ((y2 >> 8) & 0xf);
400  *q++ = y2;
401 
402  *q++ = 0x06;
403  // offset1, offset2
404  bytestream_put_be16(&q, offset1);
405  bytestream_put_be16(&q, offset2);
406 
407  *q++ = forced ? 0x00 : 0x01; // start command
408  *q++ = 0xff; // terminating command
409 
410  // send stop display command last
411  bytestream_put_be16(&q, (h->end_display_time*90) >> 10);
412  bytestream_put_be16(&q, (q - outbuf) - 2 /*+ 4*/);
413  *q++ = 0x02; // set end
414  *q++ = 0xff; // terminating command
415 
416  qq = outbuf;
417  bytestream_put_be16(&qq, q - outbuf);
418 
419  av_log(NULL, AV_LOG_DEBUG, "subtitle_packet size=%"PTRDIFF_SPECIFIER"\n", q - outbuf);
420  ret = q - outbuf;
421 
422 fail:
423  av_free(vrect_data);
424  return ret;
425 }
426 
427 static int dvdsub_init(AVCodecContext *avctx)
428 {
429  DVDSubtitleContext *dvdc = avctx->priv_data;
430  static const uint32_t default_palette[16] = {
431  0x000000, 0x0000FF, 0x00FF00, 0xFF0000,
432  0xFFFF00, 0xFF00FF, 0x00FFFF, 0xFFFFFF,
433  0x808000, 0x8080FF, 0x800080, 0x80FF80,
434  0x008080, 0xFF8080, 0x555555, 0xAAAAAA,
435  };
436  AVBPrint extradata;
437  int i, ret;
438 
439  av_assert0(sizeof(dvdc->global_palette) == sizeof(default_palette));
440  if (dvdc->palette_str) {
442  } else {
443  memcpy(dvdc->global_palette, default_palette, sizeof(dvdc->global_palette));
444  }
445 
447  if (avctx->width && avctx->height)
448  av_bprintf(&extradata, "size: %dx%d\n", avctx->width, avctx->height);
449  av_bprintf(&extradata, "palette:");
450  for (i = 0; i < 16; i++)
451  av_bprintf(&extradata, " %06"PRIx32"%c",
452  dvdc->global_palette[i] & 0xFFFFFF, i < 15 ? ',' : '\n');
453 
454  ret = avpriv_bprint_to_extradata(avctx, &extradata);
455  if (ret < 0)
456  return ret;
457 
458  return 0;
459 }
460 
461 static int dvdsub_encode(AVCodecContext *avctx,
462  unsigned char *buf, int buf_size,
463  const AVSubtitle *sub)
464 {
465  //DVDSubtitleContext *s = avctx->priv_data;
466  int ret;
467 
468  ret = encode_dvd_subtitles(avctx, buf, buf_size, sub);
469  return ret;
470 }
471 
472 #define OFFSET(x) offsetof(DVDSubtitleContext, x)
473 #define SE AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_ENCODING_PARAM
474 static const AVOption options[] = {
475  {"palette", "set the global palette", OFFSET(palette_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, SE },
476  {"even_rows_fix", "Make number of rows even (workaround for some players)", OFFSET(even_rows_fix), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, SE},
477  { NULL },
478 };
479 
480 static const AVClass dvdsubenc_class = {
481  .class_name = "VOBSUB subtitle encoder",
482  .item_name = av_default_item_name,
483  .option = options,
484  .version = LIBAVUTIL_VERSION_INT,
485 };
486 
488  .name = "dvdsub",
489  .long_name = NULL_IF_CONFIG_SMALL("DVD subtitles"),
490  .type = AVMEDIA_TYPE_SUBTITLE,
492  .init = dvdsub_init,
493  .encode_sub = dvdsub_encode,
494  .priv_class = &dvdsubenc_class,
495  .priv_data_size = sizeof(DVDSubtitleContext),
496 };
#define NULL
Definition: coverity.c:32
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
int x
top left corner of pict, undefined when pict is not set
Definition: avcodec.h:3978
AVOption.
Definition: opt.h:246
misc image utilities
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
static int color_distance(uint32_t a, uint32_t b)
Definition: dvdsubenc.c:98
unsigned num_rects
Definition: avcodec.h:4016
static const AVClass dvdsubenc_class
Definition: dvdsubenc.c:480
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3555
attribute_deprecated AVPicture pict
Definition: avcodec.h:3989
static void copy_rectangle(AVSubtitleRect *dst, AVSubtitleRect *src, int cmap[])
Definition: dvdsubenc.c:235
void * av_calloc(size_t nmemb, size_t size)
Non-inlined equivalent of av_mallocz_array().
Definition: mem.c:244
AVSubtitleRect ** rects
Definition: avcodec.h:4017
int w
width of pict, undefined when pict is not set
Definition: avcodec.h:3980
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
uint8_t
AVOptions.
static const uint32_t color[16+AV_CLASS_CATEGORY_NB]
Definition: log.c:92
static void dvd_encode_rle(uint8_t **pq, const uint8_t *bitmap, int linesize, int w, int h, const int cmap[256])
Definition: dvdsubenc.c:45
attribute_deprecated int linesize[AV_NUM_DATA_POINTERS]
number of bytes per line
Definition: avcodec.h:3949
int h
height of pict, undefined when pict is not set
Definition: avcodec.h:3981
int avpriv_bprint_to_extradata(AVCodecContext *avctx, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:1909
#define av_log(a,...)
static int dvdsub_encode(AVCodecContext *avctx, unsigned char *buf, int buf_size, const AVSubtitle *sub)
Definition: dvdsubenc.c:461
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define PTRDIFF_SPECIFIER
Definition: internal.h:261
int y
top left corner of pict, undefined when pict is not set
Definition: avcodec.h:3979
AVCodec ff_dvdsub_encoder
Definition: dvdsubenc.c:487
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
const char * r
Definition: vf_curves.c:114
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
simple assert() macros that are a bit more flexible than ISO C assert().
const char * name
Name of the codec implementation.
Definition: avcodec.h:3562
GLsizei count
Definition: opengl_enc.c:108
#define FFMAX(a, b)
Definition: common.h:94
#define fail()
Definition: checkasm.h:122
uint32_t end_display_time
Definition: avcodec.h:4015
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:282
A bitmap, pict will be set.
Definition: avcodec.h:3960
#define AV_SUBTITLE_FLAG_FORCED
Definition: avcodec.h:3975
int linesize[4]
Definition: avcodec.h:3996
#define b
Definition: input.c:41
static int16_t mult(Float11 *f1, Float11 *f2)
Definition: g726.c:55
#define FFMIN(a, b)
Definition: common.h:96
#define AVERROR_BUFFER_TOO_SMALL
Buffer too small.
Definition: error.h:51
int width
picture width / height.
Definition: avcodec.h:1794
uint8_t w
Definition: llviddspenc.c:38
attribute_deprecated uint8_t * data[AV_NUM_DATA_POINTERS]
pointers to the image data planes
Definition: avcodec.h:3947
uint8_t * data[4]
data+linesize for the bitmap of this subtitle.
Definition: avcodec.h:3995
char * palette_str
Definition: dvdsubenc.c:32
static void build_color_map(AVCodecContext *avctx, int cmap[], const uint32_t palette[], const int out_palette[], unsigned int const out_alpha[])
Definition: dvdsubenc.c:212
#define AV_BPRINT_SIZE_AUTOMATIC
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1621
static const AVOption options[]
Definition: dvdsubenc.c:474
#define SE
Definition: dvdsubenc.c:473
void * buf
Definition: avisynth_c.h:766
Describe the class of an AVClass context structure.
Definition: log.h:67
Definition: f_ebur128.c:91
void ff_dvdsub_parse_palette(uint32_t *palette, const char *p)
Definition: dvdsub.c:26
static void select_palette(AVCodecContext *avctx, int out_palette[4], int out_alpha[4], unsigned hits[33])
Definition: dvdsubenc.c:154
static void count_colors(AVCodecContext *avctx, unsigned hits[33], const AVSubtitleRect *r)
Count colors used in a rectangle, quantizing alpha and grouping by nearest global palette entry...
Definition: dvdsubenc.c:117
#define PUTNIBBLE(val)
Definition: dvdsubenc.c:37
static int encode_dvd_subtitles(AVCodecContext *avctx, uint8_t *outbuf, int outbuf_size, const AVSubtitle *h)
Definition: dvdsubenc.c:251
int
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:84
common internal api header.
uint32_t start_display_time
Definition: avcodec.h:4014
void * priv_data
Definition: avcodec.h:1648
#define av_free(p)
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:85
int len
#define av_uninit(x)
Definition: attributes.h:148
#define OFFSET(x)
Definition: dvdsubenc.c:472
#define FFSWAP(type, a, b)
Definition: common.h:99
uint32_t global_palette[16]
Definition: dvdsubenc.c:31
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
enum AVSubtitleType type
Definition: avcodec.h:3998
static int dvdsub_init(AVCodecContext *avctx)
Definition: dvdsubenc.c:427