FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vf_lut.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * Compute a look-up table for binding the input value to the output
24  * value, and apply it to input video.
25  */
26 
27 #include "libavutil/attributes.h"
28 #include "libavutil/common.h"
29 #include "libavutil/eval.h"
30 #include "libavutil/opt.h"
31 #include "libavutil/pixdesc.h"
32 #include "avfilter.h"
33 #include "drawutils.h"
34 #include "formats.h"
35 #include "internal.h"
36 #include "video.h"
37 
38 static const char *const var_names[] = {
39  "w", ///< width of the input video
40  "h", ///< height of the input video
41  "val", ///< input value for the pixel
42  "maxval", ///< max value for the pixel
43  "minval", ///< min value for the pixel
44  "negval", ///< negated value
45  "clipval",
46  NULL
47 };
48 
49 enum var_name {
58 };
59 
60 typedef struct {
61  const AVClass *class;
62  uint8_t lut[4][256]; ///< lookup table for each component
63  char *comp_expr_str[4];
64  AVExpr *comp_expr[4];
65  int hsub, vsub;
66  double var_values[VAR_VARS_NB];
67  int is_rgb, is_yuv;
68  int step;
69  int negate_alpha; /* only used by negate */
70 } LutContext;
71 
72 #define Y 0
73 #define U 1
74 #define V 2
75 #define R 0
76 #define G 1
77 #define B 2
78 #define A 3
79 
80 #define OFFSET(x) offsetof(LutContext, x)
81 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
82 
83 static const AVOption options[] = {
84  { "c0", "set component #0 expression", OFFSET(comp_expr_str[0]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
85  { "c1", "set component #1 expression", OFFSET(comp_expr_str[1]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
86  { "c2", "set component #2 expression", OFFSET(comp_expr_str[2]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
87  { "c3", "set component #3 expression", OFFSET(comp_expr_str[3]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
88  { "y", "set Y expression", OFFSET(comp_expr_str[Y]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
89  { "u", "set U expression", OFFSET(comp_expr_str[U]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
90  { "v", "set V expression", OFFSET(comp_expr_str[V]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
91  { "r", "set R expression", OFFSET(comp_expr_str[R]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
92  { "g", "set G expression", OFFSET(comp_expr_str[G]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
93  { "b", "set B expression", OFFSET(comp_expr_str[B]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
94  { "a", "set A expression", OFFSET(comp_expr_str[A]), AV_OPT_TYPE_STRING, { .str = "val" }, .flags = FLAGS },
95  { NULL }
96 };
97 
98 static av_cold void uninit(AVFilterContext *ctx)
99 {
100  LutContext *s = ctx->priv;
101  int i;
102 
103  for (i = 0; i < 4; i++) {
104  av_expr_free(s->comp_expr[i]);
105  s->comp_expr[i] = NULL;
106  av_freep(&s->comp_expr_str[i]);
107  }
108 }
109 
110 #define YUV_FORMATS \
111  AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, \
112  AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P, \
113  AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P, \
114  AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P, \
115  AV_PIX_FMT_YUVJ440P
116 
117 #define RGB_FORMATS \
118  AV_PIX_FMT_ARGB, AV_PIX_FMT_RGBA, \
119  AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, \
120  AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24
121 
125 
127 {
128  LutContext *s = ctx->priv;
129 
130  const enum AVPixelFormat *pix_fmts = s->is_rgb ? rgb_pix_fmts :
131  s->is_yuv ? yuv_pix_fmts :
132  all_pix_fmts;
133 
135  return 0;
136 }
137 
138 /**
139  * Clip value val in the minval - maxval range.
140  */
141 static double clip(void *opaque, double val)
142 {
143  LutContext *s = opaque;
144  double minval = s->var_values[VAR_MINVAL];
145  double maxval = s->var_values[VAR_MAXVAL];
146 
147  return av_clip(val, minval, maxval);
148 }
149 
150 /**
151  * Compute gamma correction for value val, assuming the minval-maxval
152  * range, val is clipped to a value contained in the same interval.
153  */
154 static double compute_gammaval(void *opaque, double gamma)
155 {
156  LutContext *s = opaque;
157  double val = s->var_values[VAR_CLIPVAL];
158  double minval = s->var_values[VAR_MINVAL];
159  double maxval = s->var_values[VAR_MAXVAL];
160 
161  return pow((val-minval)/(maxval-minval), gamma) * (maxval-minval)+minval;
162 }
163 
164 static double (* const funcs1[])(void *, double) = {
165  (void *)clip,
166  (void *)compute_gammaval,
167  NULL
168 };
169 
170 static const char * const funcs1_names[] = {
171  "clip",
172  "gammaval",
173  NULL
174 };
175 
176 static int config_props(AVFilterLink *inlink)
177 {
178  AVFilterContext *ctx = inlink->dst;
179  LutContext *s = ctx->priv;
180  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
181  uint8_t rgba_map[4]; /* component index -> RGBA color index map */
182  int min[4], max[4];
183  int val, color, ret;
184 
185  s->hsub = desc->log2_chroma_w;
186  s->vsub = desc->log2_chroma_h;
187 
188  s->var_values[VAR_W] = inlink->w;
189  s->var_values[VAR_H] = inlink->h;
190 
191  switch (inlink->format) {
192  case AV_PIX_FMT_YUV410P:
193  case AV_PIX_FMT_YUV411P:
194  case AV_PIX_FMT_YUV420P:
195  case AV_PIX_FMT_YUV422P:
196  case AV_PIX_FMT_YUV440P:
197  case AV_PIX_FMT_YUV444P:
198  case AV_PIX_FMT_YUVA420P:
199  case AV_PIX_FMT_YUVA422P:
200  case AV_PIX_FMT_YUVA444P:
201  min[Y] = min[U] = min[V] = 16;
202  max[Y] = 235;
203  max[U] = max[V] = 240;
204  min[A] = 0; max[A] = 255;
205  break;
206  default:
207  min[0] = min[1] = min[2] = min[3] = 0;
208  max[0] = max[1] = max[2] = max[3] = 255;
209  }
210 
211  s->is_yuv = s->is_rgb = 0;
212  if (ff_fmt_is_in(inlink->format, yuv_pix_fmts)) s->is_yuv = 1;
213  else if (ff_fmt_is_in(inlink->format, rgb_pix_fmts)) s->is_rgb = 1;
214 
215  if (s->is_rgb) {
216  ff_fill_rgba_map(rgba_map, inlink->format);
217  s->step = av_get_bits_per_pixel(desc) >> 3;
218  }
219 
220  for (color = 0; color < desc->nb_components; color++) {
221  double res;
222  int comp = s->is_rgb ? rgba_map[color] : color;
223 
224  /* create the parsed expression */
225  av_expr_free(s->comp_expr[color]);
226  s->comp_expr[color] = NULL;
227  ret = av_expr_parse(&s->comp_expr[color], s->comp_expr_str[color],
228  var_names, funcs1_names, funcs1, NULL, NULL, 0, ctx);
229  if (ret < 0) {
230  av_log(ctx, AV_LOG_ERROR,
231  "Error when parsing the expression '%s' for the component %d and color %d.\n",
232  s->comp_expr_str[comp], comp, color);
233  return AVERROR(EINVAL);
234  }
235 
236  /* compute the lut */
237  s->var_values[VAR_MAXVAL] = max[color];
238  s->var_values[VAR_MINVAL] = min[color];
239 
240  for (val = 0; val < 256; val++) {
241  s->var_values[VAR_VAL] = val;
242  s->var_values[VAR_CLIPVAL] = av_clip(val, min[color], max[color]);
243  s->var_values[VAR_NEGVAL] =
244  av_clip(min[color] + max[color] - s->var_values[VAR_VAL],
245  min[color], max[color]);
246 
247  res = av_expr_eval(s->comp_expr[color], s->var_values, s);
248  if (isnan(res)) {
249  av_log(ctx, AV_LOG_ERROR,
250  "Error when evaluating the expression '%s' for the value %d for the component %d.\n",
251  s->comp_expr_str[color], val, comp);
252  return AVERROR(EINVAL);
253  }
254  s->lut[comp][val] = av_clip((int)res, min[color], max[color]);
255  av_log(ctx, AV_LOG_DEBUG, "val[%d][%d] = %d\n", comp, val, s->lut[comp][val]);
256  }
257  }
258 
259  return 0;
260 }
261 
262 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
263 {
264  AVFilterContext *ctx = inlink->dst;
265  LutContext *s = ctx->priv;
266  AVFilterLink *outlink = ctx->outputs[0];
267  AVFrame *out;
268  uint8_t *inrow, *outrow, *inrow0, *outrow0;
269  int i, j, plane, direct = 0;
270 
271  if (av_frame_is_writable(in)) {
272  direct = 1;
273  out = in;
274  } else {
275  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
276  if (!out) {
277  av_frame_free(&in);
278  return AVERROR(ENOMEM);
279  }
280  av_frame_copy_props(out, in);
281  }
282 
283  if (s->is_rgb) {
284  /* packed */
285  inrow0 = in ->data[0];
286  outrow0 = out->data[0];
287 
288  for (i = 0; i < in->height; i ++) {
289  int w = inlink->w;
290  const uint8_t (*tab)[256] = (const uint8_t (*)[256])s->lut;
291  inrow = inrow0;
292  outrow = outrow0;
293  for (j = 0; j < w; j++) {
294  switch (s->step) {
295  case 4: outrow[3] = tab[3][inrow[3]]; // Fall-through
296  case 3: outrow[2] = tab[2][inrow[2]]; // Fall-through
297  case 2: outrow[1] = tab[1][inrow[1]]; // Fall-through
298  default: outrow[0] = tab[0][inrow[0]];
299  }
300  outrow += s->step;
301  inrow += s->step;
302  }
303  inrow0 += in ->linesize[0];
304  outrow0 += out->linesize[0];
305  }
306  } else {
307  /* planar */
308  for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++) {
309  int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
310  int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
311  int h = FF_CEIL_RSHIFT(inlink->h, vsub);
312  int w = FF_CEIL_RSHIFT(inlink->w, hsub);
313 
314  inrow = in ->data[plane];
315  outrow = out->data[plane];
316 
317  for (i = 0; i < h; i++) {
318  const uint8_t *tab = s->lut[plane];
319  for (j = 0; j < w; j++)
320  outrow[j] = tab[inrow[j]];
321  inrow += in ->linesize[plane];
322  outrow += out->linesize[plane];
323  }
324  }
325  }
326 
327  if (!direct)
328  av_frame_free(&in);
329 
330  return ff_filter_frame(outlink, out);
331 }
332 
333 static const AVFilterPad inputs[] = {
334  { .name = "default",
335  .type = AVMEDIA_TYPE_VIDEO,
336  .filter_frame = filter_frame,
337  .config_props = config_props,
338  },
339  { NULL }
340 };
341 static const AVFilterPad outputs[] = {
342  { .name = "default",
343  .type = AVMEDIA_TYPE_VIDEO,
344  },
345  { NULL }
346 };
347 
348 #define DEFINE_LUT_FILTER(name_, description_) \
349  AVFilter avfilter_vf_##name_ = { \
350  .name = #name_, \
351  .description = NULL_IF_CONFIG_SMALL(description_), \
352  .priv_size = sizeof(LutContext), \
353  .priv_class = &name_ ## _class, \
354  .init = name_##_init, \
355  .uninit = uninit, \
356  .query_formats = query_formats, \
357  .inputs = inputs, \
358  .outputs = outputs, \
359  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, \
360  }
361 
362 #if CONFIG_LUT_FILTER
363 
364 #define lut_options options
366 
367 static int lut_init(AVFilterContext *ctx)
368 {
369  return 0;
370 }
371 
372 DEFINE_LUT_FILTER(lut, "Compute and apply a lookup table to the RGB/YUV input video.");
373 #endif
374 
375 #if CONFIG_LUTYUV_FILTER
376 
377 #define lutyuv_options options
378 AVFILTER_DEFINE_CLASS(lutyuv);
379 
380 static av_cold int lutyuv_init(AVFilterContext *ctx)
381 {
382  LutContext *s = ctx->priv;
383 
384  s->is_yuv = 1;
385 
386  return 0;
387 }
388 
389 DEFINE_LUT_FILTER(lutyuv, "Compute and apply a lookup table to the YUV input video.");
390 #endif
391 
392 #if CONFIG_LUTRGB_FILTER
393 
394 #define lutrgb_options options
395 AVFILTER_DEFINE_CLASS(lutrgb);
396 
397 static av_cold int lutrgb_init(AVFilterContext *ctx)
398 {
399  LutContext *s = ctx->priv;
400 
401  s->is_rgb = 1;
402 
403  return 0;
404 }
405 
406 DEFINE_LUT_FILTER(lutrgb, "Compute and apply a lookup table to the RGB input video.");
407 #endif
408 
409 #if CONFIG_NEGATE_FILTER
410 
411 static const AVOption negate_options[] = {
412  { "negate_alpha", NULL, OFFSET(negate_alpha), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
413  { NULL }
414 };
415 
416 AVFILTER_DEFINE_CLASS(negate);
417 
418 static av_cold int negate_init(AVFilterContext *ctx)
419 {
420  LutContext *s = ctx->priv;
421  int i;
422 
423  av_log(ctx, AV_LOG_DEBUG, "negate_alpha:%d\n", s->negate_alpha);
424 
425  for (i = 0; i < 4; i++) {
426  s->comp_expr_str[i] = av_strdup((i == 3 && !s->negate_alpha) ?
427  "val" : "negval");
428  if (!s->comp_expr_str[i]) {
429  uninit(ctx);
430  return AVERROR(ENOMEM);
431  }
432  }
433 
434  return 0;
435 }
436 
437 DEFINE_LUT_FILTER(negate, "Negate input video.");
438 
439 #endif