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 :
132 
134  return 0;
135 }
136 
137 /**
138  * Clip value val in the minval - maxval range.
139  */
140 static double clip(void *opaque, double val)
141 {
142  LutContext *s = opaque;
143  double minval = s->var_values[VAR_MINVAL];
144  double maxval = s->var_values[VAR_MAXVAL];
145 
146  return av_clip(val, minval, maxval);
147 }
148 
149 /**
150  * Compute gamma correction for value val, assuming the minval-maxval
151  * range, val is clipped to a value contained in the same interval.
152  */
153 static double compute_gammaval(void *opaque, double gamma)
154 {
155  LutContext *s = opaque;
156  double val = s->var_values[VAR_CLIPVAL];
157  double minval = s->var_values[VAR_MINVAL];
158  double maxval = s->var_values[VAR_MAXVAL];
159 
160  return pow((val-minval)/(maxval-minval), gamma) * (maxval-minval)+minval;
161 }
162 
163 static double (* const funcs1[])(void *, double) = {
164  (void *)clip,
165  (void *)compute_gammaval,
166  NULL
167 };
168 
169 static const char * const funcs1_names[] = {
170  "clip",
171  "gammaval",
172  NULL
173 };
174 
175 static int config_props(AVFilterLink *inlink)
176 {
177  AVFilterContext *ctx = inlink->dst;
178  LutContext *s = ctx->priv;
179  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
180  uint8_t rgba_map[4]; /* component index -> RGBA color index map */
181  int min[4], max[4];
182  int val, color, ret;
183 
184  s->hsub = desc->log2_chroma_w;
185  s->vsub = desc->log2_chroma_h;
186 
187  s->var_values[VAR_W] = inlink->w;
188  s->var_values[VAR_H] = inlink->h;
189 
190  switch (inlink->format) {
191  case AV_PIX_FMT_YUV410P:
192  case AV_PIX_FMT_YUV411P:
193  case AV_PIX_FMT_YUV420P:
194  case AV_PIX_FMT_YUV422P:
195  case AV_PIX_FMT_YUV440P:
196  case AV_PIX_FMT_YUV444P:
197  case AV_PIX_FMT_YUVA420P:
198  case AV_PIX_FMT_YUVA422P:
199  case AV_PIX_FMT_YUVA444P:
200  min[Y] = min[U] = min[V] = 16;
201  max[Y] = 235;
202  max[U] = max[V] = 240;
203  min[A] = 0; max[A] = 255;
204  break;
205  default:
206  min[0] = min[1] = min[2] = min[3] = 0;
207  max[0] = max[1] = max[2] = max[3] = 255;
208  }
209 
210  s->is_yuv = s->is_rgb = 0;
211  if (ff_fmt_is_in(inlink->format, yuv_pix_fmts)) s->is_yuv = 1;
212  else if (ff_fmt_is_in(inlink->format, rgb_pix_fmts)) s->is_rgb = 1;
213 
214  if (s->is_rgb) {
215  ff_fill_rgba_map(rgba_map, inlink->format);
216  s->step = av_get_bits_per_pixel(desc) >> 3;
217  }
218 
219  for (color = 0; color < desc->nb_components; color++) {
220  double res;
221  int comp = s->is_rgb ? rgba_map[color] : color;
222 
223  /* create the parsed expression */
224  av_expr_free(s->comp_expr[color]);
225  s->comp_expr[color] = NULL;
226  ret = av_expr_parse(&s->comp_expr[color], s->comp_expr_str[color],
227  var_names, funcs1_names, funcs1, NULL, NULL, 0, ctx);
228  if (ret < 0) {
229  av_log(ctx, AV_LOG_ERROR,
230  "Error when parsing the expression '%s' for the component %d and color %d.\n",
231  s->comp_expr_str[comp], comp, color);
232  return AVERROR(EINVAL);
233  }
234 
235  /* compute the lut */
236  s->var_values[VAR_MAXVAL] = max[color];
237  s->var_values[VAR_MINVAL] = min[color];
238 
239  for (val = 0; val < 256; val++) {
240  s->var_values[VAR_VAL] = val;
241  s->var_values[VAR_CLIPVAL] = av_clip(val, min[color], max[color]);
242  s->var_values[VAR_NEGVAL] =
243  av_clip(min[color] + max[color] - s->var_values[VAR_VAL],
244  min[color], max[color]);
245 
246  res = av_expr_eval(s->comp_expr[color], s->var_values, s);
247  if (isnan(res)) {
248  av_log(ctx, AV_LOG_ERROR,
249  "Error when evaluating the expression '%s' for the value %d for the component %d.\n",
250  s->comp_expr_str[color], val, comp);
251  return AVERROR(EINVAL);
252  }
253  s->lut[comp][val] = av_clip((int)res, min[color], max[color]);
254  av_log(ctx, AV_LOG_DEBUG, "val[%d][%d] = %d\n", comp, val, s->lut[comp][val]);
255  }
256  }
257 
258  return 0;
259 }
260 
261 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
262 {
263  AVFilterContext *ctx = inlink->dst;
264  LutContext *s = ctx->priv;
265  AVFilterLink *outlink = ctx->outputs[0];
266  AVFrame *out;
267  uint8_t *inrow, *outrow, *inrow0, *outrow0;
268  int i, j, plane, direct = 0;
269 
270  if (av_frame_is_writable(in)) {
271  direct = 1;
272  out = in;
273  } else {
274  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
275  if (!out) {
276  av_frame_free(&in);
277  return AVERROR(ENOMEM);
278  }
279  av_frame_copy_props(out, in);
280  }
281 
282  if (s->is_rgb) {
283  /* packed */
284  inrow0 = in ->data[0];
285  outrow0 = out->data[0];
286 
287  for (i = 0; i < in->height; i ++) {
288  int w = inlink->w;
289  const uint8_t (*tab)[256] = (const uint8_t (*)[256])s->lut;
290  inrow = inrow0;
291  outrow = outrow0;
292  for (j = 0; j < w; j++) {
293  switch (s->step) {
294  case 4: outrow[3] = tab[3][inrow[3]]; // Fall-through
295  case 3: outrow[2] = tab[2][inrow[2]]; // Fall-through
296  case 2: outrow[1] = tab[1][inrow[1]]; // Fall-through
297  default: outrow[0] = tab[0][inrow[0]];
298  }
299  outrow += s->step;
300  inrow += s->step;
301  }
302  inrow0 += in ->linesize[0];
303  outrow0 += out->linesize[0];
304  }
305  } else {
306  /* planar */
307  for (plane = 0; plane < 4 && in->data[plane]; plane++) {
308  int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
309  int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
310  int h = FF_CEIL_RSHIFT(inlink->h, vsub);
311  int w = FF_CEIL_RSHIFT(inlink->w, hsub);
312 
313  inrow = in ->data[plane];
314  outrow = out->data[plane];
315 
316  for (i = 0; i < h; i++) {
317  const uint8_t *tab = s->lut[plane];
318  for (j = 0; j < w; j++)
319  outrow[j] = tab[inrow[j]];
320  inrow += in ->linesize[plane];
321  outrow += out->linesize[plane];
322  }
323  }
324  }
325 
326  if (!direct)
327  av_frame_free(&in);
328 
329  return ff_filter_frame(outlink, out);
330 }
331 
332 static const AVFilterPad inputs[] = {
333  { .name = "default",
334  .type = AVMEDIA_TYPE_VIDEO,
335  .filter_frame = filter_frame,
336  .config_props = config_props,
337  },
338  { .name = NULL}
339 };
340 static const AVFilterPad outputs[] = {
341  { .name = "default",
342  .type = AVMEDIA_TYPE_VIDEO, },
343  { .name = NULL}
344 };
345 
346 #define DEFINE_LUT_FILTER(name_, description_) \
347  AVFilter avfilter_vf_##name_ = { \
348  .name = #name_, \
349  .description = NULL_IF_CONFIG_SMALL(description_), \
350  .priv_size = sizeof(LutContext), \
351  .priv_class = &name_ ## _class, \
352  \
353  .init = name_##_init, \
354  .uninit = uninit, \
355  .query_formats = query_formats, \
356  \
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