FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vf_curves.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2013 Clément Bœsch
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 #include "libavutil/opt.h"
22 #include "libavutil/bprint.h"
23 #include "libavutil/eval.h"
24 #include "libavutil/file.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/avassert.h"
27 #include "libavutil/pixdesc.h"
28 #include "avfilter.h"
29 #include "drawutils.h"
30 #include "formats.h"
31 #include "internal.h"
32 #include "video.h"
33 
34 #define R 0
35 #define G 1
36 #define B 2
37 #define A 3
38 
39 struct keypoint {
40  double x, y;
41  struct keypoint *next;
42 };
43 
44 #define NB_COMP 3
45 
46 enum preset {
59 };
60 
61 typedef struct {
62  const AVClass *class;
63  enum preset preset;
64  char *comp_points_str[NB_COMP + 1];
66  uint8_t graph[NB_COMP + 1][256];
67  char *psfile;
68  uint8_t rgba_map[4];
69  int step;
71 
72 #define OFFSET(x) offsetof(CurvesContext, x)
73 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
74 static const AVOption curves_options[] = {
75  { "preset", "select a color curves preset", OFFSET(preset), AV_OPT_TYPE_INT, {.i64=PRESET_NONE}, PRESET_NONE, NB_PRESETS-1, FLAGS, "preset_name" },
76  { "none", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_NONE}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
77  { "color_negative", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_COLOR_NEGATIVE}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
78  { "cross_process", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_CROSS_PROCESS}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
79  { "darker", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_DARKER}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
80  { "increase_contrast", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_INCREASE_CONTRAST}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
81  { "lighter", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_LIGHTER}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
82  { "linear_contrast", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_LINEAR_CONTRAST}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
83  { "medium_contrast", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_MEDIUM_CONTRAST}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
84  { "negative", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_NEGATIVE}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
85  { "strong_contrast", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_STRONG_CONTRAST}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
86  { "vintage", NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_VINTAGE}, INT_MIN, INT_MAX, FLAGS, "preset_name" },
87  { "master","set master points coordinates",OFFSET(comp_points_str[NB_COMP]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
88  { "m", "set master points coordinates",OFFSET(comp_points_str[NB_COMP]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
89  { "red", "set red points coordinates", OFFSET(comp_points_str[0]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
90  { "r", "set red points coordinates", OFFSET(comp_points_str[0]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
91  { "green", "set green points coordinates", OFFSET(comp_points_str[1]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
92  { "g", "set green points coordinates", OFFSET(comp_points_str[1]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
93  { "blue", "set blue points coordinates", OFFSET(comp_points_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
94  { "b", "set blue points coordinates", OFFSET(comp_points_str[2]), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
95  { "all", "set points coordinates for all components", OFFSET(comp_points_str_all), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
96  { "psfile", "set Photoshop curves file name", OFFSET(psfile), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
97  { NULL }
98 };
99 
100 AVFILTER_DEFINE_CLASS(curves);
101 
102 static const struct {
103  const char *r;
104  const char *g;
105  const char *b;
106  const char *master;
107 } curves_presets[] = {
109  "0/1 0.129/1 0.466/0.498 0.725/0 1/0",
110  "0/1 0.109/1 0.301/0.498 0.517/0 1/0",
111  "0/1 0.098/1 0.235/0.498 0.423/0 1/0",
112  },
114  "0.25/0.156 0.501/0.501 0.686/0.745",
115  "0.25/0.188 0.38/0.501 0.745/0.815 1/0.815",
116  "0.231/0.094 0.709/0.874",
117  },
118  [PRESET_DARKER] = { .master = "0.5/0.4" },
119  [PRESET_INCREASE_CONTRAST] = { .master = "0.149/0.066 0.831/0.905 0.905/0.98" },
120  [PRESET_LIGHTER] = { .master = "0.4/0.5" },
121  [PRESET_LINEAR_CONTRAST] = { .master = "0.305/0.286 0.694/0.713" },
122  [PRESET_MEDIUM_CONTRAST] = { .master = "0.286/0.219 0.639/0.643" },
123  [PRESET_NEGATIVE] = { .master = "0/1 1/0" },
124  [PRESET_STRONG_CONTRAST] = { .master = "0.301/0.196 0.592/0.6 0.686/0.737" },
125  [PRESET_VINTAGE] = {
126  "0/0.11 0.42/0.51 1/0.95",
127  "0.50/0.48",
128  "0/0.22 0.49/0.44 1/0.8",
129  }
130 };
131 
132 static struct keypoint *make_point(double x, double y, struct keypoint *next)
133 {
134  struct keypoint *point = av_mallocz(sizeof(*point));
135 
136  if (!point)
137  return NULL;
138  point->x = x;
139  point->y = y;
140  point->next = next;
141  return point;
142 }
143 
144 static int parse_points_str(AVFilterContext *ctx, struct keypoint **points, const char *s)
145 {
146  char *p = (char *)s; // strtod won't alter the string
147  struct keypoint *last = NULL;
148 
149  /* construct a linked list based on the key points string */
150  while (p && *p) {
151  struct keypoint *point = make_point(0, 0, NULL);
152  if (!point)
153  return AVERROR(ENOMEM);
154  point->x = av_strtod(p, &p); if (p && *p) p++;
155  point->y = av_strtod(p, &p); if (p && *p) p++;
156  if (point->x < 0 || point->x > 1 || point->y < 0 || point->y > 1) {
157  av_log(ctx, AV_LOG_ERROR, "Invalid key point coordinates (%f;%f), "
158  "x and y must be in the [0;1] range.\n", point->x, point->y);
159  return AVERROR(EINVAL);
160  }
161  if (!*points)
162  *points = point;
163  if (last) {
164  if ((int)(last->x * 255) >= (int)(point->x * 255)) {
165  av_log(ctx, AV_LOG_ERROR, "Key point coordinates (%f;%f) "
166  "and (%f;%f) are too close from each other or not "
167  "strictly increasing on the x-axis\n",
168  last->x, last->y, point->x, point->y);
169  return AVERROR(EINVAL);
170  }
171  last->next = point;
172  }
173  last = point;
174  }
175 
176  /* auto insert first key point if missing at x=0 */
177  if (!*points) {
178  last = make_point(0, 0, NULL);
179  if (!last)
180  return AVERROR(ENOMEM);
181  last->x = last->y = 0;
182  *points = last;
183  } else if ((*points)->x != 0.) {
184  struct keypoint *newfirst = make_point(0, 0, *points);
185  if (!newfirst)
186  return AVERROR(ENOMEM);
187  *points = newfirst;
188  }
189 
190  av_assert0(last);
191 
192  /* auto insert last key point if missing at x=1 */
193  if (last->x != 1.) {
194  struct keypoint *point = make_point(1, 1, NULL);
195  if (!point)
196  return AVERROR(ENOMEM);
197  last->next = point;
198  }
199 
200  return 0;
201 }
202 
203 static int get_nb_points(const struct keypoint *d)
204 {
205  int n = 0;
206  while (d) {
207  n++;
208  d = d->next;
209  }
210  return n;
211 }
212 
213 /**
214  * Natural cubic spline interpolation
215  * Finding curves using Cubic Splines notes by Steven Rauch and John Stockie.
216  * @see http://people.math.sfu.ca/~stockie/teaching/macm316/notes/splines.pdf
217  */
218 static int interpolate(AVFilterContext *ctx, uint8_t *y, const struct keypoint *points)
219 {
220  int i, ret = 0;
221  const struct keypoint *point;
222  double xprev = 0;
223 
224  int n = get_nb_points(points); // number of splines
225 
226  double (*matrix)[3] = av_calloc(n, sizeof(*matrix));
227  double *h = av_malloc((n - 1) * sizeof(*h));
228  double *r = av_calloc(n, sizeof(*r));
229 
230  if (!matrix || !h || !r) {
231  ret = AVERROR(ENOMEM);
232  goto end;
233  }
234 
235  /* h(i) = x(i+1) - x(i) */
236  i = -1;
237  for (point = points; point; point = point->next) {
238  if (i != -1)
239  h[i] = point->x - xprev;
240  xprev = point->x;
241  i++;
242  }
243 
244  /* right-side of the polynomials, will be modified to contains the solution */
245  point = points;
246  for (i = 1; i < n - 1; i++) {
247  double yp = point->y,
248  yc = point->next->y,
249  yn = point->next->next->y;
250  r[i] = 6 * ((yn-yc)/h[i] - (yc-yp)/h[i-1]);
251  point = point->next;
252  }
253 
254 #define BD 0 /* sub diagonal (below main) */
255 #define MD 1 /* main diagonal (center) */
256 #define AD 2 /* sup diagonal (above main) */
257 
258  /* left side of the polynomials into a tridiagonal matrix. */
259  matrix[0][MD] = matrix[n - 1][MD] = 1;
260  for (i = 1; i < n - 1; i++) {
261  matrix[i][BD] = h[i-1];
262  matrix[i][MD] = 2 * (h[i-1] + h[i]);
263  matrix[i][AD] = h[i];
264  }
265 
266  /* tridiagonal solving of the linear system */
267  for (i = 1; i < n; i++) {
268  double den = matrix[i][MD] - matrix[i][BD] * matrix[i-1][AD];
269  double k = den ? 1./den : 1.;
270  matrix[i][AD] *= k;
271  r[i] = (r[i] - matrix[i][BD] * r[i - 1]) * k;
272  }
273  for (i = n - 2; i >= 0; i--)
274  r[i] = r[i] - matrix[i][AD] * r[i + 1];
275 
276  /* compute the graph with x=[0..255] */
277  i = 0;
278  point = points;
279  av_assert0(point->next); // always at least 2 key points
280  while (point->next) {
281  double yc = point->y;
282  double yn = point->next->y;
283 
284  double a = yc;
285  double b = (yn-yc)/h[i] - h[i]*r[i]/2. - h[i]*(r[i+1]-r[i])/6.;
286  double c = r[i] / 2.;
287  double d = (r[i+1] - r[i]) / (6.*h[i]);
288 
289  int x;
290  int x_start = point->x * 255;
291  int x_end = point->next->x * 255;
292 
293  av_assert0(x_start >= 0 && x_start <= 255 &&
294  x_end >= 0 && x_end <= 255);
295 
296  for (x = x_start; x <= x_end; x++) {
297  double xx = (x - x_start) * 1/255.;
298  double yy = a + b*xx + c*xx*xx + d*xx*xx*xx;
299  y[x] = av_clipf(yy, 0, 1) * 255;
300  av_log(ctx, AV_LOG_DEBUG, "f(%f)=%f -> y[%d]=%d\n", xx, yy, x, y[x]);
301  }
302 
303  point = point->next;
304  i++;
305  }
306 
307 end:
308  av_free(matrix);
309  av_free(h);
310  av_free(r);
311  return ret;
312 }
313 
314 static int parse_psfile(AVFilterContext *ctx, const char *fname)
315 {
316  CurvesContext *curves = ctx->priv;
317  uint8_t *buf;
318  size_t size;
319  int i, ret, av_unused(version), nb_curves;
320  AVBPrint ptstr;
321  static const int comp_ids[] = {3, 0, 1, 2};
322 
324 
325  ret = av_file_map(fname, &buf, &size, 0, NULL);
326  if (ret < 0)
327  return ret;
328 
329 #define READ16(dst) do { \
330  if (size < 2) \
331  return AVERROR_INVALIDDATA; \
332  dst = AV_RB16(buf); \
333  buf += 2; \
334  size -= 2; \
335 } while (0)
336 
337  READ16(version);
338  READ16(nb_curves);
339  for (i = 0; i < FFMIN(nb_curves, FF_ARRAY_ELEMS(comp_ids)); i++) {
340  int nb_points, n;
341  av_bprint_clear(&ptstr);
342  READ16(nb_points);
343  for (n = 0; n < nb_points; n++) {
344  int y, x;
345  READ16(y);
346  READ16(x);
347  av_bprintf(&ptstr, "%f/%f ", x / 255., y / 255.);
348  }
349  if (*ptstr.str) {
350  char **pts = &curves->comp_points_str[comp_ids[i]];
351  if (!*pts) {
352  *pts = av_strdup(ptstr.str);
353  av_log(ctx, AV_LOG_DEBUG, "curves %d (intid=%d) [%d points]: [%s]\n",
354  i, comp_ids[i], nb_points, *pts);
355  if (!*pts) {
356  ret = AVERROR(ENOMEM);
357  goto end;
358  }
359  }
360  }
361  }
362 end:
363  av_bprint_finalize(&ptstr, NULL);
364  av_file_unmap(buf, size);
365  return ret;
366 }
367 
368 static av_cold int init(AVFilterContext *ctx)
369 {
370  int i, j, ret;
371  CurvesContext *curves = ctx->priv;
372  struct keypoint *comp_points[NB_COMP + 1] = {0};
373  char **pts = curves->comp_points_str;
374  const char *allp = curves->comp_points_str_all;
375 
376  //if (!allp && curves->preset != PRESET_NONE && curves_presets[curves->preset].all)
377  // allp = curves_presets[curves->preset].all;
378 
379  if (allp) {
380  for (i = 0; i < NB_COMP; i++) {
381  if (!pts[i])
382  pts[i] = av_strdup(allp);
383  if (!pts[i])
384  return AVERROR(ENOMEM);
385  }
386  }
387 
388  if (curves->psfile) {
389  ret = parse_psfile(ctx, curves->psfile);
390  if (ret < 0)
391  return ret;
392  }
393 
394  if (curves->preset != PRESET_NONE) {
395 #define SET_COMP_IF_NOT_SET(n, name) do { \
396  if (!pts[n] && curves_presets[curves->preset].name) { \
397  pts[n] = av_strdup(curves_presets[curves->preset].name); \
398  if (!pts[n]) \
399  return AVERROR(ENOMEM); \
400  } \
401 } while (0)
406  }
407 
408  for (i = 0; i < NB_COMP + 1; i++) {
409  ret = parse_points_str(ctx, comp_points + i, curves->comp_points_str[i]);
410  if (ret < 0)
411  return ret;
412  ret = interpolate(ctx, curves->graph[i], comp_points[i]);
413  if (ret < 0)
414  return ret;
415  }
416 
417  if (pts[NB_COMP]) {
418  for (i = 0; i < NB_COMP; i++)
419  for (j = 0; j < 256; j++)
420  curves->graph[i][j] = curves->graph[NB_COMP][curves->graph[i][j]];
421  }
422 
423  if (av_log_get_level() >= AV_LOG_VERBOSE) {
424  for (i = 0; i < NB_COMP; i++) {
425  struct keypoint *point = comp_points[i];
426  av_log(ctx, AV_LOG_VERBOSE, "#%d points:", i);
427  while (point) {
428  av_log(ctx, AV_LOG_VERBOSE, " (%f;%f)", point->x, point->y);
429  point = point->next;
430  }
431  av_log(ctx, AV_LOG_VERBOSE, "\n");
432  av_log(ctx, AV_LOG_VERBOSE, "#%d values:", i);
433  for (j = 0; j < 256; j++)
434  av_log(ctx, AV_LOG_VERBOSE, " %02X", curves->graph[i][j]);
435  av_log(ctx, AV_LOG_VERBOSE, "\n");
436  }
437  }
438 
439  for (i = 0; i < NB_COMP + 1; i++) {
440  struct keypoint *point = comp_points[i];
441  while (point) {
442  struct keypoint *next = point->next;
443  av_free(point);
444  point = next;
445  }
446  }
447 
448  return 0;
449 }
450 
452 {
453  static const enum AVPixelFormat pix_fmts[] = {
460  };
462  return 0;
463 }
464 
465 static int config_input(AVFilterLink *inlink)
466 {
467  CurvesContext *curves = inlink->dst->priv;
468  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
469 
470  ff_fill_rgba_map(curves->rgba_map, inlink->format);
471  curves->step = av_get_padded_bits_per_pixel(desc) >> 3;
472 
473  return 0;
474 }
475 
476 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
477 {
478  int x, y, direct = 0;
479  AVFilterContext *ctx = inlink->dst;
480  CurvesContext *curves = ctx->priv;
481  AVFilterLink *outlink = ctx->outputs[0];
482  AVFrame *out;
483  uint8_t *dst;
484  const uint8_t *src;
485  const int step = curves->step;
486  const uint8_t r = curves->rgba_map[R];
487  const uint8_t g = curves->rgba_map[G];
488  const uint8_t b = curves->rgba_map[B];
489  const uint8_t a = curves->rgba_map[A];
490 
491  if (av_frame_is_writable(in)) {
492  direct = 1;
493  out = in;
494  } else {
495  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
496  if (!out) {
497  av_frame_free(&in);
498  return AVERROR(ENOMEM);
499  }
500  av_frame_copy_props(out, in);
501  }
502 
503  dst = out->data[0];
504  src = in ->data[0];
505 
506  for (y = 0; y < inlink->h; y++) {
507  for (x = 0; x < inlink->w * step; x += step) {
508  dst[x + r] = curves->graph[R][src[x + r]];
509  dst[x + g] = curves->graph[G][src[x + g]];
510  dst[x + b] = curves->graph[B][src[x + b]];
511  if (!direct && step == 4)
512  dst[x + a] = src[x + a];
513  }
514  dst += out->linesize[0];
515  src += in ->linesize[0];
516  }
517 
518  if (!direct)
519  av_frame_free(&in);
520 
521  return ff_filter_frame(outlink, out);
522 }
523 
524 static const AVFilterPad curves_inputs[] = {
525  {
526  .name = "default",
527  .type = AVMEDIA_TYPE_VIDEO,
528  .filter_frame = filter_frame,
529  .config_props = config_input,
530  },
531  { NULL }
532 };
533 
534 static const AVFilterPad curves_outputs[] = {
535  {
536  .name = "default",
537  .type = AVMEDIA_TYPE_VIDEO,
538  },
539  { NULL }
540 };
541 
543  .name = "curves",
544  .description = NULL_IF_CONFIG_SMALL("Adjust components curves."),
545  .priv_size = sizeof(CurvesContext),
546  .init = init,
548  .inputs = curves_inputs,
549  .outputs = curves_outputs,
550  .priv_class = &curves_class,
552 };