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vf_vignette.c
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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 <float.h> /* DBL_MAX */
22 
23 #include "libavutil/opt.h"
24 #include "libavutil/eval.h"
25 #include "libavutil/avassert.h"
26 #include "libavutil/pixdesc.h"
27 #include "avfilter.h"
28 #include "formats.h"
29 #include "internal.h"
30 #include "video.h"
31 
32 static const char *const var_names[] = {
33  "w", // stream width
34  "h", // stream height
35  "n", // frame count
36  "pts", // presentation timestamp expressed in AV_TIME_BASE units
37  "r", // frame rate
38  "t", // timestamp expressed in seconds
39  "tb", // timebase
40  NULL
41 };
42 
43 enum var_name {
52 };
53 
54 typedef struct {
55  const AVClass *class;
57  int backward;
58  enum EvalMode { EVAL_MODE_INIT, EVAL_MODE_FRAME, EVAL_MODE_NB } eval_mode;
59 #define DEF_EXPR_FIELDS(name) AVExpr *name##_pexpr; char *name##_expr; double name
60  DEF_EXPR_FIELDS(angle);
61  DEF_EXPR_FIELDS(x0);
62  DEF_EXPR_FIELDS(y0);
63  double var_values[VAR_NB];
64  float *fmap;
66  double dmax;
67  float xscale, yscale;
68  uint32_t dither;
69  int do_dither;
73 
74 #define OFFSET(x) offsetof(VignetteContext, x)
75 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
76 static const AVOption vignette_options[] = {
77  { "angle", "set lens angle", OFFSET(angle_expr), AV_OPT_TYPE_STRING, {.str="PI/5"}, .flags = FLAGS },
78  { "a", "set lens angle", OFFSET(angle_expr), AV_OPT_TYPE_STRING, {.str="PI/5"}, .flags = FLAGS },
79  { "x0", "set circle center position on x-axis", OFFSET(x0_expr), AV_OPT_TYPE_STRING, {.str="w/2"}, .flags = FLAGS },
80  { "y0", "set circle center position on y-axis", OFFSET(y0_expr), AV_OPT_TYPE_STRING, {.str="h/2"}, .flags = FLAGS },
81  { "mode", "set forward/backward mode", OFFSET(backward), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS, "mode" },
82  { "forward", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, INT_MIN, INT_MAX, FLAGS, "mode"},
83  { "backward", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, INT_MIN, INT_MAX, FLAGS, "mode"},
84  { "eval", "specify when to evaluate expressions", OFFSET(eval_mode), AV_OPT_TYPE_INT, {.i64 = EVAL_MODE_INIT}, 0, EVAL_MODE_NB-1, FLAGS, "eval" },
85  { "init", "eval expressions once during initialization", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_INIT}, .flags = FLAGS, .unit = "eval" },
86  { "frame", "eval expressions for each frame", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_FRAME}, .flags = FLAGS, .unit = "eval" },
87  { "dither", "set dithering", OFFSET(do_dither), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, FLAGS },
88  { "aspect", "set aspect ratio", OFFSET(aspect), AV_OPT_TYPE_RATIONAL, {.dbl = 1}, 0, DBL_MAX, .flags = FLAGS },
89  { NULL }
90 };
91 
92 AVFILTER_DEFINE_CLASS(vignette);
93 
94 static av_cold int init(AVFilterContext *ctx)
95 {
96  VignetteContext *s = ctx->priv;
97 
98 #define PARSE_EXPR(name) do { \
99  int ret = av_expr_parse(&s->name##_pexpr, s->name##_expr, var_names, \
100  NULL, NULL, NULL, NULL, 0, ctx); \
101  if (ret < 0) { \
102  av_log(ctx, AV_LOG_ERROR, "Unable to parse expression for '" \
103  AV_STRINGIFY(name) "'\n"); \
104  return ret; \
105  } \
106 } while (0)
107 
108  PARSE_EXPR(angle);
109  PARSE_EXPR(x0);
110  PARSE_EXPR(y0);
111  return 0;
112 }
113 
114 static av_cold void uninit(AVFilterContext *ctx)
115 {
116  VignetteContext *s = ctx->priv;
117  av_freep(&s->fmap);
118  av_expr_free(s->angle_pexpr);
119  av_expr_free(s->x0_pexpr);
120  av_expr_free(s->y0_pexpr);
121 }
122 
124 {
125  static const enum AVPixelFormat pix_fmts[] = {
132  };
134  return 0;
135 }
136 
137 static double get_natural_factor(const VignetteContext *s, int x, int y)
138 {
139  const int xx = (x - s->x0) * s->xscale;
140  const int yy = (y - s->y0) * s->yscale;
141  const double dnorm = hypot(xx, yy) / s->dmax;
142  if (dnorm > 1) {
143  return 0;
144  } else {
145  const double c = cos(s->angle * dnorm);
146  return (c*c)*(c*c); // do not remove braces, it helps compilers
147  }
148 }
149 
150 #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
151 #define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts) * av_q2d(tb))
152 
154 {
155  int x, y;
156  float *dst = s->fmap;
157  int dst_linesize = s->fmap_linesize;
158 
159  if (frame) {
160  s->var_values[VAR_N] = inlink->frame_count;
161  s->var_values[VAR_T] = TS2T(frame->pts, inlink->time_base);
162  s->var_values[VAR_PTS] = TS2D(frame->pts);
163  } else {
164  s->var_values[VAR_N] = 0;
165  s->var_values[VAR_T] = NAN;
166  s->var_values[VAR_PTS] = NAN;
167  }
168 
169  s->angle = av_clipf(av_expr_eval(s->angle_pexpr, s->var_values, NULL), 0, M_PI_2);
170  s->x0 = av_expr_eval(s->x0_pexpr, s->var_values, NULL);
171  s->y0 = av_expr_eval(s->y0_pexpr, s->var_values, NULL);
172 
173  if (s->backward) {
174  for (y = 0; y < inlink->h; y++) {
175  for (x = 0; x < inlink->w; x++)
176  dst[x] = 1. / get_natural_factor(s, x, y);
177  dst += dst_linesize;
178  }
179  } else {
180  for (y = 0; y < inlink->h; y++) {
181  for (x = 0; x < inlink->w; x++)
182  dst[x] = get_natural_factor(s, x, y);
183  dst += dst_linesize;
184  }
185  }
186 }
187 
188 static inline double get_dither_value(VignetteContext *s)
189 {
190  double dv = 0;
191  if (s->do_dither) {
192  dv = s->dither / (double)(1LL<<32);
193  s->dither = s->dither * 1664525 + 1013904223;
194  }
195  return dv;
196 }
197 
198 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
199 {
200  unsigned x, y, direct = 0;
201  AVFilterContext *ctx = inlink->dst;
202  VignetteContext *s = ctx->priv;
203  AVFilterLink *outlink = ctx->outputs[0];
204  AVFrame *out;
205 
206  if (av_frame_is_writable(in)) {
207  direct = 1;
208  out = in;
209  } else {
210  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
211  if (!out) {
212  av_frame_free(&in);
213  return AVERROR(ENOMEM);
214  }
215  av_frame_copy_props(out, in);
216  }
217 
218  if (s->eval_mode == EVAL_MODE_FRAME)
219  update_context(s, inlink, in);
220 
221  if (s->desc->flags & AV_PIX_FMT_FLAG_RGB) {
222  uint8_t *dst = out->data[0];
223  const uint8_t *src = in ->data[0];
224  const float *fmap = s->fmap;
225  const int dst_linesize = out->linesize[0];
226  const int src_linesize = in ->linesize[0];
227  const int fmap_linesize = s->fmap_linesize;
228 
229  for (y = 0; y < inlink->h; y++) {
230  uint8_t *dstp = dst;
231  const uint8_t *srcp = src;
232 
233  for (x = 0; x < inlink->w; x++, dstp += 3, srcp += 3) {
234  const float f = fmap[x];
235 
236  dstp[0] = av_clip_uint8(srcp[0] * f + get_dither_value(s));
237  dstp[1] = av_clip_uint8(srcp[1] * f + get_dither_value(s));
238  dstp[2] = av_clip_uint8(srcp[2] * f + get_dither_value(s));
239  }
240  dst += dst_linesize;
241  src += src_linesize;
242  fmap += fmap_linesize;
243  }
244  } else {
245  int plane;
246 
247  for (plane = 0; plane < 4 && in->data[plane] && in->linesize[plane]; plane++) {
248  uint8_t *dst = out->data[plane];
249  const uint8_t *src = in ->data[plane];
250  const float *fmap = s->fmap;
251  const int dst_linesize = out->linesize[plane];
252  const int src_linesize = in ->linesize[plane];
253  const int fmap_linesize = s->fmap_linesize;
254  const int chroma = plane == 1 || plane == 2;
255  const int hsub = chroma ? s->desc->log2_chroma_w : 0;
256  const int vsub = chroma ? s->desc->log2_chroma_h : 0;
257  const int w = FF_CEIL_RSHIFT(inlink->w, hsub);
258  const int h = FF_CEIL_RSHIFT(inlink->h, vsub);
259 
260  for (y = 0; y < h; y++) {
261  uint8_t *dstp = dst;
262  const uint8_t *srcp = src;
263 
264  for (x = 0; x < w; x++) {
265  const double dv = get_dither_value(s);
266  if (chroma) *dstp++ = av_clip_uint8(fmap[x << hsub] * (*srcp++ - 127) + 127 + dv);
267  else *dstp++ = av_clip_uint8(fmap[x ] * *srcp++ + dv);
268  }
269  dst += dst_linesize;
270  src += src_linesize;
271  fmap += fmap_linesize << vsub;
272  }
273  }
274  }
275 
276  if (!direct)
277  av_frame_free(&in);
278  return ff_filter_frame(outlink, out);
279 }
280 
281 static int config_props(AVFilterLink *inlink)
282 {
283  VignetteContext *s = inlink->dst->priv;
284  AVRational sar = inlink->sample_aspect_ratio;
285 
286  s->desc = av_pix_fmt_desc_get(inlink->format);
287  s->var_values[VAR_W] = inlink->w;
288  s->var_values[VAR_H] = inlink->h;
289  s->var_values[VAR_TB] = av_q2d(inlink->time_base);
290  s->var_values[VAR_R] = inlink->frame_rate.num == 0 || inlink->frame_rate.den == 0 ?
291  NAN : av_q2d(inlink->frame_rate);
292 
293  if (!sar.num || !sar.den)
294  sar.num = sar.den = 1;
295  if (sar.num > sar.den) {
296  s->xscale = av_q2d(av_div_q(sar, s->aspect));
297  s->yscale = 1;
298  } else {
299  s->yscale = av_q2d(av_div_q(s->aspect, sar));
300  s->xscale = 1;
301  }
302  s->dmax = hypot(inlink->w / 2., inlink->h / 2.);
303  av_log(s, AV_LOG_DEBUG, "xscale=%f yscale=%f dmax=%f\n",
304  s->xscale, s->yscale, s->dmax);
305 
306  s->fmap_linesize = FFALIGN(inlink->w, 32);
307  s->fmap = av_malloc_array(s->fmap_linesize, inlink->h * sizeof(*s->fmap));
308  if (!s->fmap)
309  return AVERROR(ENOMEM);
310 
311  if (s->eval_mode == EVAL_MODE_INIT)
312  update_context(s, inlink, NULL);
313 
314  return 0;
315 }
316 
317 static const AVFilterPad vignette_inputs[] = {
318  {
319  .name = "default",
320  .type = AVMEDIA_TYPE_VIDEO,
321  .filter_frame = filter_frame,
322  .config_props = config_props,
323  },
324  { NULL }
325 };
326 
327 static const AVFilterPad vignette_outputs[] = {
328  {
329  .name = "default",
330  .type = AVMEDIA_TYPE_VIDEO,
331  },
332  { NULL }
333 };
334 
336  .name = "vignette",
337  .description = NULL_IF_CONFIG_SMALL("Make or reverse a vignette effect."),
338  .priv_size = sizeof(VignetteContext),
339  .init = init,
340  .uninit = uninit,
342  .inputs = vignette_inputs,
343  .outputs = vignette_outputs,
344  .priv_class = &vignette_class,
346 };