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vf_smartblur.c
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1 /*
2  * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
3  * Copyright (c) 2012 Jeremy Tran
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (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
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License along
18  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20  */
21 
22 /**
23  * @file
24  * Apply a smartblur filter to the input video
25  * Ported from MPlayer libmpcodecs/vf_smartblur.c by Michael Niedermayer.
26  */
27 
28 #include "libavutil/opt.h"
29 #include "libavutil/pixdesc.h"
30 #include "libswscale/swscale.h"
31 
32 #include "avfilter.h"
33 #include "formats.h"
34 #include "internal.h"
35 
36 #define RADIUS_MIN 0.1
37 #define RADIUS_MAX 5.0
38 
39 #define STRENGTH_MIN -1.0
40 #define STRENGTH_MAX 1.0
41 
42 #define THRESHOLD_MIN -30
43 #define THRESHOLD_MAX 30
44 
45 typedef struct {
46  float radius;
47  float strength;
48  int threshold;
49  float quality;
50  struct SwsContext *filter_context;
51 } FilterParam;
52 
53 typedef struct {
54  const AVClass *class;
55  FilterParam luma;
56  FilterParam chroma;
57  int hsub;
58  int vsub;
59  unsigned int sws_flags;
60 } SmartblurContext;
61 
62 #define OFFSET(x) offsetof(SmartblurContext, x)
63 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
64 
65 static const AVOption smartblur_options[] = {
66  { "luma_radius", "set luma radius", OFFSET(luma.radius), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, RADIUS_MIN, RADIUS_MAX, .flags=FLAGS },
67  { "lr" , "set luma radius", OFFSET(luma.radius), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, RADIUS_MIN, RADIUS_MAX, .flags=FLAGS },
68  { "luma_strength", "set luma strength", OFFSET(luma.strength), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, STRENGTH_MIN, STRENGTH_MAX, .flags=FLAGS },
69  { "ls", "set luma strength", OFFSET(luma.strength), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, STRENGTH_MIN, STRENGTH_MAX, .flags=FLAGS },
70  { "luma_threshold", "set luma threshold", OFFSET(luma.threshold), AV_OPT_TYPE_INT, {.i64=0}, THRESHOLD_MIN, THRESHOLD_MAX, .flags=FLAGS },
71  { "lt", "set luma threshold", OFFSET(luma.threshold), AV_OPT_TYPE_INT, {.i64=0}, THRESHOLD_MIN, THRESHOLD_MAX, .flags=FLAGS },
72 
73  { "chroma_radius", "set chroma radius", OFFSET(chroma.radius), AV_OPT_TYPE_FLOAT, {.dbl=RADIUS_MIN-1}, RADIUS_MIN-1, RADIUS_MAX, .flags=FLAGS },
74  { "cr", "set chroma radius", OFFSET(chroma.radius), AV_OPT_TYPE_FLOAT, {.dbl=RADIUS_MIN-1}, RADIUS_MIN-1, RADIUS_MAX, .flags=FLAGS },
75  { "chroma_strength", "set chroma strength", OFFSET(chroma.strength), AV_OPT_TYPE_FLOAT, {.dbl=STRENGTH_MIN-1}, STRENGTH_MIN-1, STRENGTH_MAX, .flags=FLAGS },
76  { "cs", "set chroma strength", OFFSET(chroma.strength), AV_OPT_TYPE_FLOAT, {.dbl=STRENGTH_MIN-1}, STRENGTH_MIN-1, STRENGTH_MAX, .flags=FLAGS },
77  { "chroma_threshold", "set chroma threshold", OFFSET(chroma.threshold), AV_OPT_TYPE_INT, {.i64=THRESHOLD_MIN-1}, THRESHOLD_MIN-1, THRESHOLD_MAX, .flags=FLAGS },
78  { "ct", "set chroma threshold", OFFSET(chroma.threshold), AV_OPT_TYPE_INT, {.i64=THRESHOLD_MIN-1}, THRESHOLD_MIN-1, THRESHOLD_MAX, .flags=FLAGS },
79 
80  { NULL }
81 };
82 
83 AVFILTER_DEFINE_CLASS(smartblur);
84 
85 static av_cold int init(AVFilterContext *ctx)
86 {
87  SmartblurContext *sblur = ctx->priv;
88 
89  /* make chroma default to luma values, if not explicitly set */
90  if (sblur->chroma.radius < RADIUS_MIN)
91  sblur->chroma.radius = sblur->luma.radius;
92  if (sblur->chroma.strength < STRENGTH_MIN)
93  sblur->chroma.strength = sblur->luma.strength;
94  if (sblur->chroma.threshold < THRESHOLD_MIN)
95  sblur->chroma.threshold = sblur->luma.threshold;
96 
97  sblur->luma.quality = sblur->chroma.quality = 3.0;
98  sblur->sws_flags = SWS_BICUBIC;
99 
100  av_log(ctx, AV_LOG_VERBOSE,
101  "luma_radius:%f luma_strength:%f luma_threshold:%d "
102  "chroma_radius:%f chroma_strength:%f chroma_threshold:%d\n",
103  sblur->luma.radius, sblur->luma.strength, sblur->luma.threshold,
104  sblur->chroma.radius, sblur->chroma.strength, sblur->chroma.threshold);
105 
106  return 0;
107 }
108 
109 static av_cold void uninit(AVFilterContext *ctx)
110 {
111  SmartblurContext *sblur = ctx->priv;
112 
113  sws_freeContext(sblur->luma.filter_context);
114  sws_freeContext(sblur->chroma.filter_context);
115 }
116 
117 static int query_formats(AVFilterContext *ctx)
118 {
119  static const enum AVPixelFormat pix_fmts[] = {
120  AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
121  AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P,
122  AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P,
123  AV_PIX_FMT_GRAY8,
124  AV_PIX_FMT_NONE
125  };
126 
127  ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
128 
129  return 0;
130 }
131 
132 static int alloc_sws_context(FilterParam *f, int width, int height, unsigned int flags)
133 {
134  SwsVector *vec;
135  SwsFilter sws_filter;
136 
137  vec = sws_getGaussianVec(f->radius, f->quality);
138 
139  if (!vec)
140  return AVERROR(EINVAL);
141 
142  sws_scaleVec(vec, f->strength);
143  vec->coeff[vec->length / 2] += 1.0 - f->strength;
144  sws_filter.lumH = sws_filter.lumV = vec;
145  sws_filter.chrH = sws_filter.chrV = NULL;
146  f->filter_context = sws_getCachedContext(NULL,
147  width, height, AV_PIX_FMT_GRAY8,
148  width, height, AV_PIX_FMT_GRAY8,
149  flags, &sws_filter, NULL, NULL);
150 
151  sws_freeVec(vec);
152 
153  if (!f->filter_context)
154  return AVERROR(EINVAL);
155 
156  return 0;
157 }
158 
159 static int config_props(AVFilterLink *inlink)
160 {
161  SmartblurContext *sblur = inlink->dst->priv;
162  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
163 
164  sblur->hsub = desc->log2_chroma_w;
165  sblur->vsub = desc->log2_chroma_h;
166 
167  alloc_sws_context(&sblur->luma, inlink->w, inlink->h, sblur->sws_flags);
168  alloc_sws_context(&sblur->chroma,
169  FF_CEIL_RSHIFT(inlink->w, sblur->hsub),
170  FF_CEIL_RSHIFT(inlink->h, sblur->vsub),
171  sblur->sws_flags);
172 
173  return 0;
174 }
175 
176 static void blur(uint8_t *dst, const int dst_linesize,
177  const uint8_t *src, const int src_linesize,
178  const int w, const int h, const int threshold,
179  struct SwsContext *filter_context)
180 {
181  int x, y;
182  int orig, filtered;
183  int diff;
184  /* Declare arrays of 4 to get aligned data */
185  const uint8_t* const src_array[4] = {src};
186  uint8_t *dst_array[4] = {dst};
187  int src_linesize_array[4] = {src_linesize};
188  int dst_linesize_array[4] = {dst_linesize};
189 
190  sws_scale(filter_context, src_array, src_linesize_array,
191  0, h, dst_array, dst_linesize_array);
192 
193  if (threshold > 0) {
194  for (y = 0; y < h; ++y) {
195  for (x = 0; x < w; ++x) {
196  orig = src[x + y * src_linesize];
197  filtered = dst[x + y * dst_linesize];
198  diff = orig - filtered;
199 
200  if (diff > 0) {
201  if (diff > 2 * threshold)
202  dst[x + y * dst_linesize] = orig;
203  else if (diff > threshold)
204  /* add 'diff' and subtract 'threshold' from 'filtered' */
205  dst[x + y * dst_linesize] = orig - threshold;
206  } else {
207  if (-diff > 2 * threshold)
208  dst[x + y * dst_linesize] = orig;
209  else if (-diff > threshold)
210  /* add 'diff' and 'threshold' to 'filtered' */
211  dst[x + y * dst_linesize] = orig + threshold;
212  }
213  }
214  }
215  } else if (threshold < 0) {
216  for (y = 0; y < h; ++y) {
217  for (x = 0; x < w; ++x) {
218  orig = src[x + y * src_linesize];
219  filtered = dst[x + y * dst_linesize];
220  diff = orig - filtered;
221 
222  if (diff > 0) {
223  if (diff <= -threshold)
224  dst[x + y * dst_linesize] = orig;
225  else if (diff <= -2 * threshold)
226  /* subtract 'diff' and 'threshold' from 'orig' */
227  dst[x + y * dst_linesize] = filtered - threshold;
228  } else {
229  if (diff >= threshold)
230  dst[x + y * dst_linesize] = orig;
231  else if (diff >= 2 * threshold)
232  /* add 'threshold' and subtract 'diff' from 'orig' */
233  dst[x + y * dst_linesize] = filtered + threshold;
234  }
235  }
236  }
237  }
238 }
239 
240 static int filter_frame(AVFilterLink *inlink, AVFrame *inpic)
241 {
242  SmartblurContext *sblur = inlink->dst->priv;
243  AVFilterLink *outlink = inlink->dst->outputs[0];
244  AVFrame *outpic;
245  int cw = FF_CEIL_RSHIFT(inlink->w, sblur->hsub);
246  int ch = FF_CEIL_RSHIFT(inlink->h, sblur->vsub);
247 
248  outpic = ff_get_video_buffer(outlink, outlink->w, outlink->h);
249  if (!outpic) {
250  av_frame_free(&inpic);
251  return AVERROR(ENOMEM);
252  }
253  av_frame_copy_props(outpic, inpic);
254 
255  blur(outpic->data[0], outpic->linesize[0],
256  inpic->data[0], inpic->linesize[0],
257  inlink->w, inlink->h, sblur->luma.threshold,
258  sblur->luma.filter_context);
259 
260  if (inpic->data[2]) {
261  blur(outpic->data[1], outpic->linesize[1],
262  inpic->data[1], inpic->linesize[1],
263  cw, ch, sblur->chroma.threshold,
264  sblur->chroma.filter_context);
265  blur(outpic->data[2], outpic->linesize[2],
266  inpic->data[2], inpic->linesize[2],
267  cw, ch, sblur->chroma.threshold,
268  sblur->chroma.filter_context);
269  }
270 
271  av_frame_free(&inpic);
272  return ff_filter_frame(outlink, outpic);
273 }
274 
275 static const AVFilterPad smartblur_inputs[] = {
276  {
277  .name = "default",
278  .type = AVMEDIA_TYPE_VIDEO,
279  .filter_frame = filter_frame,
280  .config_props = config_props,
281  },
282  { NULL }
283 };
284 
285 static const AVFilterPad smartblur_outputs[] = {
286  {
287  .name = "default",
288  .type = AVMEDIA_TYPE_VIDEO,
289  },
290  { NULL }
291 };
292 
293 AVFilter ff_vf_smartblur = {
294  .name = "smartblur",
295  .description = NULL_IF_CONFIG_SMALL("Blur the input video without impacting the outlines."),
296  .priv_size = sizeof(SmartblurContext),
297  .init = init,
298  .uninit = uninit,
299  .query_formats = query_formats,
300  .inputs = smartblur_inputs,
301  .outputs = smartblur_outputs,
302  .priv_class = &smartblur_class,
303  .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
304 };
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