vf_gradfun.c
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1 /*
2  * Copyright (c) 2010 Nolan Lum <nol888@gmail.com>
3  * Copyright (c) 2009 Loren Merritt <lorenm@u.washignton.edu>
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav 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 GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
35 #include "libavutil/imgutils.h"
36 #include "libavutil/common.h"
37 #include "libavutil/cpu.h"
38 #include "libavutil/pixdesc.h"
39 #include "avfilter.h"
40 #include "formats.h"
41 #include "gradfun.h"
42 #include "internal.h"
43 #include "video.h"
44 
45 DECLARE_ALIGNED(16, static const uint16_t, dither)[8][8] = {
46  {0x00,0x60,0x18,0x78,0x06,0x66,0x1E,0x7E},
47  {0x40,0x20,0x58,0x38,0x46,0x26,0x5E,0x3E},
48  {0x10,0x70,0x08,0x68,0x16,0x76,0x0E,0x6E},
49  {0x50,0x30,0x48,0x28,0x56,0x36,0x4E,0x2E},
50  {0x04,0x64,0x1C,0x7C,0x02,0x62,0x1A,0x7A},
51  {0x44,0x24,0x5C,0x3C,0x42,0x22,0x5A,0x3A},
52  {0x14,0x74,0x0C,0x6C,0x12,0x72,0x0A,0x6A},
53  {0x54,0x34,0x4C,0x2C,0x52,0x32,0x4A,0x2A},
54 };
55 
56 void ff_gradfun_filter_line_c(uint8_t *dst, uint8_t *src, uint16_t *dc, int width, int thresh, const uint16_t *dithers)
57 {
58  int x;
59  for (x = 0; x < width; x++, dc += x & 1) {
60  int pix = src[x] << 7;
61  int delta = dc[0] - pix;
62  int m = abs(delta) * thresh >> 16;
63  m = FFMAX(0, 127 - m);
64  m = m * m * delta >> 14;
65  pix += m + dithers[x & 7];
66  dst[x] = av_clip_uint8(pix >> 7);
67  }
68 }
69 
70 void ff_gradfun_blur_line_c(uint16_t *dc, uint16_t *buf, uint16_t *buf1, uint8_t *src, int src_linesize, int width)
71 {
72  int x, v, old;
73  for (x = 0; x < width; x++) {
74  v = buf1[x] + src[2 * x] + src[2 * x + 1] + src[2 * x + src_linesize] + src[2 * x + 1 + src_linesize];
75  old = buf[x];
76  buf[x] = v;
77  dc[x] = v - old;
78  }
79 }
80 
81 static void filter(GradFunContext *ctx, uint8_t *dst, uint8_t *src, int width, int height, int dst_linesize, int src_linesize, int r)
82 {
83  int bstride = FFALIGN(width, 16) / 2;
84  int y;
85  uint32_t dc_factor = (1 << 21) / (r * r);
86  uint16_t *dc = ctx->buf + 16;
87  uint16_t *buf = ctx->buf + bstride + 32;
88  int thresh = ctx->thresh;
89 
90  memset(dc, 0, (bstride + 16) * sizeof(*buf));
91  for (y = 0; y < r; y++)
92  ctx->blur_line(dc, buf + y * bstride, buf + (y - 1) * bstride, src + 2 * y * src_linesize, src_linesize, width / 2);
93  for (;;) {
94  if (y < height - r) {
95  int mod = ((y + r) / 2) % r;
96  uint16_t *buf0 = buf + mod * bstride;
97  uint16_t *buf1 = buf + (mod ? mod - 1 : r - 1) * bstride;
98  int x, v;
99  ctx->blur_line(dc, buf0, buf1, src + (y + r) * src_linesize, src_linesize, width / 2);
100  for (x = v = 0; x < r; x++)
101  v += dc[x];
102  for (; x < width / 2; x++) {
103  v += dc[x] - dc[x-r];
104  dc[x-r] = v * dc_factor >> 16;
105  }
106  for (; x < (width + r + 1) / 2; x++)
107  dc[x-r] = v * dc_factor >> 16;
108  for (x = -r / 2; x < 0; x++)
109  dc[x] = dc[0];
110  }
111  if (y == r) {
112  for (y = 0; y < r; y++)
113  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
114  }
115  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
116  if (++y >= height) break;
117  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
118  if (++y >= height) break;
119  }
120  emms_c();
121 }
122 
123 static av_cold int init(AVFilterContext *ctx, const char *args)
124 {
125  GradFunContext *gf = ctx->priv;
126  float thresh = 1.2;
127  int radius = 16;
128 
129  if (args)
130  sscanf(args, "%f:%d", &thresh, &radius);
131 
132  thresh = av_clipf(thresh, 0.51, 255);
133  gf->thresh = (1 << 15) / thresh;
134  gf->radius = av_clip((radius + 1) & ~1, 4, 32);
135 
138 
139  if (ARCH_X86)
141 
142  av_log(ctx, AV_LOG_VERBOSE, "threshold:%.2f radius:%d\n", thresh, gf->radius);
143 
144  return 0;
145 }
146 
147 static av_cold void uninit(AVFilterContext *ctx)
148 {
149  GradFunContext *gf = ctx->priv;
150  av_freep(&gf->buf);
151 }
152 
154 {
155  static const enum AVPixelFormat pix_fmts[] = {
161  };
162 
164 
165  return 0;
166 }
167 
168 static int config_input(AVFilterLink *inlink)
169 {
170  GradFunContext *gf = inlink->dst->priv;
171  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
172  int hsub = desc->log2_chroma_w;
173  int vsub = desc->log2_chroma_h;
174 
175  gf->buf = av_mallocz((FFALIGN(inlink->w, 16) * (gf->radius + 1) / 2 + 32) * sizeof(uint16_t));
176  if (!gf->buf)
177  return AVERROR(ENOMEM);
178 
179  gf->chroma_w = -((-inlink->w) >> hsub);
180  gf->chroma_h = -((-inlink->h) >> vsub);
181  gf->chroma_r = av_clip(((((gf->radius >> hsub) + (gf->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32);
182 
183  return 0;
184 }
185 
187 {
188  GradFunContext *gf = inlink->dst->priv;
189  AVFilterLink *outlink = inlink->dst->outputs[0];
190  AVFilterBufferRef *out;
191  int p, direct;
192 
193  if ((in->perms & AV_PERM_WRITE) && !(in->perms & AV_PERM_PRESERVE)) {
194  direct = 1;
195  out = in;
196  } else {
197  direct = 0;
198  out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
199  if (!out) {
201  return AVERROR(ENOMEM);
202  }
203 
205  out->video->w = outlink->w;
206  out->video->h = outlink->h;
207  }
208 
209  for (p = 0; p < 4 && in->data[p]; p++) {
210  int w = inlink->w;
211  int h = inlink->h;
212  int r = gf->radius;
213  if (p) {
214  w = gf->chroma_w;
215  h = gf->chroma_h;
216  r = gf->chroma_r;
217  }
218 
219  if (FFMIN(w, h) > 2 * r)
220  filter(gf, out->data[p], in->data[p], w, h, out->linesize[p], in->linesize[p], r);
221  else if (out->data[p] != in->data[p])
222  av_image_copy_plane(out->data[p], out->linesize[p], in->data[p], in->linesize[p], w, h);
223  }
224 
225  if (!direct)
227 
228  return ff_filter_frame(outlink, out);
229 }
230 
232  {
233  .name = "default",
234  .type = AVMEDIA_TYPE_VIDEO,
235  .config_props = config_input,
236  .filter_frame = filter_frame,
237  .min_perms = AV_PERM_READ,
238  },
239  { NULL }
240 };
241 
243  {
244  .name = "default",
245  .type = AVMEDIA_TYPE_VIDEO,
246  },
247  { NULL }
248 };
249 
251  .name = "gradfun",
252  .description = NULL_IF_CONFIG_SMALL("Debands video quickly using gradients."),
253  .priv_size = sizeof(GradFunContext),
254  .init = init,
255  .uninit = uninit,
257 
258  .inputs = avfilter_vf_gradfun_inputs,
259  .outputs = avfilter_vf_gradfun_outputs,
260 };