Libav
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.washington.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/opt.h"
39 #include "libavutil/pixdesc.h"
40 #include "avfilter.h"
41 #include "formats.h"
42 #include "gradfun.h"
43 #include "internal.h"
44 #include "video.h"
45 
46 DECLARE_ALIGNED(16, static const uint16_t, dither)[8][8] = {
47  {0x00,0x60,0x18,0x78,0x06,0x66,0x1E,0x7E},
48  {0x40,0x20,0x58,0x38,0x46,0x26,0x5E,0x3E},
49  {0x10,0x70,0x08,0x68,0x16,0x76,0x0E,0x6E},
50  {0x50,0x30,0x48,0x28,0x56,0x36,0x4E,0x2E},
51  {0x04,0x64,0x1C,0x7C,0x02,0x62,0x1A,0x7A},
52  {0x44,0x24,0x5C,0x3C,0x42,0x22,0x5A,0x3A},
53  {0x14,0x74,0x0C,0x6C,0x12,0x72,0x0A,0x6A},
54  {0x54,0x34,0x4C,0x2C,0x52,0x32,0x4A,0x2A},
55 };
56 
57 void ff_gradfun_filter_line_c(uint8_t *dst, uint8_t *src, uint16_t *dc, int width, int thresh, const uint16_t *dithers)
58 {
59  int x;
60  for (x = 0; x < width; dc += x & 1, x++) {
61  int pix = src[x] << 7;
62  int delta = dc[0] - pix;
63  int m = abs(delta) * thresh >> 16;
64  m = FFMAX(0, 127 - m);
65  m = m * m * delta >> 14;
66  pix += m + dithers[x & 7];
67  dst[x] = av_clip_uint8(pix >> 7);
68  }
69 }
70 
71 void ff_gradfun_blur_line_c(uint16_t *dc, uint16_t *buf, uint16_t *buf1, uint8_t *src, int src_linesize, int width)
72 {
73  int x, v, old;
74  for (x = 0; x < width; x++) {
75  v = buf1[x] + src[2 * x] + src[2 * x + 1] + src[2 * x + src_linesize] + src[2 * x + 1 + src_linesize];
76  old = buf[x];
77  buf[x] = v;
78  dc[x] = v - old;
79  }
80 }
81 
82 static void filter(GradFunContext *ctx, uint8_t *dst, uint8_t *src, int width, int height, int dst_linesize, int src_linesize, int r)
83 {
84  int bstride = FFALIGN(width, 16) / 2;
85  int y;
86  uint32_t dc_factor = (1 << 21) / (r * r);
87  uint16_t *dc = ctx->buf + 16;
88  uint16_t *buf = ctx->buf + bstride + 32;
89  int thresh = ctx->thresh;
90 
91  memset(dc, 0, (bstride + 16) * sizeof(*buf));
92  for (y = 0; y < r; y++)
93  ctx->blur_line(dc, buf + y * bstride, buf + (y - 1) * bstride, src + 2 * y * src_linesize, src_linesize, width / 2);
94  for (;;) {
95  if (y < height - r) {
96  int mod = ((y + r) / 2) % r;
97  uint16_t *buf0 = buf + mod * bstride;
98  uint16_t *buf1 = buf + (mod ? mod - 1 : r - 1) * bstride;
99  int x, v;
100  ctx->blur_line(dc, buf0, buf1, src + (y + r) * src_linesize, src_linesize, width / 2);
101  for (x = v = 0; x < r; x++)
102  v += dc[x];
103  for (; x < width / 2; x++) {
104  v += dc[x] - dc[x-r];
105  dc[x-r] = v * dc_factor >> 16;
106  }
107  for (; x < (width + r + 1) / 2; x++)
108  dc[x-r] = v * dc_factor >> 16;
109  for (x = -r / 2; x < 0; x++)
110  dc[x] = dc[0];
111  }
112  if (y == r) {
113  for (y = 0; y < r; y++)
114  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
115  }
116  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
117  if (++y >= height) break;
118  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
119  if (++y >= height) break;
120  }
121  emms_c();
122 }
123 
124 static av_cold int init(AVFilterContext *ctx)
125 {
126  GradFunContext *s = ctx->priv;
127 
128  s->thresh = (1 << 15) / s->strength;
129  s->radius &= ~1;
130 
133 
134  if (ARCH_X86)
136 
137  av_log(ctx, AV_LOG_VERBOSE, "threshold:%.2f radius:%d\n", s->strength, s->radius);
138 
139  return 0;
140 }
141 
142 static av_cold void uninit(AVFilterContext *ctx)
143 {
144  GradFunContext *s = ctx->priv;
145  av_freep(&s->buf);
146 }
147 
149 {
150  static const enum AVPixelFormat pix_fmts[] = {
156  };
157 
159 
160  return 0;
161 }
162 
163 static int config_input(AVFilterLink *inlink)
164 {
165  GradFunContext *s = inlink->dst->priv;
166  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
167  int hsub = desc->log2_chroma_w;
168  int vsub = desc->log2_chroma_h;
169 
170  av_freep(&s->buf);
171  s->buf = av_mallocz((FFALIGN(inlink->w, 16) * (s->radius + 1) / 2 + 32) * sizeof(uint16_t));
172  if (!s->buf)
173  return AVERROR(ENOMEM);
174 
175  s->chroma_w = -((-inlink->w) >> hsub);
176  s->chroma_h = -((-inlink->h) >> vsub);
177  s->chroma_r = av_clip(((((s->radius >> hsub) + (s->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32);
178 
179  return 0;
180 }
181 
182 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
183 {
184  GradFunContext *s = inlink->dst->priv;
185  AVFilterLink *outlink = inlink->dst->outputs[0];
186  AVFrame *out;
187  int p, direct;
188 
189  if (av_frame_is_writable(in)) {
190  direct = 1;
191  out = in;
192  } else {
193  direct = 0;
194  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
195  if (!out) {
196  av_frame_free(&in);
197  return AVERROR(ENOMEM);
198  }
199 
200  av_frame_copy_props(out, in);
201  out->width = outlink->w;
202  out->height = outlink->h;
203  }
204 
205  for (p = 0; p < 4 && in->data[p]; p++) {
206  int w = inlink->w;
207  int h = inlink->h;
208  int r = s->radius;
209  if (p) {
210  w = s->chroma_w;
211  h = s->chroma_h;
212  r = s->chroma_r;
213  }
214 
215  if (FFMIN(w, h) > 2 * r)
216  filter(s, out->data[p], in->data[p], w, h, out->linesize[p], in->linesize[p], r);
217  else if (out->data[p] != in->data[p])
218  av_image_copy_plane(out->data[p], out->linesize[p], in->data[p], in->linesize[p], w, h);
219  }
220 
221  if (!direct)
222  av_frame_free(&in);
223 
224  return ff_filter_frame(outlink, out);
225 }
226 
227 #define OFFSET(x) offsetof(GradFunContext, x)
228 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
229 static const AVOption options[] = {
230  { "strength", "The maximum amount by which the filter will change any one pixel.", OFFSET(strength), AV_OPT_TYPE_FLOAT, { .dbl = 1.2 }, 0.51, 64, FLAGS },
231  { "radius", "The neighborhood to fit the gradient to.", OFFSET(radius), AV_OPT_TYPE_INT, { .i64 = 16 }, 4, 32, FLAGS },
232  { NULL },
233 };
234 
235 static const AVClass gradfun_class = {
236  .class_name = "gradfun",
237  .item_name = av_default_item_name,
238  .option = options,
239  .version = LIBAVUTIL_VERSION_INT,
240 };
241 
243  {
244  .name = "default",
245  .type = AVMEDIA_TYPE_VIDEO,
246  .config_props = config_input,
247  .filter_frame = filter_frame,
248  },
249  { NULL }
250 };
251 
253  {
254  .name = "default",
255  .type = AVMEDIA_TYPE_VIDEO,
256  },
257  { NULL }
258 };
259 
261  .name = "gradfun",
262  .description = NULL_IF_CONFIG_SMALL("Debands video quickly using gradients."),
263  .priv_size = sizeof(GradFunContext),
264  .priv_class = &gradfun_class,
265  .init = init,
266  .uninit = uninit,
268 
269  .inputs = avfilter_vf_gradfun_inputs,
270  .outputs = avfilter_vf_gradfun_outputs,
271 };