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/cpu.h"
37 #include "libavutil/pixdesc.h"
38 #include "avfilter.h"
39 #include "gradfun.h"
40 
41 DECLARE_ALIGNED(16, static const uint16_t, dither)[8][8] = {
42  {0x00,0x60,0x18,0x78,0x06,0x66,0x1E,0x7E},
43  {0x40,0x20,0x58,0x38,0x46,0x26,0x5E,0x3E},
44  {0x10,0x70,0x08,0x68,0x16,0x76,0x0E,0x6E},
45  {0x50,0x30,0x48,0x28,0x56,0x36,0x4E,0x2E},
46  {0x04,0x64,0x1C,0x7C,0x02,0x62,0x1A,0x7A},
47  {0x44,0x24,0x5C,0x3C,0x42,0x22,0x5A,0x3A},
48  {0x14,0x74,0x0C,0x6C,0x12,0x72,0x0A,0x6A},
49  {0x54,0x34,0x4C,0x2C,0x52,0x32,0x4A,0x2A},
50 };
51 
52 void ff_gradfun_filter_line_c(uint8_t *dst, uint8_t *src, uint16_t *dc, int width, int thresh, const uint16_t *dithers)
53 {
54  int x;
55  for (x = 0; x < width; x++, dc += x & 1) {
56  int pix = src[x] << 7;
57  int delta = dc[0] - pix;
58  int m = abs(delta) * thresh >> 16;
59  m = FFMAX(0, 127 - m);
60  m = m * m * delta >> 14;
61  pix += m + dithers[x & 7];
62  dst[x] = av_clip_uint8(pix >> 7);
63  }
64 }
65 
66 void ff_gradfun_blur_line_c(uint16_t *dc, uint16_t *buf, uint16_t *buf1, uint8_t *src, int src_linesize, int width)
67 {
68  int x, v, old;
69  for (x = 0; x < width; x++) {
70  v = buf1[x] + src[2 * x] + src[2 * x + 1] + src[2 * x + src_linesize] + src[2 * x + 1 + src_linesize];
71  old = buf[x];
72  buf[x] = v;
73  dc[x] = v - old;
74  }
75 }
76 
77 static void filter(GradFunContext *ctx, uint8_t *dst, uint8_t *src, int width, int height, int dst_linesize, int src_linesize, int r)
78 {
79  int bstride = FFALIGN(width, 16) / 2;
80  int y;
81  uint32_t dc_factor = (1 << 21) / (r * r);
82  uint16_t *dc = ctx->buf + 16;
83  uint16_t *buf = ctx->buf + bstride + 32;
84  int thresh = ctx->thresh;
85 
86  memset(dc, 0, (bstride + 16) * sizeof(*buf));
87  for (y = 0; y < r; y++)
88  ctx->blur_line(dc, buf + y * bstride, buf + (y - 1) * bstride, src + 2 * y * src_linesize, src_linesize, width / 2);
89  for (;;) {
90  if (y < height - r) {
91  int mod = ((y + r) / 2) % r;
92  uint16_t *buf0 = buf + mod * bstride;
93  uint16_t *buf1 = buf + (mod ? mod - 1 : r - 1) * bstride;
94  int x, v;
95  ctx->blur_line(dc, buf0, buf1, src + (y + r) * src_linesize, src_linesize, width / 2);
96  for (x = v = 0; x < r; x++)
97  v += dc[x];
98  for (; x < width / 2; x++) {
99  v += dc[x] - dc[x-r];
100  dc[x-r] = v * dc_factor >> 16;
101  }
102  for (; x < (width + r + 1) / 2; x++)
103  dc[x-r] = v * dc_factor >> 16;
104  for (x = -r / 2; x < 0; x++)
105  dc[x] = dc[0];
106  }
107  if (y == r) {
108  for (y = 0; y < r; y++)
109  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
110  }
111  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
112  if (++y >= height) break;
113  ctx->filter_line(dst + y * dst_linesize, src + y * src_linesize, dc - r / 2, width, thresh, dither[y & 7]);
114  if (++y >= height) break;
115  }
116 }
117 
118 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
119 {
120  GradFunContext *gf = ctx->priv;
121  float thresh = 1.2;
122  int radius = 16;
124 
125  if (args)
126  sscanf(args, "%f:%d", &thresh, &radius);
127 
128  thresh = av_clipf(thresh, 0.51, 255);
129  gf->thresh = (1 << 15) / thresh;
130  gf->radius = av_clip((radius + 1) & ~1, 4, 32);
131 
134 
135  if (HAVE_MMX && cpu_flags & AV_CPU_FLAG_MMX2)
137  if (HAVE_SSSE3 && cpu_flags & AV_CPU_FLAG_SSSE3)
139  if (HAVE_SSE && cpu_flags & AV_CPU_FLAG_SSE2)
141 
142  av_log(ctx, AV_LOG_INFO, "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 PixelFormat 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  int hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
172  int vsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
173 
174  gf->buf = av_mallocz((FFALIGN(inlink->w, 16) * (gf->radius + 1) / 2 + 32) * sizeof(uint16_t));
175  if (!gf->buf)
176  return AVERROR(ENOMEM);
177 
178  gf->chroma_w = -((-inlink->w) >> hsub);
179  gf->chroma_h = -((-inlink->h) >> vsub);
180  gf->chroma_r = av_clip(((((gf->radius >> hsub) + (gf->radius >> vsub)) / 2 ) + 1) & ~1, 4, 32);
181 
182  return 0;
183 }
184 
185 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
186 {
187  AVFilterLink *outlink = inlink->dst->outputs[0];
188  AVFilterBufferRef *outpicref;
189 
190  if (inpicref->perms & AV_PERM_PRESERVE) {
191  outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
192  avfilter_copy_buffer_ref_props(outpicref, inpicref);
193  outpicref->video->w = outlink->w;
194  outpicref->video->h = outlink->h;
195  } else
196  outpicref = inpicref;
197 
198  outlink->out_buf = outpicref;
199  avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
200 }
201 
202 static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
203 
204 static void end_frame(AVFilterLink *inlink)
205 {
206  GradFunContext *gf = inlink->dst->priv;
207  AVFilterBufferRef *inpic = inlink->cur_buf;
208  AVFilterLink *outlink = inlink->dst->outputs[0];
209  AVFilterBufferRef *outpic = outlink->out_buf;
210  int p;
211 
212  for (p = 0; p < 4 && inpic->data[p]; p++) {
213  int w = inlink->w;
214  int h = inlink->h;
215  int r = gf->radius;
216  if (p) {
217  w = gf->chroma_w;
218  h = gf->chroma_h;
219  r = gf->chroma_r;
220  }
221 
222  if (FFMIN(w, h) > 2 * r)
223  filter(gf, outpic->data[p], inpic->data[p], w, h, outpic->linesize[p], inpic->linesize[p], r);
224  else if (outpic->data[p] != inpic->data[p])
225  av_image_copy_plane(outpic->data[p], outpic->linesize[p], inpic->data[p], inpic->linesize[p], w, h);
226  }
227 
228  avfilter_draw_slice(outlink, 0, inlink->h, 1);
229  avfilter_end_frame(outlink);
230  avfilter_unref_buffer(inpic);
231  if (outpic != inpic)
232  avfilter_unref_buffer(outpic);
233 }
234 
236  .name = "gradfun",
237  .description = NULL_IF_CONFIG_SMALL("Debands video quickly using gradients."),
238  .priv_size = sizeof(GradFunContext),
239  .init = init,
240  .uninit = uninit,
242 
243  .inputs = (AVFilterPad[]) {{ .name = "default",
244  .type = AVMEDIA_TYPE_VIDEO,
245  .config_props = config_input,
246  .start_frame = start_frame,
247  .draw_slice = null_draw_slice,
248  .end_frame = end_frame,
249  .min_perms = AV_PERM_READ, },
250  { .name = NULL}},
251  .outputs = (AVFilterPad[]) {{ .name = "default",
252  .type = AVMEDIA_TYPE_VIDEO, },
253  { .name = NULL}},
254 };