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vf_unsharp.c
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1 /*
2  * Original copyright (c) 2002 Remi Guyomarch <rguyom@pobox.com>
3  * Port copyright (c) 2010 Daniel G. Taylor <dan@programmer-art.org>
4  * Relicensed to the LGPL with permission from Remi Guyomarch.
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * blur / sharpen filter, ported to FFmpeg from MPlayer
26  * libmpcodecs/unsharp.c.
27  *
28  * This code is based on:
29  *
30  * An Efficient algorithm for Gaussian blur using finite-state machines
31  * Frederick M. Waltz and John W. V. Miller
32  *
33  * SPIE Conf. on Machine Vision Systems for Inspection and Metrology VII
34  * Originally published Boston, Nov 98
35  *
36  * http://www.engin.umd.umich.edu/~jwvm/ece581/21_GBlur.pdf
37  */
38 
39 #include "avfilter.h"
40 #include "formats.h"
41 #include "internal.h"
42 #include "video.h"
43 #include "libavutil/common.h"
44 #include "libavutil/mem.h"
45 #include "libavutil/pixdesc.h"
46 
47 #define MIN_SIZE 3
48 #define MAX_SIZE 13
49 
50 /* right-shift and round-up */
51 #define SHIFTUP(x,shift) (-((-(x))>>(shift)))
52 
53 typedef struct FilterParam {
54  int msize_x; ///< matrix width
55  int msize_y; ///< matrix height
56  int amount; ///< effect amount
57  int steps_x; ///< horizontal step count
58  int steps_y; ///< vertical step count
59  int scalebits; ///< bits to shift pixel
60  int32_t halfscale; ///< amount to add to pixel
61  uint32_t *sc[(MAX_SIZE * MAX_SIZE) - 1]; ///< finite state machine storage
62 } FilterParam;
63 
64 typedef struct {
65  FilterParam luma; ///< luma parameters (width, height, amount)
66  FilterParam chroma; ///< chroma parameters (width, height, amount)
67  int hsub, vsub;
69 
70 static void apply_unsharp( uint8_t *dst, int dst_stride,
71  const uint8_t *src, int src_stride,
72  int width, int height, FilterParam *fp)
73 {
74  uint32_t **sc = fp->sc;
75  uint32_t sr[(MAX_SIZE * MAX_SIZE) - 1], tmp1, tmp2;
76 
77  int32_t res;
78  int x, y, z;
79  const uint8_t *src2 = NULL; //silence a warning
80 
81  if (!fp->amount) {
82  if (dst_stride == src_stride)
83  memcpy(dst, src, src_stride * height);
84  else
85  for (y = 0; y < height; y++, dst += dst_stride, src += src_stride)
86  memcpy(dst, src, width);
87  return;
88  }
89 
90  for (y = 0; y < 2 * fp->steps_y; y++)
91  memset(sc[y], 0, sizeof(sc[y][0]) * (width + 2 * fp->steps_x));
92 
93  for (y = -fp->steps_y; y < height + fp->steps_y; y++) {
94  if (y < height)
95  src2 = src;
96 
97  memset(sr, 0, sizeof(sr[0]) * (2 * fp->steps_x - 1));
98  for (x = -fp->steps_x; x < width + fp->steps_x; x++) {
99  tmp1 = x <= 0 ? src2[0] : x >= width ? src2[width-1] : src2[x];
100  for (z = 0; z < fp->steps_x * 2; z += 2) {
101  tmp2 = sr[z + 0] + tmp1; sr[z + 0] = tmp1;
102  tmp1 = sr[z + 1] + tmp2; sr[z + 1] = tmp2;
103  }
104  for (z = 0; z < fp->steps_y * 2; z += 2) {
105  tmp2 = sc[z + 0][x + fp->steps_x] + tmp1; sc[z + 0][x + fp->steps_x] = tmp1;
106  tmp1 = sc[z + 1][x + fp->steps_x] + tmp2; sc[z + 1][x + fp->steps_x] = tmp2;
107  }
108  if (x >= fp->steps_x && y >= fp->steps_y) {
109  const uint8_t *srx = src - fp->steps_y * src_stride + x - fp->steps_x;
110  uint8_t *dsx = dst - fp->steps_y * dst_stride + x - fp->steps_x;
111 
112  res = (int32_t)*srx + ((((int32_t) * srx - (int32_t)((tmp1 + fp->halfscale) >> fp->scalebits)) * fp->amount) >> 16);
113  *dsx = av_clip_uint8(res);
114  }
115  }
116  if (y >= 0) {
117  dst += dst_stride;
118  src += src_stride;
119  }
120  }
121 }
122 
123 static void set_filter_param(FilterParam *fp, int msize_x, int msize_y, double amount)
124 {
125  fp->msize_x = msize_x;
126  fp->msize_y = msize_y;
127  fp->amount = amount * 65536.0;
128 
129  fp->steps_x = msize_x / 2;
130  fp->steps_y = msize_y / 2;
131  fp->scalebits = (fp->steps_x + fp->steps_y) * 2;
132  fp->halfscale = 1 << (fp->scalebits - 1);
133 }
134 
135 static av_cold int init(AVFilterContext *ctx, const char *args)
136 {
137  UnsharpContext *unsharp = ctx->priv;
138  int lmsize_x = 5, cmsize_x = 5;
139  int lmsize_y = 5, cmsize_y = 5;
140  double lamount = 1.0f, camount = 0.0f;
141 
142  if (args)
143  sscanf(args, "%d:%d:%lf:%d:%d:%lf", &lmsize_x, &lmsize_y, &lamount,
144  &cmsize_x, &cmsize_y, &camount);
145 
146  if ((lamount && (lmsize_x < 2 || lmsize_y < 2)) ||
147  (camount && (cmsize_x < 2 || cmsize_y < 2))) {
148  av_log(ctx, AV_LOG_ERROR,
149  "Invalid value <2 for lmsize_x:%d or lmsize_y:%d or cmsize_x:%d or cmsize_y:%d\n",
150  lmsize_x, lmsize_y, cmsize_x, cmsize_y);
151  return AVERROR(EINVAL);
152  }
153 
154  set_filter_param(&unsharp->luma, lmsize_x, lmsize_y, lamount);
155  set_filter_param(&unsharp->chroma, cmsize_x, cmsize_y, camount);
156 
157  return 0;
158 }
159 
161 {
162  static const enum AVPixelFormat pix_fmts[] = {
166  };
167 
169 
170  return 0;
171 }
172 
173 static void init_filter_param(AVFilterContext *ctx, FilterParam *fp, const char *effect_type, int width)
174 {
175  int z;
176  const char *effect;
177 
178  effect = fp->amount == 0 ? "none" : fp->amount < 0 ? "blur" : "sharpen";
179 
180  av_log(ctx, AV_LOG_VERBOSE, "effect:%s type:%s msize_x:%d msize_y:%d amount:%0.2f\n",
181  effect, effect_type, fp->msize_x, fp->msize_y, fp->amount / 65535.0);
182 
183  for (z = 0; z < 2 * fp->steps_y; z++)
184  fp->sc[z] = av_malloc(sizeof(*(fp->sc[z])) * (width + 2 * fp->steps_x));
185 }
186 
187 static int config_props(AVFilterLink *link)
188 {
189  UnsharpContext *unsharp = link->dst->priv;
190  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
191 
192  unsharp->hsub = desc->log2_chroma_w;
193  unsharp->vsub = desc->log2_chroma_h;
194 
195  init_filter_param(link->dst, &unsharp->luma, "luma", link->w);
196  init_filter_param(link->dst, &unsharp->chroma, "chroma", SHIFTUP(link->w, unsharp->hsub));
197 
198  return 0;
199 }
200 
202 {
203  int z;
204 
205  for (z = 0; z < 2 * fp->steps_y; z++)
206  av_free(fp->sc[z]);
207 }
208 
209 static av_cold void uninit(AVFilterContext *ctx)
210 {
211  UnsharpContext *unsharp = ctx->priv;
212 
213  free_filter_param(&unsharp->luma);
214  free_filter_param(&unsharp->chroma);
215 }
216 
218 {
219  UnsharpContext *unsharp = link->dst->priv;
220  AVFilterLink *outlink = link->dst->outputs[0];
221  AVFilterBufferRef *out;
222  int cw = SHIFTUP(link->w, unsharp->hsub);
223  int ch = SHIFTUP(link->h, unsharp->vsub);
224 
225  out = ff_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
226  if (!out) {
228  return AVERROR(ENOMEM);
229  }
231 
232  apply_unsharp(out->data[0], out->linesize[0], in->data[0], in->linesize[0], link->w, link->h, &unsharp->luma);
233  apply_unsharp(out->data[1], out->linesize[1], in->data[1], in->linesize[1], cw, ch, &unsharp->chroma);
234  apply_unsharp(out->data[2], out->linesize[2], in->data[2], in->linesize[2], cw, ch, &unsharp->chroma);
235 
237  return ff_filter_frame(outlink, out);
238 }
239 
241  {
242  .name = "default",
243  .type = AVMEDIA_TYPE_VIDEO,
244  .filter_frame = filter_frame,
245  .config_props = config_props,
246  .min_perms = AV_PERM_READ,
247  },
248  { NULL }
249 };
250 
252  {
253  .name = "default",
254  .type = AVMEDIA_TYPE_VIDEO,
255  },
256  { NULL }
257 };
258 
260  .name = "unsharp",
261  .description = NULL_IF_CONFIG_SMALL("Sharpen or blur the input video."),
262 
263  .priv_size = sizeof(UnsharpContext),
264 
265  .init = init,
266  .uninit = uninit,
268 
269  .inputs = avfilter_vf_unsharp_inputs,
270 
271  .outputs = avfilter_vf_unsharp_outputs,
272 };