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vf_phase.c
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1 /*
2  * Copyright (c) 2004 Ville Saari
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/avassert.h"
22 #include "libavutil/imgutils.h"
23 #include "libavutil/pixdesc.h"
24 #include "libavutil/opt.h"
25 #include "avfilter.h"
26 #include "formats.h"
27 #include "internal.h"
28 #include "video.h"
29 
30 enum PhaseMode {
40 };
41 
42 typedef struct PhaseContext {
43  const AVClass *class;
46  int nb_planes;
47  int planeheight[4];
48  int linesize[4];
49 } PhaseContext;
50 
51 #define OFFSET(x) offsetof(PhaseContext, x)
52 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
53 #define CONST(name, help, val, unit) { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, 0, 0, FLAGS, unit }
54 
55 static const AVOption phase_options[] = {
56  { "mode", "set phase mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=AUTO_ANALYZE}, PROGRESSIVE, AUTO_ANALYZE, FLAGS, "mode" },
57  CONST("p", "progressive", PROGRESSIVE, "mode"),
58  CONST("t", "top first", TOP_FIRST, "mode"),
59  CONST("b", "bottom first", BOTTOM_FIRST, "mode"),
60  CONST("T", "top first analyze", TOP_FIRST_ANALYZE, "mode"),
61  CONST("B", "bottom first analyze", BOTTOM_FIRST_ANALYZE, "mode"),
62  CONST("u", "analyze", ANALYZE, "mode"),
63  CONST("U", "full analyze", FULL_ANALYZE, "mode"),
64  CONST("a", "auto", AUTO, "mode"),
65  CONST("A", "auto analyze", AUTO_ANALYZE, "mode"),
66  { NULL }
67 };
68 
70 
72 {
73  static const enum AVPixelFormat pix_fmts[] = {
78  };
79 
81  return 0;
82 }
83 
84 static int config_input(AVFilterLink *inlink)
85 {
86  PhaseContext *s = inlink->dst->priv;
87  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
88  int ret;
89 
90  if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
91  return ret;
92 
93  s->planeheight[1] = s->planeheight[2] = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
94  s->planeheight[0] = s->planeheight[3] = inlink->h;
95 
97 
98  return 0;
99 }
100 
101 /*
102  * This macro interpolates the value of both fields at a point halfway
103  * between lines and takes the squared difference. In field resolution
104  * the point is a quarter pixel below a line in one field and a quarter
105  * pixel above a line in other.
106  *
107  * (The result is actually multiplied by 25)
108  */
109 #define DIFF(a, as, b, bs) (t = ((*a - b[bs]) << 2) + a[as << 1] - b[-bs], t * t)
110 
111 /*
112  * Find which field combination has the smallest average squared difference
113  * between the fields.
114  */
116  AVFrame *old, AVFrame *new)
117 {
118  double bdiff, tdiff, pdiff, scale;
119  const int ns = new->linesize[0];
120  const int os = old->linesize[0];
121  uint8_t *nptr = new->data[0];
122  uint8_t *optr = old->data[0];
123  const int h = new->height;
124  const int w = new->width;
125  int bdif, tdif, pdif;
126  enum PhaseMode mode = s->mode;
127  uint8_t *end, *rend;
128  int top, t;
129 
130  if (mode == AUTO) {
131  mode = new->interlaced_frame ? new->top_field_first ?
133  } else if (mode == AUTO_ANALYZE) {
134  mode = new->interlaced_frame ? new->top_field_first ?
136  }
137 
138  if (mode <= BOTTOM_FIRST) {
139  bdiff = pdiff = tdiff = 65536.0;
140  } else {
141  bdiff = pdiff = tdiff = 0.0;
142 
143  for (end = nptr + (h - 2) * ns, nptr += ns, optr += os, top = 0;
144  nptr < end; nptr += ns - w, optr += os - w, top ^= 1) {
145  pdif = tdif = bdif = 0;
146 
147  switch (mode) {
148  case TOP_FIRST_ANALYZE:
149  if (top) {
150  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
151  pdif += DIFF(nptr, ns, nptr, ns);
152  tdif += DIFF(nptr, ns, optr, os);
153  }
154  } else {
155  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
156  pdif += DIFF(nptr, ns, nptr, ns);
157  tdif += DIFF(optr, os, nptr, ns);
158  }
159  }
160  break;
162  if (top) {
163  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
164  pdif += DIFF(nptr, ns, nptr, ns);
165  bdif += DIFF(optr, os, nptr, ns);
166  }
167  } else {
168  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
169  pdif += DIFF(nptr, ns, nptr, ns);
170  bdif += DIFF(nptr, ns, optr, os);
171  }
172  }
173  break;
174  case ANALYZE:
175  if (top) {
176  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
177  tdif += DIFF(nptr, ns, optr, os);
178  bdif += DIFF(optr, os, nptr, ns);
179  }
180  } else {
181  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
182  bdif += DIFF(nptr, ns, optr, os);
183  tdif += DIFF(optr, os, nptr, ns);
184  }
185  }
186  break;
187  case FULL_ANALYZE:
188  if (top) {
189  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
190  pdif += DIFF(nptr, ns, nptr, ns);
191  tdif += DIFF(nptr, ns, optr, os);
192  bdif += DIFF(optr, os, nptr, ns);
193  }
194  } else {
195  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
196  pdif += DIFF(nptr, ns, nptr, ns);
197  bdif += DIFF(nptr, ns, optr, os);
198  tdif += DIFF(optr, os, nptr, ns);
199  }
200  }
201  break;
202  default:
203  av_assert0(0);
204  }
205 
206  pdiff += (double)pdif;
207  tdiff += (double)tdif;
208  bdiff += (double)bdif;
209  }
210 
211  scale = 1.0 / (w * (h - 3)) / 25.0;
212  pdiff *= scale;
213  tdiff *= scale;
214  bdiff *= scale;
215 
216  if (mode == TOP_FIRST_ANALYZE) {
217  bdiff = 65536.0;
218  } else if (mode == BOTTOM_FIRST_ANALYZE) {
219  tdiff = 65536.0;
220  } else if (mode == ANALYZE) {
221  pdiff = 65536.0;
222  }
223 
224  if (bdiff < pdiff && bdiff < tdiff) {
225  mode = BOTTOM_FIRST;
226  } else if (tdiff < pdiff && tdiff < bdiff) {
227  mode = TOP_FIRST;
228  } else {
229  mode = PROGRESSIVE;
230  }
231  }
232 
233  av_log(ctx, AV_LOG_DEBUG, "mode=%c tdiff=%f bdiff=%f pdiff=%f\n",
234  mode == BOTTOM_FIRST ? 'b' : mode == TOP_FIRST ? 't' : 'p',
235  tdiff, bdiff, pdiff);
236  return mode;
237 }
238 
239 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
240 {
241  AVFilterContext *ctx = inlink->dst;
242  AVFilterLink *outlink = ctx->outputs[0];
243  PhaseContext *s = ctx->priv;
244  enum PhaseMode mode;
245  int plane, top, y;
246  AVFrame *out;
247 
248  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
249  if (!out) {
250  av_frame_free(&in);
251  return AVERROR(ENOMEM);
252  }
253  av_frame_copy_props(out, in);
254 
255  if (!s->frame) {
256  mode = PROGRESSIVE;
257  s->frame = ff_get_video_buffer(outlink, outlink->w, outlink->h);
258  if (!s->frame) {
259  av_frame_free(&in);
260  av_frame_free(&out);
261  return AVERROR(ENOMEM);
262  }
263  } else {
264  mode = analyze_plane(ctx, s, s->frame, in);
265  }
266 
267  for (plane = 0; plane < s->nb_planes; plane++) {
268  uint8_t *buf = s->frame->data[plane];
269  uint8_t *from = in->data[plane];
270  uint8_t *to = out->data[plane];
271 
272  for (y = 0, top = 1; y < s->planeheight[plane]; y++, top ^= 1) {
273  memcpy(to, mode == (top ? BOTTOM_FIRST : TOP_FIRST) ? buf : from, s->linesize[plane]);
274  memcpy(buf, from, s->linesize[plane]);
275 
276  buf += s->frame->linesize[plane];
277  from += in->linesize[plane];
278  to += out->linesize[plane];
279  }
280  }
281 
282  av_frame_free(&in);
283  return ff_filter_frame(outlink, out);
284 }
285 
286 static av_cold void uninit(AVFilterContext *ctx)
287 {
288  PhaseContext *s = ctx->priv;
289 
290  av_frame_free(&s->frame);
291 }
292 
293 static const AVFilterPad phase_inputs[] = {
294  {
295  .name = "default",
296  .type = AVMEDIA_TYPE_VIDEO,
297  .filter_frame = filter_frame,
298  .config_props = config_input,
299  },
300  { NULL }
301 };
302 
303 static const AVFilterPad phase_outputs[] = {
304  {
305  .name = "default",
306  .type = AVMEDIA_TYPE_VIDEO,
307  },
308  { NULL }
309 };
310 
312  .name = "phase",
313  .description = NULL_IF_CONFIG_SMALL("Phase shift fields."),
314  .priv_size = sizeof(PhaseContext),
315  .priv_class = &phase_class,
316  .uninit = uninit,
318  .inputs = phase_inputs,
319  .outputs = phase_outputs,
320 };