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vf_idet.c
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1 /*
2  * Copyright (C) 2012 Michael Niedermayer <michaelni@gmx.at>
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 Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 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 GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along 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 <float.h> /* FLT_MAX */
22 
23 #include "libavutil/cpu.h"
24 #include "libavutil/common.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/pixdesc.h"
27 #include "avfilter.h"
28 #include "internal.h"
29 
30 #define HIST_SIZE 4
31 
32 typedef enum {
33  TFF,
34  BFF,
37 } Type;
38 
39 typedef struct {
40  const AVClass *class;
43 
45  int prestat[4];
46  int poststat[4];
47 
48  uint8_t history[HIST_SIZE];
49 
53  int (*filter_line)(const uint8_t *prev, const uint8_t *cur, const uint8_t *next, int w);
54 
56 } IDETContext;
57 
58 #define OFFSET(x) offsetof(IDETContext, x)
59 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
60 
61 static const AVOption idet_options[] = {
62  { "intl_thres", "set interlacing threshold", OFFSET(interlace_threshold), AV_OPT_TYPE_FLOAT, {.dbl = 1.04}, -1, FLT_MAX, FLAGS },
63  { "prog_thres", "set progressive threshold", OFFSET(progressive_threshold), AV_OPT_TYPE_FLOAT, {.dbl = 1.5}, -1, FLT_MAX, FLAGS },
64  { NULL }
65 };
66 
68 
69 static const char *type2str(Type type)
70 {
71  switch(type) {
72  case TFF : return "Top Field First ";
73  case BFF : return "Bottom Field First";
74  case PROGRSSIVE : return "Progressive ";
75  case UNDETERMINED: return "Undetermined ";
76  }
77  return NULL;
78 }
79 
80 static int filter_line_c(const uint8_t *a, const uint8_t *b, const uint8_t *c, int w)
81 {
82  int x;
83  int ret=0;
84 
85  for(x=0; x<w; x++){
86  int v = (*a++ + *c++) - 2 * *b++;
87  ret += FFABS(v);
88  }
89 
90  return ret;
91 }
92 
93 static int filter_line_c_16bit(const uint16_t *a, const uint16_t *b, const uint16_t *c, int w)
94 {
95  int x;
96  int ret=0;
97 
98  for(x=0; x<w; x++){
99  int v = (*a++ + *c++) - 2 * *b++;
100  ret += FFABS(v);
101  }
102 
103  return ret;
104 }
105 
106 static void filter(AVFilterContext *ctx)
107 {
108  IDETContext *idet = ctx->priv;
109  int y, i;
110  int64_t alpha[2]={0};
111  int64_t delta=0;
112  Type type, best_type;
113  int match = 0;
114 
115  for (i = 0; i < idet->csp->nb_components; i++) {
116  int w = idet->cur->width;
117  int h = idet->cur->height;
118  int refs = idet->cur->linesize[i];
119 
120  if (i && i<3) {
121  w = FF_CEIL_RSHIFT(w, idet->csp->log2_chroma_w);
122  h = FF_CEIL_RSHIFT(h, idet->csp->log2_chroma_h);
123  }
124 
125  for (y = 2; y < h - 2; y++) {
126  uint8_t *prev = &idet->prev->data[i][y*refs];
127  uint8_t *cur = &idet->cur ->data[i][y*refs];
128  uint8_t *next = &idet->next->data[i][y*refs];
129  alpha[ y &1] += idet->filter_line(cur-refs, prev, cur+refs, w);
130  alpha[(y^1)&1] += idet->filter_line(cur-refs, next, cur+refs, w);
131  delta += idet->filter_line(cur-refs, cur, cur+refs, w);
132  }
133  }
134 
135  if (alpha[0] > idet->interlace_threshold * alpha[1]){
136  type = TFF;
137  }else if(alpha[1] > idet->interlace_threshold * alpha[0]){
138  type = BFF;
139  }else if(alpha[1] > idet->progressive_threshold * delta){
140  type = PROGRSSIVE;
141  }else{
142  type = UNDETERMINED;
143  }
144 
145  memmove(idet->history+1, idet->history, HIST_SIZE-1);
146  idet->history[0] = type;
147  best_type = UNDETERMINED;
148  for(i=0; i<HIST_SIZE; i++){
149  if(idet->history[i] != UNDETERMINED){
150  if(best_type == UNDETERMINED)
151  best_type = idet->history[i];
152 
153  if(idet->history[i] == best_type) {
154  match++;
155  }else{
156  match=0;
157  break;
158  }
159  }
160  }
161  if(idet->last_type == UNDETERMINED){
162  if(match ) idet->last_type = best_type;
163  }else{
164  if(match>2) idet->last_type = best_type;
165  }
166 
167  if (idet->last_type == TFF){
168  idet->cur->top_field_first = 1;
169  idet->cur->interlaced_frame = 1;
170  }else if(idet->last_type == BFF){
171  idet->cur->top_field_first = 0;
172  idet->cur->interlaced_frame = 1;
173  }else if(idet->last_type == PROGRSSIVE){
174  idet->cur->interlaced_frame = 0;
175  }
176 
177  idet->prestat [ type] ++;
178  idet->poststat[idet->last_type] ++;
179  av_log(ctx, AV_LOG_DEBUG, "Single frame:%s, Multi frame:%s\n", type2str(type), type2str(idet->last_type));
180 }
181 
182 static int filter_frame(AVFilterLink *link, AVFrame *picref)
183 {
184  AVFilterContext *ctx = link->dst;
185  IDETContext *idet = ctx->priv;
186 
187  if (idet->prev)
188  av_frame_free(&idet->prev);
189  idet->prev = idet->cur;
190  idet->cur = idet->next;
191  idet->next = picref;
192 
193  if (!idet->cur)
194  return 0;
195 
196  if (!idet->prev)
197  idet->prev = av_frame_clone(idet->cur);
198 
199  if (!idet->csp)
200  idet->csp = av_pix_fmt_desc_get(link->format);
201  if (idet->csp->comp[0].depth_minus1 / 8 == 1)
202  idet->filter_line = (void*)filter_line_c_16bit;
203 
204  filter(ctx);
205 
206  return ff_filter_frame(ctx->outputs[0], av_frame_clone(idet->cur));
207 }
208 
209 static av_cold void uninit(AVFilterContext *ctx)
210 {
211  IDETContext *idet = ctx->priv;
212 
213  av_log(ctx, AV_LOG_INFO, "Single frame detection: TFF:%d BFF:%d Progressive:%d Undetermined:%d\n",
214  idet->prestat[TFF],
215  idet->prestat[BFF],
216  idet->prestat[PROGRSSIVE],
217  idet->prestat[UNDETERMINED]
218  );
219  av_log(ctx, AV_LOG_INFO, "Multi frame detection: TFF:%d BFF:%d Progressive:%d Undetermined:%d\n",
220  idet->poststat[TFF],
221  idet->poststat[BFF],
222  idet->poststat[PROGRSSIVE],
223  idet->poststat[UNDETERMINED]
224  );
225 
226  av_frame_free(&idet->prev);
227  av_frame_free(&idet->cur );
228  av_frame_free(&idet->next);
229 }
230 
232 {
233  static const enum AVPixelFormat pix_fmts[] = {
254  };
255 
257 
258  return 0;
259 }
260 
261 static int config_output(AVFilterLink *outlink)
262 {
263  outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
264  return 0;
265 }
266 
267 static av_cold int init(AVFilterContext *ctx)
268 {
269  IDETContext *idet = ctx->priv;
270 
271  idet->last_type = UNDETERMINED;
272  memset(idet->history, UNDETERMINED, HIST_SIZE);
273 
274  idet->filter_line = filter_line_c;
275 
276  return 0;
277 }
278 
279 
280 static const AVFilterPad idet_inputs[] = {
281  {
282  .name = "default",
283  .type = AVMEDIA_TYPE_VIDEO,
284  .filter_frame = filter_frame,
285  },
286  { NULL }
287 };
288 
289 static const AVFilterPad idet_outputs[] = {
290  {
291  .name = "default",
292  .type = AVMEDIA_TYPE_VIDEO,
293  .config_props = config_output,
294  },
295  { NULL }
296 };
297 
299  .name = "idet",
300  .description = NULL_IF_CONFIG_SMALL("Interlace detect Filter."),
301  .priv_size = sizeof(IDETContext),
302  .init = init,
303  .uninit = uninit,
305  .inputs = idet_inputs,
306  .outputs = idet_outputs,
307  .priv_class = &idet_class,
308 };