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vf_tinterlace.c
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1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  * Copyright (c) 2010 Baptiste Coudurier
4  * Copyright (c) 2003 Michael Zucchi <notzed@ximian.com>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (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
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License along
19  * with FFmpeg if not, write to the Free Software Foundation, Inc.,
20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21  */
22 
23 /**
24  * @file
25  * temporal field interlace filter, ported from MPlayer/libmpcodecs
26  */
27 
28 #include "libavutil/opt.h"
29 #include "libavutil/imgutils.h"
30 #include "libavutil/avassert.h"
31 #include "avfilter.h"
32 #include "internal.h"
33 
43 };
44 
45 typedef struct {
46  const AVClass *class;
47  enum TInterlaceMode mode; ///< interlace mode selected
48  int flags; ///< flags affecting interlacing algorithm
49  int frame; ///< number of the output frame
50  int vsub; ///< chroma vertical subsampling
53  uint8_t *black_data[4]; ///< buffer used to fill padded lines
54  int black_linesize[4];
56 
57 #define OFFSET(x) offsetof(TInterlaceContext, x)
58 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
59 #define TINTERLACE_FLAG_VLPF 01
60 
61 static const AVOption tinterlace_options[] = {
62  {"mode", "select interlace mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=MODE_MERGE}, 0, MODE_NB-1, FLAGS, "mode"},
63  {"merge", "merge fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_MERGE}, INT_MIN, INT_MAX, FLAGS, "mode"},
64  {"drop_even", "drop even fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_DROP_EVEN}, INT_MIN, INT_MAX, FLAGS, "mode"},
65  {"drop_odd", "drop odd fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_DROP_ODD}, INT_MIN, INT_MAX, FLAGS, "mode"},
66  {"pad", "pad alternate lines with black", 0, AV_OPT_TYPE_CONST, {.i64=MODE_PAD}, INT_MIN, INT_MAX, FLAGS, "mode"},
67  {"interleave_top", "interleave top and bottom fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_INTERLEAVE_TOP}, INT_MIN, INT_MAX, FLAGS, "mode"},
68  {"interleave_bottom", "interleave bottom and top fields", 0, AV_OPT_TYPE_CONST, {.i64=MODE_INTERLEAVE_BOTTOM}, INT_MIN, INT_MAX, FLAGS, "mode"},
69  {"interlacex2", "interlace fields from two consecutive frames", 0, AV_OPT_TYPE_CONST, {.i64=MODE_INTERLACEX2}, INT_MIN, INT_MAX, FLAGS, "mode"},
70 
71  {"flags", "set flags", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0}, 0, INT_MAX, 0, "flags" },
72  {"low_pass_filter", "enable vertical low-pass filter", 0, AV_OPT_TYPE_CONST, {.i64 = TINTERLACE_FLAG_VLPF}, INT_MIN, INT_MAX, FLAGS, "flags" },
73  {"vlpf", "enable vertical low-pass filter", 0, AV_OPT_TYPE_CONST, {.i64 = TINTERLACE_FLAG_VLPF}, INT_MIN, INT_MAX, FLAGS, "flags" },
74 
75  {NULL}
76 };
77 
78 AVFILTER_DEFINE_CLASS(tinterlace);
79 
80 #define FULL_SCALE_YUVJ_FORMATS \
81  AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P
82 
85 };
86 
88 {
89  static const enum AVPixelFormat pix_fmts[] = {
96  };
97 
99  return 0;
100 }
101 
102 static av_cold void uninit(AVFilterContext *ctx)
103 {
104  TInterlaceContext *tinterlace = ctx->priv;
105 
106  av_frame_free(&tinterlace->cur );
107  av_frame_free(&tinterlace->next);
108  av_freep(&tinterlace->black_data[0]);
109 }
110 
111 static int config_out_props(AVFilterLink *outlink)
112 {
113  AVFilterContext *ctx = outlink->src;
114  AVFilterLink *inlink = outlink->src->inputs[0];
115  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
116  TInterlaceContext *tinterlace = ctx->priv;
117 
118  tinterlace->vsub = desc->log2_chroma_h;
119  outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
120  outlink->w = inlink->w;
121  outlink->h = tinterlace->mode == MODE_MERGE || tinterlace->mode == MODE_PAD ?
122  inlink->h*2 : inlink->h;
123 
124  if (tinterlace->mode == MODE_PAD) {
125  uint8_t black[4] = { 16, 128, 128, 16 };
126  int i, ret;
128  black[0] = black[3] = 0;
129  ret = av_image_alloc(tinterlace->black_data, tinterlace->black_linesize,
130  outlink->w, outlink->h, outlink->format, 1);
131  if (ret < 0)
132  return ret;
133 
134  /* fill black picture with black */
135  for (i = 0; i < 4 && tinterlace->black_data[i]; i++) {
136  int h = i == 1 || i == 2 ? FF_CEIL_RSHIFT(outlink->h, desc->log2_chroma_h) : outlink->h;
137  memset(tinterlace->black_data[i], black[i],
138  tinterlace->black_linesize[i] * h);
139  }
140  }
141  if ((tinterlace->flags & TINTERLACE_FLAG_VLPF)
142  && !(tinterlace->mode == MODE_INTERLEAVE_TOP
143  || tinterlace->mode == MODE_INTERLEAVE_BOTTOM)) {
144  av_log(ctx, AV_LOG_WARNING, "low_pass_filter flag ignored with mode %d\n",
145  tinterlace->mode);
146  tinterlace->flags &= ~TINTERLACE_FLAG_VLPF;
147  }
148  if (tinterlace->mode == MODE_INTERLACEX2) {
149  outlink->time_base.num = inlink->time_base.num;
150  outlink->time_base.den = inlink->time_base.den * 2;
151  outlink->frame_rate = av_mul_q(inlink->frame_rate, (AVRational){2,1});
152  }
153 
154  av_log(ctx, AV_LOG_VERBOSE, "mode:%d filter:%s h:%d -> h:%d\n",
155  tinterlace->mode, (tinterlace->flags & TINTERLACE_FLAG_VLPF) ? "on" : "off",
156  inlink->h, outlink->h);
157 
158  return 0;
159 }
160 
161 #define FIELD_UPPER 0
162 #define FIELD_LOWER 1
163 #define FIELD_UPPER_AND_LOWER 2
164 
165 /**
166  * Copy picture field from src to dst.
167  *
168  * @param src_field copy from upper, lower field or both
169  * @param interleave leave a padding line between each copied line
170  * @param dst_field copy to upper or lower field,
171  * only meaningful when interleave is selected
172  * @param flags context flags
173  */
174 static inline
175 void copy_picture_field(uint8_t *dst[4], int dst_linesize[4],
176  const uint8_t *src[4], int src_linesize[4],
177  enum AVPixelFormat format, int w, int src_h,
178  int src_field, int interleave, int dst_field,
179  int flags)
180 {
181  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(format);
182  int plane, vsub = desc->log2_chroma_h;
183  int k = src_field == FIELD_UPPER_AND_LOWER ? 1 : 2;
184  int h, i;
185 
186  for (plane = 0; plane < desc->nb_components; plane++) {
187  int lines = plane == 1 || plane == 2 ? FF_CEIL_RSHIFT(src_h, vsub) : src_h;
188  int linesize = av_image_get_linesize(format, w, plane);
189  uint8_t *dstp = dst[plane];
190  const uint8_t *srcp = src[plane];
191 
192  if (linesize < 0)
193  return;
194 
195  lines = (lines + (src_field == FIELD_UPPER)) / k;
196  if (src_field == FIELD_LOWER)
197  srcp += src_linesize[plane];
198  if (interleave && dst_field == FIELD_LOWER)
199  dstp += dst_linesize[plane];
200  if (flags & TINTERLACE_FLAG_VLPF) {
201  // Low-pass filtering is required when creating an interlaced destination from
202  // a progressive source which contains high-frequency vertical detail.
203  // Filtering will reduce interlace 'twitter' and Moire patterning.
204  int srcp_linesize = src_linesize[plane] * k;
205  int dstp_linesize = dst_linesize[plane] * (interleave ? 2 : 1);
206  for (h = lines; h > 0; h--) {
207  const uint8_t *srcp_above = srcp - src_linesize[plane];
208  const uint8_t *srcp_below = srcp + src_linesize[plane];
209  if (h == lines) srcp_above = srcp; // there is no line above
210  if (h == 1) srcp_below = srcp; // there is no line below
211  for (i = 0; i < linesize; i++) {
212  // this calculation is an integer representation of
213  // '0.5 * current + 0.25 * above + 0.25 * below'
214  // '1 +' is for rounding. */
215  dstp[i] = (1 + srcp[i] + srcp[i] + srcp_above[i] + srcp_below[i]) >> 2;
216  }
217  dstp += dstp_linesize;
218  srcp += srcp_linesize;
219  }
220  } else {
221  av_image_copy_plane(dstp, dst_linesize[plane] * (interleave ? 2 : 1),
222  srcp, src_linesize[plane]*k, linesize, lines);
223  }
224  }
225 }
226 
227 static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
228 {
229  AVFilterContext *ctx = inlink->dst;
230  AVFilterLink *outlink = ctx->outputs[0];
231  TInterlaceContext *tinterlace = ctx->priv;
232  AVFrame *cur, *next, *out;
233  int field, tff, ret;
234 
235  av_frame_free(&tinterlace->cur);
236  tinterlace->cur = tinterlace->next;
237  tinterlace->next = picref;
238 
239  cur = tinterlace->cur;
240  next = tinterlace->next;
241  /* we need at least two frames */
242  if (!tinterlace->cur)
243  return 0;
244 
245  switch (tinterlace->mode) {
246  case MODE_MERGE: /* move the odd frame into the upper field of the new image, even into
247  * the lower field, generating a double-height video at half framerate */
248  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
249  if (!out)
250  return AVERROR(ENOMEM);
251  av_frame_copy_props(out, cur);
252  out->height = outlink->h;
253  out->interlaced_frame = 1;
254  out->top_field_first = 1;
255 
256  /* write odd frame lines into the upper field of the new frame */
257  copy_picture_field(out->data, out->linesize,
258  (const uint8_t **)cur->data, cur->linesize,
259  inlink->format, inlink->w, inlink->h,
260  FIELD_UPPER_AND_LOWER, 1, FIELD_UPPER, tinterlace->flags);
261  /* write even frame lines into the lower field of the new frame */
262  copy_picture_field(out->data, out->linesize,
263  (const uint8_t **)next->data, next->linesize,
264  inlink->format, inlink->w, inlink->h,
265  FIELD_UPPER_AND_LOWER, 1, FIELD_LOWER, tinterlace->flags);
266  av_frame_free(&tinterlace->next);
267  break;
268 
269  case MODE_DROP_ODD: /* only output even frames, odd frames are dropped; height unchanged, half framerate */
270  case MODE_DROP_EVEN: /* only output odd frames, even frames are dropped; height unchanged, half framerate */
271  out = av_frame_clone(tinterlace->mode == MODE_DROP_EVEN ? cur : next);
272  if (!out)
273  return AVERROR(ENOMEM);
274  av_frame_free(&tinterlace->next);
275  break;
276 
277  case MODE_PAD: /* expand each frame to double height, but pad alternate
278  * lines with black; framerate unchanged */
279  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
280  if (!out)
281  return AVERROR(ENOMEM);
282  av_frame_copy_props(out, cur);
283  out->height = outlink->h;
284 
285  field = (1 + tinterlace->frame) & 1 ? FIELD_UPPER : FIELD_LOWER;
286  /* copy upper and lower fields */
287  copy_picture_field(out->data, out->linesize,
288  (const uint8_t **)cur->data, cur->linesize,
289  inlink->format, inlink->w, inlink->h,
290  FIELD_UPPER_AND_LOWER, 1, field, tinterlace->flags);
291  /* pad with black the other field */
292  copy_picture_field(out->data, out->linesize,
293  (const uint8_t **)tinterlace->black_data, tinterlace->black_linesize,
294  inlink->format, inlink->w, inlink->h,
295  FIELD_UPPER_AND_LOWER, 1, !field, tinterlace->flags);
296  break;
297 
298  /* interleave upper/lower lines from odd frames with lower/upper lines from even frames,
299  * halving the frame rate and preserving image height */
300  case MODE_INTERLEAVE_TOP: /* top field first */
301  case MODE_INTERLEAVE_BOTTOM: /* bottom field first */
302  tff = tinterlace->mode == MODE_INTERLEAVE_TOP;
303  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
304  if (!out)
305  return AVERROR(ENOMEM);
306  av_frame_copy_props(out, cur);
307  out->interlaced_frame = 1;
308  out->top_field_first = tff;
309 
310  /* copy upper/lower field from cur */
311  copy_picture_field(out->data, out->linesize,
312  (const uint8_t **)cur->data, cur->linesize,
313  inlink->format, inlink->w, inlink->h,
314  tff ? FIELD_UPPER : FIELD_LOWER, 1, tff ? FIELD_UPPER : FIELD_LOWER,
315  tinterlace->flags);
316  /* copy lower/upper field from next */
317  copy_picture_field(out->data, out->linesize,
318  (const uint8_t **)next->data, next->linesize,
319  inlink->format, inlink->w, inlink->h,
320  tff ? FIELD_LOWER : FIELD_UPPER, 1, tff ? FIELD_LOWER : FIELD_UPPER,
321  tinterlace->flags);
322  av_frame_free(&tinterlace->next);
323  break;
324  case MODE_INTERLACEX2: /* re-interlace preserving image height, double frame rate */
325  /* output current frame first */
326  out = av_frame_clone(cur);
327  if (!out)
328  return AVERROR(ENOMEM);
329  out->interlaced_frame = 1;
330  if (cur->pts != AV_NOPTS_VALUE)
331  out->pts = cur->pts*2;
332 
333  if ((ret = ff_filter_frame(outlink, out)) < 0)
334  return ret;
335 
336  /* output mix of current and next frame */
337  tff = next->top_field_first;
338  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
339  if (!out)
340  return AVERROR(ENOMEM);
341  av_frame_copy_props(out, next);
342  out->interlaced_frame = 1;
343 
344  if (next->pts != AV_NOPTS_VALUE && cur->pts != AV_NOPTS_VALUE)
345  out->pts = cur->pts + next->pts;
346  else
347  out->pts = AV_NOPTS_VALUE;
348  /* write current frame second field lines into the second field of the new frame */
349  copy_picture_field(out->data, out->linesize,
350  (const uint8_t **)cur->data, cur->linesize,
351  inlink->format, inlink->w, inlink->h,
352  tff ? FIELD_LOWER : FIELD_UPPER, 1, tff ? FIELD_LOWER : FIELD_UPPER,
353  tinterlace->flags);
354  /* write next frame first field lines into the first field of the new frame */
355  copy_picture_field(out->data, out->linesize,
356  (const uint8_t **)next->data, next->linesize,
357  inlink->format, inlink->w, inlink->h,
358  tff ? FIELD_UPPER : FIELD_LOWER, 1, tff ? FIELD_UPPER : FIELD_LOWER,
359  tinterlace->flags);
360  break;
361  default:
362  av_assert0(0);
363  }
364 
365  ret = ff_filter_frame(outlink, out);
366  tinterlace->frame++;
367 
368  return ret;
369 }
370 
371 static const AVFilterPad tinterlace_inputs[] = {
372  {
373  .name = "default",
374  .type = AVMEDIA_TYPE_VIDEO,
375  .filter_frame = filter_frame,
376  },
377  { NULL }
378 };
379 
380 static const AVFilterPad tinterlace_outputs[] = {
381  {
382  .name = "default",
383  .type = AVMEDIA_TYPE_VIDEO,
384  .config_props = config_out_props,
385  },
386  { NULL }
387 };
388 
390  .name = "tinterlace",
391  .description = NULL_IF_CONFIG_SMALL("Perform temporal field interlacing."),
392  .priv_size = sizeof(TInterlaceContext),
393  .uninit = uninit,
395  .inputs = tinterlace_inputs,
396  .outputs = tinterlace_outputs,
397  .priv_class = &tinterlace_class,
398 };