FFmpeg
vf_scale.c
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1 /*
2  * Copyright (c) 2007 Bobby Bingham
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 /**
22  * @file
23  * scale video filter
24  */
25 
26 #include <stdio.h>
27 #include <string.h>
28 
29 #include "avfilter.h"
30 #include "formats.h"
31 #include "internal.h"
32 #include "scale_eval.h"
33 #include "video.h"
34 #include "libavutil/avstring.h"
35 #include "libavutil/eval.h"
36 #include "libavutil/internal.h"
37 #include "libavutil/mathematics.h"
38 #include "libavutil/opt.h"
39 #include "libavutil/parseutils.h"
40 #include "libavutil/pixdesc.h"
41 #include "libavutil/imgutils.h"
42 #include "libswscale/swscale.h"
43 
44 static const char *const var_names[] = {
45  "in_w", "iw",
46  "in_h", "ih",
47  "out_w", "ow",
48  "out_h", "oh",
49  "a",
50  "sar",
51  "dar",
52  "hsub",
53  "vsub",
54  "ohsub",
55  "ovsub",
56  "n",
57  "t",
58  "pos",
59  "main_w",
60  "main_h",
61  "main_a",
62  "main_sar",
63  "main_dar", "mdar",
64  "main_hsub",
65  "main_vsub",
66  "main_n",
67  "main_t",
68  "main_pos",
69  NULL
70 };
71 
72 enum var_name {
98 };
99 
100 enum EvalMode {
104 };
105 
106 typedef struct ScaleContext {
107  const AVClass *class;
108  struct SwsContext *sws; ///< software scaler context
109  struct SwsContext *isws[2]; ///< software scaler context for interlaced material
111 
112  /**
113  * New dimensions. Special values are:
114  * 0 = original width/height
115  * -1 = keep original aspect
116  * -N = try to keep aspect but make sure it is divisible by N
117  */
118  int w, h;
119  char *size_str;
120  unsigned int flags; ///sws flags
121  double param[2]; // sws params
122 
123  int hsub, vsub; ///< chroma subsampling
124  int slice_y; ///< top of current output slice
125  int input_is_pal; ///< set to 1 if the input format is paletted
126  int output_is_pal; ///< set to 1 if the output format is paletted
128 
129  char *w_expr; ///< width expression string
130  char *h_expr; ///< height expression string
134 
135  char *flags_str;
136 
139 
140  int in_range;
142 
147 
150 
151  int eval_mode; ///< expression evaluation mode
152 
153 } ScaleContext;
154 
156 
157 static int config_props(AVFilterLink *outlink);
158 
160 {
161  ScaleContext *scale = ctx->priv;
162  unsigned vars_w[VARS_NB] = { 0 }, vars_h[VARS_NB] = { 0 };
163 
164  if (!scale->w_pexpr && !scale->h_pexpr)
165  return AVERROR(EINVAL);
166 
167  if (scale->w_pexpr)
168  av_expr_count_vars(scale->w_pexpr, vars_w, VARS_NB);
169  if (scale->h_pexpr)
170  av_expr_count_vars(scale->h_pexpr, vars_h, VARS_NB);
171 
172  if (vars_w[VAR_OUT_W] || vars_w[VAR_OW]) {
173  av_log(ctx, AV_LOG_ERROR, "Width expression cannot be self-referencing: '%s'.\n", scale->w_expr);
174  return AVERROR(EINVAL);
175  }
176 
177  if (vars_h[VAR_OUT_H] || vars_h[VAR_OH]) {
178  av_log(ctx, AV_LOG_ERROR, "Height expression cannot be self-referencing: '%s'.\n", scale->h_expr);
179  return AVERROR(EINVAL);
180  }
181 
182  if ((vars_w[VAR_OUT_H] || vars_w[VAR_OH]) &&
183  (vars_h[VAR_OUT_W] || vars_h[VAR_OW])) {
184  av_log(ctx, AV_LOG_WARNING, "Circular references detected for width '%s' and height '%s' - possibly invalid.\n", scale->w_expr, scale->h_expr);
185  }
186 
187  if (ctx->filter != &ff_vf_scale2ref &&
188  (vars_w[VAR_S2R_MAIN_W] || vars_h[VAR_S2R_MAIN_W] ||
189  vars_w[VAR_S2R_MAIN_H] || vars_h[VAR_S2R_MAIN_H] ||
190  vars_w[VAR_S2R_MAIN_A] || vars_h[VAR_S2R_MAIN_A] ||
191  vars_w[VAR_S2R_MAIN_SAR] || vars_h[VAR_S2R_MAIN_SAR] ||
192  vars_w[VAR_S2R_MAIN_DAR] || vars_h[VAR_S2R_MAIN_DAR] ||
193  vars_w[VAR_S2R_MDAR] || vars_h[VAR_S2R_MDAR] ||
194  vars_w[VAR_S2R_MAIN_HSUB] || vars_h[VAR_S2R_MAIN_HSUB] ||
195  vars_w[VAR_S2R_MAIN_VSUB] || vars_h[VAR_S2R_MAIN_VSUB] ||
196  vars_w[VAR_S2R_MAIN_N] || vars_h[VAR_S2R_MAIN_N] ||
197  vars_w[VAR_S2R_MAIN_T] || vars_h[VAR_S2R_MAIN_T] ||
198  vars_w[VAR_S2R_MAIN_POS] || vars_h[VAR_S2R_MAIN_POS]) ) {
199  av_log(ctx, AV_LOG_ERROR, "Expressions with scale2ref variables are not valid in scale filter.\n");
200  return AVERROR(EINVAL);
201  }
202 
203  if (scale->eval_mode == EVAL_MODE_INIT &&
204  (vars_w[VAR_N] || vars_h[VAR_N] ||
205  vars_w[VAR_T] || vars_h[VAR_T] ||
206  vars_w[VAR_POS] || vars_h[VAR_POS] ||
207  vars_w[VAR_S2R_MAIN_N] || vars_h[VAR_S2R_MAIN_N] ||
208  vars_w[VAR_S2R_MAIN_T] || vars_h[VAR_S2R_MAIN_T] ||
209  vars_w[VAR_S2R_MAIN_POS] || vars_h[VAR_S2R_MAIN_POS]) ) {
210  av_log(ctx, AV_LOG_ERROR, "Expressions with frame variables 'n', 't', 'pos' are not valid in init eval_mode.\n");
211  return AVERROR(EINVAL);
212  }
213 
214  return 0;
215 }
216 
217 static int scale_parse_expr(AVFilterContext *ctx, char *str_expr, AVExpr **pexpr_ptr, const char *var, const char *args)
218 {
219  ScaleContext *scale = ctx->priv;
220  int ret, is_inited = 0;
221  char *old_str_expr = NULL;
222  AVExpr *old_pexpr = NULL;
223 
224  if (str_expr) {
225  old_str_expr = av_strdup(str_expr);
226  if (!old_str_expr)
227  return AVERROR(ENOMEM);
228  av_opt_set(scale, var, args, 0);
229  }
230 
231  if (*pexpr_ptr) {
232  old_pexpr = *pexpr_ptr;
233  *pexpr_ptr = NULL;
234  is_inited = 1;
235  }
236 
237  ret = av_expr_parse(pexpr_ptr, args, var_names,
238  NULL, NULL, NULL, NULL, 0, ctx);
239  if (ret < 0) {
240  av_log(ctx, AV_LOG_ERROR, "Cannot parse expression for %s: '%s'\n", var, args);
241  goto revert;
242  }
243 
244  ret = check_exprs(ctx);
245  if (ret < 0)
246  goto revert;
247 
248  if (is_inited && (ret = config_props(ctx->outputs[0])) < 0)
249  goto revert;
250 
251  av_expr_free(old_pexpr);
252  old_pexpr = NULL;
253  av_freep(&old_str_expr);
254 
255  return 0;
256 
257 revert:
258  av_expr_free(*pexpr_ptr);
259  *pexpr_ptr = NULL;
260  if (old_str_expr) {
261  av_opt_set(scale, var, old_str_expr, 0);
262  av_free(old_str_expr);
263  }
264  if (old_pexpr)
265  *pexpr_ptr = old_pexpr;
266 
267  return ret;
268 }
269 
271 {
272  ScaleContext *scale = ctx->priv;
273  int ret;
274 
275  if (scale->size_str && (scale->w_expr || scale->h_expr)) {
277  "Size and width/height expressions cannot be set at the same time.\n");
278  return AVERROR(EINVAL);
279  }
280 
281  if (scale->w_expr && !scale->h_expr)
282  FFSWAP(char *, scale->w_expr, scale->size_str);
283 
284  if (scale->size_str) {
285  char buf[32];
286  if ((ret = av_parse_video_size(&scale->w, &scale->h, scale->size_str)) < 0) {
288  "Invalid size '%s'\n", scale->size_str);
289  return ret;
290  }
291  snprintf(buf, sizeof(buf)-1, "%d", scale->w);
292  av_opt_set(scale, "w", buf, 0);
293  snprintf(buf, sizeof(buf)-1, "%d", scale->h);
294  av_opt_set(scale, "h", buf, 0);
295  }
296  if (!scale->w_expr)
297  av_opt_set(scale, "w", "iw", 0);
298  if (!scale->h_expr)
299  av_opt_set(scale, "h", "ih", 0);
300 
301  ret = scale_parse_expr(ctx, NULL, &scale->w_pexpr, "width", scale->w_expr);
302  if (ret < 0)
303  return ret;
304 
305  ret = scale_parse_expr(ctx, NULL, &scale->h_pexpr, "height", scale->h_expr);
306  if (ret < 0)
307  return ret;
308 
309  av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s flags:'%s' interl:%d\n",
310  scale->w_expr, scale->h_expr, (char *)av_x_if_null(scale->flags_str, ""), scale->interlaced);
311 
312  scale->flags = 0;
313 
314  if (scale->flags_str && *scale->flags_str) {
315  const AVClass *class = sws_get_class();
316  const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
318  int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);
319  if (ret < 0)
320  return ret;
321  }
322  scale->opts = *opts;
323  *opts = NULL;
324 
325  return 0;
326 }
327 
329 {
330  ScaleContext *scale = ctx->priv;
331  av_expr_free(scale->w_pexpr);
332  av_expr_free(scale->h_pexpr);
333  scale->w_pexpr = scale->h_pexpr = NULL;
334  sws_freeContext(scale->sws);
335  sws_freeContext(scale->isws[0]);
336  sws_freeContext(scale->isws[1]);
337  scale->sws = NULL;
338  av_dict_free(&scale->opts);
339 }
340 
342 {
344  enum AVPixelFormat pix_fmt;
345  int ret;
346 
347  if (ctx->inputs[0]) {
348  const AVPixFmtDescriptor *desc = NULL;
349  formats = NULL;
350  while ((desc = av_pix_fmt_desc_next(desc))) {
354  && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
355  return ret;
356  }
357  }
358  if ((ret = ff_formats_ref(formats, &ctx->inputs[0]->outcfg.formats)) < 0)
359  return ret;
360  }
361  if (ctx->outputs[0]) {
362  const AVPixFmtDescriptor *desc = NULL;
363  formats = NULL;
364  while ((desc = av_pix_fmt_desc_next(desc))) {
368  && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
369  return ret;
370  }
371  }
372  if ((ret = ff_formats_ref(formats, &ctx->outputs[0]->incfg.formats)) < 0)
373  return ret;
374  }
375 
376  return 0;
377 }
378 
379 static const int *parse_yuv_type(const char *s, enum AVColorSpace colorspace)
380 {
381  if (!s)
382  s = "bt601";
383 
384  if (s && strstr(s, "bt709")) {
385  colorspace = AVCOL_SPC_BT709;
386  } else if (s && strstr(s, "fcc")) {
387  colorspace = AVCOL_SPC_FCC;
388  } else if (s && strstr(s, "smpte240m")) {
389  colorspace = AVCOL_SPC_SMPTE240M;
390  } else if (s && (strstr(s, "bt601") || strstr(s, "bt470") || strstr(s, "smpte170m"))) {
391  colorspace = AVCOL_SPC_BT470BG;
392  } else if (s && strstr(s, "bt2020")) {
393  colorspace = AVCOL_SPC_BT2020_NCL;
394  }
395 
396  if (colorspace < 1 || colorspace > 10 || colorspace == 8) {
397  colorspace = AVCOL_SPC_BT470BG;
398  }
399 
400  return sws_getCoefficients(colorspace);
401 }
402 
404 {
405  ScaleContext *scale = ctx->priv;
406  const char scale2ref = ctx->filter == &ff_vf_scale2ref;
407  const AVFilterLink *inlink = scale2ref ? ctx->inputs[1] : ctx->inputs[0];
408  const AVFilterLink *outlink = ctx->outputs[0];
410  const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
411  char *expr;
412  int eval_w, eval_h;
413  int ret;
414  double res;
415  const AVPixFmtDescriptor *main_desc;
416  const AVFilterLink *main_link;
417 
418  if (scale2ref) {
419  main_link = ctx->inputs[0];
420  main_desc = av_pix_fmt_desc_get(main_link->format);
421  }
422 
423  scale->var_values[VAR_IN_W] = scale->var_values[VAR_IW] = inlink->w;
424  scale->var_values[VAR_IN_H] = scale->var_values[VAR_IH] = inlink->h;
425  scale->var_values[VAR_OUT_W] = scale->var_values[VAR_OW] = NAN;
426  scale->var_values[VAR_OUT_H] = scale->var_values[VAR_OH] = NAN;
427  scale->var_values[VAR_A] = (double) inlink->w / inlink->h;
428  scale->var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
429  (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
430  scale->var_values[VAR_DAR] = scale->var_values[VAR_A] * scale->var_values[VAR_SAR];
431  scale->var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
432  scale->var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
433  scale->var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
434  scale->var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
435 
436  if (scale2ref) {
437  scale->var_values[VAR_S2R_MAIN_W] = main_link->w;
438  scale->var_values[VAR_S2R_MAIN_H] = main_link->h;
439  scale->var_values[VAR_S2R_MAIN_A] = (double) main_link->w / main_link->h;
440  scale->var_values[VAR_S2R_MAIN_SAR] = main_link->sample_aspect_ratio.num ?
441  (double) main_link->sample_aspect_ratio.num / main_link->sample_aspect_ratio.den : 1;
444  scale->var_values[VAR_S2R_MAIN_HSUB] = 1 << main_desc->log2_chroma_w;
445  scale->var_values[VAR_S2R_MAIN_VSUB] = 1 << main_desc->log2_chroma_h;
446  }
447 
448  res = av_expr_eval(scale->w_pexpr, scale->var_values, NULL);
449  eval_w = scale->var_values[VAR_OUT_W] = scale->var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res;
450 
451  res = av_expr_eval(scale->h_pexpr, scale->var_values, NULL);
452  if (isnan(res)) {
453  expr = scale->h_expr;
454  ret = AVERROR(EINVAL);
455  goto fail;
456  }
457  eval_h = scale->var_values[VAR_OUT_H] = scale->var_values[VAR_OH] = (int) res == 0 ? inlink->h : (int) res;
458 
459  res = av_expr_eval(scale->w_pexpr, scale->var_values, NULL);
460  if (isnan(res)) {
461  expr = scale->w_expr;
462  ret = AVERROR(EINVAL);
463  goto fail;
464  }
465  eval_w = scale->var_values[VAR_OUT_W] = scale->var_values[VAR_OW] = (int) res == 0 ? inlink->w : (int) res;
466 
467  scale->w = eval_w;
468  scale->h = eval_h;
469 
470  return 0;
471 
472 fail:
474  "Error when evaluating the expression '%s'.\n", expr);
475  return ret;
476 }
477 
478 static int config_props(AVFilterLink *outlink)
479 {
480  AVFilterContext *ctx = outlink->src;
481  AVFilterLink *inlink0 = outlink->src->inputs[0];
482  AVFilterLink *inlink = ctx->filter == &ff_vf_scale2ref ?
483  outlink->src->inputs[1] :
484  outlink->src->inputs[0];
485  enum AVPixelFormat outfmt = outlink->format;
487  ScaleContext *scale = ctx->priv;
488  int ret;
489 
490  if ((ret = scale_eval_dimensions(ctx)) < 0)
491  goto fail;
492 
493  ff_scale_adjust_dimensions(inlink, &scale->w, &scale->h,
495  scale->force_divisible_by);
496 
497  if (scale->w > INT_MAX ||
498  scale->h > INT_MAX ||
499  (scale->h * inlink->w) > INT_MAX ||
500  (scale->w * inlink->h) > INT_MAX)
501  av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
502 
503  outlink->w = scale->w;
504  outlink->h = scale->h;
505 
506  /* TODO: make algorithm configurable */
507 
508  scale->input_is_pal = desc->flags & AV_PIX_FMT_FLAG_PAL;
509  if (outfmt == AV_PIX_FMT_PAL8) outfmt = AV_PIX_FMT_BGR8;
511 
512  if (scale->sws)
513  sws_freeContext(scale->sws);
514  if (scale->isws[0])
515  sws_freeContext(scale->isws[0]);
516  if (scale->isws[1])
517  sws_freeContext(scale->isws[1]);
518  scale->isws[0] = scale->isws[1] = scale->sws = NULL;
519  if (inlink0->w == outlink->w &&
520  inlink0->h == outlink->h &&
521  !scale->out_color_matrix &&
522  scale->in_range == scale->out_range &&
523  inlink0->format == outlink->format)
524  ;
525  else {
526  struct SwsContext **swscs[3] = {&scale->sws, &scale->isws[0], &scale->isws[1]};
527  int i;
528 
529  for (i = 0; i < 3; i++) {
530  int in_v_chr_pos = scale->in_v_chr_pos, out_v_chr_pos = scale->out_v_chr_pos;
531  struct SwsContext *const s = sws_alloc_context();
532  if (!s)
533  return AVERROR(ENOMEM);
534  *swscs[i] = s;
535 
536  av_opt_set_int(s, "srcw", inlink0 ->w, 0);
537  av_opt_set_int(s, "srch", inlink0 ->h >> !!i, 0);
538  av_opt_set_int(s, "src_format", inlink0->format, 0);
539  av_opt_set_int(s, "dstw", outlink->w, 0);
540  av_opt_set_int(s, "dsth", outlink->h >> !!i, 0);
541  av_opt_set_int(s, "dst_format", outfmt, 0);
542  av_opt_set_int(s, "sws_flags", scale->flags, 0);
543  av_opt_set_int(s, "param0", scale->param[0], 0);
544  av_opt_set_int(s, "param1", scale->param[1], 0);
545  av_opt_set_int(s, "threads", ff_filter_get_nb_threads(ctx), 0);
546  if (scale->in_range != AVCOL_RANGE_UNSPECIFIED)
547  av_opt_set_int(s, "src_range",
548  scale->in_range == AVCOL_RANGE_JPEG, 0);
549  if (scale->out_range != AVCOL_RANGE_UNSPECIFIED)
550  av_opt_set_int(s, "dst_range",
551  scale->out_range == AVCOL_RANGE_JPEG, 0);
552 
553  if (scale->opts) {
554  AVDictionaryEntry *e = NULL;
555  while ((e = av_dict_get(scale->opts, "", e, AV_DICT_IGNORE_SUFFIX))) {
556  if ((ret = av_opt_set(s, e->key, e->value, 0)) < 0)
557  return ret;
558  }
559  }
560  /* Override YUV420P default settings to have the correct (MPEG-2) chroma positions
561  * MPEG-2 chroma positions are used by convention
562  * XXX: support other 4:2:0 pixel formats */
563  if (inlink0->format == AV_PIX_FMT_YUV420P && scale->in_v_chr_pos == -513) {
564  in_v_chr_pos = (i == 0) ? 128 : (i == 1) ? 64 : 192;
565  }
566 
567  if (outlink->format == AV_PIX_FMT_YUV420P && scale->out_v_chr_pos == -513) {
568  out_v_chr_pos = (i == 0) ? 128 : (i == 1) ? 64 : 192;
569  }
570 
571  av_opt_set_int(s, "src_h_chr_pos", scale->in_h_chr_pos, 0);
572  av_opt_set_int(s, "src_v_chr_pos", in_v_chr_pos, 0);
573  av_opt_set_int(s, "dst_h_chr_pos", scale->out_h_chr_pos, 0);
574  av_opt_set_int(s, "dst_v_chr_pos", out_v_chr_pos, 0);
575 
576  if ((ret = sws_init_context(s, NULL, NULL)) < 0)
577  return ret;
578  if (!scale->interlaced)
579  break;
580  }
581  }
582 
583  if (inlink0->sample_aspect_ratio.num){
584  outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink0->w, outlink->w * inlink0->h}, inlink0->sample_aspect_ratio);
585  } else
586  outlink->sample_aspect_ratio = inlink0->sample_aspect_ratio;
587 
588  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d fmt:%s sar:%d/%d flags:0x%0x\n",
589  inlink ->w, inlink ->h, av_get_pix_fmt_name( inlink->format),
590  inlink->sample_aspect_ratio.num, inlink->sample_aspect_ratio.den,
591  outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
592  outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den,
593  scale->flags);
594  return 0;
595 
596 fail:
597  return ret;
598 }
599 
600 static int config_props_ref(AVFilterLink *outlink)
601 {
602  AVFilterLink *inlink = outlink->src->inputs[1];
603 
604  outlink->w = inlink->w;
605  outlink->h = inlink->h;
606  outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
607  outlink->time_base = inlink->time_base;
608  outlink->frame_rate = inlink->frame_rate;
609 
610  return 0;
611 }
612 
613 static int request_frame(AVFilterLink *outlink)
614 {
615  return ff_request_frame(outlink->src->inputs[0]);
616 }
617 
618 static int request_frame_ref(AVFilterLink *outlink)
619 {
620  return ff_request_frame(outlink->src->inputs[1]);
621 }
622 
623 static void frame_offset(AVFrame *frame, int dir, int is_pal)
624 {
625  for (int i = 0; i < 4 && frame->data[i]; i++) {
626  if (i == 1 && is_pal)
627  break;
628  frame->data[i] += frame->linesize[i] * dir;
629  }
630 }
631 
632 static int scale_field(ScaleContext *scale, AVFrame *dst, AVFrame *src,
633  int field)
634 {
635  int orig_h_src = src->height;
636  int orig_h_dst = dst->height;
637  int ret;
638 
639  // offset the data pointers for the bottom field
640  if (field) {
641  frame_offset(src, 1, scale->input_is_pal);
642  frame_offset(dst, 1, scale->output_is_pal);
643  }
644 
645  // take every second line
646  for (int i = 0; i < 4; i++) {
647  src->linesize[i] *= 2;
648  dst->linesize[i] *= 2;
649  }
650  src->height /= 2;
651  dst->height /= 2;
652 
653  ret = sws_scale_frame(scale->isws[field], dst, src);
654  if (ret < 0)
655  return ret;
656 
657  // undo the changes we made above
658  for (int i = 0; i < 4; i++) {
659  src->linesize[i] /= 2;
660  dst->linesize[i] /= 2;
661  }
662  src->height = orig_h_src;
663  dst->height = orig_h_dst;
664 
665  if (field) {
666  frame_offset(src, -1, scale->input_is_pal);
667  frame_offset(dst, -1, scale->output_is_pal);
668  }
669 
670  return 0;
671 }
672 
673 static int scale_frame(AVFilterLink *link, AVFrame *in, AVFrame **frame_out)
674 {
675  AVFilterContext *ctx = link->dst;
676  ScaleContext *scale = ctx->priv;
677  AVFilterLink *outlink = ctx->outputs[0];
678  AVFrame *out;
680  char buf[32];
681  int ret;
682  int in_range;
683  int frame_changed;
684 
685  *frame_out = NULL;
686  if (in->colorspace == AVCOL_SPC_YCGCO)
687  av_log(link->dst, AV_LOG_WARNING, "Detected unsupported YCgCo colorspace.\n");
688 
689  frame_changed = in->width != link->w ||
690  in->height != link->h ||
691  in->format != link->format ||
694 
695  if (scale->eval_mode == EVAL_MODE_FRAME || frame_changed) {
696  unsigned vars_w[VARS_NB] = { 0 }, vars_h[VARS_NB] = { 0 };
697 
698  av_expr_count_vars(scale->w_pexpr, vars_w, VARS_NB);
699  av_expr_count_vars(scale->h_pexpr, vars_h, VARS_NB);
700 
701  if (scale->eval_mode == EVAL_MODE_FRAME &&
702  !frame_changed &&
703  ctx->filter != &ff_vf_scale2ref &&
704  !(vars_w[VAR_N] || vars_w[VAR_T] || vars_w[VAR_POS]) &&
705  !(vars_h[VAR_N] || vars_h[VAR_T] || vars_h[VAR_POS]) &&
706  scale->w && scale->h)
707  goto scale;
708 
709  if (scale->eval_mode == EVAL_MODE_INIT) {
710  snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
711  av_opt_set(scale, "w", buf, 0);
712  snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
713  av_opt_set(scale, "h", buf, 0);
714 
715  ret = scale_parse_expr(ctx, NULL, &scale->w_pexpr, "width", scale->w_expr);
716  if (ret < 0)
717  return ret;
718 
719  ret = scale_parse_expr(ctx, NULL, &scale->h_pexpr, "height", scale->h_expr);
720  if (ret < 0)
721  return ret;
722  }
723 
724  if (ctx->filter == &ff_vf_scale2ref) {
725  scale->var_values[VAR_S2R_MAIN_N] = link->frame_count_out;
726  scale->var_values[VAR_S2R_MAIN_T] = TS2T(in->pts, link->time_base);
727  scale->var_values[VAR_S2R_MAIN_POS] = in->pkt_pos == -1 ? NAN : in->pkt_pos;
728  } else {
729  scale->var_values[VAR_N] = link->frame_count_out;
730  scale->var_values[VAR_T] = TS2T(in->pts, link->time_base);
731  scale->var_values[VAR_POS] = in->pkt_pos == -1 ? NAN : in->pkt_pos;
732  }
733 
734  link->dst->inputs[0]->format = in->format;
735  link->dst->inputs[0]->w = in->width;
736  link->dst->inputs[0]->h = in->height;
737 
738  link->dst->inputs[0]->sample_aspect_ratio.den = in->sample_aspect_ratio.den;
739  link->dst->inputs[0]->sample_aspect_ratio.num = in->sample_aspect_ratio.num;
740 
741  if ((ret = config_props(outlink)) < 0)
742  return ret;
743  }
744 
745 scale:
746  if (!scale->sws) {
747  *frame_out = in;
748  return 0;
749  }
750 
751  scale->hsub = desc->log2_chroma_w;
752  scale->vsub = desc->log2_chroma_h;
753 
754  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
755  if (!out) {
756  av_frame_free(&in);
757  return AVERROR(ENOMEM);
758  }
759  *frame_out = out;
760 
762  out->width = outlink->w;
763  out->height = outlink->h;
764 
765  // Sanity checks:
766  // 1. If the output is RGB, set the matrix coefficients to RGB.
767  // 2. If the output is not RGB and we've got the RGB/XYZ (identity)
768  // matrix configured, unset the matrix.
769  // In theory these should be in swscale itself as the AVFrame
770  // based API gets in, so that not every swscale API user has
771  // to go through duplicating such sanity checks.
773  out->colorspace = AVCOL_SPC_RGB;
774  else if (out->colorspace == AVCOL_SPC_RGB)
775  out->colorspace = AVCOL_SPC_UNSPECIFIED;
776 
777  if (scale->output_is_pal)
778  avpriv_set_systematic_pal2((uint32_t*)out->data[1], outlink->format == AV_PIX_FMT_PAL8 ? AV_PIX_FMT_BGR8 : outlink->format);
779 
780  in_range = in->color_range;
781 
782  if ( scale->in_color_matrix
783  || scale->out_color_matrix
784  || scale-> in_range != AVCOL_RANGE_UNSPECIFIED
785  || in_range != AVCOL_RANGE_UNSPECIFIED
786  || scale->out_range != AVCOL_RANGE_UNSPECIFIED) {
787  int in_full, out_full, brightness, contrast, saturation;
788  const int *inv_table, *table;
789 
790  sws_getColorspaceDetails(scale->sws, (int **)&inv_table, &in_full,
791  (int **)&table, &out_full,
793 
794  if (scale->in_color_matrix)
795  inv_table = parse_yuv_type(scale->in_color_matrix, in->colorspace);
796  if (scale->out_color_matrix)
798  else if (scale->in_color_matrix)
799  table = inv_table;
800 
801  if (scale-> in_range != AVCOL_RANGE_UNSPECIFIED)
802  in_full = (scale-> in_range == AVCOL_RANGE_JPEG);
803  else if (in_range != AVCOL_RANGE_UNSPECIFIED)
804  in_full = (in_range == AVCOL_RANGE_JPEG);
805  if (scale->out_range != AVCOL_RANGE_UNSPECIFIED)
806  out_full = (scale->out_range == AVCOL_RANGE_JPEG);
807 
808  sws_setColorspaceDetails(scale->sws, inv_table, in_full,
809  table, out_full,
811  if (scale->isws[0])
812  sws_setColorspaceDetails(scale->isws[0], inv_table, in_full,
813  table, out_full,
815  if (scale->isws[1])
816  sws_setColorspaceDetails(scale->isws[1], inv_table, in_full,
817  table, out_full,
819 
820  out->color_range = out_full ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
821  }
822 
823  av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
824  (int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
825  (int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
826  INT_MAX);
827 
828  if (scale->interlaced>0 || (scale->interlaced<0 && in->interlaced_frame)) {
829  ret = scale_field(scale, out, in, 0);
830  if (ret >= 0)
831  ret = scale_field(scale, out, in, 1);
832  } else {
833  ret = sws_scale_frame(scale->sws, out, in);
834  }
835 
836  av_frame_free(&in);
837  if (ret < 0)
838  av_frame_free(frame_out);
839  return ret;
840 }
841 
843 {
844  AVFilterContext *ctx = link->dst;
845  AVFilterLink *outlink = ctx->outputs[0];
846  AVFrame *out;
847  int ret;
848 
849  ret = scale_frame(link, in, &out);
850  if (out)
851  return ff_filter_frame(outlink, out);
852 
853  return ret;
854 }
855 
857 {
858  ScaleContext *scale = link->dst->priv;
859  AVFilterLink *outlink = link->dst->outputs[1];
860  int frame_changed;
861 
862  frame_changed = in->width != link->w ||
863  in->height != link->h ||
864  in->format != link->format ||
867 
868  if (frame_changed) {
869  link->format = in->format;
870  link->w = in->width;
871  link->h = in->height;
874 
875  config_props_ref(outlink);
876  }
877 
878  if (scale->eval_mode == EVAL_MODE_FRAME) {
879  scale->var_values[VAR_N] = link->frame_count_out;
880  scale->var_values[VAR_T] = TS2T(in->pts, link->time_base);
881  scale->var_values[VAR_POS] = in->pkt_pos == -1 ? NAN : in->pkt_pos;
882  }
883 
884  return ff_filter_frame(outlink, in);
885 }
886 
887 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
888  char *res, int res_len, int flags)
889 {
890  ScaleContext *scale = ctx->priv;
891  char *str_expr;
892  AVExpr **pexpr_ptr;
893  int ret, w, h;
894 
895  w = !strcmp(cmd, "width") || !strcmp(cmd, "w");
896  h = !strcmp(cmd, "height") || !strcmp(cmd, "h");
897 
898  if (w || h) {
899  str_expr = w ? scale->w_expr : scale->h_expr;
900  pexpr_ptr = w ? &scale->w_pexpr : &scale->h_pexpr;
901 
902  ret = scale_parse_expr(ctx, str_expr, pexpr_ptr, cmd, args);
903  } else
904  ret = AVERROR(ENOSYS);
905 
906  if (ret < 0)
907  av_log(ctx, AV_LOG_ERROR, "Failed to process command. Continuing with existing parameters.\n");
908 
909  return ret;
910 }
911 
912 static const AVClass *child_class_iterate(void **iter)
913 {
914  const AVClass *c = *iter ? NULL : sws_get_class();
915  *iter = (void*)(uintptr_t)c;
916  return c;
917 }
918 
919 #define OFFSET(x) offsetof(ScaleContext, x)
920 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
921 #define TFLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
922 
923 static const AVOption scale_options[] = {
924  { "w", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, .flags = TFLAGS },
925  { "width", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, .flags = TFLAGS },
926  { "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, .flags = TFLAGS },
927  { "height","Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, .flags = TFLAGS },
928  { "flags", "Flags to pass to libswscale", OFFSET(flags_str), AV_OPT_TYPE_STRING, { .str = "" }, .flags = FLAGS },
929  { "interl", "set interlacing", OFFSET(interlaced), AV_OPT_TYPE_BOOL, {.i64 = 0 }, -1, 1, FLAGS },
930  { "size", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
931  { "s", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
932  { "in_color_matrix", "set input YCbCr type", OFFSET(in_color_matrix), AV_OPT_TYPE_STRING, { .str = "auto" }, .flags = FLAGS, "color" },
933  { "out_color_matrix", "set output YCbCr type", OFFSET(out_color_matrix), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS, "color"},
934  { "auto", NULL, 0, AV_OPT_TYPE_CONST, { .str = "auto" }, 0, 0, FLAGS, "color" },
935  { "bt601", NULL, 0, AV_OPT_TYPE_CONST, { .str = "bt601" }, 0, 0, FLAGS, "color" },
936  { "bt470", NULL, 0, AV_OPT_TYPE_CONST, { .str = "bt470" }, 0, 0, FLAGS, "color" },
937  { "smpte170m", NULL, 0, AV_OPT_TYPE_CONST, { .str = "smpte170m" }, 0, 0, FLAGS, "color" },
938  { "bt709", NULL, 0, AV_OPT_TYPE_CONST, { .str = "bt709" }, 0, 0, FLAGS, "color" },
939  { "fcc", NULL, 0, AV_OPT_TYPE_CONST, { .str = "fcc" }, 0, 0, FLAGS, "color" },
940  { "smpte240m", NULL, 0, AV_OPT_TYPE_CONST, { .str = "smpte240m" }, 0, 0, FLAGS, "color" },
941  { "bt2020", NULL, 0, AV_OPT_TYPE_CONST, { .str = "bt2020" }, 0, 0, FLAGS, "color" },
942  { "in_range", "set input color range", OFFSET( in_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
943  { "out_range", "set output color range", OFFSET(out_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
944  { "auto", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, "range" },
945  { "unknown", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, "range" },
946  { "full", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
947  { "limited",NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
948  { "jpeg", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
949  { "mpeg", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
950  { "tv", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
951  { "pc", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
952  { "in_v_chr_pos", "input vertical chroma position in luma grid/256" , OFFSET(in_v_chr_pos), AV_OPT_TYPE_INT, { .i64 = -513}, -513, 512, FLAGS },
953  { "in_h_chr_pos", "input horizontal chroma position in luma grid/256", OFFSET(in_h_chr_pos), AV_OPT_TYPE_INT, { .i64 = -513}, -513, 512, FLAGS },
954  { "out_v_chr_pos", "output vertical chroma position in luma grid/256" , OFFSET(out_v_chr_pos), AV_OPT_TYPE_INT, { .i64 = -513}, -513, 512, FLAGS },
955  { "out_h_chr_pos", "output horizontal chroma position in luma grid/256", OFFSET(out_h_chr_pos), AV_OPT_TYPE_INT, { .i64 = -513}, -513, 512, FLAGS },
956  { "force_original_aspect_ratio", "decrease or increase w/h if necessary to keep the original AR", OFFSET(force_original_aspect_ratio), AV_OPT_TYPE_INT, { .i64 = 0}, 0, 2, FLAGS, "force_oar" },
957  { "disable", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "force_oar" },
958  { "decrease", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "force_oar" },
959  { "increase", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2 }, 0, 0, FLAGS, "force_oar" },
960  { "force_divisible_by", "enforce that the output resolution is divisible by a defined integer when force_original_aspect_ratio is used", OFFSET(force_divisible_by), AV_OPT_TYPE_INT, { .i64 = 1}, 1, 256, FLAGS },
961  { "param0", "Scaler param 0", OFFSET(param[0]), AV_OPT_TYPE_DOUBLE, { .dbl = SWS_PARAM_DEFAULT }, INT_MIN, INT_MAX, FLAGS },
962  { "param1", "Scaler param 1", OFFSET(param[1]), AV_OPT_TYPE_DOUBLE, { .dbl = SWS_PARAM_DEFAULT }, INT_MIN, INT_MAX, FLAGS },
963  { "eval", "specify when to evaluate expressions", OFFSET(eval_mode), AV_OPT_TYPE_INT, {.i64 = EVAL_MODE_INIT}, 0, EVAL_MODE_NB-1, FLAGS, "eval" },
964  { "init", "eval expressions once during initialization", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_INIT}, .flags = FLAGS, .unit = "eval" },
965  { "frame", "eval expressions during initialization and per-frame", 0, AV_OPT_TYPE_CONST, {.i64=EVAL_MODE_FRAME}, .flags = FLAGS, .unit = "eval" },
966  { NULL }
967 };
968 
969 static const AVClass scale_class = {
970  .class_name = "scale",
971  .item_name = av_default_item_name,
972  .option = scale_options,
973  .version = LIBAVUTIL_VERSION_INT,
974  .category = AV_CLASS_CATEGORY_FILTER,
975  .child_class_iterate = child_class_iterate,
976 };
977 
979  {
980  .name = "default",
981  .type = AVMEDIA_TYPE_VIDEO,
982  .filter_frame = filter_frame,
983  },
984 };
985 
987  {
988  .name = "default",
989  .type = AVMEDIA_TYPE_VIDEO,
990  .config_props = config_props,
991  },
992 };
993 
995  .name = "scale",
996  .description = NULL_IF_CONFIG_SMALL("Scale the input video size and/or convert the image format."),
997  .init_dict = init_dict,
998  .uninit = uninit,
999  .query_formats = query_formats,
1000  .priv_size = sizeof(ScaleContext),
1001  .priv_class = &scale_class,
1004  .process_command = process_command,
1005 };
1006 
1007 static const AVClass scale2ref_class = {
1008  .class_name = "scale2ref",
1009  .item_name = av_default_item_name,
1010  .option = scale_options,
1011  .version = LIBAVUTIL_VERSION_INT,
1012  .category = AV_CLASS_CATEGORY_FILTER,
1013  .child_class_iterate = child_class_iterate,
1014 };
1015 
1017  {
1018  .name = "default",
1019  .type = AVMEDIA_TYPE_VIDEO,
1020  .filter_frame = filter_frame,
1021  },
1022  {
1023  .name = "ref",
1024  .type = AVMEDIA_TYPE_VIDEO,
1025  .filter_frame = filter_frame_ref,
1026  },
1027 };
1028 
1030  {
1031  .name = "default",
1032  .type = AVMEDIA_TYPE_VIDEO,
1033  .config_props = config_props,
1034  .request_frame= request_frame,
1035  },
1036  {
1037  .name = "ref",
1038  .type = AVMEDIA_TYPE_VIDEO,
1039  .config_props = config_props_ref,
1040  .request_frame= request_frame_ref,
1041  },
1042 };
1043 
1045  .name = "scale2ref",
1046  .description = NULL_IF_CONFIG_SMALL("Scale the input video size and/or convert the image format to the given reference."),
1047  .init_dict = init_dict,
1048  .uninit = uninit,
1049  .query_formats = query_formats,
1050  .priv_size = sizeof(ScaleContext),
1051  .priv_class = &scale2ref_class,
1054  .process_command = process_command,
1055 };
filter_frame_ref
static int filter_frame_ref(AVFilterLink *link, AVFrame *in)
Definition: vf_scale.c:856
ScaleContext::param
double param[2]
sws flags
Definition: vf_scale.c:121
VAR_S2R_MAIN_SAR
@ VAR_S2R_MAIN_SAR
Definition: vf_scale.c:90
formats
formats
Definition: signature.h:48
ff_get_video_buffer
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
Definition: video.c:98
VAR_S2R_MAIN_A
@ VAR_S2R_MAIN_A
Definition: vf_scale.c:89
VAR_HSUB
@ VAR_HSUB
Definition: vf_scale.c:80
config_props_ref
static int config_props_ref(AVFilterLink *outlink)
Definition: vf_scale.c:600
SwsContext::saturation
int saturation
Definition: swscale_internal.h:451
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVFrame::color_range
enum AVColorRange color_range
MPEG vs JPEG YUV range.
Definition: frame.h:530
sws_isSupportedOutput
#define sws_isSupportedOutput(x)
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
TFLAGS
#define TFLAGS
Definition: vf_scale.c:921
sws_isSupportedInput
#define sws_isSupportedInput(x)
check_exprs
static int check_exprs(AVFilterContext *ctx)
Definition: vf_scale.c:159
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
ScaleContext::input_is_pal
int input_is_pal
set to 1 if the input format is paletted
Definition: vf_scale.c:125
out
FILE * out
Definition: movenc.c:54
ScaleContext
Definition: vf_scale.c:106
ScaleContext::flags
unsigned int flags
Definition: vf_scale.c:120
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1019
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2540
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: vf_scale.c:341
ScaleContext::force_divisible_by
int force_divisible_by
Definition: vf_scale.c:149
avfilter_vf_scale2ref_outputs
static const AVFilterPad avfilter_vf_scale2ref_outputs[]
Definition: vf_scale.c:1029
FLAGS
#define FLAGS
Definition: vf_scale.c:920
ScaleContext::flags_str
char * flags_str
Definition: vf_scale.c:135
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
AVFrame::colorspace
enum AVColorSpace colorspace
YUV colorspace type.
Definition: frame.h:541
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
pixdesc.h
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:396
AVFrame::width
int width
Definition: frame.h:361
w
uint8_t w
Definition: llviddspenc.c:38
AVCOL_RANGE_JPEG
@ AVCOL_RANGE_JPEG
Full range content.
Definition: pixfmt.h:576
VAR_A
@ VAR_A
Definition: vf_scale.c:77
request_frame_ref
static int request_frame_ref(AVFilterLink *outlink)
Definition: vf_scale.c:618
AVOption
AVOption.
Definition: opt.h:247
scale_parse_expr
static int scale_parse_expr(AVFilterContext *ctx, char *str_expr, AVExpr **pexpr_ptr, const char *var, const char *args)
Definition: vf_scale.c:217
scale2ref_class
static const AVClass scale2ref_class
Definition: vf_scale.c:1007
table
static const uint16_t table[]
Definition: prosumer.c:206
request_frame
static int request_frame(AVFilterLink *outlink)
Definition: vf_scale.c:613
av_pix_fmt_desc_next
const AVPixFmtDescriptor * av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev)
Iterate over all pixel format descriptors known to libavutil.
Definition: pixdesc.c:2547
ff_request_frame
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:421
AV_DICT_IGNORE_SUFFIX
#define AV_DICT_IGNORE_SUFFIX
Return first entry in a dictionary whose first part corresponds to the search key,...
Definition: dict.h:68
VAR_S2R_MAIN_HSUB
@ VAR_S2R_MAIN_HSUB
Definition: vf_scale.c:92
ScaleContext::var_values
double var_values[VARS_NB]
Definition: vf_scale.c:133
ScaleContext::out_range
int out_range
Definition: vf_scale.c:141
VAR_S2R_MDAR
@ VAR_S2R_MDAR
Definition: vf_scale.c:91
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
AVCOL_SPC_RGB
@ AVCOL_SPC_RGB
order of coefficients is actually GBR, also IEC 61966-2-1 (sRGB), YZX and ST 428-1
Definition: pixfmt.h:503
EVAL_MODE_FRAME
@ EVAL_MODE_FRAME
Definition: vf_scale.c:102
VAR_S2R_MAIN_H
@ VAR_S2R_MAIN_H
Definition: vf_scale.c:88
mathematics.h
AVDictionary
Definition: dict.c:30
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
ScaleContext::in_h_chr_pos
int in_h_chr_pos
Definition: vf_scale.c:145
VAR_OUT_H
@ VAR_OUT_H
Definition: vf_scale.c:76
ScaleContext::opts
AVDictionary * opts
Definition: vf_scale.c:110
video.h
AVFilterFormats
A list of supported formats for one end of a filter link.
Definition: formats.h:64
formats.h
av_expr_parse
int av_expr_parse(AVExpr **expr, const char *s, const char *const *const_names, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), int log_offset, void *log_ctx)
Parse an expression.
Definition: eval.c:685
VAR_S2R_MAIN_POS
@ VAR_S2R_MAIN_POS
Definition: vf_scale.c:96
AVCOL_SPC_BT470BG
@ AVCOL_SPC_BT470BG
also ITU-R BT601-6 625 / ITU-R BT1358 625 / ITU-R BT1700 625 PAL & SECAM / IEC 61966-2-4 xvYCC601
Definition: pixfmt.h:508
VAR_DAR
@ VAR_DAR
Definition: vf_scale.c:79
avfilter_vf_scale_inputs
static const AVFilterPad avfilter_vf_scale_inputs[]
Definition: vf_scale.c:978
fail
#define fail()
Definition: checkasm.h:127
VARS_NB
@ VARS_NB
Definition: vf_scale.c:97
frame_offset
static void frame_offset(AVFrame *frame, int dir, int is_pal)
Definition: vf_scale.c:623
ScaleContext::isws
struct SwsContext * isws[2]
software scaler context for interlaced material
Definition: vf_scale.c:109
ScaleContext::eval_mode
int eval_mode
expression evaluation mode
Definition: vf_scale.c:151
VAR_IN_H
@ VAR_IN_H
Definition: vf_scale.c:74
EVAL_MODE_NB
@ EVAL_MODE_NB
Definition: vf_scale.c:103
sws_get_class
const AVClass * sws_get_class(void)
Get the AVClass for swsContext.
Definition: options.c:98
av_opt_set
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:465
av_reduce
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
av_expr_free
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse().
Definition: eval.c:336
AVRational::num
int num
Numerator.
Definition: rational.h:59
OFFSET
#define OFFSET(x)
Definition: vf_scale.c:919
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
AV_PIX_FMT_BGR8
@ AV_PIX_FMT_BGR8
packed RGB 3:3:2, 8bpp, (msb)2B 3G 3R(lsb)
Definition: pixfmt.h:83
TS2T
#define TS2T(ts, tb)
Definition: internal.h:225
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
ScaleContext::sws
struct SwsContext * sws
software scaler context
Definition: vf_scale.c:108
av_dict_get
AVDictionaryEntry * av_dict_get(const AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags)
Get a dictionary entry with matching key.
Definition: dict.c:40
s
#define s(width, name)
Definition: cbs_vp9.c:257
VAR_OH
@ VAR_OH
Definition: vf_scale.c:76
VAR_S2R_MAIN_W
@ VAR_S2R_MAIN_W
Definition: vf_scale.c:87
SwsContext::brightness
int brightness
Definition: swscale_internal.h:451
scale_frame
static int scale_frame(AVFilterLink *link, AVFrame *in, AVFrame **frame_out)
Definition: vf_scale.c:673
ScaleContext::slice_y
int slice_y
top of current output slice
Definition: vf_scale.c:124
AVFrame::pkt_pos
int64_t pkt_pos
reordered pos from the last AVPacket that has been input into the decoder
Definition: frame.h:557
AVDictionaryEntry::key
char * key
Definition: dict.h:80
AV_OPT_TYPE_DOUBLE
@ AV_OPT_TYPE_DOUBLE
Definition: opt.h:226
av_expr_count_vars
int av_expr_count_vars(AVExpr *e, unsigned *counter, int size)
Track the presence of variables and their number of occurrences in a parsed expression.
Definition: eval.c:756
ff_formats_ref
int ff_formats_ref(AVFilterFormats *f, AVFilterFormats **ref)
Add *ref as a new reference to formats.
Definition: formats.c:553
init_dict
static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
Definition: vf_scale.c:270
VAR_OVSUB
@ VAR_OVSUB
Definition: vf_scale.c:83
ScaleContext::in_color_matrix
char * in_color_matrix
Definition: vf_scale.c:137
var_name
var_name
Definition: noise_bsf.c:47
ctx
AVFormatContext * ctx
Definition: movenc.c:48
process_command
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, char *res, int res_len, int flags)
Definition: vf_scale.c:887
av_expr_eval
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:766
pix_fmt
static enum AVPixelFormat pix_fmt
Definition: demuxing_decoding.c:41
AVExpr
Definition: eval.c:157
field
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this field
Definition: writing_filters.txt:78
AVPixFmtDescriptor::log2_chroma_w
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:80
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
SwsContext::contrast
int contrast
Definition: swscale_internal.h:451
ScaleContext::w_pexpr
AVExpr * w_pexpr
Definition: vf_scale.c:131
avpriv_set_systematic_pal2
int avpriv_set_systematic_pal2(uint32_t pal[256], enum AVPixelFormat pix_fmt)
Definition: imgutils.c:178
NAN
#define NAN
Definition: mathematics.h:64
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:152
link
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a link
Definition: filter_design.txt:23
av_opt_find
const AVOption * av_opt_find(void *obj, const char *name, const char *unit, int opt_flags, int search_flags)
Look for an option in an object.
Definition: opt.c:1661
ScaleContext::out_h_chr_pos
int out_h_chr_pos
Definition: vf_scale.c:143
scale_field
static int scale_field(ScaleContext *scale, AVFrame *dst, AVFrame *src, int field)
Definition: vf_scale.c:632
opts
AVDictionary * opts
Definition: movenc.c:50
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
ScaleContext::out_v_chr_pos
int out_v_chr_pos
Definition: vf_scale.c:144
av_frame_copy_props
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:537
VAR_T
@ VAR_T
Definition: vf_scale.c:85
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
isnan
#define isnan(x)
Definition: libm.h:340
ScaleContext::in_range
int in_range
Definition: vf_scale.c:140
AVFilterContext::inputs
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:354
VAR_IN_W
@ VAR_IN_W
Definition: vf_scale.c:73
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
src
#define src
Definition: vp8dsp.c:255
ff_add_format
int ff_add_format(AVFilterFormats **avff, int64_t fmt)
Add fmt to the list of media formats contained in *avff.
Definition: formats.c:419
parseutils.h
sws_alloc_context
struct SwsContext * sws_alloc_context(void)
Allocate an empty SwsContext.
Definition: utils.c:1106
ScaleContext::h_pexpr
AVExpr * h_pexpr
Definition: vf_scale.c:132
AVCOL_SPC_YCGCO
@ AVCOL_SPC_YCGCO
used by Dirac / VC-2 and H.264 FRext, see ITU-T SG16
Definition: pixfmt.h:511
sws_setColorspaceDetails
int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4], int srcRange, const int table[4], int dstRange, int brightness, int contrast, int saturation)
Definition: utils.c:867
AVPixFmtDescriptor::flags
uint64_t flags
Combination of AV_PIX_FMT_FLAG_...
Definition: pixdesc.h:94
ff_vf_scale2ref
const AVFilter ff_vf_scale2ref
Definition: vf_scale.c:155
AVCOL_RANGE_UNSPECIFIED
@ AVCOL_RANGE_UNSPECIFIED
Definition: pixfmt.h:542
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
av_opt_set_int
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
Definition: opt.c:586
AV_OPT_SEARCH_FAKE_OBJ
#define AV_OPT_SEARCH_FAKE_OBJ
The obj passed to av_opt_find() is fake – only a double pointer to AVClass instead of a required poin...
Definition: opt.h:567
AV_CLASS_CATEGORY_FILTER
@ AV_CLASS_CATEGORY_FILTER
Definition: log.h:36
VAR_IW
@ VAR_IW
Definition: vf_scale.c:73
SWS_PARAM_DEFAULT
#define SWS_PARAM_DEFAULT
Definition: swscale.h:74
eval.h
VAR_IH
@ VAR_IH
Definition: vf_scale.c:74
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AV_PIX_FMT_FLAG_RGB
#define AV_PIX_FMT_FLAG_RGB
The pixel format contains RGB-like data (as opposed to YUV/grayscale).
Definition: pixdesc.h:136
child_class_iterate
static const AVClass * child_class_iterate(void **iter)
Definition: vf_scale.c:912
ScaleContext::w
int w
New dimensions.
Definition: vf_scale.c:118
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:376
scale_eval.h
ScaleContext::hsub
int hsub
Definition: vf_scale.c:123
VAR_OUT_W
@ VAR_OUT_W
Definition: vf_scale.c:75
av_pix_fmt_desc_get_id
enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc)
Definition: pixdesc.c:2559
av_dict_free
void av_dict_free(AVDictionary **pm)
Free all the memory allocated for an AVDictionary struct and all keys and values.
Definition: dict.c:203
filter_frame
static int filter_frame(AVFilterLink *link, AVFrame *in)
Definition: vf_scale.c:842
av_parse_video_size
int av_parse_video_size(int *width_ptr, int *height_ptr, const char *str)
Parse str and put in width_ptr and height_ptr the detected values.
Definition: parseutils.c:148
internal.h
VAR_POS
@ VAR_POS
Definition: vf_scale.c:86
AVCOL_SPC_SMPTE240M
@ AVCOL_SPC_SMPTE240M
derived from 170M primaries and D65 white point, 170M is derived from BT470 System M's primaries
Definition: pixfmt.h:510
AVFrame::interlaced_frame
int interlaced_frame
The content of the picture is interlaced.
Definition: frame.h:433
ScaleContext::vsub
int vsub
chroma subsampling
Definition: vf_scale.c:123
sws_scale_frame
int sws_scale_frame(struct SwsContext *c, AVFrame *dst, const AVFrame *src)
Scale source data from src and write the output to dst.
Definition: swscale.c:1173
config_props
static int config_props(AVFilterLink *outlink)
Definition: vf_scale.c:478
interlaced
uint8_t interlaced
Definition: mxfenc.c:2209
ScaleContext::output_is_pal
int output_is_pal
set to 1 if the output format is paletted
Definition: vf_scale.c:126
VAR_SAR
@ VAR_SAR
Definition: vf_scale.c:78
sws_isSupportedEndiannessConversion
int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt)
Definition: utils.c:284
i
int i
Definition: input.c:406
AVCOL_SPC_BT2020_NCL
@ AVCOL_SPC_BT2020_NCL
ITU-R BT2020 non-constant luminance system.
Definition: pixfmt.h:513
VAR_S2R_MAIN_N
@ VAR_S2R_MAIN_N
Definition: vf_scale.c:94
internal.h
AVColorSpace
AVColorSpace
YUV colorspace type.
Definition: pixfmt.h:502
ff_filter_get_nb_threads
int ff_filter_get_nb_threads(AVFilterContext *ctx)
Get number of threads for current filter instance.
Definition: avfilter.c:804
EvalMode
EvalMode
Definition: af_volume.h:39
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
AVCOL_SPC_UNSPECIFIED
@ AVCOL_SPC_UNSPECIFIED
Definition: pixfmt.h:505
ScaleContext::h_expr
char * h_expr
height expression string
Definition: vf_scale.c:130
AVCOL_RANGE_MPEG
@ AVCOL_RANGE_MPEG
Narrow or limited range content.
Definition: pixfmt.h:559
avfilter_vf_scale_outputs
static const AVFilterPad avfilter_vf_scale_outputs[]
Definition: vf_scale.c:986
AVFilter
Filter definition.
Definition: avfilter.h:149
av_opt_eval_flags
int av_opt_eval_flags(void *obj, const AVOption *o, const char *val, int *flags_out)
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ret
ret
Definition: filter_design.txt:187
FFSWAP
#define FFSWAP(type, a, b)
Definition: macros.h:52
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
parse_yuv_type
static const int * parse_yuv_type(const char *s, enum AVColorSpace colorspace)
Definition: vf_scale.c:379
AVFrame::sample_aspect_ratio
AVRational sample_aspect_ratio
Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
Definition: frame.h:391
sws_getColorspaceDetails
int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table, int *srcRange, int **table, int *dstRange, int *brightness, int *contrast, int *saturation)
Definition: utils.c:1014
ff_scale_adjust_dimensions
int ff_scale_adjust_dimensions(AVFilterLink *inlink, int *ret_w, int *ret_h, int force_original_aspect_ratio, int force_divisible_by)
Transform evaluated width and height obtained from ff_scale_eval_dimensions into actual target width ...
Definition: scale_eval.c:113
sws_init_context
av_warn_unused_result int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter)
Initialize the swscaler context sws_context.
Definition: utils.c:1244
VAR_S2R_MAIN_T
@ VAR_S2R_MAIN_T
Definition: vf_scale.c:95
ScaleContext::out_color_matrix
char * out_color_matrix
Definition: vf_scale.c:138
scale_eval_dimensions
static int scale_eval_dimensions(AVFilterContext *ctx)
Definition: vf_scale.c:403
var_names
static const char *const var_names[]
Definition: vf_scale.c:44
AVFrame::height
int height
Definition: frame.h:361
VAR_S2R_MAIN_DAR
@ VAR_S2R_MAIN_DAR
Definition: vf_scale.c:91
scale_options
static const AVOption scale_options[]
Definition: vf_scale.c:923
sws_freeContext
void sws_freeContext(struct SwsContext *swsContext)
Free the swscaler context swsContext.
Definition: utils.c:2329
AVRational::den
int den
Denominator.
Definition: rational.h:60
AVCOL_SPC_FCC
@ AVCOL_SPC_FCC
FCC Title 47 Code of Federal Regulations 73.682 (a)(20)
Definition: pixfmt.h:507
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:224
avfilter.h
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_scale.c:328
ScaleContext::force_original_aspect_ratio
int force_original_aspect_ratio
Definition: vf_scale.c:148
avfilter_vf_scale2ref_inputs
static const AVFilterPad avfilter_vf_scale2ref_inputs[]
Definition: vf_scale.c:1016
av_mul_q
AVRational av_mul_q(AVRational b, AVRational c)
Multiply two rationals.
Definition: rational.c:80
AVFilterContext
An instance of a filter.
Definition: avfilter.h:346
VAR_OW
@ VAR_OW
Definition: vf_scale.c:75
av_strdup
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:277
desc
const char * desc
Definition: libsvtav1.c:79
VAR_VSUB
@ VAR_VSUB
Definition: vf_scale.c:81
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
sws_getCoefficients
const int * sws_getCoefficients(int colorspace)
Return a pointer to yuv<->rgb coefficients for the given colorspace suitable for sws_setColorspaceDet...
Definition: yuv2rgb.c:62
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
ScaleContext::interlaced
int interlaced
Definition: vf_scale.c:127
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVDictionaryEntry
Definition: dict.h:79
VAR_N
@ VAR_N
Definition: vf_scale.c:84
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:241
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:153
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
scale_class
static const AVClass scale_class
Definition: vf_scale.c:969
ScaleContext::w_expr
char * w_expr
width expression string
Definition: vf_scale.c:129
EVAL_MODE_INIT
@ EVAL_MODE_INIT
Definition: vf_scale.c:101
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:334
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
h
h
Definition: vp9dsp_template.c:2038
AVDictionaryEntry::value
char * value
Definition: dict.h:81
avstring.h
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:228
VAR_OHSUB
@ VAR_OHSUB
Definition: vf_scale.c:82
AVCOL_SPC_BT709
@ AVCOL_SPC_BT709
also ITU-R BT1361 / IEC 61966-2-4 xvYCC709 / derived in SMPTE RP 177 Annex B
Definition: pixfmt.h:504
int
int
Definition: ffmpeg_filter.c:156
SwsContext
Definition: swscale_internal.h:298
AV_PIX_FMT_FLAG_PAL
#define AV_PIX_FMT_FLAG_PAL
Pixel format has a palette in data[1], values are indexes in this palette.
Definition: pixdesc.h:120
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Definition: opt.h:233
ff_vf_scale
const AVFilter ff_vf_scale
Definition: vf_scale.c:994
snprintf
#define snprintf
Definition: snprintf.h:34
ScaleContext::size_str
char * size_str
Definition: vf_scale.c:119
VAR_S2R_MAIN_VSUB
@ VAR_S2R_MAIN_VSUB
Definition: vf_scale.c:93
AVPixFmtDescriptor::log2_chroma_h
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:89
swscale.h
ScaleContext::h
int h
Definition: vf_scale.c:118
av_x_if_null
static void * av_x_if_null(const void *p, const void *x)
Return x default pointer in case p is NULL.
Definition: avutil.h:308
av_get_pix_fmt_name
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2460
ScaleContext::in_v_chr_pos
int in_v_chr_pos
Definition: vf_scale.c:146
SwsContext::param
double param[2]
Input parameters for scaling algorithms that need them.
Definition: swscale_internal.h:339