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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 "video.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/eval.h"
35 #include "libavutil/internal.h"
36 #include "libavutil/mathematics.h"
37 #include "libavutil/opt.h"
38 #include "libavutil/parseutils.h"
39 #include "libavutil/pixdesc.h"
40 #include "libavutil/imgutils.h"
41 #include "libavutil/avassert.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  NULL
57 };
58 
59 enum var_name {
72 };
73 
74 typedef struct ScaleContext {
75  const AVClass *class;
76  struct SwsContext *sws; ///< software scaler context
77  struct SwsContext *isws[2]; ///< software scaler context for interlaced material
79 
80  /**
81  * New dimensions. Special values are:
82  * 0 = original width/height
83  * -1 = keep original aspect
84  * -N = try to keep aspect but make sure it is divisible by N
85  */
86  int w, h;
87  char *size_str;
88  unsigned int flags; ///sws flags
89 
90  int hsub, vsub; ///< chroma subsampling
91  int slice_y; ///< top of current output slice
92  int input_is_pal; ///< set to 1 if the input format is paletted
93  int output_is_pal; ///< set to 1 if the output format is paletted
95 
96  char *w_expr; ///< width expression string
97  char *h_expr; ///< height expression string
98  char *flags_str;
99 
102 
103  int in_range;
105 
110 
112 } ScaleContext;
113 
115 {
116  ScaleContext *scale = ctx->priv;
117  int ret;
118 
119  if (scale->size_str && (scale->w_expr || scale->h_expr)) {
120  av_log(ctx, AV_LOG_ERROR,
121  "Size and width/height expressions cannot be set at the same time.\n");
122  return AVERROR(EINVAL);
123  }
124 
125  if (scale->w_expr && !scale->h_expr)
126  FFSWAP(char *, scale->w_expr, scale->size_str);
127 
128  if (scale->size_str) {
129  char buf[32];
130  if ((ret = av_parse_video_size(&scale->w, &scale->h, scale->size_str)) < 0) {
131  av_log(ctx, AV_LOG_ERROR,
132  "Invalid size '%s'\n", scale->size_str);
133  return ret;
134  }
135  snprintf(buf, sizeof(buf)-1, "%d", scale->w);
136  av_opt_set(scale, "w", buf, 0);
137  snprintf(buf, sizeof(buf)-1, "%d", scale->h);
138  av_opt_set(scale, "h", buf, 0);
139  }
140  if (!scale->w_expr)
141  av_opt_set(scale, "w", "iw", 0);
142  if (!scale->h_expr)
143  av_opt_set(scale, "h", "ih", 0);
144 
145  av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s flags:'%s' interl:%d\n",
146  scale->w_expr, scale->h_expr, (char *)av_x_if_null(scale->flags_str, ""), scale->interlaced);
147 
148  scale->flags = 0;
149 
150  if (scale->flags_str) {
151  const AVClass *class = sws_get_class();
152  const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
154  int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);
155  if (ret < 0)
156  return ret;
157  }
158  scale->opts = *opts;
159  *opts = NULL;
160 
161  return 0;
162 }
163 
164 static av_cold void uninit(AVFilterContext *ctx)
165 {
166  ScaleContext *scale = ctx->priv;
167  sws_freeContext(scale->sws);
168  sws_freeContext(scale->isws[0]);
169  sws_freeContext(scale->isws[1]);
170  scale->sws = NULL;
171  av_dict_free(&scale->opts);
172 }
173 
175 {
177  enum AVPixelFormat pix_fmt;
178  int ret;
179 
180  if (ctx->inputs[0]) {
181  const AVPixFmtDescriptor *desc = NULL;
182  formats = NULL;
183  while ((desc = av_pix_fmt_desc_next(desc))) {
184  pix_fmt = av_pix_fmt_desc_get_id(desc);
185  if ((sws_isSupportedInput(pix_fmt) ||
187  && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
188  ff_formats_unref(&formats);
189  return ret;
190  }
191  }
192  ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
193  }
194  if (ctx->outputs[0]) {
195  const AVPixFmtDescriptor *desc = NULL;
196  formats = NULL;
197  while ((desc = av_pix_fmt_desc_next(desc))) {
198  pix_fmt = av_pix_fmt_desc_get_id(desc);
199  if ((sws_isSupportedOutput(pix_fmt) || pix_fmt == AV_PIX_FMT_PAL8 ||
201  && (ret = ff_add_format(&formats, pix_fmt)) < 0) {
202  ff_formats_unref(&formats);
203  return ret;
204  }
205  }
206  ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
207  }
208 
209  return 0;
210 }
211 
212 static const int *parse_yuv_type(const char *s, enum AVColorSpace colorspace)
213 {
214  if (!s)
215  s = "bt601";
216 
217  if (s && strstr(s, "bt709")) {
218  colorspace = AVCOL_SPC_BT709;
219  } else if (s && strstr(s, "fcc")) {
220  colorspace = AVCOL_SPC_FCC;
221  } else if (s && strstr(s, "smpte240m")) {
222  colorspace = AVCOL_SPC_SMPTE240M;
223  } else if (s && (strstr(s, "bt601") || strstr(s, "bt470") || strstr(s, "smpte170m"))) {
224  colorspace = AVCOL_SPC_BT470BG;
225  }
226 
227  if (colorspace < 1 || colorspace > 7) {
228  colorspace = AVCOL_SPC_BT470BG;
229  }
230 
231  return sws_getCoefficients(colorspace);
232 }
233 
234 static int config_props(AVFilterLink *outlink)
235 {
236  AVFilterContext *ctx = outlink->src;
237  AVFilterLink *inlink = outlink->src->inputs[0];
238  enum AVPixelFormat outfmt = outlink->format;
239  ScaleContext *scale = ctx->priv;
240  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
241  const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
242  int64_t w, h;
243  double var_values[VARS_NB], res;
244  char *expr;
245  int ret;
246  int factor_w, factor_h;
247 
248  var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
249  var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
250  var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
251  var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
252  var_values[VAR_A] = (double) inlink->w / inlink->h;
253  var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
254  (double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
255  var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
256  var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
257  var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
258  var_values[VAR_OHSUB] = 1 << out_desc->log2_chroma_w;
259  var_values[VAR_OVSUB] = 1 << out_desc->log2_chroma_h;
260 
261  /* evaluate width and height */
262  av_expr_parse_and_eval(&res, (expr = scale->w_expr),
263  var_names, var_values,
264  NULL, NULL, NULL, NULL, NULL, 0, ctx);
265  scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
266  if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
267  var_names, var_values,
268  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
269  goto fail;
270  scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
271  /* evaluate again the width, as it may depend on the output height */
272  if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
273  var_names, var_values,
274  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
275  goto fail;
276  scale->w = res;
277 
278  w = scale->w;
279  h = scale->h;
280 
281  /* Check if it is requested that the result has to be divisible by a some
282  * factor (w or h = -n with n being the factor). */
283  factor_w = 1;
284  factor_h = 1;
285  if (w < -1) {
286  factor_w = -w;
287  }
288  if (h < -1) {
289  factor_h = -h;
290  }
291 
292  if (w < 0 && h < 0)
293  scale->w = scale->h = 0;
294 
295  if (!(w = scale->w))
296  w = inlink->w;
297  if (!(h = scale->h))
298  h = inlink->h;
299 
300  /* Make sure that the result is divisible by the factor we determined
301  * earlier. If no factor was set, it is nothing will happen as the default
302  * factor is 1 */
303  if (w < 0)
304  w = av_rescale(h, inlink->w, inlink->h * factor_w) * factor_w;
305  if (h < 0)
306  h = av_rescale(w, inlink->h, inlink->w * factor_h) * factor_h;
307 
308  /* Note that force_original_aspect_ratio may overwrite the previous set
309  * dimensions so that it is not divisible by the set factors anymore. */
310  if (scale->force_original_aspect_ratio) {
311  int tmp_w = av_rescale(h, inlink->w, inlink->h);
312  int tmp_h = av_rescale(w, inlink->h, inlink->w);
313 
314  if (scale->force_original_aspect_ratio == 1) {
315  w = FFMIN(tmp_w, w);
316  h = FFMIN(tmp_h, h);
317  } else {
318  w = FFMAX(tmp_w, w);
319  h = FFMAX(tmp_h, h);
320  }
321  }
322 
323  if (w > INT_MAX || h > INT_MAX ||
324  (h * inlink->w) > INT_MAX ||
325  (w * inlink->h) > INT_MAX)
326  av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
327 
328  outlink->w = w;
329  outlink->h = h;
330 
331  /* TODO: make algorithm configurable */
332 
333  scale->input_is_pal = desc->flags & AV_PIX_FMT_FLAG_PAL ||
335  if (outfmt == AV_PIX_FMT_PAL8) outfmt = AV_PIX_FMT_BGR8;
338 
339  if (scale->sws)
340  sws_freeContext(scale->sws);
341  if (scale->isws[0])
342  sws_freeContext(scale->isws[0]);
343  if (scale->isws[1])
344  sws_freeContext(scale->isws[1]);
345  scale->isws[0] = scale->isws[1] = scale->sws = NULL;
346  if (inlink->w == outlink->w && inlink->h == outlink->h &&
347  inlink->format == outlink->format)
348  ;
349  else {
350  struct SwsContext **swscs[3] = {&scale->sws, &scale->isws[0], &scale->isws[1]};
351  int i;
352 
353  for (i = 0; i < 3; i++) {
354  struct SwsContext **s = swscs[i];
355  *s = sws_alloc_context();
356  if (!*s)
357  return AVERROR(ENOMEM);
358 
359  if (scale->opts) {
360  AVDictionaryEntry *e = NULL;
361 
362  while ((e = av_dict_get(scale->opts, "", e, AV_DICT_IGNORE_SUFFIX))) {
363  if ((ret = av_opt_set(*s, e->key, e->value, 0)) < 0)
364  return ret;
365  }
366  }
367 
368  av_opt_set_int(*s, "srcw", inlink ->w, 0);
369  av_opt_set_int(*s, "srch", inlink ->h >> !!i, 0);
370  av_opt_set_int(*s, "src_format", inlink->format, 0);
371  av_opt_set_int(*s, "dstw", outlink->w, 0);
372  av_opt_set_int(*s, "dsth", outlink->h >> !!i, 0);
373  av_opt_set_int(*s, "dst_format", outfmt, 0);
374  av_opt_set_int(*s, "sws_flags", scale->flags, 0);
375 
376  /* Override YUV420P settings to have the correct (MPEG-2) chroma positions
377  * MPEG-2 chroma positions are used by convention
378  * XXX: support other 4:2:0 pixel formats */
379  if (inlink->format == AV_PIX_FMT_YUV420P) {
380  scale->in_v_chr_pos = (i == 0) ? 128 : (i == 1) ? 64 : 192;
381  }
382 
383  if (outlink->format == AV_PIX_FMT_YUV420P) {
384  scale->out_v_chr_pos = (i == 0) ? 128 : (i == 1) ? 64 : 192;
385  }
386 
387  av_opt_set_int(*s, "src_h_chr_pos", scale->in_h_chr_pos, 0);
388  av_opt_set_int(*s, "src_v_chr_pos", scale->in_v_chr_pos, 0);
389  av_opt_set_int(*s, "dst_h_chr_pos", scale->out_h_chr_pos, 0);
390  av_opt_set_int(*s, "dst_v_chr_pos", scale->out_v_chr_pos, 0);
391 
392  if ((ret = sws_init_context(*s, NULL, NULL)) < 0)
393  return ret;
394  if (!scale->interlaced)
395  break;
396  }
397  }
398 
399  if (inlink->sample_aspect_ratio.num){
400  outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
401  } else
402  outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
403 
404  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",
405  inlink ->w, inlink ->h, av_get_pix_fmt_name( inlink->format),
407  outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
408  outlink->sample_aspect_ratio.num, outlink->sample_aspect_ratio.den,
409  scale->flags);
410  return 0;
411 
412 fail:
414  "Error when evaluating the expression '%s'.\n"
415  "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
416  expr, scale->w_expr, scale->h_expr);
417  return ret;
418 }
419 
420 static int scale_slice(AVFilterLink *link, AVFrame *out_buf, AVFrame *cur_pic, struct SwsContext *sws, int y, int h, int mul, int field)
421 {
422  ScaleContext *scale = link->dst->priv;
423  const uint8_t *in[4];
424  uint8_t *out[4];
425  int in_stride[4],out_stride[4];
426  int i;
427 
428  for(i=0; i<4; i++){
429  int vsub= ((i+1)&2) ? scale->vsub : 0;
430  in_stride[i] = cur_pic->linesize[i] * mul;
431  out_stride[i] = out_buf->linesize[i] * mul;
432  in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];
433  out[i] = out_buf->data[i] + field * out_buf->linesize[i];
434  }
435  if(scale->input_is_pal)
436  in[1] = cur_pic->data[1];
437  if(scale->output_is_pal)
438  out[1] = out_buf->data[1];
439 
440  return sws_scale(sws, in, in_stride, y/mul, h,
441  out,out_stride);
442 }
443 
444 static int filter_frame(AVFilterLink *link, AVFrame *in)
445 {
446  ScaleContext *scale = link->dst->priv;
447  AVFilterLink *outlink = link->dst->outputs[0];
448  AVFrame *out;
449  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
450  char buf[32];
451  int in_range;
452 
454  av_log(link->dst, AV_LOG_WARNING, "Detected unsupported YCgCo colorspace.\n");
455 
456  if( in->width != link->w
457  || in->height != link->h
458  || in->format != link->format) {
459  int ret;
460  snprintf(buf, sizeof(buf)-1, "%d", outlink->w);
461  av_opt_set(scale, "w", buf, 0);
462  snprintf(buf, sizeof(buf)-1, "%d", outlink->h);
463  av_opt_set(scale, "h", buf, 0);
464 
465  link->dst->inputs[0]->format = in->format;
466  link->dst->inputs[0]->w = in->width;
467  link->dst->inputs[0]->h = in->height;
468 
469  if ((ret = config_props(outlink)) < 0)
470  return ret;
471  }
472 
473  if (!scale->sws)
474  return ff_filter_frame(outlink, in);
475 
476  scale->hsub = desc->log2_chroma_w;
477  scale->vsub = desc->log2_chroma_h;
478 
479  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
480  if (!out) {
481  av_frame_free(&in);
482  return AVERROR(ENOMEM);
483  }
484 
485  av_frame_copy_props(out, in);
486  out->width = outlink->w;
487  out->height = outlink->h;
488 
489  if(scale->output_is_pal)
490  avpriv_set_systematic_pal2((uint32_t*)out->data[1], outlink->format == AV_PIX_FMT_PAL8 ? AV_PIX_FMT_BGR8 : outlink->format);
491 
492  in_range = av_frame_get_color_range(in);
493 
494  if ( scale->in_color_matrix
495  || scale->out_color_matrix
496  || scale-> in_range != AVCOL_RANGE_UNSPECIFIED
497  || in_range != AVCOL_RANGE_UNSPECIFIED
498  || scale->out_range != AVCOL_RANGE_UNSPECIFIED) {
499  int in_full, out_full, brightness, contrast, saturation;
500  const int *inv_table, *table;
501 
502  sws_getColorspaceDetails(scale->sws, (int **)&inv_table, &in_full,
503  (int **)&table, &out_full,
504  &brightness, &contrast, &saturation);
505 
506  if (scale->in_color_matrix)
507  inv_table = parse_yuv_type(scale->in_color_matrix, av_frame_get_colorspace(in));
508  if (scale->out_color_matrix)
510 
511  if (scale-> in_range != AVCOL_RANGE_UNSPECIFIED)
512  in_full = (scale-> in_range == AVCOL_RANGE_JPEG);
513  else if (in_range != AVCOL_RANGE_UNSPECIFIED)
514  in_full = (in_range == AVCOL_RANGE_JPEG);
515  if (scale->out_range != AVCOL_RANGE_UNSPECIFIED)
516  out_full = (scale->out_range == AVCOL_RANGE_JPEG);
517 
518  sws_setColorspaceDetails(scale->sws, inv_table, in_full,
519  table, out_full,
520  brightness, contrast, saturation);
521  if (scale->isws[0])
522  sws_setColorspaceDetails(scale->isws[0], inv_table, in_full,
523  table, out_full,
524  brightness, contrast, saturation);
525  if (scale->isws[1])
526  sws_setColorspaceDetails(scale->isws[1], inv_table, in_full,
527  table, out_full,
528  brightness, contrast, saturation);
529  }
530 
532  (int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
533  (int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
534  INT_MAX);
535 
536  if(scale->interlaced>0 || (scale->interlaced<0 && in->interlaced_frame)){
537  scale_slice(link, out, in, scale->isws[0], 0, (link->h+1)/2, 2, 0);
538  scale_slice(link, out, in, scale->isws[1], 0, link->h /2, 2, 1);
539  }else{
540  scale_slice(link, out, in, scale->sws, 0, link->h, 1, 0);
541  }
542 
543  av_frame_free(&in);
544  return ff_filter_frame(outlink, out);
545 }
546 
547 static const AVClass *child_class_next(const AVClass *prev)
548 {
549  return prev ? NULL : sws_get_class();
550 }
551 
552 #define OFFSET(x) offsetof(ScaleContext, x)
553 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
554 
555 static const AVOption scale_options[] = {
556  { "w", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
557  { "width", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
558  { "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
559  { "height","Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, .flags = FLAGS },
560  { "flags", "Flags to pass to libswscale", OFFSET(flags_str), AV_OPT_TYPE_STRING, { .str = "bilinear" }, .flags = FLAGS },
561  { "interl", "set interlacing", OFFSET(interlaced), AV_OPT_TYPE_INT, {.i64 = 0 }, -1, 1, FLAGS },
562  { "size", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
563  { "s", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
564  { "in_color_matrix", "set input YCbCr type", OFFSET(in_color_matrix), AV_OPT_TYPE_STRING, { .str = "auto" }, .flags = FLAGS },
565  { "out_color_matrix", "set output YCbCr type", OFFSET(out_color_matrix), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = FLAGS },
566  { "in_range", "set input color range", OFFSET( in_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
567  { "out_range", "set output color range", OFFSET(out_range), AV_OPT_TYPE_INT, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 2, FLAGS, "range" },
568  { "auto", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_UNSPECIFIED }, 0, 0, FLAGS, "range" },
569  { "full", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
570  { "jpeg", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
571  { "mpeg", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
572  { "tv", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_MPEG}, 0, 0, FLAGS, "range" },
573  { "pc", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = AVCOL_RANGE_JPEG}, 0, 0, FLAGS, "range" },
574  { "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 },
575  { "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 },
576  { "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 },
577  { "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 },
578  { "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" },
579  { "disable", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "force_oar" },
580  { "decrease", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "force_oar" },
581  { "increase", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2 }, 0, 0, FLAGS, "force_oar" },
582  { NULL }
583 };
584 
585 static const AVClass scale_class = {
586  .class_name = "scale",
587  .item_name = av_default_item_name,
588  .option = scale_options,
589  .version = LIBAVUTIL_VERSION_INT,
590  .category = AV_CLASS_CATEGORY_FILTER,
591  .child_class_next = child_class_next,
592 };
593 
595  {
596  .name = "default",
597  .type = AVMEDIA_TYPE_VIDEO,
598  .filter_frame = filter_frame,
599  },
600  { NULL }
601 };
602 
604  {
605  .name = "default",
606  .type = AVMEDIA_TYPE_VIDEO,
607  .config_props = config_props,
608  },
609  { NULL }
610 };
611 
613  .name = "scale",
614  .description = NULL_IF_CONFIG_SMALL("Scale the input video size and/or convert the image format."),
615  .init_dict = init_dict,
616  .uninit = uninit,
617  .query_formats = query_formats,
618  .priv_size = sizeof(ScaleContext),
619  .priv_class = &scale_class,
620  .inputs = avfilter_vf_scale_inputs,
621  .outputs = avfilter_vf_scale_outputs,
622 };