FFmpeg
vf_crop.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  * video crop filter
24  */
25 
26 #include <stdio.h>
27 
28 #include "avfilter.h"
29 #include "formats.h"
30 #include "internal.h"
31 #include "video.h"
32 #include "libavutil/eval.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/internal.h"
35 #include "libavutil/libm.h"
36 #include "libavutil/imgutils.h"
37 #include "libavutil/mathematics.h"
38 #include "libavutil/opt.h"
39 
40 static const char *const var_names[] = {
41  "in_w", "iw", ///< width of the input video
42  "in_h", "ih", ///< height of the input video
43  "out_w", "ow", ///< width of the cropped video
44  "out_h", "oh", ///< height of the cropped video
45  "a",
46  "sar",
47  "dar",
48  "hsub",
49  "vsub",
50  "x",
51  "y",
52  "n", ///< number of frame
53  "pos", ///< position in the file
54  "t", ///< timestamp expressed in seconds
55  NULL
56 };
57 
58 enum var_name {
59  VAR_IN_W, VAR_IW,
60  VAR_IN_H, VAR_IH,
61  VAR_OUT_W, VAR_OW,
62  VAR_OUT_H, VAR_OH,
63  VAR_A,
64  VAR_SAR,
65  VAR_DAR,
66  VAR_HSUB,
67  VAR_VSUB,
68  VAR_X,
69  VAR_Y,
70  VAR_N,
71  VAR_POS,
72  VAR_T,
73  VAR_VARS_NB
74 };
75 
76 typedef struct CropContext {
77  const AVClass *class;
78  int x; ///< x offset of the non-cropped area with respect to the input area
79  int y; ///< y offset of the non-cropped area with respect to the input area
80  int w; ///< width of the cropped area
81  int h; ///< height of the cropped area
82 
83  AVRational out_sar; ///< output sample aspect ratio
84  int keep_aspect; ///< keep display aspect ratio when cropping
85  int exact; ///< exact cropping, for subsampled formats
86 
87  int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
88  int hsub, vsub; ///< chroma subsampling
89  char *x_expr, *y_expr, *w_expr, *h_expr;
90  AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
91  double var_values[VAR_VARS_NB];
92 } CropContext;
93 
94 static int query_formats(AVFilterContext *ctx)
95 {
96  int reject_flags = AV_PIX_FMT_FLAG_BITSTREAM | FF_PIX_FMT_FLAG_SW_FLAT_SUB;
97 
98  return ff_set_common_formats(ctx, ff_formats_pixdesc_filter(0, reject_flags));
99 }
100 
101 static av_cold void uninit(AVFilterContext *ctx)
102 {
103  CropContext *s = ctx->priv;
104 
105  av_expr_free(s->x_pexpr);
106  s->x_pexpr = NULL;
107  av_expr_free(s->y_pexpr);
108  s->y_pexpr = NULL;
109 }
110 
111 static inline int normalize_double(int *n, double d)
112 {
113  int ret = 0;
114 
115  if (isnan(d)) {
116  ret = AVERROR(EINVAL);
117  } else if (d > INT_MAX || d < INT_MIN) {
118  *n = d > INT_MAX ? INT_MAX : INT_MIN;
119  ret = AVERROR(EINVAL);
120  } else
121  *n = lrint(d);
122 
123  return ret;
124 }
125 
126 static int config_input(AVFilterLink *link)
127 {
128  AVFilterContext *ctx = link->dst;
129  CropContext *s = ctx->priv;
130  const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
131  int ret;
132  const char *expr;
133  double res;
134 
135  s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w;
136  s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h;
137  s->var_values[VAR_A] = (float) link->w / link->h;
138  s->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
139  s->var_values[VAR_DAR] = s->var_values[VAR_A] * s->var_values[VAR_SAR];
140  s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
141  s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
142  s->var_values[VAR_X] = NAN;
143  s->var_values[VAR_Y] = NAN;
144  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = NAN;
145  s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = NAN;
146  s->var_values[VAR_N] = 0;
147  s->var_values[VAR_T] = NAN;
148  s->var_values[VAR_POS] = NAN;
149 
150  av_image_fill_max_pixsteps(s->max_step, NULL, pix_desc);
151 
152  if (pix_desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
153  s->hsub = 1;
154  s->vsub = 1;
155  } else {
156  s->hsub = pix_desc->log2_chroma_w;
157  s->vsub = pix_desc->log2_chroma_h;
158  }
159 
160  av_expr_parse_and_eval(&res, (expr = s->w_expr),
161  var_names, s->var_values,
162  NULL, NULL, NULL, NULL, NULL, 0, ctx);
163  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
164  if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
165  var_names, s->var_values,
166  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
167  goto fail_expr;
168  s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res;
169  /* evaluate again ow as it may depend on oh */
170  if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
171  var_names, s->var_values,
172  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
173  goto fail_expr;
174 
175  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
176  if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 ||
177  normalize_double(&s->h, s->var_values[VAR_OUT_H]) < 0) {
178  av_log(ctx, AV_LOG_ERROR,
179  "Too big value or invalid expression for out_w/ow or out_h/oh. "
180  "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
181  s->w_expr, s->h_expr);
182  return AVERROR(EINVAL);
183  }
184 
185  if (!s->exact) {
186  s->w &= ~((1 << s->hsub) - 1);
187  s->h &= ~((1 << s->vsub) - 1);
188  }
189 
190  av_expr_free(s->x_pexpr);
191  av_expr_free(s->y_pexpr);
192  s->x_pexpr = s->y_pexpr = NULL;
193  if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
194  NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
195  (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
196  NULL, NULL, NULL, NULL, 0, ctx)) < 0)
197  return AVERROR(EINVAL);
198 
199  if (s->keep_aspect) {
200  AVRational dar = av_mul_q(link->sample_aspect_ratio,
201  (AVRational){ link->w, link->h });
202  av_reduce(&s->out_sar.num, &s->out_sar.den,
203  dar.num * s->h, dar.den * s->w, INT_MAX);
204  } else
205  s->out_sar = link->sample_aspect_ratio;
206 
207  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
208  link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
209  s->w, s->h, s->out_sar.num, s->out_sar.den);
210 
211  if (s->w <= 0 || s->h <= 0 ||
212  s->w > link->w || s->h > link->h) {
213  av_log(ctx, AV_LOG_ERROR,
214  "Invalid too big or non positive size for width '%d' or height '%d'\n",
215  s->w, s->h);
216  return AVERROR(EINVAL);
217  }
218 
219  /* set default, required in the case the first computed value for x/y is NAN */
220  s->x = (link->w - s->w) / 2;
221  s->y = (link->h - s->h) / 2;
222  if (!s->exact) {
223  s->x &= ~((1 << s->hsub) - 1);
224  s->y &= ~((1 << s->vsub) - 1);
225  }
226  return 0;
227 
228 fail_expr:
229  av_log(ctx, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
230  return ret;
231 }
232 
233 static int config_output(AVFilterLink *link)
234 {
235  CropContext *s = link->src->priv;
236  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
237 
238  if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
239  // Hardware frames adjust the cropping regions rather than
240  // changing the frame size.
241  } else {
242  link->w = s->w;
243  link->h = s->h;
244  }
245  link->sample_aspect_ratio = s->out_sar;
246 
247  return 0;
248 }
249 
250 static int filter_frame(AVFilterLink *link, AVFrame *frame)
251 {
252  AVFilterContext *ctx = link->dst;
253  CropContext *s = ctx->priv;
254  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
255  int i;
256 
257  s->var_values[VAR_N] = link->frame_count_out;
258  s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
259  NAN : frame->pts * av_q2d(link->time_base);
260  s->var_values[VAR_POS] = frame->pkt_pos == -1 ?
261  NAN : frame->pkt_pos;
262  s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
263  s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, NULL);
264  /* It is necessary if x is expressed from y */
265  s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
266 
267  normalize_double(&s->x, s->var_values[VAR_X]);
268  normalize_double(&s->y, s->var_values[VAR_Y]);
269 
270  if (s->x < 0)
271  s->x = 0;
272  if (s->y < 0)
273  s->y = 0;
274  if ((unsigned)s->x + (unsigned)s->w > link->w)
275  s->x = link->w - s->w;
276  if ((unsigned)s->y + (unsigned)s->h > link->h)
277  s->y = link->h - s->h;
278  if (!s->exact) {
279  s->x &= ~((1 << s->hsub) - 1);
280  s->y &= ~((1 << s->vsub) - 1);
281  }
282 
283  av_log(ctx, AV_LOG_TRACE, "n:%d t:%f pos:%f x:%d y:%d x+w:%d y+h:%d\n",
284  (int)s->var_values[VAR_N], s->var_values[VAR_T], s->var_values[VAR_POS],
285  s->x, s->y, s->x+s->w, s->y+s->h);
286 
287  if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
288  frame->crop_top += s->y;
289  frame->crop_left += s->x;
290  frame->crop_bottom = frame->height - frame->crop_top - frame->crop_bottom - s->h;
291  frame->crop_right = frame->width - frame->crop_left - frame->crop_right - s->w;
292  } else {
293  frame->width = s->w;
294  frame->height = s->h;
295 
296  frame->data[0] += s->y * frame->linesize[0];
297  frame->data[0] += s->x * s->max_step[0];
298 
299  if (!(desc->flags & AV_PIX_FMT_FLAG_PAL)) {
300  for (i = 1; i < 3; i ++) {
301  if (frame->data[i]) {
302  frame->data[i] += (s->y >> s->vsub) * frame->linesize[i];
303  frame->data[i] += (s->x * s->max_step[i]) >> s->hsub;
304  }
305  }
306  }
307 
308  /* alpha plane */
309  if (frame->data[3]) {
310  frame->data[3] += s->y * frame->linesize[3];
311  frame->data[3] += s->x * s->max_step[3];
312  }
313  }
314 
315  return ff_filter_frame(link->dst->outputs[0], frame);
316 }
317 
318 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
319  char *res, int res_len, int flags)
320 {
321  CropContext *s = ctx->priv;
322  int ret;
323 
324  if ( !strcmp(cmd, "out_w") || !strcmp(cmd, "w")
325  || !strcmp(cmd, "out_h") || !strcmp(cmd, "h")
326  || !strcmp(cmd, "x") || !strcmp(cmd, "y")) {
327 
328  int old_x = s->x;
329  int old_y = s->y;
330  int old_w = s->w;
331  int old_h = s->h;
332 
333  AVFilterLink *outlink = ctx->outputs[0];
334  AVFilterLink *inlink = ctx->inputs[0];
335 
336  av_opt_set(s, cmd, args, 0);
337 
338  if ((ret = config_input(inlink)) < 0) {
339  s->x = old_x;
340  s->y = old_y;
341  s->w = old_w;
342  s->h = old_h;
343  return ret;
344  }
345 
346  ret = config_output(outlink);
347 
348  } else
349  ret = AVERROR(ENOSYS);
350 
351  return ret;
352 }
353 
354 #define OFFSET(x) offsetof(CropContext, x)
355 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
356 #define TFLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
357 
358 static const AVOption crop_options[] = {
359  { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, TFLAGS },
360  { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, TFLAGS },
361  { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, TFLAGS },
362  { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, TFLAGS },
363  { "x", "set the x crop area expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, 0, 0, TFLAGS },
364  { "y", "set the y crop area expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, 0, 0, TFLAGS },
365  { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
366  { "exact", "do exact cropping", OFFSET(exact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
367  { NULL }
368 };
369 
370 AVFILTER_DEFINE_CLASS(crop);
371 
372 static const AVFilterPad avfilter_vf_crop_inputs[] = {
373  {
374  .name = "default",
375  .type = AVMEDIA_TYPE_VIDEO,
376  .filter_frame = filter_frame,
377  .config_props = config_input,
378  },
379 };
380 
381 static const AVFilterPad avfilter_vf_crop_outputs[] = {
382  {
383  .name = "default",
384  .type = AVMEDIA_TYPE_VIDEO,
385  .config_props = config_output,
386  },
387 };
388 
389 const AVFilter ff_vf_crop = {
390  .name = "crop",
391  .description = NULL_IF_CONFIG_SMALL("Crop the input video."),
392  .priv_size = sizeof(CropContext),
393  .priv_class = &crop_class,
394  .uninit = uninit,
395  FILTER_INPUTS(avfilter_vf_crop_inputs),
396  FILTER_OUTPUTS(avfilter_vf_crop_outputs),
397  FILTER_QUERY_FUNC(query_formats),
398  .process_command = process_command,
399 };
OFFSET
#define OFFSET(x)
Definition: vf_crop.c:354
VAR_VSUB
@ VAR_VSUB
Definition: vf_crop.c:67
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: vf_crop.c:94
VAR_SAR
@ VAR_SAR
Definition: vf_crop.c:64
CropContext::var_values
double var_values[VAR_VARS_NB]
Definition: vf_crop.c:91
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_crop.c:101
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
CropContext::x
int x
x offset of the non-cropped area with respect to the input area
Definition: vf_crop.c:78
libm.h
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:999
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2662
VAR_T
@ VAR_T
Definition: vf_crop.c:72
CropContext::x_pexpr
AVExpr * x_pexpr
Definition: vf_crop.c:90
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
CropContext::y
int y
y offset of the non-cropped area with respect to the input area
Definition: vf_crop.c:79
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
CropContext::keep_aspect
int keep_aspect
keep display aspect ratio when cropping
Definition: vf_crop.c:84
crop_options
static const AVOption crop_options[]
Definition: vf_crop.c:358
AVOption
AVOption.
Definition: opt.h:251
FILTER_QUERY_FUNC
#define FILTER_QUERY_FUNC(func)
Definition: internal.h:167
CropContext::y_expr
char * y_expr
Definition: vf_crop.c:89
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
mathematics.h
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:175
VAR_POS
@ VAR_POS
Definition: vf_crop.c:71
VAR_HSUB
@ VAR_HSUB
Definition: vf_crop.c:66
video.h
normalize_double
static int normalize_double(int *n, double d)
Definition: vf_crop.c:111
CropContext::w
int w
width of the cropped area
Definition: vf_crop.c:80
VAR_A
@ VAR_A
Definition: vf_crop.c:63
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_IN_W
@ VAR_IN_W
Definition: vf_crop.c:59
CropContext::vsub
int vsub
chroma subsampling
Definition: vf_crop.c:88
VAR_OUT_W
@ VAR_OUT_W
Definition: vf_crop.c:61
config_output
static int config_output(AVFilterLink *link)
Definition: vf_crop.c:233
AV_PIX_FMT_FLAG_HWACCEL
#define AV_PIX_FMT_FLAG_HWACCEL
Pixel format is an HW accelerated format.
Definition: pixdesc.h:128
CropContext::w_expr
char * w_expr
Definition: vf_crop.c:89
TFLAGS
#define TFLAGS
Definition: vf_crop.c:356
av_opt_set
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:487
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
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:49
VAR_X
@ VAR_X
Definition: vf_crop.c:68
lrint
#define lrint
Definition: tablegen.h:53
AV_LOG_TRACE
#define AV_LOG_TRACE
Extremely verbose debugging, useful for libav* development.
Definition: log.h:206
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
ff_set_common_formats
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:749
ff_vf_crop
const AVFilter ff_vf_crop
Definition: vf_crop.c:389
float
float
Definition: af_crystalizer.c:122
VAR_IW
@ VAR_IW
Definition: vf_crop.c:59
s
#define s(width, name)
Definition: cbs_vp9.c:256
av_q2d
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
var_names
static const char *const var_names[]
Definition: vf_crop.c:40
VAR_IN_H
@ VAR_IN_H
Definition: vf_crop.c:60
var_name
var_name
Definition: noise_bsf.c:46
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_expr_eval
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:766
AVExpr
Definition: eval.c:157
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
NAN
#define NAN
Definition: mathematics.h:64
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:190
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
CropContext
Definition: vf_crop.c:76
FLAGS
#define FLAGS
Definition: vf_crop.c:355
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(crop)
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
isnan
#define isnan(x)
Definition: libm.h:340
VAR_Y
@ VAR_Y
Definition: vf_crop.c:69
CropContext::h
int h
height of the cropped area
Definition: vf_crop.c:81
VAR_OH
@ VAR_OH
Definition: vf_crop.c:62
AVPixFmtDescriptor::flags
uint64_t flags
Combination of AV_PIX_FMT_FLAG_...
Definition: pixdesc.h:94
VAR_DAR
@ VAR_DAR
Definition: vf_crop.c:65
VAR_OUT_H
@ VAR_OUT_H
Definition: vf_crop.c:62
eval.h
filter_frame
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_crop.c:250
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_expr_parse_and_eval
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:776
FF_PIX_FMT_FLAG_SW_FLAT_SUB
#define FF_PIX_FMT_FLAG_SW_FLAT_SUB
Definition: formats.h:245
CropContext::y_pexpr
AVExpr * y_pexpr
Definition: vf_crop.c:90
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
AVFrame::time_base
AVRational time_base
Time base for the timestamps in this frame.
Definition: frame.h:447
AV_PIX_FMT_FLAG_BITSTREAM
#define AV_PIX_FMT_FLAG_BITSTREAM
All values of a component are bit-wise packed end to end.
Definition: pixdesc.h:124
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:412
CropContext::max_step
int max_step[4]
max pixel step for each plane, expressed as a number of bytes
Definition: vf_crop.c:87
VAR_N
@ VAR_N
Definition: vf_crop.c:70
internal.h
ff_formats_pixdesc_filter
AVFilterFormats * ff_formats_pixdesc_filter(unsigned want, unsigned rej)
Construct a formats list containing all pixel formats with certain properties.
Definition: formats.c:498
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
config_input
static int config_input(AVFilterLink *link)
Definition: vf_crop.c:126
internal.h
avfilter_vf_crop_inputs
static const AVFilterPad avfilter_vf_crop_inputs[]
Definition: vf_crop.c:372
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
CropContext::out_sar
AVRational out_sar
output sample aspect ratio
Definition: vf_crop.c:83
AVFilter
Filter definition.
Definition: avfilter.h:171
ret
ret
Definition: filter_design.txt:187
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
AVFrame::sample_aspect_ratio
AVRational sample_aspect_ratio
Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
Definition: frame.h:427
VAR_VARS_NB
@ VAR_VARS_NB
Definition: vf_crop.c:73
AVRational::den
int den
Denominator.
Definition: rational.h:60
avfilter.h
CropContext::exact
int exact
exact cropping, for subsampled formats
Definition: vf_crop.c:85
av_mul_q
AVRational av_mul_q(AVRational b, AVRational c)
Multiply two rationals.
Definition: rational.c:80
av_image_fill_max_pixsteps
void av_image_fill_max_pixsteps(int max_pixsteps[4], int max_pixstep_comps[4], const AVPixFmtDescriptor *pixdesc)
Compute the max pixel step for each plane of an image with a format described by pixdesc.
Definition: imgutils.c:35
AVFilterContext
An instance of a filter.
Definition: avfilter.h:408
CropContext::h_expr
char * h_expr
Definition: vf_crop.c:89
desc
const char * desc
Definition: libsvtav1.c:83
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
CropContext::x_expr
char * x_expr
Definition: vf_crop.c:89
CropContext::hsub
int hsub
Definition: vf_crop.c:88
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:244
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:191
avfilter_vf_crop_outputs
static const AVFilterPad avfilter_vf_crop_outputs[]
Definition: vf_crop.c:381
process_command
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, char *res, int res_len, int flags)
Definition: vf_crop.c:318
d
d
Definition: ffmpeg_filter.c:153
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
avstring.h
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:229
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
VAR_OW
@ VAR_OW
Definition: vf_crop.c:61
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
VAR_IH
@ VAR_IH
Definition: vf_crop.c:60
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