FFmpeg
vf_crop.c
Go to the documentation of this file.
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 #if FF_API_FRAME_PKT
54  "pos", ///< position in the file
55 #endif
56  "t", ///< timestamp expressed in seconds
57  NULL
58 };
59 
60 enum var_name {
61  VAR_IN_W, VAR_IW,
62  VAR_IN_H, VAR_IH,
63  VAR_OUT_W, VAR_OW,
64  VAR_OUT_H, VAR_OH,
65  VAR_A,
66  VAR_SAR,
67  VAR_DAR,
68  VAR_HSUB,
69  VAR_VSUB,
70  VAR_X,
71  VAR_Y,
72  VAR_N,
73 #if FF_API_FRAME_PKT
74  VAR_POS,
75 #endif
76  VAR_T,
77  VAR_VARS_NB
78 };
79 
80 typedef struct CropContext {
81  const AVClass *class;
82  int x; ///< x offset of the non-cropped area with respect to the input area
83  int y; ///< y offset of the non-cropped area with respect to the input area
84  int w; ///< width of the cropped area
85  int h; ///< height of the cropped area
86 
87  AVRational out_sar; ///< output sample aspect ratio
88  int keep_aspect; ///< keep display aspect ratio when cropping
89  int exact; ///< exact cropping, for subsampled formats
90 
91  int max_step[4]; ///< max pixel step for each plane, expressed as a number of bytes
92  int hsub, vsub; ///< chroma subsampling
93  char *x_expr, *y_expr, *w_expr, *h_expr;
94  AVExpr *x_pexpr, *y_pexpr; /* parsed expressions for x and y */
95  double var_values[VAR_VARS_NB];
96 } CropContext;
97 
98 static int query_formats(AVFilterContext *ctx)
99 {
100  int reject_flags = AV_PIX_FMT_FLAG_BITSTREAM | FF_PIX_FMT_FLAG_SW_FLAT_SUB;
101 
102  return ff_set_common_formats(ctx, ff_formats_pixdesc_filter(0, reject_flags));
103 }
104 
105 static av_cold void uninit(AVFilterContext *ctx)
106 {
107  CropContext *s = ctx->priv;
108 
109  av_expr_free(s->x_pexpr);
110  s->x_pexpr = NULL;
111  av_expr_free(s->y_pexpr);
112  s->y_pexpr = NULL;
113 }
114 
115 static inline int normalize_double(int *n, double d)
116 {
117  int ret = 0;
118 
119  if (isnan(d)) {
120  ret = AVERROR(EINVAL);
121  } else if (d > INT_MAX || d < INT_MIN) {
122  *n = d > INT_MAX ? INT_MAX : INT_MIN;
123  ret = AVERROR(EINVAL);
124  } else
125  *n = lrint(d);
126 
127  return ret;
128 }
129 
130 static int config_input(AVFilterLink *link)
131 {
132  AVFilterContext *ctx = link->dst;
133  CropContext *s = ctx->priv;
134  const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
135  int ret;
136  const char *expr;
137  double res;
138 
139  s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w;
140  s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h;
141  s->var_values[VAR_A] = (float) link->w / link->h;
142  s->var_values[VAR_SAR] = link->sample_aspect_ratio.num ? av_q2d(link->sample_aspect_ratio) : 1;
143  s->var_values[VAR_DAR] = s->var_values[VAR_A] * s->var_values[VAR_SAR];
144  s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
145  s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
146  s->var_values[VAR_X] = NAN;
147  s->var_values[VAR_Y] = NAN;
148  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = NAN;
149  s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = NAN;
150  s->var_values[VAR_N] = 0;
151  s->var_values[VAR_T] = NAN;
152 #if FF_API_FRAME_PKT
153  s->var_values[VAR_POS] = NAN;
154 #endif
155 
156  av_image_fill_max_pixsteps(s->max_step, NULL, pix_desc);
157 
158  if (pix_desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
159  s->hsub = 1;
160  s->vsub = 1;
161  } else {
162  s->hsub = pix_desc->log2_chroma_w;
163  s->vsub = pix_desc->log2_chroma_h;
164  }
165 
166  av_expr_parse_and_eval(&res, (expr = s->w_expr),
167  var_names, s->var_values,
168  NULL, NULL, NULL, NULL, NULL, 0, ctx);
169  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
170  if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
171  var_names, s->var_values,
172  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
173  goto fail_expr;
174  s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res;
175  /* evaluate again ow as it may depend on oh */
176  if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
177  var_names, s->var_values,
178  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
179  goto fail_expr;
180 
181  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
182  if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 ||
183  normalize_double(&s->h, s->var_values[VAR_OUT_H]) < 0) {
184  av_log(ctx, AV_LOG_ERROR,
185  "Too big value or invalid expression for out_w/ow or out_h/oh. "
186  "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
187  s->w_expr, s->h_expr);
188  return AVERROR(EINVAL);
189  }
190 
191  if (!s->exact) {
192  s->w &= ~((1 << s->hsub) - 1);
193  s->h &= ~((1 << s->vsub) - 1);
194  }
195 
196  av_expr_free(s->x_pexpr);
197  av_expr_free(s->y_pexpr);
198  s->x_pexpr = s->y_pexpr = NULL;
199  if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
200  NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
201  (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
202  NULL, NULL, NULL, NULL, 0, ctx)) < 0)
203  return AVERROR(EINVAL);
204 
205  if (s->keep_aspect) {
206  AVRational dar = av_mul_q(link->sample_aspect_ratio,
207  (AVRational){ link->w, link->h });
208  av_reduce(&s->out_sar.num, &s->out_sar.den,
209  dar.num * s->h, dar.den * s->w, INT_MAX);
210  } else
211  s->out_sar = link->sample_aspect_ratio;
212 
213  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
214  link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
215  s->w, s->h, s->out_sar.num, s->out_sar.den);
216 
217  if (s->w <= 0 || s->h <= 0 ||
218  s->w > link->w || s->h > link->h) {
219  av_log(ctx, AV_LOG_ERROR,
220  "Invalid too big or non positive size for width '%d' or height '%d'\n",
221  s->w, s->h);
222  return AVERROR(EINVAL);
223  }
224 
225  /* set default, required in the case the first computed value for x/y is NAN */
226  s->x = (link->w - s->w) / 2;
227  s->y = (link->h - s->h) / 2;
228  if (!s->exact) {
229  s->x &= ~((1 << s->hsub) - 1);
230  s->y &= ~((1 << s->vsub) - 1);
231  }
232  return 0;
233 
234 fail_expr:
235  av_log(ctx, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
236  return ret;
237 }
238 
239 static int config_output(AVFilterLink *link)
240 {
241  CropContext *s = link->src->priv;
242  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
243 
244  if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
245  // Hardware frames adjust the cropping regions rather than
246  // changing the frame size.
247  } else {
248  link->w = s->w;
249  link->h = s->h;
250  }
251  link->sample_aspect_ratio = s->out_sar;
252 
253  return 0;
254 }
255 
256 static int filter_frame(AVFilterLink *link, AVFrame *frame)
257 {
258  AVFilterContext *ctx = link->dst;
259  CropContext *s = ctx->priv;
260  const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
261  int i;
262 
263  s->var_values[VAR_N] = link->frame_count_out;
264  s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
265  NAN : frame->pts * av_q2d(link->time_base);
266 #if FF_API_FRAME_PKT
267 FF_DISABLE_DEPRECATION_WARNINGS
268  s->var_values[VAR_POS] = frame->pkt_pos == -1 ?
269  NAN : frame->pkt_pos;
270 FF_ENABLE_DEPRECATION_WARNINGS
271 #endif
272  s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
273  s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, NULL);
274  /* It is necessary if x is expressed from y */
275  s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, NULL);
276 
277  normalize_double(&s->x, s->var_values[VAR_X]);
278  normalize_double(&s->y, s->var_values[VAR_Y]);
279 
280  if (s->x < 0)
281  s->x = 0;
282  if (s->y < 0)
283  s->y = 0;
284  if ((unsigned)s->x + (unsigned)s->w > link->w)
285  s->x = link->w - s->w;
286  if ((unsigned)s->y + (unsigned)s->h > link->h)
287  s->y = link->h - s->h;
288  if (!s->exact) {
289  s->x &= ~((1 << s->hsub) - 1);
290  s->y &= ~((1 << s->vsub) - 1);
291  }
292 
293  av_log(ctx, AV_LOG_TRACE, "n:%d t:%f x:%d y:%d x+w:%d y+h:%d\n",
294  (int)s->var_values[VAR_N], s->var_values[VAR_T],
295  s->x, s->y, s->x+s->w, s->y+s->h);
296 
297  if (desc->flags & AV_PIX_FMT_FLAG_HWACCEL) {
298  frame->crop_top += s->y;
299  frame->crop_left += s->x;
300  frame->crop_bottom = frame->height - frame->crop_top - frame->crop_bottom - s->h;
301  frame->crop_right = frame->width - frame->crop_left - frame->crop_right - s->w;
302  } else {
303  frame->width = s->w;
304  frame->height = s->h;
305 
306  frame->data[0] += s->y * frame->linesize[0];
307  frame->data[0] += s->x * s->max_step[0];
308 
309  if (!(desc->flags & AV_PIX_FMT_FLAG_PAL)) {
310  for (i = 1; i < 3; i ++) {
311  if (frame->data[i]) {
312  frame->data[i] += (s->y >> s->vsub) * frame->linesize[i];
313  frame->data[i] += (s->x * s->max_step[i]) >> s->hsub;
314  }
315  }
316  }
317 
318  /* alpha plane */
319  if (frame->data[3]) {
320  frame->data[3] += s->y * frame->linesize[3];
321  frame->data[3] += s->x * s->max_step[3];
322  }
323  }
324 
325  return ff_filter_frame(link->dst->outputs[0], frame);
326 }
327 
328 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
329  char *res, int res_len, int flags)
330 {
331  CropContext *s = ctx->priv;
332  int ret;
333 
334  if ( !strcmp(cmd, "out_w") || !strcmp(cmd, "w")
335  || !strcmp(cmd, "out_h") || !strcmp(cmd, "h")
336  || !strcmp(cmd, "x") || !strcmp(cmd, "y")) {
337 
338  int old_x = s->x;
339  int old_y = s->y;
340  int old_w = s->w;
341  int old_h = s->h;
342 
343  AVFilterLink *outlink = ctx->outputs[0];
344  AVFilterLink *inlink = ctx->inputs[0];
345 
346  av_opt_set(s, cmd, args, 0);
347 
348  if ((ret = config_input(inlink)) < 0) {
349  s->x = old_x;
350  s->y = old_y;
351  s->w = old_w;
352  s->h = old_h;
353  return ret;
354  }
355 
356  ret = config_output(outlink);
357 
358  } else
359  ret = AVERROR(ENOSYS);
360 
361  return ret;
362 }
363 
364 #define OFFSET(x) offsetof(CropContext, x)
365 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
366 #define TFLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
367 
368 static const AVOption crop_options[] = {
369  { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, TFLAGS },
370  { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, TFLAGS },
371  { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, TFLAGS },
372  { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, TFLAGS },
373  { "x", "set the x crop area expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, 0, 0, TFLAGS },
374  { "y", "set the y crop area expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, 0, 0, TFLAGS },
375  { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
376  { "exact", "do exact cropping", OFFSET(exact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
377  { NULL }
378 };
379 
380 AVFILTER_DEFINE_CLASS(crop);
381 
382 static const AVFilterPad avfilter_vf_crop_inputs[] = {
383  {
384  .name = "default",
385  .type = AVMEDIA_TYPE_VIDEO,
386  .filter_frame = filter_frame,
387  .config_props = config_input,
388  },
389 };
390 
391 static const AVFilterPad avfilter_vf_crop_outputs[] = {
392  {
393  .name = "default",
394  .type = AVMEDIA_TYPE_VIDEO,
395  .config_props = config_output,
396  },
397 };
398 
399 const AVFilter ff_vf_crop = {
400  .name = "crop",
401  .description = NULL_IF_CONFIG_SMALL("Crop the input video."),
402  .priv_size = sizeof(CropContext),
403  .priv_class = &crop_class,
404  .uninit = uninit,
405  FILTER_INPUTS(avfilter_vf_crop_inputs),
406  FILTER_OUTPUTS(avfilter_vf_crop_outputs),
407  FILTER_QUERY_FUNC(query_formats),
408  .process_command = process_command,
409 };
OFFSET
#define OFFSET(x)
Definition: vf_crop.c:364
VAR_VSUB
@ VAR_VSUB
Definition: vf_crop.c:69
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: vf_crop.c:98
FF_ENABLE_DEPRECATION_WARNINGS
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:73
VAR_SAR
@ VAR_SAR
Definition: vf_crop.c:66
CropContext::var_values
double var_values[VAR_VARS_NB]
Definition: vf_crop.c:95
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_crop.c:105
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:82
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:978
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2964
VAR_T
@ VAR_T
Definition: vf_crop.c:76
CropContext::x_pexpr
AVExpr * x_pexpr
Definition: vf_crop.c:94
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:83
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:452
AVFrame::width
int width
Definition: frame.h:412
CropContext::keep_aspect
int keep_aspect
keep display aspect ratio when cropping
Definition: vf_crop.c:88
crop_options
static const AVOption crop_options[]
Definition: vf_crop.c:368
AVOption
AVOption.
Definition: opt.h:251
FILTER_QUERY_FUNC
#define FILTER_QUERY_FUNC(func)
Definition: internal.h:169
CropContext::y_expr
char * y_expr
Definition: vf_crop.c:93
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:170
VAR_HSUB
@ VAR_HSUB
Definition: vf_crop.c:68
video.h
normalize_double
static int normalize_double(int *n, double d)
Definition: vf_crop.c:115
CropContext::w
int w
width of the cropped area
Definition: vf_crop.c:84
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
VAR_A
@ VAR_A
Definition: vf_crop.c:65
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:61
CropContext::vsub
int vsub
chroma subsampling
Definition: vf_crop.c:92
VAR_OUT_W
@ VAR_OUT_W
Definition: vf_crop.c:63
config_output
static int config_output(AVFilterLink *link)
Definition: vf_crop.c:239
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:93
TFLAGS
#define TFLAGS
Definition: vf_crop.c:366
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:47
VAR_X
@ VAR_X
Definition: vf_crop.c:70
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:770
ff_vf_crop
const AVFilter ff_vf_crop
Definition: vf_crop.c:399
float
float
Definition: af_crystalizer.c:121
VAR_IW
@ VAR_IW
Definition: vf_crop.c:61
s
#define s(width, name)
Definition: cbs_vp9.c:198
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:62
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
AVFrame::crop_right
size_t crop_right
Definition: frame.h:781
NAN
#define NAN
Definition: mathematics.h:115
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:192
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:80
frame
static AVFrame * frame
Definition: demux_decode.c:54
FLAGS
#define FLAGS
Definition: vf_crop.c:365
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_POS
@ VAR_POS
Definition: noise_bsf.c:55
VAR_Y
@ VAR_Y
Definition: vf_crop.c:71
CropContext::h
int h
height of the cropped area
Definition: vf_crop.c:85
VAR_OH
@ VAR_OH
Definition: vf_crop.c:64
AVPixFmtDescriptor::flags
uint64_t flags
Combination of AV_PIX_FMT_FLAG_...
Definition: pixdesc.h:94
AVFrame::crop_bottom
size_t crop_bottom
Definition: frame.h:779
VAR_DAR
@ VAR_DAR
Definition: vf_crop.c:67
VAR_OUT_H
@ VAR_OUT_H
Definition: vf_crop.c:64
AVFrame::crop_left
size_t crop_left
Definition: frame.h:780
eval.h
filter_frame
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_crop.c:256
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:106
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:94
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:467
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::pkt_pos
attribute_deprecated int64_t pkt_pos
reordered pos from the last AVPacket that has been input into the decoder
Definition: frame.h:687
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:427
CropContext::max_step
int max_step[4]
max pixel step for each plane, expressed as a number of bytes
Definition: vf_crop.c:91
VAR_N
@ VAR_N
Definition: vf_crop.c:72
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:519
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
config_input
static int config_input(AVFilterLink *link)
Definition: vf_crop.c:130
internal.h
avfilter_vf_crop_inputs
static const AVFilterPad avfilter_vf_crop_inputs[]
Definition: vf_crop.c:382
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:53
CropContext::out_sar
AVRational out_sar
output sample aspect ratio
Definition: vf_crop.c:87
AVFilter
Filter definition.
Definition: avfilter.h:166
ret
ret
Definition: filter_design.txt:187
AVFrame::sample_aspect_ratio
AVRational sample_aspect_ratio
Sample aspect ratio for the video frame, 0/1 if unknown/unspecified.
Definition: frame.h:447
AVFrame::height
int height
Definition: frame.h:412
VAR_VARS_NB
@ VAR_VARS_NB
Definition: vf_crop.c:77
AVRational::den
int den
Denominator.
Definition: rational.h:60
avfilter.h
CropContext::exact
int exact
exact cropping, for subsampled formats
Definition: vf_crop.c:89
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:397
CropContext::h_expr
char * h_expr
Definition: vf_crop.c:93
FF_DISABLE_DEPRECATION_WARNINGS
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:72
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:93
CropContext::hsub
int hsub
Definition: vf_crop.c:92
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:193
avfilter_vf_crop_outputs
static const AVFilterPad avfilter_vf_crop_outputs[]
Definition: vf_crop.c:391
AVFrame::crop_top
size_t crop_top
Definition: frame.h:778
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:328
d
d
Definition: ffmpeg_filter.c:368
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:385
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:63
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:62
Generated on Thu Apr 18 2024 22:42:25 for FFmpeg by   doxygen 1.8.17