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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 {
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 */
92 } CropContext;
93 
95 {
97  int fmt, ret;
98 
99  for (fmt = 0; av_pix_fmt_desc_get(fmt); fmt++) {
102  !((desc->log2_chroma_w || desc->log2_chroma_h) && !(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) &&
103  (ret = ff_add_format(&formats, fmt)) < 0)
104  return ret;
105  }
106 
107  return ff_set_common_formats(ctx, formats);
108 }
109 
111 {
112  CropContext *s = ctx->priv;
113 
114  av_expr_free(s->x_pexpr);
115  s->x_pexpr = NULL;
116  av_expr_free(s->y_pexpr);
117  s->y_pexpr = NULL;
118 }
119 
120 static inline int normalize_double(int *n, double d)
121 {
122  int ret = 0;
123 
124  if (isnan(d)) {
125  ret = AVERROR(EINVAL);
126  } else if (d > INT_MAX || d < INT_MIN) {
127  *n = d > INT_MAX ? INT_MAX : INT_MIN;
128  ret = AVERROR(EINVAL);
129  } else
130  *n = lrint(d);
131 
132  return ret;
133 }
134 
135 static int config_input(AVFilterLink *link)
136 {
137  AVFilterContext *ctx = link->dst;
138  CropContext *s = ctx->priv;
139  const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(link->format);
140  int ret;
141  const char *expr;
142  double res;
143 
144  s->var_values[VAR_IN_W] = s->var_values[VAR_IW] = ctx->inputs[0]->w;
145  s->var_values[VAR_IN_H] = s->var_values[VAR_IH] = ctx->inputs[0]->h;
146  s->var_values[VAR_A] = (float) link->w / link->h;
149  s->var_values[VAR_HSUB] = 1<<pix_desc->log2_chroma_w;
150  s->var_values[VAR_VSUB] = 1<<pix_desc->log2_chroma_h;
151  s->var_values[VAR_X] = NAN;
152  s->var_values[VAR_Y] = NAN;
155  s->var_values[VAR_N] = 0;
156  s->var_values[VAR_T] = NAN;
157  s->var_values[VAR_POS] = NAN;
158 
160  s->hsub = pix_desc->log2_chroma_w;
161  s->vsub = pix_desc->log2_chroma_h;
162 
163  if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
164  var_names, s->var_values,
165  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
166  goto fail_expr;
167  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
168  if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
169  var_names, s->var_values,
170  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
171  goto fail_expr;
172  s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = res;
173  /* evaluate again ow as it may depend on oh */
174  if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
175  var_names, s->var_values,
176  NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
177  goto fail_expr;
178 
179  s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = res;
180  if (normalize_double(&s->w, s->var_values[VAR_OUT_W]) < 0 ||
181  normalize_double(&s->h, s->var_values[VAR_OUT_H]) < 0) {
182  av_log(ctx, AV_LOG_ERROR,
183  "Too big value or invalid expression for out_w/ow or out_h/oh. "
184  "Maybe the expression for out_w:'%s' or for out_h:'%s' is self-referencing.\n",
185  s->w_expr, s->h_expr);
186  return AVERROR(EINVAL);
187  }
188 
189  if (!s->exact) {
190  s->w &= ~((1 << s->hsub) - 1);
191  s->h &= ~((1 << s->vsub) - 1);
192  }
193 
194  av_expr_free(s->x_pexpr);
195  av_expr_free(s->y_pexpr);
196  s->x_pexpr = s->y_pexpr = NULL;
197  if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
198  NULL, NULL, NULL, NULL, 0, ctx)) < 0 ||
199  (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
200  NULL, NULL, NULL, NULL, 0, ctx)) < 0)
201  return AVERROR(EINVAL);
202 
203  if (s->keep_aspect) {
205  (AVRational){ link->w, link->h });
206  av_reduce(&s->out_sar.num, &s->out_sar.den,
207  dar.num * s->h, dar.den * s->w, INT_MAX);
208  } else
209  s->out_sar = link->sample_aspect_ratio;
210 
211  av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d sar:%d/%d -> w:%d h:%d sar:%d/%d\n",
212  link->w, link->h, link->sample_aspect_ratio.num, link->sample_aspect_ratio.den,
213  s->w, s->h, s->out_sar.num, s->out_sar.den);
214 
215  if (s->w <= 0 || s->h <= 0 ||
216  s->w > link->w || s->h > link->h) {
218  "Invalid too big or non positive size for width '%d' or height '%d'\n",
219  s->w, s->h);
220  return AVERROR(EINVAL);
221  }
222 
223  /* set default, required in the case the first computed value for x/y is NAN */
224  s->x = (link->w - s->w) / 2;
225  s->y = (link->h - s->h) / 2;
226  if (!s->exact) {
227  s->x &= ~((1 << s->hsub) - 1);
228  s->y &= ~((1 << s->vsub) - 1);
229  }
230  return 0;
231 
232 fail_expr:
233  av_log(NULL, AV_LOG_ERROR, "Error when evaluating the expression '%s'\n", expr);
234  return ret;
235 }
236 
237 static int config_output(AVFilterLink *link)
238 {
239  CropContext *s = link->src->priv;
240 
241  link->w = s->w;
242  link->h = s->h;
243  link->sample_aspect_ratio = s->out_sar;
244 
245  return 0;
246 }
247 
249 {
250  AVFilterContext *ctx = link->dst;
251  CropContext *s = ctx->priv;
253  int i;
254 
255  frame->width = s->w;
256  frame->height = s->h;
257 
258  s->var_values[VAR_N] = link->frame_count;
259  s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
260  NAN : frame->pts * av_q2d(link->time_base);
261  s->var_values[VAR_POS] = av_frame_get_pkt_pos(frame) == -1 ?
262  NAN : av_frame_get_pkt_pos(frame);
266 
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  frame->data[0] += s->y * frame->linesize[0];
288  frame->data[0] += s->x * s->max_step[0];
289 
290  if (!(desc->flags & AV_PIX_FMT_FLAG_PAL || desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL)) {
291  for (i = 1; i < 3; i ++) {
292  if (frame->data[i]) {
293  frame->data[i] += (s->y >> s->vsub) * frame->linesize[i];
294  frame->data[i] += (s->x * s->max_step[i]) >> s->hsub;
295  }
296  }
297  }
298 
299  /* alpha plane */
300  if (frame->data[3]) {
301  frame->data[3] += s->y * frame->linesize[3];
302  frame->data[3] += s->x * s->max_step[3];
303  }
304 
305  return ff_filter_frame(link->dst->outputs[0], frame);
306 }
307 
308 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
309  char *res, int res_len, int flags)
310 {
311  CropContext *s = ctx->priv;
312  int ret;
313 
314  if ( !strcmp(cmd, "out_w") || !strcmp(cmd, "w")
315  || !strcmp(cmd, "out_h") || !strcmp(cmd, "h")
316  || !strcmp(cmd, "x") || !strcmp(cmd, "y")) {
317 
318  int old_x = s->x;
319  int old_y = s->y;
320  int old_w = s->w;
321  int old_h = s->h;
322 
323  AVFilterLink *outlink = ctx->outputs[0];
324  AVFilterLink *inlink = ctx->inputs[0];
325 
326  av_opt_set(s, cmd, args, 0);
327 
328  if ((ret = config_input(inlink)) < 0) {
329  s->x = old_x;
330  s->y = old_y;
331  s->w = old_w;
332  s->h = old_h;
333  return ret;
334  }
335 
336  ret = config_output(outlink);
337 
338  } else
339  ret = AVERROR(ENOSYS);
340 
341  return ret;
342 }
343 
344 #define OFFSET(x) offsetof(CropContext, x)
345 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
346 
347 static const AVOption crop_options[] = {
348  { "out_w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
349  { "w", "set the width crop area expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, CHAR_MIN, CHAR_MAX, FLAGS },
350  { "out_h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
351  { "h", "set the height crop area expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, CHAR_MIN, CHAR_MAX, FLAGS },
352  { "x", "set the x crop area expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str = "(in_w-out_w)/2"}, CHAR_MIN, CHAR_MAX, FLAGS },
353  { "y", "set the y crop area expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str = "(in_h-out_h)/2"}, CHAR_MIN, CHAR_MAX, FLAGS },
354  { "keep_aspect", "keep aspect ratio", OFFSET(keep_aspect), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
355  { "exact", "do exact cropping", OFFSET(exact), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
356  { NULL }
357 };
358 
360 
362  {
363  .name = "default",
364  .type = AVMEDIA_TYPE_VIDEO,
365  .filter_frame = filter_frame,
366  .config_props = config_input,
367  },
368  { NULL }
369 };
370 
372  {
373  .name = "default",
374  .type = AVMEDIA_TYPE_VIDEO,
375  .config_props = config_output,
376  },
377  { NULL }
378 };
379 
381  .name = "crop",
382  .description = NULL_IF_CONFIG_SMALL("Crop the input video."),
383  .priv_size = sizeof(CropContext),
384  .priv_class = &crop_class,
386  .uninit = uninit,
387  .inputs = avfilter_vf_crop_inputs,
388  .outputs = avfilter_vf_crop_outputs,
390 };
#define AV_PIX_FMT_FLAG_PAL
Pixel format has a palette in data[1], values are indexes in this palette.
Definition: pixdesc.h:132
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
AVExpr * x_pexpr
Definition: vf_crop.c:90
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2263
This structure describes decoded (raw) audio or video data.
Definition: frame.h:184
#define FLAGS
Definition: vf_crop.c:345
AVOption.
Definition: opt.h:245
const char * fmt
Definition: avisynth_c.h:769
static int config_input(AVFilterLink *link)
Definition: vf_crop.c:135
misc image utilities
Main libavfilter public API header.
int exact
exact cropping, for subsampled formats
Definition: vf_crop.c:85
const char * desc
Definition: nvenc.c:89
int num
Numerator.
Definition: rational.h:59
static enum AVSampleFormat formats[]
Definition: avresample.c:163
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:658
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:92
AVFilter ff_vf_crop
Definition: vf_crop.c:380
Definition: vf_crop.c:61
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:34
const char * name
Pad name.
Definition: internal.h:59
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:315
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1180
#define av_cold
Definition: attributes.h:82
int x
x offset of the non-cropped area with respect to the input area
Definition: vf_crop.c:78
AVOptions.
int y
y offset of the non-cropped area with respect to the input area
Definition: vf_crop.c:79
#define AV_LOG_TRACE
Extremely verbose debugging, useful for libav* development.
Definition: log.h:202
int max_step[4]
max pixel step for each plane, expressed as a number of bytes
Definition: vf_crop.c:87
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:268
Definition: eval.c:149
static const AVFilterPad avfilter_vf_crop_outputs[]
Definition: vf_crop.c:371
static AVFrame * frame
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
Definition: vf_crop.c:60
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:192
char * w_expr
Definition: vf_crop.c:89
static const AVFilterPad avfilter_vf_crop_inputs[]
Definition: vf_crop.c:361
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
#define av_log(a,...)
A filter pad used for either input or output.
Definition: internal.h:53
int hsub
Definition: vf_crop.c:88
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:723
int width
width and height of the video frame
Definition: frame.h:236
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
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:568
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:101
Definition: vf_crop.c:70
double var_values[VAR_VARS_NB]
Definition: vf_crop.c:91
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
void * priv
private data for use by the filter
Definition: avfilter.h:322
#define AV_PIX_FMT_FLAG_HWACCEL
Pixel format is an HW accelerated format.
Definition: pixdesc.h:140
int ff_add_format(AVFilterFormats **avff, int64_t fmt)
Add fmt to the list of media formats contained in *avff.
Definition: formats.c:337
var_name
Definition: aeval.c:46
common internal API header
uint64_t flags
Combination of AV_PIX_FMT_FLAG_...
Definition: pixdesc.h:106
char * x_expr
Definition: vf_crop.c:89
static int process_command(AVFilterContext *ctx, const char *cmd, const char *args, char *res, int res_len, int flags)
Definition: vf_crop.c:308
#define AV_PIX_FMT_FLAG_PSEUDOPAL
The pixel format is "pseudo-paletted".
Definition: pixdesc.h:158
AVRational out_sar
output sample aspect ratio
Definition: vf_crop.c:83
AVFormatContext * ctx
Definition: movenc.c:48
int n
Definition: avisynth_c.h:684
#define OFFSET(x)
Definition: vf_crop.c:344
AVExpr * y_pexpr
Definition: vf_crop.c:90
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
static int query_formats(AVFilterContext *ctx)
Definition: vf_crop.c:94
char * h_expr
Definition: vf_crop.c:89
int h
height of the cropped area
Definition: vf_crop.c:81
int vsub
chroma subsampling
Definition: vf_crop.c:88
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
Definition: vf_crop.c:68
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse().
Definition: eval.c:318
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:215
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_crop.c:110
Definition: vf_crop.c:59
Replacements for frequently missing libm functions.
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
Rational number (pair of numerator and denominator).
Definition: rational.h:58
#define isnan(x)
Definition: libm.h:340
const char * name
Filter name.
Definition: avfilter.h:148
static const AVOption crop_options[]
Definition: vf_crop.c:347
#define AV_PIX_FMT_FLAG_BITSTREAM
All values of a component are bit-wise packed end to end.
Definition: pixdesc.h:136
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:319
Definition: vf_crop.c:62
static const char *const var_names[]
Definition: vf_crop.c:40
static int flags
Definition: cpu.c:47
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
static int normalize_double(int *n, double d)
Definition: vf_crop.c:120
static int config_output(AVFilterLink *link)
Definition: vf_crop.c:237
Definition: vf_crop.c:69
AVFILTER_DEFINE_CLASS(crop)
int den
Denominator.
Definition: rational.h:60
Definition: vf_crop.c:72
Definition: vf_crop.c:63
#define NAN
Definition: math.h:28
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:713
int64_t av_frame_get_pkt_pos(const AVFrame *frame)
int keep_aspect
keep display aspect ratio when cropping
Definition: vf_crop.c:84
A list of supported formats for one end of a filter link.
Definition: formats.h:64
#define lrint
Definition: tablegen.h:53
An instance of a filter.
Definition: avfilter.h:307
AVRational av_mul_q(AVRational b, AVRational c)
Multiply two rationals.
Definition: rational.c:80
int height
Definition: frame.h:236
int w
width of the cropped area
Definition: vf_crop.c:80
internal API functions
int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
Definition: opt.c:431
#define AV_PIX_FMT_FLAG_PLANAR
At least one pixel component is not in the first data plane.
Definition: pixdesc.h:144
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:242
simple arithmetic expression evaluator
static int filter_frame(AVFilterLink *link, AVFrame *frame)
Definition: vf_crop.c:248
char * y_expr
Definition: vf_crop.c:89