Statistics
| Branch: | Revision:

ffmpeg / doc / filters.texi @ 7e3373d2

History | View | Annotate | Download (43 KB)

1 1ebe5c4c Stefano Sabatini
@chapter Filtergraph description
2
@c man begin FILTERGRAPH DESCRIPTION
3
4
A filtergraph is a directed graph of connected filters. It can contain
5
cycles, and there can be multiple links between a pair of
6
filters. Each link has one input pad on one side connecting it to one
7
filter from which it takes its input, and one output pad on the other
8
side connecting it to the one filter accepting its output.
9
10
Each filter in a filtergraph is an instance of a filter class
11
registered in the application, which defines the features and the
12
number of input and output pads of the filter.
13
14
A filter with no input pads is called a "source", a filter with no
15
output pads is called a "sink".
16
17
@section Filtergraph syntax
18
19
A filtergraph can be represented using a textual representation, which
20
is recognized by the @code{-vf} and @code{-af} options of the ff*
21
tools, and by the @code{av_parse_graph()} function defined in
22
@file{libavfilter/avfiltergraph}.
23
24
A filterchain consists of a sequence of connected filters, each one
25
connected to the previous one in the sequence. A filterchain is
26
represented by a list of ","-separated filter descriptions.
27
28
A filtergraph consists of a sequence of filterchains. A sequence of
29
filterchains is represented by a list of ";"-separated filterchain
30
descriptions.
31
32
A filter is represented by a string of the form:
33
[@var{in_link_1}]...[@var{in_link_N}]@var{filter_name}=@var{arguments}[@var{out_link_1}]...[@var{out_link_M}]
34
35
@var{filter_name} is the name of the filter class of which the
36
described filter is an instance of, and has to be the name of one of
37
the filter classes registered in the program.
38
The name of the filter class is optionally followed by a string
39
"=@var{arguments}".
40
41
@var{arguments} is a string which contains the parameters used to
42
initialize the filter instance, and are described in the filter
43
descriptions below.
44
45
The list of arguments can be quoted using the character "'" as initial
46
and ending mark, and the character '\' for escaping the characters
47
within the quoted text; otherwise the argument string is considered
48
terminated when the next special character (belonging to the set
49
"[]=;,") is encountered.
50
51
The name and arguments of the filter are optionally preceded and
52
followed by a list of link labels.
53
A link label allows to name a link and associate it to a filter output
54
or input pad. The preceding labels @var{in_link_1}
55
... @var{in_link_N}, are associated to the filter input pads,
56
the following labels @var{out_link_1} ... @var{out_link_M}, are
57
associated to the output pads.
58
59
When two link labels with the same name are found in the
60
filtergraph, a link between the corresponding input and output pad is
61
created.
62
63
If an output pad is not labelled, it is linked by default to the first
64
unlabelled input pad of the next filter in the filterchain.
65
For example in the filterchain:
66
@example
67
nullsrc, split[L1], [L2]overlay, nullsink
68
@end example
69
the split filter instance has two output pads, and the overlay filter
70
instance two input pads. The first output pad of split is labelled
71
"L1", the first input pad of overlay is labelled "L2", and the second
72
output pad of split is linked to the second input pad of overlay,
73
which are both unlabelled.
74
75
In a complete filterchain all the unlabelled filter input and output
76
pads must be connected. A filtergraph is considered valid if all the
77
filter input and output pads of all the filterchains are connected.
78
79
Follows a BNF description for the filtergraph syntax:
80
@example
81
@var{NAME}             ::= sequence of alphanumeric characters and '_'
82
@var{LINKLABEL}        ::= "[" @var{NAME} "]"
83
@var{LINKLABELS}       ::= @var{LINKLABEL} [@var{LINKLABELS}]
84
@var{FILTER_ARGUMENTS} ::= sequence of chars (eventually quoted)
85
@var{FILTER}           ::= [@var{LINKNAMES}] @var{NAME} ["=" @var{ARGUMENTS}] [@var{LINKNAMES}]
86
@var{FILTERCHAIN}      ::= @var{FILTER} [,@var{FILTERCHAIN}]
87
@var{FILTERGRAPH}      ::= @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
88
@end example
89
90
@c man end FILTERGRAPH DESCRIPTION
91
92 f59e9eaf Stefano Sabatini
@chapter Audio Filters
93
@c man begin AUDIO FILTERS
94
95 a6be21d3 Michael Niedermayer
When you configure your FFmpeg build, you can disable any of the
96 f59e9eaf Stefano Sabatini
existing filters using --disable-filters.
97
The configure output will show the audio filters included in your
98
build.
99
100
Below is a description of the currently available audio filters.
101
102 99046339 S.N. Hemanth Meenakshisundaram
@section anull
103
104
Pass the audio source unchanged to the output.
105
106 f59e9eaf Stefano Sabatini
@c man end AUDIO FILTERS
107
108 1ee410f3 Stefano Sabatini
@chapter Audio Sources
109
@c man begin AUDIO SOURCES
110
111
Below is a description of the currently available audio sources.
112
113
@section anullsrc
114
115
Null audio source, never return audio frames. It is mainly useful as a
116
template and to be employed in analysis / debugging tools.
117
118
It accepts as optional parameter a string of the form
119
@var{sample_rate}:@var{channel_layout}.
120
121
@var{sample_rate} specify the sample rate, and defaults to 44100.
122
123
@var{channel_layout} specify the channel layout, and can be either an
124
integer or a string representing a channel layout. The default value
125
of @var{channel_layout} is 3, which corresponds to CH_LAYOUT_STEREO.
126
127
Check the channel_layout_map definition in
128 6ef93402 Stefano Sabatini
@file{libavcodec/audioconvert.c} for the mapping between strings and
129
channel layout values.
130 1ee410f3 Stefano Sabatini
131
Follow some examples:
132
@example
133
#  set the sample rate to 48000 Hz and the channel layout to CH_LAYOUT_MONO.
134
anullsrc=48000:4
135
136
# same as
137
anullsrc=48000:mono
138
@end example
139
140
@c man end AUDIO SOURCES
141
142 f0a55438 S.N. Hemanth Meenakshisundaram
@chapter Audio Sinks
143
@c man begin AUDIO SINKS
144
145
Below is a description of the currently available audio sinks.
146
147
@section anullsink
148
149
Null audio sink, do absolutely nothing with the input audio. It is
150
mainly useful as a template and to be employed in analysis / debugging
151
tools.
152
153
@c man end AUDIO SINKS
154
155 3275ac6a Stefano Sabatini
@chapter Video Filters
156
@c man begin VIDEO FILTERS
157
158 a6be21d3 Michael Niedermayer
When you configure your FFmpeg build, you can disable any of the
159 3275ac6a Stefano Sabatini
existing filters using --disable-filters.
160
The configure output will show the video filters included in your
161
build.
162
163
Below is a description of the currently available video filters.
164
165 13fabd7a Stefano Sabatini
@section blackframe
166
167
Detect frames that are (almost) completely black. Can be useful to
168
detect chapter transitions or commercials. Output lines consist of
169
the frame number of the detected frame, the percentage of blackness,
170
the position in the file if known or -1 and the timestamp in seconds.
171
172
In order to display the output lines, you need to set the loglevel at
173
least to the AV_LOG_INFO value.
174
175
The filter accepts the syntax:
176
@example
177
blackframe[=@var{amount}:[@var{threshold}]]
178
@end example
179
180
@var{amount} is the percentage of the pixels that have to be below the
181
threshold, and defaults to 98.
182
183
@var{threshold} is the threshold below which a pixel value is
184
considered black, and defaults to 32.
185
186 b5670209 Stefano Sabatini
@section copy
187
188
Copy the input source unchanged to the output. Mainly useful for
189
testing purposes.
190
191 3275ac6a Stefano Sabatini
@section crop
192
193 75b67a8a Stefano Sabatini
Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}.
194 3275ac6a Stefano Sabatini
195 75b67a8a Stefano Sabatini
The parameters are expressions containing the following constants:
196
197
@table @option
198
@item E, PI, PHI
199
the corresponding mathematical approximated values for e
200
(euler number), pi (greek PI), PHI (golden ratio)
201
202
@item x, y
203
the computed values for @var{x} and @var{y}. They are evaluated for
204
each new frame.
205
206
@item in_w, in_h
207
the input width and heigth
208
209
@item iw, ih
210
same as @var{in_w} and @var{in_h}
211
212
@item out_w, out_h
213
the output (cropped) width and heigth
214
215
@item ow, oh
216
same as @var{out_w} and @var{out_h}
217
218
@item n
219
the number of input frame, starting from 0
220
221
@item pos
222
the position in the file of the input frame, NAN if unknown
223
224
@item t
225
timestamp expressed in seconds, NAN if the input timestamp is unknown
226 3275ac6a Stefano Sabatini
227 75b67a8a Stefano Sabatini
@end table
228 3275ac6a Stefano Sabatini
229 75b67a8a Stefano Sabatini
The @var{out_w} and @var{out_h} parameters specify the expressions for
230
the width and height of the output (cropped) video. They are
231
evaluated just at the configuration of the filter.
232 3275ac6a Stefano Sabatini
233 75b67a8a Stefano Sabatini
The default value of @var{out_w} is "in_w", and the default value of
234
@var{out_h} is "in_h".
235 2bc05d35 Stefano Sabatini
236 75b67a8a Stefano Sabatini
The expression for @var{out_w} may depend on the value of @var{out_h},
237
and the expression for @var{out_h} may depend on @var{out_w}, but they
238
cannot depend on @var{x} and @var{y}, as @var{x} and @var{y} are
239
evaluated after @var{out_w} and @var{out_h}.
240 2bc05d35 Stefano Sabatini
241 75b67a8a Stefano Sabatini
The @var{x} and @var{y} parameters specify the expressions for the
242
position of the top-left corner of the output (non-cropped) area. They
243
are evaluated for each frame. If the evaluated value is not valid, it
244
is approximated to the nearest valid value.
245 3275ac6a Stefano Sabatini
246 75b67a8a Stefano Sabatini
The default value of @var{x} is "(in_w-out_w)/2", and the default
247
value for @var{y} is "(in_h-out_h)/2", which set the cropped area at
248
the center of the input image.
249
250
The expression for @var{x} may depend on @var{y}, and the expression
251
for @var{y} may depend on @var{x}.
252
253
Follow some examples:
254 3275ac6a Stefano Sabatini
@example
255 75b67a8a Stefano Sabatini
# crop the central input area with size 100x100
256
crop=100:100
257
258
# crop the central input area with size 2/3 of the input video
259
"crop=2/3*in_w:2/3*in_h"
260
261
# crop the input video central square
262
crop=in_h
263
264
# delimit the rectangle with the top-left corner placed at position
265
# 100:100 and the right-bottom corner corresponding to the right-bottom
266
# corner of the input image.
267
crop=in_w-100:in_h-100:100:100
268 3275ac6a Stefano Sabatini
269 e6dba1d8 Stefano Sabatini
# crop 10 pixels from the left and right borders, and 20 pixels from
270 75b67a8a Stefano Sabatini
# the top and bottom borders
271
"crop=in_w-2*10:in_h-2*20"
272 3275ac6a Stefano Sabatini
273 75b67a8a Stefano Sabatini
# keep only the bottom right quarter of the input image
274
"crop=in_w/2:in_h/2:in_w/2:in_h/2"
275
276
# crop height for getting Greek harmony
277
"crop=in_w:1/PHI*in_w"
278
279
# trembling effect
280
"crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)"
281
282 e6dba1d8 Stefano Sabatini
# erratic camera effect depending on timestamp
283 75b67a8a Stefano Sabatini
"crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
284
285
# set x depending on the value of y
286
"crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
287
@end example
288 3275ac6a Stefano Sabatini
289 68b79bfc Stefano Sabatini
@section cropdetect
290
291
Auto-detect crop size.
292
293
Calculate necessary cropping parameters and prints the recommended
294
parameters through the logging system. The detected dimensions
295
correspond to the non-black area of the input video.
296
297
It accepts the syntax:
298
@example
299 3699c1f1 Stefano Sabatini
cropdetect[=@var{limit}[:@var{round}[:@var{reset}]]]
300 68b79bfc Stefano Sabatini
@end example
301
302
@table @option
303
304
@item limit
305
Threshold, which can be optionally specified from nothing (0) to
306
everything (255), defaults to 24.
307
308
@item round
309
Value which the width/height should be divisible by, defaults to
310
16. The offset is automatically adjusted to center the video. Use 2 to
311
get only even dimensions (needed for 4:2:2 video). 16 is best when
312
encoding to most video codecs.
313
314
@item reset
315
Counter that determines after how many frames cropdetect will reset
316
the previously detected largest video area and start over to detect
317
the current optimal crop area. Defaults to 0.
318
319
This can be useful when channel logos distort the video area. 0
320
indicates never reset and return the largest area encountered during
321
playback.
322
@end table
323
324 e40032e2 Stefano Sabatini
@section drawbox
325
326
Draw a colored box on the input image.
327
328
It accepts the syntax:
329
@example
330
drawbox=@var{x}:@var{y}:@var{width}:@var{height}:@var{color}
331
@end example
332
333
@table @option
334
335
@item x, y
336
Specify the top left corner coordinates of the box. Default to 0.
337
338
@item width, height
339
Specify the width and height of the box, if 0 they are interpreted as
340
the input width and height. Default to 0.
341
342
@item color
343
Specify the color of the box to write, it can be the name of a color
344
(case insensitive match) or a 0xRRGGBB[AA] sequence.
345
@end table
346
347
Follow some examples:
348
@example
349
# draw a black box around the edge of the input image
350
drawbox
351
352
# draw a box with color red and an opacity of 50%
353
drawbox=10:20:200:60:red@@0.5"
354
@end example
355
356 bd8e7503 Stefano Sabatini
@section drawtext
357
358
Draw text string or text from specified file on top of video using the
359
libfreetype library.
360
361
To enable compilation of this filter you need to configure FFmpeg with
362
@code{--enable-libfreetype}.
363
364
The filter also recognizes strftime() sequences in the provided text
365
and expands them accordingly. Check the documentation of strftime().
366
367
The filter accepts parameters as a list of @var{key}=@var{value} pairs,
368
separated by ":".
369
370
The description of the accepted parameters follows.
371
372
@table @option
373
374
@item fontfile
375
The font file to be used for drawing text. Path must be included.
376
This parameter is mandatory.
377
378
@item text
379
The text string to be drawn. The text must be a sequence of UTF-8
380
encoded characters.
381 5c5816c4 Stefano Sabatini
This parameter is mandatory if no file is specified with the parameter
382
@var{textfile}.
383 bd8e7503 Stefano Sabatini
384
@item textfile
385
A text file containing text to be drawn. The text must be a sequence
386 5c5816c4 Stefano Sabatini
of UTF-8 encoded characters.
387 bd8e7503 Stefano Sabatini
388 5c5816c4 Stefano Sabatini
This parameter is mandatory if no text string is specified with the
389
parameter @var{text}.
390 bd8e7503 Stefano Sabatini
391
If both text and textfile are specified, an error is thrown.
392
393
@item x, y
394
The offsets where text will be drawn within the video frame.
395
Relative to the top/left border of the output image.
396
397
The default value of @var{x} and @var{y} is 0.
398
399
@item fontsize
400
The font size to be used for drawing text.
401 5c5816c4 Stefano Sabatini
The default value of @var{fontsize} is 16.
402 bd8e7503 Stefano Sabatini
403
@item fontcolor
404
The color to be used for drawing fonts.
405
Either a string (e.g. "red") or in 0xRRGGBB[AA] format
406
(e.g. "0xff000033"), possibly followed by an alpha specifier.
407
The default value of @var{fontcolor} is "black".
408
409
@item boxcolor
410
The color to be used for drawing box around text.
411
Either a string (e.g. "yellow") or in 0xRRGGBB[AA] format
412
(e.g. "0xff00ff"), possibly followed by an alpha specifier.
413 7e3373d2 Stefano Sabatini
The default value of @var{boxcolor} is "white".
414 bd8e7503 Stefano Sabatini
415
@item box
416
Used to draw a box around text using background color.
417
Value should be either 1 (enable) or 0 (disable).
418
The default value of @var{box} is 0.
419
420 17be8ef7 Stefano Sabatini
@item shadowx, shadowy
421
The x and y offsets for the text shadow position with respect to the
422
position of the text. They can be either positive or negative
423
values. Default value for both is "0".
424
425
@item shadowcolor
426
The color to be used for drawing a shadow behind the drawn text.  It
427
can be a color name (e.g. "yellow") or a string in the 0xRRGGBB[AA]
428
form (e.g. "0xff00ff"), possibly followed by an alpha specifier.
429
The default value of @var{shadowcolor} is "black".
430
431 bd8e7503 Stefano Sabatini
@item ft_load_flags
432
Flags to be used for loading the fonts.
433
434
The flags map the corresponding flags supported by libfreetype, and are
435
a combination of the following values:
436
@table @var
437
@item default
438
@item no_scale
439
@item no_hinting
440
@item render
441
@item no_bitmap
442
@item vertical_layout
443
@item force_autohint
444
@item crop_bitmap
445
@item pedantic
446
@item ignore_global_advance_width
447
@item no_recurse
448
@item ignore_transform
449
@item monochrome
450
@item linear_design
451
@item no_autohint
452
@item end table
453
@end table
454
455
Default value is "render".
456
457
For more information consult the documentation for the FT_LOAD_*
458
libfreetype flags.
459
460
@item tabsize
461
The size in number of spaces to use for rendering the tab.
462
Default value is 4.
463
@end table
464
465
For example the command:
466
@example
467 5c5816c4 Stefano Sabatini
drawtext="fontfile=FreeSerif.ttf: text='Test Text': x=100: y=50: fontsize=24: fontcolor=yellow@@0.2: boxcolor=red@@0.2: box=1"
468 bd8e7503 Stefano Sabatini
@end example
469
470
will draw 'Test Text' with font FreeSerif of size 24 at position
471
(100,50), text color is yellow, and draw a red box around text. Both
472
the text and the box have an opacity of 20%.
473
474
Note that the double quotes are not necessary if spaces are not used
475
within the parameter list.
476
477
For more information about libfreetype, check:
478 5c5816c4 Stefano Sabatini
@url{http://www.freetype.org/}.
479 bd8e7503 Stefano Sabatini
480 681ba722 Stefano Sabatini
@section fade
481
482
Apply fade-in/out effect to input video.
483
484
It accepts the parameters:
485
@var{type}:@var{start_frame}:@var{nb_frames}
486
487
@var{type} specifies if the effect type, can be either "in" for
488
fade-in, or "out" for a fade-out effect.
489
490
@var{start_frame} specifies the number of the start frame for starting
491
to apply the fade effect.
492
493
@var{nb_frames} specifies the number of frames for which the fade
494
effect has to last. At the end of the fade-in effect the output video
495
will have the same intensity as the input video, at the end of the
496
fade-out transition the output video will be completely black.
497
498
A few usage examples follow, usable too as test scenarios.
499
@example
500
# fade in first 30 frames of video
501
fade=in:0:30
502
503
# fade out last 45 frames of a 200-frame video
504
fade=out:155:45
505
506
# fade in first 25 frames and fade out last 25 frames of a 1000-frame video
507
fade=in:0:25, fade=out:975:25
508
509
# make first 5 frames black, then fade in from frame 5-24
510
fade=in:5:20
511
@end example
512
513 7f1af825 Stefano Sabatini
@section fifo
514
515
Buffer input images and send them when they are requested.
516
517
This filter is mainly useful when auto-inserted by the libavfilter
518
framework.
519
520
The filter does not take parameters.
521
522 3275ac6a Stefano Sabatini
@section format
523
524
Convert the input video to one of the specified pixel formats.
525
Libavfilter will try to pick one that is supported for the input to
526
the next filter.
527
528 b1094275 Stefano Sabatini
The filter accepts a list of pixel format names, separated by ":",
529
for example "yuv420p:monow:rgb24".
530 3275ac6a Stefano Sabatini
531 f150e4dc Stefano Sabatini
Some examples follow:
532 3275ac6a Stefano Sabatini
@example
533 f150e4dc Stefano Sabatini
# convert the input video to the format "yuv420p"
534
format=yuv420p
535 3275ac6a Stefano Sabatini
536 f150e4dc Stefano Sabatini
# convert the input video to any of the formats in the list
537
format=yuv420p:yuv444p:yuv410p
538
@end example
539 3275ac6a Stefano Sabatini
540 f8608dca Stefano Sabatini
@anchor{frei0r}
541 47941088 Stefano Sabatini
@section frei0r
542
543
Apply a frei0r effect to the input video.
544
545
To enable compilation of this filter you need to install the frei0r
546 a6be21d3 Michael Niedermayer
header and configure FFmpeg with --enable-frei0r.
547 47941088 Stefano Sabatini
548
The filter supports the syntax:
549
@example
550 f51aeedd Stefano Sabatini
@var{filter_name}[@{:|=@}@var{param1}:@var{param2}:...:@var{paramN}]
551 47941088 Stefano Sabatini
@end example
552
553
@var{filter_name} is the name to the frei0r effect to load. If the
554
environment variable @env{FREI0R_PATH} is defined, the frei0r effect
555
is searched in each one of the directories specified by the colon
556
separated list in @env{FREIOR_PATH}, otherwise in the standard frei0r
557
paths, which are in this order: @file{HOME/.frei0r-1/lib/},
558
@file{/usr/local/lib/frei0r-1/}, @file{/usr/lib/frei0r-1/}.
559
560
@var{param1}, @var{param2}, ... , @var{paramN} specify the parameters
561
for the frei0r effect.
562
563
A frei0r effect parameter can be a boolean (whose values are specified
564
with "y" and "n"), a double, a color (specified by the syntax
565
@var{R}/@var{G}/@var{B}, @var{R}, @var{G}, and @var{B} being float
566
numbers from 0.0 to 1.0) or by an @code{av_parse_color()} color
567
description), a position (specified by the syntax @var{X}/@var{Y},
568
@var{X} and @var{Y} being float numbers) and a string.
569
570
The number and kind of parameters depend on the loaded effect. If an
571
effect parameter is not specified the default value is set.
572
573
Some examples follow:
574
@example
575
# apply the distort0r effect, set the first two double parameters
576
frei0r=distort0r:0.5:0.01
577
578
# apply the colordistance effect, takes a color as first parameter
579
frei0r=colordistance:0.2/0.3/0.4
580
frei0r=colordistance:violet
581
frei0r=colordistance:0x112233
582
583
# apply the perspective effect, specify the top left and top right
584
# image positions
585
frei0r=perspective:0.2/0.2:0.8/0.2
586
@end example
587
588
For more information see:
589
@url{http://piksel.org/frei0r}
590
591 d5f187fd Nolan L
@section gradfun
592
593
Fix the banding artifacts that are sometimes introduced into nearly flat
594
regions by truncation to 8bit colordepth.
595
Interpolate the gradients that should go where the bands are, and
596
dither them.
597
598 da3534b0 Stefano Sabatini
This filter is designed for playback only.  Do not use it prior to
599
lossy compression, because compression tends to lose the dither and
600
bring back the bands.
601
602 d5f187fd Nolan L
The filter takes two optional parameters, separated by ':':
603
@var{strength}:@var{radius}
604
605
@var{strength} is the maximum amount by which the filter will change
606
any one pixel. Also the threshold for detecting nearly flat
607
regions. Acceptable values range from .51 to 255, default value is
608
1.2, out-of-range values will be clipped to the valid range.
609
610
@var{radius} is the neighborhood to fit the gradient to. A larger
611
radius makes for smoother gradients, but also prevents the filter from
612
modifying the pixels near detailed regions. Acceptable values are
613
8-32, default value is 16, out-of-range values will be clipped to the
614
valid range.
615
616
@example
617
# default parameters
618
gradfun=1.2:16
619
620
# omitting radius
621
gradfun=1.2
622
@end example
623
624 a1e171df Stefano Sabatini
@section hflip
625
626
Flip the input video horizontally.
627
628
For example to horizontally flip the video in input with
629
@file{ffmpeg}:
630
@example
631
ffmpeg -i in.avi -vf "hflip" out.avi
632
@end example
633
634 a4dc7aa5 Baptiste Coudurier
@section hqdn3d
635
636
High precision/quality 3d denoise filter. This filter aims to reduce
637
image noise producing smooth images and making still images really
638
still. It should enhance compressibility.
639
640
It accepts the following optional parameters:
641
@var{luma_spatial}:@var{chroma_spatial}:@var{luma_tmp}:@var{chroma_tmp}
642
643
@table @option
644
@item luma_spatial
645
a non-negative float number which specifies spatial luma strength,
646
defaults to 4.0
647
648
@item chroma_spatial
649
a non-negative float number which specifies spatial chroma strength,
650
defaults to 3.0*@var{luma_spatial}/4.0
651
652
@item luma_tmp
653
a float number which specifies luma temporal strength, defaults to
654
6.0*@var{luma_spatial}/4.0
655
656
@item chroma_tmp
657
a float number which specifies chroma temporal strength, defaults to
658
@var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}
659
@end table
660
661 cd39549e Stefano Sabatini
@section mp
662
663
Apply an MPlayer filter to the input video.
664
665
This filter provides a wrapper around most of the filters of
666
MPlayer/MEncoder.
667
668
This wrapper is considered experimental. Some of the wrapped filters
669
may not work properly and we may drop support for them, as they will
670
be implemented natively into FFmpeg. Thus you should avoid
671
depending on them when writing portable scripts.
672
673
The filters accepts the parameters:
674
@var{filter_name}[:=]@var{filter_params}
675
676
@var{filter_name} is the name of a supported MPlayer filter,
677
@var{filter_params} is a string containing the parameters accepted by
678
the named filter.
679
680
The list of the currently supported filters follows:
681
@table @var
682
@item 2xsai
683
@item blackframe
684
@item boxblur
685
@item cropdetect
686
@item decimate
687
@item delogo
688
@item denoise3d
689
@item detc
690
@item dint
691
@item divtc
692
@item down3dright
693
@item dsize
694
@item eq2
695
@item eq
696
@item field
697
@item fil
698
@item fixpts
699
@item framestep
700
@item fspp
701
@item geq
702
@item gradfun
703
@item harddup
704
@item hqdn3d
705
@item hue
706
@item il
707
@item ilpack
708
@item ivtc
709
@item kerndeint
710
@item mcdeint
711
@item mirror
712
@item noise
713
@item ow
714
@item palette
715
@item perspective
716
@item phase
717
@item pp7
718
@item pullup
719
@item qp
720
@item rectangle
721
@item remove_logo
722
@item rgbtest
723
@item rotate
724
@item sab
725
@item screenshot
726
@item smartblur
727
@item softpulldown
728
@item softskip
729
@item spp
730
@item swapuv
731
@item telecine
732
@item test
733
@item tile
734
@item tinterlace
735
@item unsharp
736
@item uspp
737
@item yuvcsp
738
@item yvu9
739
@end table
740
741
The parameter syntax and behavior for the listed filters are the same
742
of the corresponding MPlayer filters. For detailed instructions check
743
the "VIDEO FILTERS" section in the MPlayer manual.
744
745
Some examples follow:
746
@example
747
# remove a logo by interpolating the surrounding pixels
748
mp=delogo=200:200:80:20:1
749
750
# adjust gamma, brightness, contrast
751
mp=eq2=1.0:2:0.5
752
753
# tweak hue and saturation
754
mp=hue=100:-10
755
@end example
756
757
See also mplayer(1), @url{http://www.mplayerhq.hu/}.
758
759 3275ac6a Stefano Sabatini
@section noformat
760
761
Force libavfilter not to use any of the specified pixel formats for the
762
input to the next filter.
763
764 b1094275 Stefano Sabatini
The filter accepts a list of pixel format names, separated by ":",
765
for example "yuv420p:monow:rgb24".
766 3275ac6a Stefano Sabatini
767 f150e4dc Stefano Sabatini
Some examples follow:
768 3275ac6a Stefano Sabatini
@example
769 f150e4dc Stefano Sabatini
# force libavfilter to use a format different from "yuv420p" for the
770
# input to the vflip filter
771
noformat=yuv420p,vflip
772 3275ac6a Stefano Sabatini
773 f150e4dc Stefano Sabatini
# convert the input video to any of the formats not contained in the list
774
noformat=yuv420p:yuv444p:yuv410p
775
@end example
776 3275ac6a Stefano Sabatini
777
@section null
778
779 99046339 S.N. Hemanth Meenakshisundaram
Pass the video source unchanged to the output.
780 3275ac6a Stefano Sabatini
781 cf69ad35 Stefano Sabatini
@section ocv
782 6ebf0bfc Stefano Sabatini
783 cf69ad35 Stefano Sabatini
Apply video transform using libopencv.
784 6ebf0bfc Stefano Sabatini
785
To enable this filter install libopencv library and headers and
786 a6be21d3 Michael Niedermayer
configure FFmpeg with --enable-libopencv.
787 6ebf0bfc Stefano Sabatini
788 cf69ad35 Stefano Sabatini
The filter takes the parameters: @var{filter_name}@{:=@}@var{filter_params}.
789
790
@var{filter_name} is the name of the libopencv filter to apply.
791
792
@var{filter_params} specifies the parameters to pass to the libopencv
793
filter. If not specified the default values are assumed.
794
795
Refer to the official libopencv documentation for more precise
796
informations:
797
@url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
798
799
Follows the list of supported libopencv filters.
800
801 17fc9493 Stefano Sabatini
@anchor{dilate}
802 91cbb6ba Stefano Sabatini
@subsection dilate
803
804
Dilate an image by using a specific structuring element.
805
This filter corresponds to the libopencv function @code{cvDilate}.
806
807
It accepts the parameters: @var{struct_el}:@var{nb_iterations}.
808
809
@var{struct_el} represents a structuring element, and has the syntax:
810
@var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
811
812
@var{cols} and @var{rows} represent the number of colums and rows of
813
the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
814
point, and @var{shape} the shape for the structuring element, and
815
can be one of the values "rect", "cross", "ellipse", "custom".
816
817
If the value for @var{shape} is "custom", it must be followed by a
818
string of the form "=@var{filename}". The file with name
819
@var{filename} is assumed to represent a binary image, with each
820
printable character corresponding to a bright pixel. When a custom
821
@var{shape} is used, @var{cols} and @var{rows} are ignored, the number
822
or columns and rows of the read file are assumed instead.
823
824
The default value for @var{struct_el} is "3x3+0x0/rect".
825
826
@var{nb_iterations} specifies the number of times the transform is
827
applied to the image, and defaults to 1.
828
829
Follow some example:
830
@example
831
# use the default values
832
ocv=dilate
833
834
# dilate using a structuring element with a 5x5 cross, iterate two times
835
ocv=dilate=5x5+2x2/cross:2
836
837
# read the shape from the file diamond.shape, iterate two times
838
# the file diamond.shape may contain a pattern of characters like this:
839
#   *
840
#  ***
841
# *****
842
#  ***
843
#   *
844
# the specified cols and rows are ignored (but not the anchor point coordinates)
845
ocv=0x0+2x2/custom=diamond.shape:2
846
@end example
847
848 17fc9493 Stefano Sabatini
@subsection erode
849
850
Erode an image by using a specific structuring element.
851
This filter corresponds to the libopencv function @code{cvErode}.
852
853
The filter accepts the parameters: @var{struct_el}:@var{nb_iterations},
854
with the same meaning and use of those of the dilate filter
855
(@pxref{dilate}).
856
857 cf69ad35 Stefano Sabatini
@subsection smooth
858
859
Smooth the input video.
860
861
The filter takes the following parameters:
862 6ebf0bfc Stefano Sabatini
@var{type}:@var{param1}:@var{param2}:@var{param3}:@var{param4}.
863
864
@var{type} is the type of smooth filter to apply, and can be one of
865 58d94364 Stefano Sabatini
the following values: "blur", "blur_no_scale", "median", "gaussian",
866 6ebf0bfc Stefano Sabatini
"bilateral". The default value is "gaussian".
867
868
@var{param1}, @var{param2}, @var{param3}, and @var{param4} are
869
parameters whose meanings depend on smooth type. @var{param1} and
870
@var{param2} accept integer positive values or 0, @var{param3} and
871
@var{param4} accept float values.
872
873
The default value for @var{param1} is 3, the default value for the
874
other parameters is 0.
875
876 58d94364 Stefano Sabatini
These parameters correspond to the parameters assigned to the
877 cf69ad35 Stefano Sabatini
libopencv function @code{cvSmooth}.
878 6ebf0bfc Stefano Sabatini
879 58935b25 Stefano Sabatini
@section overlay
880
881
Overlay one video on top of another.
882
883
It takes two inputs and one output, the first input is the "main"
884
video on which the second input is overlayed.
885
886
It accepts the parameters: @var{x}:@var{y}.
887
888
@var{x} is the x coordinate of the overlayed video on the main video,
889
@var{y} is the y coordinate. The parameters are expressions containing
890
the following parameters:
891
892
@table @option
893
@item main_w, main_h
894
main input width and height
895
896
@item W, H
897
same as @var{main_w} and @var{main_h}
898
899
@item overlay_w, overlay_h
900
overlay input width and height
901
902
@item w, h
903
same as @var{overlay_w} and @var{overlay_h}
904
@end table
905
906
Be aware that frames are taken from each input video in timestamp
907
order, hence, if their initial timestamps differ, it is a a good idea
908
to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
909
have them begin in the same zero timestamp, as it does the example for
910
the @var{movie} filter.
911
912
Follow some examples:
913
@example
914
# draw the overlay at 10 pixels from the bottom right
915
# corner of the main video.
916
overlay=main_w-overlay_w-10:main_h-overlay_h-10
917
918
# insert a transparent PNG logo in the bottom left corner of the input
919 b423996b Stefano Sabatini
movie=logo.png [logo];
920 58935b25 Stefano Sabatini
[in][logo] overlay=10:main_h-overlay_h-10 [out]
921
922
# insert 2 different transparent PNG logos (second logo on bottom
923
# right corner):
924 b423996b Stefano Sabatini
movie=logo1.png [logo1];
925
movie=logo2.png [logo2];
926 58935b25 Stefano Sabatini
[in][logo1]       overlay=10:H-h-10 [in+logo1];
927
[in+logo1][logo2] overlay=W-w-10:H-h-10 [out]
928
929
# add a transparent color layer on top of the main video,
930
# WxH specifies the size of the main input to the overlay filter
931
color=red@.3:WxH [over]; [in][over] overlay [out]
932
@end example
933
934
You can chain togheter more overlays but the efficiency of such
935
approach is yet to be tested.
936
937 3275ac6a Stefano Sabatini
@section pad
938
939
Add paddings to the input image, and places the original input at the
940
given coordinates @var{x}, @var{y}.
941
942
It accepts the following parameters:
943
@var{width}:@var{height}:@var{x}:@var{y}:@var{color}.
944
945
Follows the description of the accepted parameters.
946
947
@table @option
948
@item width, height
949
950
Specify the size of the output image with the paddings added. If the
951
value for @var{width} or @var{height} is 0, the corresponding input size
952
is used for the output.
953
954
The default value of @var{width} and @var{height} is 0.
955
956
@item x, y
957
958
Specify the offsets where to place the input image in the padded area
959
with respect to the top/left border of the output image.
960
961
The default value of @var{x} and @var{y} is 0.
962
963
@item color
964
965
Specify the color of the padded area, it can be the name of a color
966
(case insensitive match) or a 0xRRGGBB[AA] sequence.
967
968 b1094275 Stefano Sabatini
The default value of @var{color} is "black".
969 3275ac6a Stefano Sabatini
970
@end table
971
972 3d17f4b9 Stefano Sabatini
For example:
973
974
@example
975
# Add paddings with color "violet" to the input video. Output video
976
# size is 640x480, the top-left corner of the input video is placed at
977
# row 0, column 40.
978
pad=640:480:0:40:violet
979
@end example
980
981 ce2e4ae3 Stefano Sabatini
@section pixdesctest
982
983
Pixel format descriptor test filter, mainly useful for internal
984
testing. The output video should be equal to the input video.
985
986
For example:
987
@example
988
format=monow, pixdesctest
989
@end example
990
991
can be used to test the monowhite pixel format descriptor definition.
992
993 3275ac6a Stefano Sabatini
@section scale
994
995
Scale the input video to @var{width}:@var{height} and/or convert the image format.
996
997
For example the command:
998
999
@example
1000
./ffmpeg -i in.avi -vf "scale=200:100" out.avi
1001
@end example
1002
1003
will scale the input video to a size of 200x100.
1004
1005
If the input image format is different from the format requested by
1006
the next filter, the scale filter will convert the input to the
1007
requested format.
1008
1009
If the value for @var{width} or @var{height} is 0, the respective input
1010
size is used for the output.
1011
1012
If the value for @var{width} or @var{height} is -1, the scale filter will
1013
use, for the respective output size, a value that maintains the aspect
1014
ratio of the input image.
1015
1016
The default value of @var{width} and @var{height} is 0.
1017
1018 2ccbb342 Stefano Sabatini
@anchor{setdar}
1019
@section setdar
1020
1021
Set the Display Aspect Ratio for the filter output video.
1022
1023
This is done by changing the specified Sample (aka Pixel) Aspect
1024
Ratio, according to the following equation:
1025
@math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
1026
1027
Keep in mind that this filter does not modify the pixel dimensions of
1028
the video frame. Also the display aspect ratio set by this filter may
1029
be changed by later filters in the filterchain, e.g. in case of
1030
scaling or if another "setdar" or a "setsar" filter is applied.
1031
1032
The filter accepts a parameter string which represents the wanted
1033
display aspect ratio.
1034
The parameter can be a floating point number string, or an expression
1035
of the form @var{num}:@var{den}, where @var{num} and @var{den} are the
1036
numerator and denominator of the aspect ratio.
1037
If the parameter is not specified, it is assumed the value "0:1".
1038
1039
For example to change the display aspect ratio to 16:9, specify:
1040
@example
1041
setdar=16:9
1042
# the above is equivalent to
1043
setdar=1.77777
1044
@end example
1045
1046
See also the "setsar" filter documentation (@pxref{setsar}).
1047
1048 a532bb39 Stefano Sabatini
@section setpts
1049
1050
Change the PTS (presentation timestamp) of the input video frames.
1051
1052
Accept in input an expression evaluated through the eval API, which
1053
can contain the following constants:
1054
1055
@table @option
1056
@item PTS
1057
the presentation timestamp in input
1058
1059
@item PI
1060
Greek PI
1061
1062
@item PHI
1063
golden ratio
1064
1065
@item E
1066
Euler number
1067
1068
@item N
1069
the count of the input frame, starting from 0.
1070
1071
@item STARTPTS
1072
the PTS of the first video frame
1073
1074
@item INTERLACED
1075
tell if the current frame is interlaced
1076
1077
@item POS
1078
original position in the file of the frame, or undefined if undefined
1079
for the current frame
1080
1081
@item PREV_INPTS
1082
previous input PTS
1083
1084
@item PREV_OUTPTS
1085
previous output PTS
1086
1087
@end table
1088
1089
Some examples follow:
1090
1091
@example
1092
# start counting PTS from zero
1093
setpts=PTS-STARTPTS
1094
1095
# fast motion
1096
setpts=0.5*PTS
1097
1098
# slow motion
1099
setpts=2.0*PTS
1100
1101
# fixed rate 25 fps
1102
setpts=N/(25*TB)
1103
1104
# fixed rate 25 fps with some jitter
1105
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
1106
@end example
1107
1108 2ccbb342 Stefano Sabatini
@anchor{setsar}
1109
@section setsar
1110
1111
Set the Sample (aka Pixel) Aspect Ratio for the filter output video.
1112
1113
Note that as a consequence of the application of this filter, the
1114
output display aspect ratio will change according to the following
1115
equation:
1116
@math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
1117
1118
Keep in mind that the sample aspect ratio set by this filter may be
1119
changed by later filters in the filterchain, e.g. if another "setsar"
1120
or a "setdar" filter is applied.
1121
1122
The filter accepts a parameter string which represents the wanted
1123
sample aspect ratio.
1124
The parameter can be a floating point number string, or an expression
1125
of the form @var{num}:@var{den}, where @var{num} and @var{den} are the
1126
numerator and denominator of the aspect ratio.
1127
If the parameter is not specified, it is assumed the value "0:1".
1128
1129
For example to change the sample aspect ratio to 10:11, specify:
1130
@example
1131
setsar=10:11
1132
@end example
1133
1134 d89e3b36 Stefano Sabatini
@section settb
1135
1136
Set the timebase to use for the output frames timestamps.
1137
It is mainly useful for testing timebase configuration.
1138
1139
It accepts in input an arithmetic expression representing a rational.
1140
The expression can contain the constants "PI", "E", "PHI", "AVTB" (the
1141
default timebase), and "intb" (the input timebase).
1142
1143
The default value for the input is "intb".
1144
1145
Follow some examples.
1146
1147
@example
1148
# set the timebase to 1/25
1149
settb=1/25
1150
1151
# set the timebase to 1/10
1152
settb=0.1
1153
1154
#set the timebase to 1001/1000
1155
settb=1+0.001
1156
1157
#set the timebase to 2*intb
1158
settb=2*intb
1159
1160
#set the default timebase value
1161
settb=AVTB
1162
@end example
1163
1164 3275ac6a Stefano Sabatini
@section slicify
1165
1166
Pass the images of input video on to next video filter as multiple
1167
slices.
1168
1169
@example
1170
./ffmpeg -i in.avi -vf "slicify=32" out.avi
1171
@end example
1172
1173
The filter accepts the slice height as parameter. If the parameter is
1174
not specified it will use the default value of 16.
1175
1176
Adding this in the beginning of filter chains should make filtering
1177
faster due to better use of the memory cache.
1178
1179 43945b27 Stefano Sabatini
@section transpose
1180
1181
Transpose rows with columns in the input video and optionally flip it.
1182
1183
It accepts a parameter representing an integer, which can assume the
1184
values:
1185
1186
@table @samp
1187
@item 0
1188
Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
1189
@example
1190
L.R     L.l
1191
. . ->  . .
1192
l.r     R.r
1193
@end example
1194
1195
@item 1
1196
Rotate by 90 degrees clockwise, that is:
1197
@example
1198
L.R     l.L
1199
. . ->  . .
1200
l.r     r.R
1201
@end example
1202
1203
@item 2
1204
Rotate by 90 degrees counterclockwise, that is:
1205
@example
1206
L.R     R.r
1207
. . ->  . .
1208
l.r     L.l
1209
@end example
1210
1211
@item 3
1212
Rotate by 90 degrees clockwise and vertically flip, that is:
1213
@example
1214
L.R     r.R
1215
. . ->  . .
1216
l.r     l.L
1217
@end example
1218
@end table
1219
1220 3275ac6a Stefano Sabatini
@section unsharp
1221
1222 843b5fd0 Stefano Sabatini
Sharpen or blur the input video.
1223
1224
It accepts the following parameters:
1225
@var{luma_msize_x}:@var{luma_msize_y}:@var{luma_amount}:@var{chroma_msize_x}:@var{chroma_msize_y}:@var{chroma_amount}
1226 3275ac6a Stefano Sabatini
1227
Negative values for the amount will blur the input video, while positive
1228
values will sharpen. All parameters are optional and default to the
1229
equivalent of the string '5:5:1.0:0:0:0.0'.
1230
1231
@table @option
1232
1233
@item luma_msize_x
1234
Set the luma matrix horizontal size. It can be an integer between 3
1235
and 13, default value is 5.
1236
1237
@item luma_msize_y
1238
Set the luma matrix vertical size. It can be an integer between 3
1239
and 13, default value is 5.
1240
1241
@item luma_amount
1242
Set the luma effect strength. It can be a float number between -2.0
1243
and 5.0, default value is 1.0.
1244
1245
@item chroma_msize_x
1246
Set the chroma matrix horizontal size. It can be an integer between 3
1247
and 13, default value is 0.
1248
1249
@item chroma_msize_y
1250
Set the chroma matrix vertical size. It can be an integer between 3
1251
and 13, default value is 0.
1252
1253
@item luma_amount
1254
Set the chroma effect strength. It can be a float number between -2.0
1255
and 5.0, default value is 0.0.
1256
1257
@end table
1258
1259
@example
1260
# Strong luma sharpen effect parameters
1261
unsharp=7:7:2.5
1262
1263
# Strong blur of both luma and chroma parameters
1264
unsharp=7:7:-2:7:7:-2
1265
1266
# Use the default values with @command{ffmpeg}
1267
./ffmpeg -i in.avi -vf "unsharp" out.mp4
1268
@end example
1269
1270
@section vflip
1271
1272
Flip the input video vertically.
1273
1274
@example
1275
./ffmpeg -i in.avi -vf "vflip" out.avi
1276
@end example
1277
1278 acbac567 Michael Niedermayer
@section yadif
1279
1280 1653027a Stefano Sabatini
Deinterlace the input video ("yadif" means "yet another deinterlacing
1281
filter").
1282 acbac567 Michael Niedermayer
1283 1653027a Stefano Sabatini
It accepts the optional parameters: @var{mode}:@var{parity}.
1284 acbac567 Michael Niedermayer
1285 1653027a Stefano Sabatini
@var{mode} specifies the interlacing mode to adopt, accepts one of the
1286
following values:
1287 acbac567 Michael Niedermayer
1288 1653027a Stefano Sabatini
@table @option
1289
@item 0
1290
output 1 frame for each frame
1291
@item 1
1292
output 1 frame for each field
1293
@item 2
1294
like 0 but skips spatial interlacing check
1295
@item 3
1296
like 1 but skips spatial interlacing check
1297
@end table
1298 acbac567 Michael Niedermayer
1299
Default value is 0.
1300
1301 1653027a Stefano Sabatini
@var{parity} specifies the picture field parity assumed for the input
1302
interlaced video, accepts one of the following values:
1303 acbac567 Michael Niedermayer
1304 1653027a Stefano Sabatini
@table @option
1305
@item 0
1306
assume bottom field first
1307
@item 1
1308
assume top field first
1309
@item -1
1310
enable automatic detection
1311 acbac567 Michael Niedermayer
@end table
1312
1313 1653027a Stefano Sabatini
Default value is -1.
1314 a51c71bb Baptiste Coudurier
If interlacing is unknown or decoder does not export this information,
1315
top field first will be assumed.
1316 1653027a Stefano Sabatini
1317 3275ac6a Stefano Sabatini
@c man end VIDEO FILTERS
1318
1319
@chapter Video Sources
1320
@c man begin VIDEO SOURCES
1321
1322
Below is a description of the currently available video sources.
1323
1324 24413399 Stefano Sabatini
@section buffer
1325
1326
Buffer video frames, and make them available to the filter chain.
1327
1328
This source is mainly intended for a programmatic use, in particular
1329 ac1a31ab VĂ­ctor Paesa
through the interface defined in @file{libavfilter/vsrc_buffer.h}.
1330 24413399 Stefano Sabatini
1331
It accepts the following parameters:
1332 7b3ea550 Michael Niedermayer
@var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}:@var{sample_aspect_ratio_num}:@var{sample_aspect_ratio.den}
1333 24413399 Stefano Sabatini
1334
All the parameters need to be explicitely defined.
1335
1336
Follows the list of the accepted parameters.
1337
1338
@table @option
1339
1340
@item width, height
1341
Specify the width and height of the buffered video frames.
1342
1343
@item pix_fmt_string
1344
A string representing the pixel format of the buffered video frames.
1345
It may be a number corresponding to a pixel format, or a pixel format
1346
name.
1347
1348 94498ec9 Stefano Sabatini
@item timebase_num, timebase_den
1349
Specify numerator and denomitor of the timebase assumed by the
1350
timestamps of the buffered frames.
1351 7b3ea550 Michael Niedermayer
1352
@item sample_aspect_ratio.num, sample_aspect_ratio.den
1353
Specify numerator and denominator of the sample aspect ratio assumed
1354
by the video frames.
1355 24413399 Stefano Sabatini
@end table
1356
1357
For example:
1358
@example
1359 7b3ea550 Michael Niedermayer
buffer=320:240:yuv410p:1:24:1:1
1360 24413399 Stefano Sabatini
@end example
1361
1362
will instruct the source to accept video frames with size 320x240 and
1363 7b3ea550 Michael Niedermayer
with format "yuv410p", assuming 1/24 as the timestamps timebase and
1364
square pixels (1:1 sample aspect ratio).
1365 94498ec9 Stefano Sabatini
Since the pixel format with name "yuv410p" corresponds to the number 6
1366
(check the enum PixelFormat definition in @file{libavutil/pixfmt.h}),
1367
this example corresponds to:
1368 24413399 Stefano Sabatini
@example
1369 94498ec9 Stefano Sabatini
buffer=320:240:6:1:24
1370 24413399 Stefano Sabatini
@end example
1371
1372 23ccf3c7 Stefano Sabatini
@section color
1373
1374
Provide an uniformly colored input.
1375
1376
It accepts the following parameters:
1377 b5f47309 Stefano Sabatini
@var{color}:@var{frame_size}:@var{frame_rate}
1378 23ccf3c7 Stefano Sabatini
1379
Follows the description of the accepted parameters.
1380
1381
@table @option
1382
1383
@item color
1384
Specify the color of the source. It can be the name of a color (case
1385
insensitive match) or a 0xRRGGBB[AA] sequence, possibly followed by an
1386
alpha specifier. The default value is "black".
1387
1388
@item frame_size
1389
Specify the size of the sourced video, it may be a string of the form
1390
@var{width}x@var{heigth}, or the name of a size abbreviation. The
1391
default value is "320x240".
1392
1393
@item frame_rate
1394
Specify the frame rate of the sourced video, as the number of frames
1395
generated per second. It has to be a string in the format
1396
@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
1397
number or a valid video frame rate abbreviation. The default value is
1398
"25".
1399
1400
@end table
1401
1402
For example the following graph description will generate a red source
1403
with an opacity of 0.2, with size "qcif" and a frame rate of 10
1404
frames per second, which will be overlayed over the source connected
1405
to the pad with identifier "in".
1406
1407
@example
1408
"color=red@@0.2:qcif:10 [color]; [in][color] overlay [out]"
1409
@end example
1410
1411 9b8bb626 Stefano Sabatini
@section movie
1412
1413
Read a video stream from a movie container.
1414
1415
It accepts the syntax: @var{movie_name}[:@var{options}] where
1416
@var{movie_name} is the name of the resource to read (not necessarily
1417
a file but also a device or a stream accessed through some protocol),
1418
and @var{options} is an optional sequence of @var{key}=@var{value}
1419
pairs, separated by ":".
1420
1421
The description of the accepted options follows.
1422
1423
@table @option
1424
1425
@item format_name, f
1426
Specifies the format assumed for the movie to read, and can be either
1427
the name of a container or an input device. If not specified the
1428
format is guessed from @var{movie_name} or by probing.
1429
1430
@item seek_point, sp
1431
Specifies the seek point in seconds, the frames will be output
1432
starting from this seek point, the parameter is evaluated with
1433
@code{av_strtod} so the numerical value may be suffixed by an IS
1434
postfix. Default value is "0".
1435
1436
@item stream_index, si
1437
Specifies the index of the video stream to read. If the value is -1,
1438
the best suited video stream will be automatically selected. Default
1439
value is "-1".
1440
1441
@end table
1442
1443
This filter allows to overlay a second video on top of main input of
1444
a filtergraph as shown in this graph:
1445
@example
1446
input -----------> deltapts0 --> overlay --> output
1447
                                    ^
1448
                                    |
1449
movie --> scale--> deltapts1 -------+
1450
@end example
1451
1452
Some examples follow:
1453
@example
1454
# skip 3.2 seconds from the start of the avi file in.avi, and overlay it
1455
# on top of the input labelled as "in".
1456
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [movie];
1457
[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
1458
1459
# read from a video4linux2 device, and overlay it on top of the input
1460
# labelled as "in"
1461
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [movie];
1462
[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
1463
1464
@end example
1465
1466 3275ac6a Stefano Sabatini
@section nullsrc
1467
1468
Null video source, never return images. It is mainly useful as a
1469
template and to be employed in analysis / debugging tools.
1470
1471
It accepts as optional parameter a string of the form
1472 16134b7c Stefano Sabatini
@var{width}:@var{height}:@var{timebase}.
1473 3275ac6a Stefano Sabatini
1474 16134b7c Stefano Sabatini
@var{width} and @var{height} specify the size of the configured
1475
source. The default values of @var{width} and @var{height} are
1476
respectively 352 and 288 (corresponding to the CIF size format).
1477
1478
@var{timebase} specifies an arithmetic expression representing a
1479
timebase. The expression can contain the constants "PI", "E", "PHI",
1480
"AVTB" (the default timebase), and defaults to the value "AVTB".
1481 3275ac6a Stefano Sabatini
1482 f8608dca Stefano Sabatini
@section frei0r_src
1483
1484
Provide a frei0r source.
1485
1486
To enable compilation of this filter you need to install the frei0r
1487 a6be21d3 Michael Niedermayer
header and configure FFmpeg with --enable-frei0r.
1488 f8608dca Stefano Sabatini
1489
The source supports the syntax:
1490
@example
1491
@var{size}:@var{rate}:@var{src_name}[@{=|:@}@var{param1}:@var{param2}:...:@var{paramN}]
1492
@end example
1493
1494
@var{size} is the size of the video to generate, may be a string of the
1495
form @var{width}x@var{height} or a frame size abbreviation.
1496
@var{rate} is the rate of the video to generate, may be a string of
1497
the form @var{num}/@var{den} or a frame rate abbreviation.
1498
@var{src_name} is the name to the frei0r source to load. For more
1499
information regarding frei0r and how to set the parameters read the
1500
section "frei0r" (@pxref{frei0r}) in the description of the video
1501
filters.
1502
1503
Some examples follow:
1504
@example
1505
# generate a frei0r partik0l source with size 200x200 and framerate 10
1506
# which is overlayed on the overlay filter main input
1507
frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
1508
@end example
1509
1510 3275ac6a Stefano Sabatini
@c man end VIDEO SOURCES
1511
1512
@chapter Video Sinks
1513
@c man begin VIDEO SINKS
1514
1515
Below is a description of the currently available video sinks.
1516
1517
@section nullsink
1518
1519
Null video sink, do absolutely nothing with the input video. It is
1520
mainly useful as a template and to be employed in analysis / debugging
1521
tools.
1522
1523
@c man end VIDEO SINKS