mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
b423996b57
Overlay documentation is still using the old unsupported syntax.
Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit aa8ac53b51)
1210 lines
34 KiB
Plaintext
1210 lines
34 KiB
Plaintext
@chapter Filtergraph description
|
|
@c man begin FILTERGRAPH DESCRIPTION
|
|
|
|
A filtergraph is a directed graph of connected filters. It can contain
|
|
cycles, and there can be multiple links between a pair of
|
|
filters. Each link has one input pad on one side connecting it to one
|
|
filter from which it takes its input, and one output pad on the other
|
|
side connecting it to the one filter accepting its output.
|
|
|
|
Each filter in a filtergraph is an instance of a filter class
|
|
registered in the application, which defines the features and the
|
|
number of input and output pads of the filter.
|
|
|
|
A filter with no input pads is called a "source", a filter with no
|
|
output pads is called a "sink".
|
|
|
|
@section Filtergraph syntax
|
|
|
|
A filtergraph can be represented using a textual representation, which
|
|
is recognized by the @code{-vf} and @code{-af} options of the ff*
|
|
tools, and by the @code{av_parse_graph()} function defined in
|
|
@file{libavfilter/avfiltergraph}.
|
|
|
|
A filterchain consists of a sequence of connected filters, each one
|
|
connected to the previous one in the sequence. A filterchain is
|
|
represented by a list of ","-separated filter descriptions.
|
|
|
|
A filtergraph consists of a sequence of filterchains. A sequence of
|
|
filterchains is represented by a list of ";"-separated filterchain
|
|
descriptions.
|
|
|
|
A filter is represented by a string of the form:
|
|
[@var{in_link_1}]...[@var{in_link_N}]@var{filter_name}=@var{arguments}[@var{out_link_1}]...[@var{out_link_M}]
|
|
|
|
@var{filter_name} is the name of the filter class of which the
|
|
described filter is an instance of, and has to be the name of one of
|
|
the filter classes registered in the program.
|
|
The name of the filter class is optionally followed by a string
|
|
"=@var{arguments}".
|
|
|
|
@var{arguments} is a string which contains the parameters used to
|
|
initialize the filter instance, and are described in the filter
|
|
descriptions below.
|
|
|
|
The list of arguments can be quoted using the character "'" as initial
|
|
and ending mark, and the character '\' for escaping the characters
|
|
within the quoted text; otherwise the argument string is considered
|
|
terminated when the next special character (belonging to the set
|
|
"[]=;,") is encountered.
|
|
|
|
The name and arguments of the filter are optionally preceded and
|
|
followed by a list of link labels.
|
|
A link label allows to name a link and associate it to a filter output
|
|
or input pad. The preceding labels @var{in_link_1}
|
|
... @var{in_link_N}, are associated to the filter input pads,
|
|
the following labels @var{out_link_1} ... @var{out_link_M}, are
|
|
associated to the output pads.
|
|
|
|
When two link labels with the same name are found in the
|
|
filtergraph, a link between the corresponding input and output pad is
|
|
created.
|
|
|
|
If an output pad is not labelled, it is linked by default to the first
|
|
unlabelled input pad of the next filter in the filterchain.
|
|
For example in the filterchain:
|
|
@example
|
|
nullsrc, split[L1], [L2]overlay, nullsink
|
|
@end example
|
|
the split filter instance has two output pads, and the overlay filter
|
|
instance two input pads. The first output pad of split is labelled
|
|
"L1", the first input pad of overlay is labelled "L2", and the second
|
|
output pad of split is linked to the second input pad of overlay,
|
|
which are both unlabelled.
|
|
|
|
In a complete filterchain all the unlabelled filter input and output
|
|
pads must be connected. A filtergraph is considered valid if all the
|
|
filter input and output pads of all the filterchains are connected.
|
|
|
|
Follows a BNF description for the filtergraph syntax:
|
|
@example
|
|
@var{NAME} ::= sequence of alphanumeric characters and '_'
|
|
@var{LINKLABEL} ::= "[" @var{NAME} "]"
|
|
@var{LINKLABELS} ::= @var{LINKLABEL} [@var{LINKLABELS}]
|
|
@var{FILTER_ARGUMENTS} ::= sequence of chars (eventually quoted)
|
|
@var{FILTER} ::= [@var{LINKNAMES}] @var{NAME} ["=" @var{ARGUMENTS}] [@var{LINKNAMES}]
|
|
@var{FILTERCHAIN} ::= @var{FILTER} [,@var{FILTERCHAIN}]
|
|
@var{FILTERGRAPH} ::= @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
|
|
@end example
|
|
|
|
@c man end FILTERGRAPH DESCRIPTION
|
|
|
|
@chapter Audio Filters
|
|
@c man begin AUDIO FILTERS
|
|
|
|
When you configure your FFmpeg build, you can disable any of the
|
|
existing filters using --disable-filters.
|
|
The configure output will show the audio filters included in your
|
|
build.
|
|
|
|
Below is a description of the currently available audio filters.
|
|
|
|
@section anull
|
|
|
|
Pass the audio source unchanged to the output.
|
|
|
|
@c man end AUDIO FILTERS
|
|
|
|
@chapter Audio Sources
|
|
@c man begin AUDIO SOURCES
|
|
|
|
Below is a description of the currently available audio sources.
|
|
|
|
@section anullsrc
|
|
|
|
Null audio source, never return audio frames. It is mainly useful as a
|
|
template and to be employed in analysis / debugging tools.
|
|
|
|
It accepts as optional parameter a string of the form
|
|
@var{sample_rate}:@var{channel_layout}.
|
|
|
|
@var{sample_rate} specify the sample rate, and defaults to 44100.
|
|
|
|
@var{channel_layout} specify the channel layout, and can be either an
|
|
integer or a string representing a channel layout. The default value
|
|
of @var{channel_layout} is 3, which corresponds to CH_LAYOUT_STEREO.
|
|
|
|
Check the channel_layout_map definition in
|
|
@file{libavcodec/audioconvert.c} for the mapping between strings and
|
|
channel layout values.
|
|
|
|
Follow some examples:
|
|
@example
|
|
# set the sample rate to 48000 Hz and the channel layout to CH_LAYOUT_MONO.
|
|
anullsrc=48000:4
|
|
|
|
# same as
|
|
anullsrc=48000:mono
|
|
@end example
|
|
|
|
@c man end AUDIO SOURCES
|
|
|
|
@chapter Audio Sinks
|
|
@c man begin AUDIO SINKS
|
|
|
|
Below is a description of the currently available audio sinks.
|
|
|
|
@section anullsink
|
|
|
|
Null audio sink, do absolutely nothing with the input audio. It is
|
|
mainly useful as a template and to be employed in analysis / debugging
|
|
tools.
|
|
|
|
@c man end AUDIO SINKS
|
|
|
|
@chapter Video Filters
|
|
@c man begin VIDEO FILTERS
|
|
|
|
When you configure your FFmpeg build, you can disable any of the
|
|
existing filters using --disable-filters.
|
|
The configure output will show the video filters included in your
|
|
build.
|
|
|
|
Below is a description of the currently available video filters.
|
|
|
|
@section blackframe
|
|
|
|
Detect frames that are (almost) completely black. Can be useful to
|
|
detect chapter transitions or commercials. Output lines consist of
|
|
the frame number of the detected frame, the percentage of blackness,
|
|
the position in the file if known or -1 and the timestamp in seconds.
|
|
|
|
In order to display the output lines, you need to set the loglevel at
|
|
least to the AV_LOG_INFO value.
|
|
|
|
The filter accepts the syntax:
|
|
@example
|
|
blackframe[=@var{amount}:[@var{threshold}]]
|
|
@end example
|
|
|
|
@var{amount} is the percentage of the pixels that have to be below the
|
|
threshold, and defaults to 98.
|
|
|
|
@var{threshold} is the threshold below which a pixel value is
|
|
considered black, and defaults to 32.
|
|
|
|
@section copy
|
|
|
|
Copy the input source unchanged to the output. Mainly useful for
|
|
testing purposes.
|
|
|
|
@section crop
|
|
|
|
Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}.
|
|
|
|
The parameters are expressions containing the following constants:
|
|
|
|
@table @option
|
|
@item E, PI, PHI
|
|
the corresponding mathematical approximated values for e
|
|
(euler number), pi (greek PI), PHI (golden ratio)
|
|
|
|
@item x, y
|
|
the computed values for @var{x} and @var{y}. They are evaluated for
|
|
each new frame.
|
|
|
|
@item in_w, in_h
|
|
the input width and heigth
|
|
|
|
@item iw, ih
|
|
same as @var{in_w} and @var{in_h}
|
|
|
|
@item out_w, out_h
|
|
the output (cropped) width and heigth
|
|
|
|
@item ow, oh
|
|
same as @var{out_w} and @var{out_h}
|
|
|
|
@item n
|
|
the number of input frame, starting from 0
|
|
|
|
@item pos
|
|
the position in the file of the input frame, NAN if unknown
|
|
|
|
@item t
|
|
timestamp expressed in seconds, NAN if the input timestamp is unknown
|
|
|
|
@end table
|
|
|
|
The @var{out_w} and @var{out_h} parameters specify the expressions for
|
|
the width and height of the output (cropped) video. They are
|
|
evaluated just at the configuration of the filter.
|
|
|
|
The default value of @var{out_w} is "in_w", and the default value of
|
|
@var{out_h} is "in_h".
|
|
|
|
The expression for @var{out_w} may depend on the value of @var{out_h},
|
|
and the expression for @var{out_h} may depend on @var{out_w}, but they
|
|
cannot depend on @var{x} and @var{y}, as @var{x} and @var{y} are
|
|
evaluated after @var{out_w} and @var{out_h}.
|
|
|
|
The @var{x} and @var{y} parameters specify the expressions for the
|
|
position of the top-left corner of the output (non-cropped) area. They
|
|
are evaluated for each frame. If the evaluated value is not valid, it
|
|
is approximated to the nearest valid value.
|
|
|
|
The default value of @var{x} is "(in_w-out_w)/2", and the default
|
|
value for @var{y} is "(in_h-out_h)/2", which set the cropped area at
|
|
the center of the input image.
|
|
|
|
The expression for @var{x} may depend on @var{y}, and the expression
|
|
for @var{y} may depend on @var{x}.
|
|
|
|
Follow some examples:
|
|
@example
|
|
# crop the central input area with size 100x100
|
|
crop=100:100
|
|
|
|
# crop the central input area with size 2/3 of the input video
|
|
"crop=2/3*in_w:2/3*in_h"
|
|
|
|
# crop the input video central square
|
|
crop=in_h
|
|
|
|
# delimit the rectangle with the top-left corner placed at position
|
|
# 100:100 and the right-bottom corner corresponding to the right-bottom
|
|
# corner of the input image.
|
|
crop=in_w-100:in_h-100:100:100
|
|
|
|
# crop 10 pixels from the left and right borders, and 20 pixels from
|
|
# the top and bottom borders
|
|
"crop=in_w-2*10:in_h-2*20"
|
|
|
|
# keep only the bottom right quarter of the input image
|
|
"crop=in_w/2:in_h/2:in_w/2:in_h/2"
|
|
|
|
# crop height for getting Greek harmony
|
|
"crop=in_w:1/PHI*in_w"
|
|
|
|
# trembling effect
|
|
"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)"
|
|
|
|
# erratic camera effect depending on timestamp
|
|
"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)"
|
|
|
|
# set x depending on the value of y
|
|
"crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
|
|
@end example
|
|
|
|
@section cropdetect
|
|
|
|
Auto-detect crop size.
|
|
|
|
Calculate necessary cropping parameters and prints the recommended
|
|
parameters through the logging system. The detected dimensions
|
|
correspond to the non-black area of the input video.
|
|
|
|
It accepts the syntax:
|
|
@example
|
|
cropdetect[=@var{limit}[:@var{round}[:@var{reset}]]]
|
|
@end example
|
|
|
|
@table @option
|
|
|
|
@item limit
|
|
Threshold, which can be optionally specified from nothing (0) to
|
|
everything (255), defaults to 24.
|
|
|
|
@item round
|
|
Value which the width/height should be divisible by, defaults to
|
|
16. The offset is automatically adjusted to center the video. Use 2 to
|
|
get only even dimensions (needed for 4:2:2 video). 16 is best when
|
|
encoding to most video codecs.
|
|
|
|
@item reset
|
|
Counter that determines after how many frames cropdetect will reset
|
|
the previously detected largest video area and start over to detect
|
|
the current optimal crop area. Defaults to 0.
|
|
|
|
This can be useful when channel logos distort the video area. 0
|
|
indicates never reset and return the largest area encountered during
|
|
playback.
|
|
@end table
|
|
|
|
@section drawbox
|
|
|
|
Draw a colored box on the input image.
|
|
|
|
It accepts the syntax:
|
|
@example
|
|
drawbox=@var{x}:@var{y}:@var{width}:@var{height}:@var{color}
|
|
@end example
|
|
|
|
@table @option
|
|
|
|
@item x, y
|
|
Specify the top left corner coordinates of the box. Default to 0.
|
|
|
|
@item width, height
|
|
Specify the width and height of the box, if 0 they are interpreted as
|
|
the input width and height. Default to 0.
|
|
|
|
@item color
|
|
Specify the color of the box to write, it can be the name of a color
|
|
(case insensitive match) or a 0xRRGGBB[AA] sequence.
|
|
@end table
|
|
|
|
Follow some examples:
|
|
@example
|
|
# draw a black box around the edge of the input image
|
|
drawbox
|
|
|
|
# draw a box with color red and an opacity of 50%
|
|
drawbox=10:20:200:60:red@@0.5"
|
|
@end example
|
|
|
|
@section fifo
|
|
|
|
Buffer input images and send them when they are requested.
|
|
|
|
This filter is mainly useful when auto-inserted by the libavfilter
|
|
framework.
|
|
|
|
The filter does not take parameters.
|
|
|
|
@section format
|
|
|
|
Convert the input video to one of the specified pixel formats.
|
|
Libavfilter will try to pick one that is supported for the input to
|
|
the next filter.
|
|
|
|
The filter accepts a list of pixel format names, separated by ":",
|
|
for example "yuv420p:monow:rgb24".
|
|
|
|
Some examples follow:
|
|
@example
|
|
# convert the input video to the format "yuv420p"
|
|
format=yuv420p
|
|
|
|
# convert the input video to any of the formats in the list
|
|
format=yuv420p:yuv444p:yuv410p
|
|
@end example
|
|
|
|
@anchor{frei0r}
|
|
@section frei0r
|
|
|
|
Apply a frei0r effect to the input video.
|
|
|
|
To enable compilation of this filter you need to install the frei0r
|
|
header and configure FFmpeg with --enable-frei0r.
|
|
|
|
The filter supports the syntax:
|
|
@example
|
|
@var{filter_name}[@{:|=@}@var{param1}:@var{param2}:...:@var{paramN}]
|
|
@end example
|
|
|
|
@var{filter_name} is the name to the frei0r effect to load. If the
|
|
environment variable @env{FREI0R_PATH} is defined, the frei0r effect
|
|
is searched in each one of the directories specified by the colon
|
|
separated list in @env{FREIOR_PATH}, otherwise in the standard frei0r
|
|
paths, which are in this order: @file{HOME/.frei0r-1/lib/},
|
|
@file{/usr/local/lib/frei0r-1/}, @file{/usr/lib/frei0r-1/}.
|
|
|
|
@var{param1}, @var{param2}, ... , @var{paramN} specify the parameters
|
|
for the frei0r effect.
|
|
|
|
A frei0r effect parameter can be a boolean (whose values are specified
|
|
with "y" and "n"), a double, a color (specified by the syntax
|
|
@var{R}/@var{G}/@var{B}, @var{R}, @var{G}, and @var{B} being float
|
|
numbers from 0.0 to 1.0) or by an @code{av_parse_color()} color
|
|
description), a position (specified by the syntax @var{X}/@var{Y},
|
|
@var{X} and @var{Y} being float numbers) and a string.
|
|
|
|
The number and kind of parameters depend on the loaded effect. If an
|
|
effect parameter is not specified the default value is set.
|
|
|
|
Some examples follow:
|
|
@example
|
|
# apply the distort0r effect, set the first two double parameters
|
|
frei0r=distort0r:0.5:0.01
|
|
|
|
# apply the colordistance effect, takes a color as first parameter
|
|
frei0r=colordistance:0.2/0.3/0.4
|
|
frei0r=colordistance:violet
|
|
frei0r=colordistance:0x112233
|
|
|
|
# apply the perspective effect, specify the top left and top right
|
|
# image positions
|
|
frei0r=perspective:0.2/0.2:0.8/0.2
|
|
@end example
|
|
|
|
For more information see:
|
|
@url{http://piksel.org/frei0r}
|
|
|
|
@section gradfun
|
|
|
|
Fix the banding artifacts that are sometimes introduced into nearly flat
|
|
regions by truncation to 8bit colordepth.
|
|
Interpolate the gradients that should go where the bands are, and
|
|
dither them.
|
|
|
|
The filter takes two optional parameters, separated by ':':
|
|
@var{strength}:@var{radius}
|
|
|
|
@var{strength} is the maximum amount by which the filter will change
|
|
any one pixel. Also the threshold for detecting nearly flat
|
|
regions. Acceptable values range from .51 to 255, default value is
|
|
1.2, out-of-range values will be clipped to the valid range.
|
|
|
|
@var{radius} is the neighborhood to fit the gradient to. A larger
|
|
radius makes for smoother gradients, but also prevents the filter from
|
|
modifying the pixels near detailed regions. Acceptable values are
|
|
8-32, default value is 16, out-of-range values will be clipped to the
|
|
valid range.
|
|
|
|
@example
|
|
# default parameters
|
|
gradfun=1.2:16
|
|
|
|
# omitting radius
|
|
gradfun=1.2
|
|
@end example
|
|
|
|
@section hflip
|
|
|
|
Flip the input video horizontally.
|
|
|
|
For example to horizontally flip the video in input with
|
|
@file{ffmpeg}:
|
|
@example
|
|
ffmpeg -i in.avi -vf "hflip" out.avi
|
|
@end example
|
|
|
|
@section hqdn3d
|
|
|
|
High precision/quality 3d denoise filter. This filter aims to reduce
|
|
image noise producing smooth images and making still images really
|
|
still. It should enhance compressibility.
|
|
|
|
It accepts the following optional parameters:
|
|
@var{luma_spatial}:@var{chroma_spatial}:@var{luma_tmp}:@var{chroma_tmp}
|
|
|
|
@table @option
|
|
@item luma_spatial
|
|
a non-negative float number which specifies spatial luma strength,
|
|
defaults to 4.0
|
|
|
|
@item chroma_spatial
|
|
a non-negative float number which specifies spatial chroma strength,
|
|
defaults to 3.0*@var{luma_spatial}/4.0
|
|
|
|
@item luma_tmp
|
|
a float number which specifies luma temporal strength, defaults to
|
|
6.0*@var{luma_spatial}/4.0
|
|
|
|
@item chroma_tmp
|
|
a float number which specifies chroma temporal strength, defaults to
|
|
@var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}
|
|
@end table
|
|
|
|
@section noformat
|
|
|
|
Force libavfilter not to use any of the specified pixel formats for the
|
|
input to the next filter.
|
|
|
|
The filter accepts a list of pixel format names, separated by ":",
|
|
for example "yuv420p:monow:rgb24".
|
|
|
|
Some examples follow:
|
|
@example
|
|
# force libavfilter to use a format different from "yuv420p" for the
|
|
# input to the vflip filter
|
|
noformat=yuv420p,vflip
|
|
|
|
# convert the input video to any of the formats not contained in the list
|
|
noformat=yuv420p:yuv444p:yuv410p
|
|
@end example
|
|
|
|
@section null
|
|
|
|
Pass the video source unchanged to the output.
|
|
|
|
@section ocv
|
|
|
|
Apply video transform using libopencv.
|
|
|
|
To enable this filter install libopencv library and headers and
|
|
configure FFmpeg with --enable-libopencv.
|
|
|
|
The filter takes the parameters: @var{filter_name}@{:=@}@var{filter_params}.
|
|
|
|
@var{filter_name} is the name of the libopencv filter to apply.
|
|
|
|
@var{filter_params} specifies the parameters to pass to the libopencv
|
|
filter. If not specified the default values are assumed.
|
|
|
|
Refer to the official libopencv documentation for more precise
|
|
informations:
|
|
@url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
|
|
|
|
Follows the list of supported libopencv filters.
|
|
|
|
@anchor{dilate}
|
|
@subsection dilate
|
|
|
|
Dilate an image by using a specific structuring element.
|
|
This filter corresponds to the libopencv function @code{cvDilate}.
|
|
|
|
It accepts the parameters: @var{struct_el}:@var{nb_iterations}.
|
|
|
|
@var{struct_el} represents a structuring element, and has the syntax:
|
|
@var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
|
|
|
|
@var{cols} and @var{rows} represent the number of colums and rows of
|
|
the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
|
|
point, and @var{shape} the shape for the structuring element, and
|
|
can be one of the values "rect", "cross", "ellipse", "custom".
|
|
|
|
If the value for @var{shape} is "custom", it must be followed by a
|
|
string of the form "=@var{filename}". The file with name
|
|
@var{filename} is assumed to represent a binary image, with each
|
|
printable character corresponding to a bright pixel. When a custom
|
|
@var{shape} is used, @var{cols} and @var{rows} are ignored, the number
|
|
or columns and rows of the read file are assumed instead.
|
|
|
|
The default value for @var{struct_el} is "3x3+0x0/rect".
|
|
|
|
@var{nb_iterations} specifies the number of times the transform is
|
|
applied to the image, and defaults to 1.
|
|
|
|
Follow some example:
|
|
@example
|
|
# use the default values
|
|
ocv=dilate
|
|
|
|
# dilate using a structuring element with a 5x5 cross, iterate two times
|
|
ocv=dilate=5x5+2x2/cross:2
|
|
|
|
# read the shape from the file diamond.shape, iterate two times
|
|
# the file diamond.shape may contain a pattern of characters like this:
|
|
# *
|
|
# ***
|
|
# *****
|
|
# ***
|
|
# *
|
|
# the specified cols and rows are ignored (but not the anchor point coordinates)
|
|
ocv=0x0+2x2/custom=diamond.shape:2
|
|
@end example
|
|
|
|
@subsection erode
|
|
|
|
Erode an image by using a specific structuring element.
|
|
This filter corresponds to the libopencv function @code{cvErode}.
|
|
|
|
The filter accepts the parameters: @var{struct_el}:@var{nb_iterations},
|
|
with the same meaning and use of those of the dilate filter
|
|
(@pxref{dilate}).
|
|
|
|
@subsection smooth
|
|
|
|
Smooth the input video.
|
|
|
|
The filter takes the following parameters:
|
|
@var{type}:@var{param1}:@var{param2}:@var{param3}:@var{param4}.
|
|
|
|
@var{type} is the type of smooth filter to apply, and can be one of
|
|
the following values: "blur", "blur_no_scale", "median", "gaussian",
|
|
"bilateral". The default value is "gaussian".
|
|
|
|
@var{param1}, @var{param2}, @var{param3}, and @var{param4} are
|
|
parameters whose meanings depend on smooth type. @var{param1} and
|
|
@var{param2} accept integer positive values or 0, @var{param3} and
|
|
@var{param4} accept float values.
|
|
|
|
The default value for @var{param1} is 3, the default value for the
|
|
other parameters is 0.
|
|
|
|
These parameters correspond to the parameters assigned to the
|
|
libopencv function @code{cvSmooth}.
|
|
|
|
@section overlay
|
|
|
|
Overlay one video on top of another.
|
|
|
|
It takes two inputs and one output, the first input is the "main"
|
|
video on which the second input is overlayed.
|
|
|
|
It accepts the parameters: @var{x}:@var{y}.
|
|
|
|
@var{x} is the x coordinate of the overlayed video on the main video,
|
|
@var{y} is the y coordinate. The parameters are expressions containing
|
|
the following parameters:
|
|
|
|
@table @option
|
|
@item main_w, main_h
|
|
main input width and height
|
|
|
|
@item W, H
|
|
same as @var{main_w} and @var{main_h}
|
|
|
|
@item overlay_w, overlay_h
|
|
overlay input width and height
|
|
|
|
@item w, h
|
|
same as @var{overlay_w} and @var{overlay_h}
|
|
@end table
|
|
|
|
Be aware that frames are taken from each input video in timestamp
|
|
order, hence, if their initial timestamps differ, it is a a good idea
|
|
to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
|
|
have them begin in the same zero timestamp, as it does the example for
|
|
the @var{movie} filter.
|
|
|
|
Follow some examples:
|
|
@example
|
|
# draw the overlay at 10 pixels from the bottom right
|
|
# corner of the main video.
|
|
overlay=main_w-overlay_w-10:main_h-overlay_h-10
|
|
|
|
# insert a transparent PNG logo in the bottom left corner of the input
|
|
movie=logo.png [logo];
|
|
[in][logo] overlay=10:main_h-overlay_h-10 [out]
|
|
|
|
# insert 2 different transparent PNG logos (second logo on bottom
|
|
# right corner):
|
|
movie=logo1.png [logo1];
|
|
movie=logo2.png [logo2];
|
|
[in][logo1] overlay=10:H-h-10 [in+logo1];
|
|
[in+logo1][logo2] overlay=W-w-10:H-h-10 [out]
|
|
|
|
# add a transparent color layer on top of the main video,
|
|
# WxH specifies the size of the main input to the overlay filter
|
|
color=red@.3:WxH [over]; [in][over] overlay [out]
|
|
@end example
|
|
|
|
You can chain togheter more overlays but the efficiency of such
|
|
approach is yet to be tested.
|
|
|
|
@section pad
|
|
|
|
Add paddings to the input image, and places the original input at the
|
|
given coordinates @var{x}, @var{y}.
|
|
|
|
It accepts the following parameters:
|
|
@var{width}:@var{height}:@var{x}:@var{y}:@var{color}.
|
|
|
|
Follows the description of the accepted parameters.
|
|
|
|
@table @option
|
|
@item width, height
|
|
|
|
Specify the size of the output image with the paddings added. If the
|
|
value for @var{width} or @var{height} is 0, the corresponding input size
|
|
is used for the output.
|
|
|
|
The default value of @var{width} and @var{height} is 0.
|
|
|
|
@item x, y
|
|
|
|
Specify the offsets where to place the input image in the padded area
|
|
with respect to the top/left border of the output image.
|
|
|
|
The default value of @var{x} and @var{y} is 0.
|
|
|
|
@item color
|
|
|
|
Specify the color of the padded area, it can be the name of a color
|
|
(case insensitive match) or a 0xRRGGBB[AA] sequence.
|
|
|
|
The default value of @var{color} is "black".
|
|
|
|
@end table
|
|
|
|
For example:
|
|
|
|
@example
|
|
# Add paddings with color "violet" to the input video. Output video
|
|
# size is 640x480, the top-left corner of the input video is placed at
|
|
# row 0, column 40.
|
|
pad=640:480:0:40:violet
|
|
@end example
|
|
|
|
@section pixdesctest
|
|
|
|
Pixel format descriptor test filter, mainly useful for internal
|
|
testing. The output video should be equal to the input video.
|
|
|
|
For example:
|
|
@example
|
|
format=monow, pixdesctest
|
|
@end example
|
|
|
|
can be used to test the monowhite pixel format descriptor definition.
|
|
|
|
@section scale
|
|
|
|
Scale the input video to @var{width}:@var{height} and/or convert the image format.
|
|
|
|
For example the command:
|
|
|
|
@example
|
|
./ffmpeg -i in.avi -vf "scale=200:100" out.avi
|
|
@end example
|
|
|
|
will scale the input video to a size of 200x100.
|
|
|
|
If the input image format is different from the format requested by
|
|
the next filter, the scale filter will convert the input to the
|
|
requested format.
|
|
|
|
If the value for @var{width} or @var{height} is 0, the respective input
|
|
size is used for the output.
|
|
|
|
If the value for @var{width} or @var{height} is -1, the scale filter will
|
|
use, for the respective output size, a value that maintains the aspect
|
|
ratio of the input image.
|
|
|
|
The default value of @var{width} and @var{height} is 0.
|
|
|
|
@section setpts
|
|
|
|
Change the PTS (presentation timestamp) of the input video frames.
|
|
|
|
Accept in input an expression evaluated through the eval API, which
|
|
can contain the following constants:
|
|
|
|
@table @option
|
|
@item PTS
|
|
the presentation timestamp in input
|
|
|
|
@item PI
|
|
Greek PI
|
|
|
|
@item PHI
|
|
golden ratio
|
|
|
|
@item E
|
|
Euler number
|
|
|
|
@item N
|
|
the count of the input frame, starting from 0.
|
|
|
|
@item STARTPTS
|
|
the PTS of the first video frame
|
|
|
|
@item INTERLACED
|
|
tell if the current frame is interlaced
|
|
|
|
@item POS
|
|
original position in the file of the frame, or undefined if undefined
|
|
for the current frame
|
|
|
|
@item PREV_INPTS
|
|
previous input PTS
|
|
|
|
@item PREV_OUTPTS
|
|
previous output PTS
|
|
|
|
@end table
|
|
|
|
Some examples follow:
|
|
|
|
@example
|
|
# start counting PTS from zero
|
|
setpts=PTS-STARTPTS
|
|
|
|
# fast motion
|
|
setpts=0.5*PTS
|
|
|
|
# slow motion
|
|
setpts=2.0*PTS
|
|
|
|
# fixed rate 25 fps
|
|
setpts=N/(25*TB)
|
|
|
|
# fixed rate 25 fps with some jitter
|
|
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
|
|
@end example
|
|
|
|
@section settb
|
|
|
|
Set the timebase to use for the output frames timestamps.
|
|
It is mainly useful for testing timebase configuration.
|
|
|
|
It accepts in input an arithmetic expression representing a rational.
|
|
The expression can contain the constants "PI", "E", "PHI", "AVTB" (the
|
|
default timebase), and "intb" (the input timebase).
|
|
|
|
The default value for the input is "intb".
|
|
|
|
Follow some examples.
|
|
|
|
@example
|
|
# set the timebase to 1/25
|
|
settb=1/25
|
|
|
|
# set the timebase to 1/10
|
|
settb=0.1
|
|
|
|
#set the timebase to 1001/1000
|
|
settb=1+0.001
|
|
|
|
#set the timebase to 2*intb
|
|
settb=2*intb
|
|
|
|
#set the default timebase value
|
|
settb=AVTB
|
|
@end example
|
|
|
|
@section slicify
|
|
|
|
Pass the images of input video on to next video filter as multiple
|
|
slices.
|
|
|
|
@example
|
|
./ffmpeg -i in.avi -vf "slicify=32" out.avi
|
|
@end example
|
|
|
|
The filter accepts the slice height as parameter. If the parameter is
|
|
not specified it will use the default value of 16.
|
|
|
|
Adding this in the beginning of filter chains should make filtering
|
|
faster due to better use of the memory cache.
|
|
|
|
@section transpose
|
|
|
|
Transpose rows with columns in the input video and optionally flip it.
|
|
|
|
It accepts a parameter representing an integer, which can assume the
|
|
values:
|
|
|
|
@table @samp
|
|
@item 0
|
|
Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
|
|
@example
|
|
L.R L.l
|
|
. . -> . .
|
|
l.r R.r
|
|
@end example
|
|
|
|
@item 1
|
|
Rotate by 90 degrees clockwise, that is:
|
|
@example
|
|
L.R l.L
|
|
. . -> . .
|
|
l.r r.R
|
|
@end example
|
|
|
|
@item 2
|
|
Rotate by 90 degrees counterclockwise, that is:
|
|
@example
|
|
L.R R.r
|
|
. . -> . .
|
|
l.r L.l
|
|
@end example
|
|
|
|
@item 3
|
|
Rotate by 90 degrees clockwise and vertically flip, that is:
|
|
@example
|
|
L.R r.R
|
|
. . -> . .
|
|
l.r l.L
|
|
@end example
|
|
@end table
|
|
|
|
@section unsharp
|
|
|
|
Sharpen or blur the input video.
|
|
|
|
It accepts the following parameters:
|
|
@var{luma_msize_x}:@var{luma_msize_y}:@var{luma_amount}:@var{chroma_msize_x}:@var{chroma_msize_y}:@var{chroma_amount}
|
|
|
|
Negative values for the amount will blur the input video, while positive
|
|
values will sharpen. All parameters are optional and default to the
|
|
equivalent of the string '5:5:1.0:0:0:0.0'.
|
|
|
|
@table @option
|
|
|
|
@item luma_msize_x
|
|
Set the luma matrix horizontal size. It can be an integer between 3
|
|
and 13, default value is 5.
|
|
|
|
@item luma_msize_y
|
|
Set the luma matrix vertical size. It can be an integer between 3
|
|
and 13, default value is 5.
|
|
|
|
@item luma_amount
|
|
Set the luma effect strength. It can be a float number between -2.0
|
|
and 5.0, default value is 1.0.
|
|
|
|
@item chroma_msize_x
|
|
Set the chroma matrix horizontal size. It can be an integer between 3
|
|
and 13, default value is 0.
|
|
|
|
@item chroma_msize_y
|
|
Set the chroma matrix vertical size. It can be an integer between 3
|
|
and 13, default value is 0.
|
|
|
|
@item luma_amount
|
|
Set the chroma effect strength. It can be a float number between -2.0
|
|
and 5.0, default value is 0.0.
|
|
|
|
@end table
|
|
|
|
@example
|
|
# Strong luma sharpen effect parameters
|
|
unsharp=7:7:2.5
|
|
|
|
# Strong blur of both luma and chroma parameters
|
|
unsharp=7:7:-2:7:7:-2
|
|
|
|
# Use the default values with @command{ffmpeg}
|
|
./ffmpeg -i in.avi -vf "unsharp" out.mp4
|
|
@end example
|
|
|
|
@section vflip
|
|
|
|
Flip the input video vertically.
|
|
|
|
@example
|
|
./ffmpeg -i in.avi -vf "vflip" out.avi
|
|
@end example
|
|
|
|
@section yadif
|
|
|
|
Deinterlace the input video ("yadif" means "yet another deinterlacing
|
|
filter").
|
|
|
|
It accepts the optional parameters: @var{mode}:@var{parity}.
|
|
|
|
@var{mode} specifies the interlacing mode to adopt, accepts one of the
|
|
following values:
|
|
|
|
@table @option
|
|
@item 0
|
|
output 1 frame for each frame
|
|
@item 1
|
|
output 1 frame for each field
|
|
@item 2
|
|
like 0 but skips spatial interlacing check
|
|
@item 3
|
|
like 1 but skips spatial interlacing check
|
|
@end table
|
|
|
|
Default value is 0.
|
|
|
|
@var{parity} specifies the picture field parity assumed for the input
|
|
interlaced video, accepts one of the following values:
|
|
|
|
@table @option
|
|
@item 0
|
|
assume bottom field first
|
|
@item 1
|
|
assume top field first
|
|
@item -1
|
|
enable automatic detection
|
|
@end table
|
|
|
|
Default value is -1.
|
|
If interlacing is unknown or decoder does not export this information,
|
|
top field first will be assumed.
|
|
|
|
@c man end VIDEO FILTERS
|
|
|
|
@chapter Video Sources
|
|
@c man begin VIDEO SOURCES
|
|
|
|
Below is a description of the currently available video sources.
|
|
|
|
@section buffer
|
|
|
|
Buffer video frames, and make them available to the filter chain.
|
|
|
|
This source is mainly intended for a programmatic use, in particular
|
|
through the interface defined in @file{libavfilter/vsrc_buffer.h}.
|
|
|
|
It accepts the following parameters:
|
|
@var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}:@var{sample_aspect_ratio_num}:@var{sample_aspect_ratio.den}
|
|
|
|
All the parameters need to be explicitely defined.
|
|
|
|
Follows the list of the accepted parameters.
|
|
|
|
@table @option
|
|
|
|
@item width, height
|
|
Specify the width and height of the buffered video frames.
|
|
|
|
@item pix_fmt_string
|
|
A string representing the pixel format of the buffered video frames.
|
|
It may be a number corresponding to a pixel format, or a pixel format
|
|
name.
|
|
|
|
@item timebase_num, timebase_den
|
|
Specify numerator and denomitor of the timebase assumed by the
|
|
timestamps of the buffered frames.
|
|
|
|
@item sample_aspect_ratio.num, sample_aspect_ratio.den
|
|
Specify numerator and denominator of the sample aspect ratio assumed
|
|
by the video frames.
|
|
@end table
|
|
|
|
For example:
|
|
@example
|
|
buffer=320:240:yuv410p:1:24:1:1
|
|
@end example
|
|
|
|
will instruct the source to accept video frames with size 320x240 and
|
|
with format "yuv410p", assuming 1/24 as the timestamps timebase and
|
|
square pixels (1:1 sample aspect ratio).
|
|
Since the pixel format with name "yuv410p" corresponds to the number 6
|
|
(check the enum PixelFormat definition in @file{libavutil/pixfmt.h}),
|
|
this example corresponds to:
|
|
@example
|
|
buffer=320:240:6:1:24
|
|
@end example
|
|
|
|
@section color
|
|
|
|
Provide an uniformly colored input.
|
|
|
|
It accepts the following parameters:
|
|
@var{color}:@var{frame_size}:@var{frame_rate}
|
|
|
|
Follows the description of the accepted parameters.
|
|
|
|
@table @option
|
|
|
|
@item color
|
|
Specify the color of the source. It can be the name of a color (case
|
|
insensitive match) or a 0xRRGGBB[AA] sequence, possibly followed by an
|
|
alpha specifier. The default value is "black".
|
|
|
|
@item frame_size
|
|
Specify the size of the sourced video, it may be a string of the form
|
|
@var{width}x@var{heigth}, or the name of a size abbreviation. The
|
|
default value is "320x240".
|
|
|
|
@item frame_rate
|
|
Specify the frame rate of the sourced video, as the number of frames
|
|
generated per second. It has to be a string in the format
|
|
@var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
|
|
number or a valid video frame rate abbreviation. The default value is
|
|
"25".
|
|
|
|
@end table
|
|
|
|
For example the following graph description will generate a red source
|
|
with an opacity of 0.2, with size "qcif" and a frame rate of 10
|
|
frames per second, which will be overlayed over the source connected
|
|
to the pad with identifier "in".
|
|
|
|
@example
|
|
"color=red@@0.2:qcif:10 [color]; [in][color] overlay [out]"
|
|
@end example
|
|
|
|
@section movie
|
|
|
|
Read a video stream from a movie container.
|
|
|
|
It accepts the syntax: @var{movie_name}[:@var{options}] where
|
|
@var{movie_name} is the name of the resource to read (not necessarily
|
|
a file but also a device or a stream accessed through some protocol),
|
|
and @var{options} is an optional sequence of @var{key}=@var{value}
|
|
pairs, separated by ":".
|
|
|
|
The description of the accepted options follows.
|
|
|
|
@table @option
|
|
|
|
@item format_name, f
|
|
Specifies the format assumed for the movie to read, and can be either
|
|
the name of a container or an input device. If not specified the
|
|
format is guessed from @var{movie_name} or by probing.
|
|
|
|
@item seek_point, sp
|
|
Specifies the seek point in seconds, the frames will be output
|
|
starting from this seek point, the parameter is evaluated with
|
|
@code{av_strtod} so the numerical value may be suffixed by an IS
|
|
postfix. Default value is "0".
|
|
|
|
@item stream_index, si
|
|
Specifies the index of the video stream to read. If the value is -1,
|
|
the best suited video stream will be automatically selected. Default
|
|
value is "-1".
|
|
|
|
@end table
|
|
|
|
This filter allows to overlay a second video on top of main input of
|
|
a filtergraph as shown in this graph:
|
|
@example
|
|
input -----------> deltapts0 --> overlay --> output
|
|
^
|
|
|
|
|
movie --> scale--> deltapts1 -------+
|
|
@end example
|
|
|
|
Some examples follow:
|
|
@example
|
|
# skip 3.2 seconds from the start of the avi file in.avi, and overlay it
|
|
# on top of the input labelled as "in".
|
|
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [movie];
|
|
[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
|
|
|
|
# read from a video4linux2 device, and overlay it on top of the input
|
|
# labelled as "in"
|
|
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [movie];
|
|
[in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
|
|
|
|
@end example
|
|
|
|
@section nullsrc
|
|
|
|
Null video source, never return images. It is mainly useful as a
|
|
template and to be employed in analysis / debugging tools.
|
|
|
|
It accepts as optional parameter a string of the form
|
|
@var{width}:@var{height}:@var{timebase}.
|
|
|
|
@var{width} and @var{height} specify the size of the configured
|
|
source. The default values of @var{width} and @var{height} are
|
|
respectively 352 and 288 (corresponding to the CIF size format).
|
|
|
|
@var{timebase} specifies an arithmetic expression representing a
|
|
timebase. The expression can contain the constants "PI", "E", "PHI",
|
|
"AVTB" (the default timebase), and defaults to the value "AVTB".
|
|
|
|
@section frei0r_src
|
|
|
|
Provide a frei0r source.
|
|
|
|
To enable compilation of this filter you need to install the frei0r
|
|
header and configure FFmpeg with --enable-frei0r.
|
|
|
|
The source supports the syntax:
|
|
@example
|
|
@var{size}:@var{rate}:@var{src_name}[@{=|:@}@var{param1}:@var{param2}:...:@var{paramN}]
|
|
@end example
|
|
|
|
@var{size} is the size of the video to generate, may be a string of the
|
|
form @var{width}x@var{height} or a frame size abbreviation.
|
|
@var{rate} is the rate of the video to generate, may be a string of
|
|
the form @var{num}/@var{den} or a frame rate abbreviation.
|
|
@var{src_name} is the name to the frei0r source to load. For more
|
|
information regarding frei0r and how to set the parameters read the
|
|
section "frei0r" (@pxref{frei0r}) in the description of the video
|
|
filters.
|
|
|
|
Some examples follow:
|
|
@example
|
|
# generate a frei0r partik0l source with size 200x200 and framerate 10
|
|
# which is overlayed on the overlay filter main input
|
|
frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
|
|
@end example
|
|
|
|
@c man end VIDEO SOURCES
|
|
|
|
@chapter Video Sinks
|
|
@c man begin VIDEO SINKS
|
|
|
|
Below is a description of the currently available video sinks.
|
|
|
|
@section nullsink
|
|
|
|
Null video sink, do absolutely nothing with the input video. It is
|
|
mainly useful as a template and to be employed in analysis / debugging
|
|
tools.
|
|
|
|
@c man end VIDEO SINKS
|
|
|