@item level_in
Set input gain. Default is 1. Range is between 0.015625 and 64.
+@item mode
+Set mode of compressor operation. Can be @code{upward} or @code{downward}.
+Default is @code{downward}.
+
@item threshold
If a signal of stream rises above this level it will affect the gain
reduction.
@end table
@item win_size
-Set window size.
-
-It accepts the following values:
-@table @samp
-@item w16
-@item w32
-@item w64
-@item w128
-@item w256
-@item w512
-@item w1024
-@item w2048
-@item w4096
-@item w8192
-@item w16384
-@item w32768
-@item w65536
-@end table
-Default is @code{w4096}
+Set window size. Allowed range is from 16 to 131072.
+Default is @code{4096}
@item win_func
Set window function. Default is @code{hann}.
Set input level before filtering.
Default is 1. Allowed range is from 0.015625 to 64.
+@item mode
+Set the mode of operation. Can be @code{upward} or @code{downward}.
+Default is @code{downward}. If set to @code{upward} mode, higher parts of signal
+will be amplified, expanding dynamic range in upward direction.
+Otherwise, in case of @code{downward} lower parts of signal will be reduced.
+
@item range
Set the level of gain reduction when the signal is below the threshold.
Default is 0.06125. Allowed range is from 0 to 1.
+Setting this to 0 disables reduction and then filter behaves like expander.
@item threshold
If a signal rises above this level the gain reduction is released.
16-bit integers
@end table
+@item mix
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item response
Show IR frequency response, magnitude and phase in additional video stream.
By default it is disabled.
@item width, w
Specify the band-width of a filter in width_type units.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item width, w
Change allpass width.
Syntax for the command is : "@var{width}"
+
+@item mix, m
+Change allpass mix.
+Syntax for the command is : "@var{mix}"
@end table
@section aloop
Default value is @var{o}.
@end table
+
+@item m
+Set smooth factor. Default value is @var{11}. Allowed range is from @var{1} to @var{15}.
+@end table
+
+@subsection Commands
+
+This filter supports the following commands:
+@table @option
+@item s
+Change denoise strength. Argument is single float number.
+Syntax for the command is : "@var{s}"
+
+@item o
+Change output mode.
+Syntax for the command is : "i", "o" or "n" string.
@end table
@section anull
A list of Adler-32 checksums for each data plane.
@end table
+@section asoftclip
+Apply audio soft clipping.
+
+Soft clipping is a type of distortion effect where the amplitude of a signal is saturated
+along a smooth curve, rather than the abrupt shape of hard-clipping.
+
+This filter accepts the following options:
+
+@table @option
+@item type
+Set type of soft-clipping.
+
+It accepts the following values:
+@table @option
+@item tanh
+@item atan
+@item cubic
+@item exp
+@item alg
+@item quintic
+@item sin
+@end table
+
+@item param
+Set additional parameter which controls sigmoid function.
+@end table
+
+@section asr
+Automatic Speech Recognition
+
+This filter uses PocketSphinx for speech recognition. To enable
+compilation of this filter, you need to configure FFmpeg with
+@code{--enable-pocketsphinx}.
+
+It accepts the following options:
+
+@table @option
+@item rate
+Set sampling rate of input audio. Defaults is @code{16000}.
+This need to match speech models, otherwise one will get poor results.
+
+@item hmm
+Set dictionary containing acoustic model files.
+
+@item dict
+Set pronunciation dictionary.
+
+@item lm
+Set language model file.
+
+@item lmctl
+Set language model set.
+
+@item lmname
+Set which language model to use.
+
+@item logfn
+Set output for log messages.
+@end table
+
+The filter exports recognized speech as the frame metadata @code{lavfi.asr.text}.
+
@anchor{astats}
@section astats
Dynamic_range
Zero_crossings
Zero_crossings_rate
+Number_of_NaNs
+Number_of_Infs
+Number_of_denormals
and for Overall:
DC_offset
Peak_count
Bit_depth
Number_of_samples
+Number_of_NaNs
+Number_of_Infs
+Number_of_denormals
For example full key look like this @code{lavfi.astats.1.DC_offset} or
this @code{lavfi.astats.Overall.Peak_count}.
@item width, w
Specify the band-width of a filter in width_type units.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item width, w
Change bandpass width.
Syntax for the command is : "@var{width}"
+
+@item mix, m
+Change bandpass mix.
+Syntax for the command is : "@var{mix}"
@end table
@section bandreject
@item width, w
Specify the band-width of a filter in width_type units.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item width, w
Change bandreject width.
Syntax for the command is : "@var{width}"
+
+@item mix, m
+Change bandreject mix.
+Syntax for the command is : "@var{mix}"
@end table
@section bass, lowshelf
@item width, w
Determine how steep is the filter's shelf transition.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item gain, g
Change bass gain.
Syntax for the command is : "@var{gain}"
+
+@item mix, m
+Change bass mix.
+Syntax for the command is : "@var{mix}"
@end table
@section biquad
@item b2
Change biquad parameter.
Syntax for the command is : "@var{value}"
+
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
@end table
@section bs2b
used to prevent clipping.
@end table
+@section deesser
+
+Apply de-essing to the audio samples.
+
+@table @option
+@item i
+Set intensity for triggering de-essing. Allowed range is from 0 to 1.
+Default is 0.
+
+@item m
+Set amount of ducking on treble part of sound. Allowed range is from 0 to 1.
+Default is 0.5.
+
+@item f
+How much of original frequency content to keep when de-essing. Allowed range is from 0 to 1.
+Default is 0.5.
+
+@item s
+Set the output mode.
+
+It accepts the following values:
+@table @option
+@item i
+Pass input unchanged.
+
+@item o
+Pass ess filtered out.
+
+@item e
+Pass only ess.
+
+Default value is @var{o}.
+@end table
+
+@end table
+
@section drmeter
Measure audio dynamic range.
Set the required gain or attenuation in dB.
Beware of clipping when using a positive gain.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item gain, g
Change equalizer gain.
Syntax for the command is : "@var{gain}"
+
+@item mix, m
+Change equalizer mix.
+Syntax for the command is : "@var{mix}"
@end table
@section extrastereo
Applies only to double-pole filter.
The default is 0.707q and gives a Butterworth response.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item width, w
Change highpass width.
Syntax for the command is : "@var{width}"
+
+@item mix, m
+Change highpass mix.
+Syntax for the command is : "@var{mix}"
@end table
@section join
Applies only to double-pole filter.
The default is 0.707q and gives a Butterworth response.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item width, w
Change lowpass width.
Syntax for the command is : "@var{width}"
+
+@item mix, m
+Change lowpass mix.
+Syntax for the command is : "@var{mix}"
@end table
@section lv2
@item level_in
Set input gain. Default is 1. Range is between 0.015625 and 64.
+@item mode
+Set mode of compressor operation. Can be @code{upward} or @code{downward}.
+Default is @code{downward}.
+
@item threshold
If a signal of second stream raises above this level it will affect the gain
reduction of first stream.
Set input level before filtering.
Default is 1. Allowed range is from 0.015625 to 64.
+@item mode
+Set the mode of operation. Can be @code{upward} or @code{downward}.
+Default is @code{downward}. If set to @code{upward} mode, higher parts of signal
+will be amplified, expanding dynamic range in upward direction.
+Otherwise, in case of @code{downward} lower parts of signal will be reduced.
+
@item range
Set the level of gain reduction when the signal is below the threshold.
Default is 0.06125. Allowed range is from 0 to 1.
+Setting this to 0 disables reduction and then filter behaves like expander.
@item threshold
If a signal rises above this level the gain reduction is released.
@item lfe_high
Set LFE high cut off frequency. By default, this is @var{256} Hz.
+@item lfe_mode
+Set LFE mode, can be @var{add} or @var{sub}. Default is @var{add}.
+In @var{add} mode, LFE channel is created from input audio and added to output.
+In @var{sub} mode, LFE channel is created from input audio and added to output but
+also all non-LFE output channels are subtracted with output LFE channel.
+
+@item angle
+Set angle of stereo surround transform, Allowed range is from @var{0} to @var{360}.
+Default is @var{90}.
+
@item fc_in
Set front center input volume. By default, this is @var{1}.
@item fc_out
Set front center output volume. By default, this is @var{1}.
+@item fl_in
+Set front left input volume. By default, this is @var{1}.
+
+@item fl_out
+Set front left output volume. By default, this is @var{1}.
+
+@item fr_in
+Set front right input volume. By default, this is @var{1}.
+
+@item fr_out
+Set front right output volume. By default, this is @var{1}.
+
+@item sl_in
+Set side left input volume. By default, this is @var{1}.
+
+@item sl_out
+Set side left output volume. By default, this is @var{1}.
+
+@item sr_in
+Set side right input volume. By default, this is @var{1}.
+
+@item sr_out
+Set side right output volume. By default, this is @var{1}.
+
+@item bl_in
+Set back left input volume. By default, this is @var{1}.
+
+@item bl_out
+Set back left output volume. By default, this is @var{1}.
+
+@item br_in
+Set back right input volume. By default, this is @var{1}.
+
+@item br_out
+Set back right output volume. By default, this is @var{1}.
+
+@item bc_in
+Set back center input volume. By default, this is @var{1}.
+
+@item bc_out
+Set back center output volume. By default, this is @var{1}.
+
@item lfe_in
Set LFE input volume. By default, this is @var{1}.
@item lfe_out
Set LFE output volume. By default, this is @var{1}.
+
+@item allx
+Set spread usage of stereo image across X axis for all channels.
+
+@item ally
+Set spread usage of stereo image across Y axis for all channels.
+
+@item fcx, flx, frx, blx, brx, slx, srx, bcx
+Set spread usage of stereo image across X axis for each channel.
+
+@item fcy, fly, fry, bly, bry, sly, sry, bcy
+Set spread usage of stereo image across Y axis for each channel.
+
+@item win_size
+Set window size. Allowed range is from @var{1024} to @var{65536}. Default size is @var{4096}.
+
+@item win_func
+Set window function.
+
+It accepts the following values:
+@table @samp
+@item rect
+@item bartlett
+@item hann, hanning
+@item hamming
+@item blackman
+@item welch
+@item flattop
+@item bharris
+@item bnuttall
+@item bhann
+@item sine
+@item nuttall
+@item lanczos
+@item gauss
+@item tukey
+@item dolph
+@item cauchy
+@item parzen
+@item poisson
+@item bohman
+@end table
+Default is @code{hann}.
+
+@item overlap
+Set window overlap. If set to 1, the recommended overlap for selected
+window function will be picked. Default is @code{0.5}.
@end table
@section treble, highshelf
@item width, w
Determine how steep is the filter's shelf transition.
+@item mix, m
+How much to use filtered signal in output. Default is 1.
+Range is between 0 and 1.
+
@item channels, c
Specify which channels to filter, by default all available are filtered.
@end table
@item gain, g
Change treble gain.
Syntax for the command is : "@var{gain}"
+
+@item mix, m
+Change treble mix.
+Syntax for the command is : "@var{mix}"
@end table
@section tremolo
Similarity percentage with the above color.
0.01 matches only the exact key color, while 1.0 matches everything.
+@item blend
+Blend percentage.
+0.0 makes pixels either fully gray, or not gray at all.
+Higher values result in more preserved color.
+
@item yuv
Signals that the color passed is already in YUV instead of RGB.
@end example
@end itemize
+@section colorhold
+Remove all color information for all RGB colors except for certain one.
+
+The filter accepts the following options:
+
+@table @option
+@item color
+The color which will not be replaced with neutral gray.
+
+@item similarity
+Similarity percentage with the above color.
+0.01 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage. 0.0 makes pixels fully gray.
+Higher values result in more preserved color.
+@end table
+
@section colorlevels
Adjust video input frames using levels.
@end itemize
+@section derain
+
+Remove the rain in the input image/video by applying the derain methods based on
+convolutional neural networks. Supported models:
+
+@itemize
+@item
+Recurrent Squeeze-and-Excitation Context Aggregation Net (RESCAN).
+See @url{http://openaccess.thecvf.com/content_ECCV_2018/papers/Xia_Li_Recurrent_Squeeze-and-Excitation_Context_ECCV_2018_paper.pdf}.
+@end itemize
+
+Training scripts as well as scripts for model generation are provided in
+the repository at @url{https://github.com/XueweiMeng/derain_filter.git}.
+
+The filter accepts the following options:
+
+@table @option
+@item dnn_backend
+Specify which DNN backend to use for model loading and execution. This option accepts
+the following values:
+
+@table @samp
+@item native
+Native implementation of DNN loading and execution.
+@end table
+Default value is @samp{native}.
+
+@item model
+Set path to model file specifying network architecture and its parameters.
+Note that different backends use different file formats. TensorFlow backend
+can load files for both formats, while native backend can load files for only
+its format.
+@end table
+
@section deshake
Attempt to fix small changes in horizontal and/or vertical shift. This
the x and y offset coordinates where the text is drawn.
These parameters allow the @var{x} and @var{y} expressions to refer
-each other, so you can for example specify @code{y=x/dar}.
+to each other, so you can for example specify @code{y=x/dar}.
+
+@item pict_type
+A one character description of the current frame's picture type.
+
+@item pkt_pos
+The current packet's position in the input file or stream
+(in bytes, from the start of the input). A value of -1 indicates
+this info is not available.
+
+@item pkt_duration
+The current packet's duration, in seconds.
+
+@item pkt_size
+The current packet's size (in bytes).
@end table
@anchor{drawtext_expansion}
The second argument is optional and specifies a default value, used when the
metadata key is not found or empty.
+Available metadata can be identified by inspecting entries
+starting with TAG included within each frame section
+printed by running @code{ffprobe -show_frames}.
+
+String metadata generated in filters leading to
+the drawtext filter are also available.
+
@item n, frame_num
The frame number, starting from 0.
@item pict_type
-A 1 character description of the current picture type.
+A one character description of the current picture type.
@item pts
The timestamp of the current frame.
By default, @var{YYYY-MM-DD HH:MM:SS} format will be used.
@end table
+@subsection Commands
+
+This filter supports altering parameters via commands:
+@table @option
+@item reinit
+Alter existing filter parameters.
+
+Syntax for the argument is the same as for filter invocation, e.g.
+
+@example
+fontsize=56:fontcolor=green:text='Hello World'
+@end example
+
+Full filter invocation with sendcmd would look like this:
+
+@example
+sendcmd=c='56.0 drawtext reinit fontsize=56\:fontcolor=green\:text=Hello\\ World'
+@end example
+@end table
+
+If the entire argument can't be parsed or applied as valid values then the filter will
+continue with its existing parameters.
+
@subsection Examples
@itemize
@itemize
@item
-Generate a representative palette of a given video using @command{ffmpeg}:
+Cover a rectangular object by the supplied image of a given video using @command{ffmpeg}:
@example
ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
@end example
@itemize
@item
-Generate a representative palette of a given video using @command{ffmpeg}:
+Cover a rectangular object by the supplied image of a given video using @command{ffmpeg}:
@example
ffmpeg -i file.ts -vf find_rect=newref.pgm,cover_rect=cover.jpg:mode=cover new.mkv
@end example
@code{haldclut} also has the same interpolation options as @ref{lut3d} (both
filters share the same internals).
+This filter also supports the @ref{framesync} options.
+
More information about the Hald CLUT can be found on Eskil Steenberg's website
(Hald CLUT author) at @url{http://www.quelsolaar.com/technology/clut.html}.
@end example
@end itemize
+@section lagfun
+
+Slowly update darker pixels.
+
+This filter makes short flashes of light appear longer.
+This filter accepts the following options:
+
+@table @option
+@item decay
+Set factor for decaying. Default is .95. Allowed range is from 0 to 1.
+
+@item planes
+Set which planes to filter. Default is all. Allowed range is from 0 to 15.
+@end table
+
@section lenscorrection
Correct radial lens distortion
vignetting correction process. If unknown, leave it at the default value (which
is 1000).
+@item scale
+The scale factor which is applied after transformation. After correction the
+video is no longer necessarily rectangular. This parameter controls how much of
+the resulting image is visible. The value 0 means that a value will be chosen
+automatically such that there is little or no unmapped area in the output
+image. 1.0 means that no additional scaling is done. Lower values may result
+in more of the corrected image being visible, while higher values may avoid
+unmapped areas in the output.
+
@item target_geometry
The target geometry of the output image/video. The following values are valid
options:
@table @samp
@item cube
Iridas
+@item csp
+cineSpace
@end table
@item interp
DaVinci
@item m3d
Pandora
+@item csp
+cineSpace
@end table
@item interp
Select interpolation mode.
@end table
@end table
-This filter also supports the @ref{framesync} options.
-
@section lumakey
Turn certain luma values into transparency.
@end table
The filter exports recognized text as the frame metadata @code{lavfi.ocr.text}.
+The filter exports confidence of recognized words as the frame metadata @code{lavfi.ocr.confidence}.
@section ocv
@item chp
Enable checking the parity bit. In the event of a parity error, the filter will output
@code{0x00} for that character. Default is false.
+
+@item lp
+Lowpass lines prior further proccessing. Default is disabled.
@end table
@subsection Examples
Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
@item bt601
+@item bt470
+@item smpte170m
Set color space conforming to:
@itemize
@item smpte240m
Set color space conforming to SMPTE ST 240:1999.
+
+@item bt2020
+Set color space conforming to ITU-R BT.2020 non-constant luminance system.
@end table
@item in_range
@example
'scale2ref[b][a];[a][b]overlay'
@end example
+
+@item
+Scale a logo to 1/10th the height of a video, while preserving its display aspect ratio.
+@example
+[logo-in][video-in]scale2ref=w=oh*mdar:h=ih/10[logo-out][video-out]
+@end example
@end itemize
@anchor{selectivecolor}
See @url{https://arxiv.org/abs/1609.05158}.
@end itemize
-Training scripts as well as scripts for model generation are provided in
-the repository at @url{https://github.com/HighVoltageRocknRoll/sr.git}.
+Training scripts as well as scripts for model file (.pb) saving can be found at
+@url{https://github.com/XueweiMeng/sr/tree/sr_dnn_native}. Original repository
+is at @url{https://github.com/HighVoltageRocknRoll/sr.git}.
+
+Native model files (.model) can be generated from TensorFlow model
+files (.pb) by using tools/python/convert.py
The filter accepts the following options:
Available value for @var{flags} is:
@table @option
-@item low_pass_filter, vlfp
+@item low_pass_filter, vlpf
Enable linear vertical low-pass filtering in the filter.
Vertical low-pass filtering is required when creating an interlaced
destination from a progressive source which contains high-frequency
vertical detail. Filtering will reduce interlace 'twitter' and Moire
patterning.
-@item complex_filter, cvlfp
+@item complex_filter, cvlpf
Enable complex vertical low-pass filtering.
This will slightly less reduce interlace 'twitter' and Moire
patterning but better retain detail and subjective sharpness impression.
@item blum
Set the blue luma coefficient.
+
+@item alternate
+If @code{intensity} is negative and this is set to 1, colors will change,
+otherwise colors will be less saturated, more towards gray.
@end table
@anchor{vignette}
Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
uses filter coefficients calculated by BBC R&D.
+This filter use field-dominance information in frame to decide which
+of each pair of fields to place first in the output.
+If it gets it wrong use @ref{setfield} filter before @code{w3fdif} filter.
+
There are two sets of filter coefficients, so called "simple":
and "complex". Which set of filter coefficients is used can
be set by passing an optional parameter:
Default is @code{3}.
@end table
+@section xmedian
+Pick median pixels from several input videos.
+
+The filter accept the following options:
+
+@table @option
+@item inputs
+Set number of inputs.
+Default is 3. Allowed range is from 3 to 255.
+If number of inputs is even number, than result will be mean value between two median values.
+
+@item planes
+Set which planes to filter. Default value is @code{15}, by which all planes are processed.
+@end table
+
@section xstack
Stack video inputs into custom layout.
Multiple values can be used when separated by '+'. In such
case values are summed together.
+For 2 inputs, a default layout of @code{0_0|w0_0} is set. In all other cases,
+a layout must be set by the user.
+
@item shortest
If set to 1, force the output to terminate when the shortest input
terminates. Default value is 0.
@table @option
@item zoom, z
-Set the zoom expression. Default is 1.
+Set the zoom expression. Range is 1-10. Default is 1.
@item x
@item y
@end example
@end itemize
+@section colorkey_opencl
+RGB colorspace color keying.
+
+The filter accepts the following options:
+
+@table @option
+@item color
+The color which will be replaced with transparency.
+
+@item similarity
+Similarity percentage with the key color.
+
+0.01 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage.
+
+0.0 makes pixels either fully transparent, or not transparent at all.
+
+Higher values result in semi-transparent pixels, with a higher transparency
+the more similar the pixels color is to the key color.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Make every semi-green pixel in the input transparent with some slight blending:
+@example
+-i INPUT -vf "hwupload, colorkey_opencl=green:0.3:0.1, hwdownload" OUTPUT
+@end example
+@end itemize
+
+@section nlmeans_opencl
+
+Non-local Means denoise filter through OpenCL, this filter accepts same options as @ref{nlmeans}.
+
@section overlay_opencl
Overlay one video on top of another.
@anchor{ebur128}
@section ebur128
-EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
+EBU R128 scanner filter. This filter takes an audio stream and analyzes its loudness
+level. By default, it logs a message at a frequency of 10Hz with the
Momentary loudness (identified by @code{M}), Short-term loudness (@code{S}),
Integrated loudness (@code{I}) and Loudness Range (@code{LRA}).
+The filter can only analyze streams which have a sampling rate of 48000 Hz and whose
+sample format is double-precision floating point. The input stream will be converted to
+this specification, if needed. Users may need to insert aformat and/or aresample filters
+after this filter to obtain the original parameters.
+
The filter also has a video output (see the @var{video} option) with a real
time graph to observe the loudness evolution. The graphic contains the logged
message mentioned above, so it is not printed anymore when this option is set,
@item limit
Time limit for the pauses. Any pause longer than that will be considered
a timestamp discontinuity and reset the timer. Default is 2 seconds.
+@item speed
+Speed factor for processing. The value must be a float larger than zero.
+Values larger than 1.0 will result in faster than realtime processing,
+smaller will slow processing down. The @var{limit} is automatically adapted
+accordingly. Default is 1.0.
+
+A processing speed faster than what is possible without these filters cannot
+be achieved.
@end table
@anchor{select}
@end table
+@section showspatial
+
+Convert stereo input audio to a video output, representing the spatial relationship
+between two channels.
+
+The filter accepts the following options:
+
+@table @option
+@item size, s
+Specify the video size for the output. For the syntax of this option, check the
+@ref{video size syntax,,"Video size" section in the ffmpeg-utils manual,ffmpeg-utils}.
+Default value is @code{512x512}.
+
+@item win_size
+Set window size. Allowed range is from @var{1024} to @var{65536}. Default size is @var{4096}.
+
+@item win_func
+Set window function.
+
+It accepts the following values:
+@table @samp
+@item rect
+@item bartlett
+@item hann
+@item hanning
+@item hamming
+@item blackman
+@item welch
+@item flattop
+@item bharris
+@item bnuttall
+@item bhann
+@item sine
+@item nuttall
+@item lanczos
+@item gauss
+@item tukey
+@item dolph
+@item cauchy
+@item parzen
+@item poisson
+@item bohman
+@end table
+
+Default value is @code{hann}.
+
+@item overlap
+Set ratio of overlap window. Default value is @code{0.5}.
+When value is @code{1} overlap is set to recommended size for specific
+window function currently used.
+@end table
+
@anchor{showspectrum}
@section showspectrum
Default value is @samp{sqrt}.
+@item fscale
+Specify frequency scale.
+
+It accepts the following values:
+@table @samp
+@item lin
+linear
+@item log
+logarithmic
+@end table
+
+Default value is @samp{lin}.
+
@item saturation
Set saturation modifier for displayed colors. Negative values provide
alternative color scheme. @code{0} is no saturation at all.
@end table
Default value is @samp{log}.
+@item fscale
+Specify frequency scale.
+
+It accepts the following values:
+@table @samp
+@item lin
+linear
+@item log
+logarithmic
+@end table
+
+Default value is @samp{lin}.
+
@item saturation
Set saturation modifier for displayed colors. Negative values provide
alternative color scheme. @code{0} is no saturation at all.
@end table
Default is linear.
+
+@item draw
+Set the draw mode.
+
+Available values are:
+@table @samp
+@item scale
+Scale pixel values for each drawn sample.
+
+@item full
+Draw every sample directly.
+@end table
+
+Default value is @code{scale}.
@end table
@subsection Examples