@end example
@section compand
-
Compress or expand audio dynamic range.
A description of the accepted options follows.
@table @option
+
@item attacks
@item decays
-Set list of times in seconds for each channel over which the instantaneous
-level of the input signal is averaged to determine its volume.
-@option{attacks} refers to increase of volume and @option{decays} refers
-to decrease of volume.
-For most situations, the attack time (response to the audio getting louder)
-should be shorter than the decay time because the human ear is more sensitive
-to sudden loud audio than sudden soft audio.
-Typical value for attack is @code{0.3} seconds and for decay @code{0.8}
-seconds.
+Set list of times in seconds for each channel over which the instantaneous level
+of the input signal is averaged to determine its volume. @var{attacks} refers to
+increase of volume and @var{decays} refers to decrease of volume. For most
+situations, the attack time (response to the audio getting louder) should be
+shorter than the decay time because the human ear is more sensitive to sudden
+loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
+a typical value for decay is 0.8 seconds.
@item points
-Set list of points for transfer function, specified in dB relative to maximum
-possible signal amplitude.
-Each key points list need to be defined using the following syntax:
-@code{x0/y0 x1/y1 x2/y2 ...}.
+Set list of points for the transfer function, specified in dB relative to the
+maximum possible signal amplitude. Each key points list must be defined using
+the following syntax: @code{x0/y0|x1/y1|x2/y2|....} or
+@code{x0/y0 x1/y1 x2/y2 ....}
-The input values must be in strictly increasing order but the transfer
-function does not have to be monotonically rising.
-The point @code{0/0} is assumed but may be overridden (by @code{0/out-dBn}).
-Typical values for the transfer function are @code{-70/-70 -60/-20}.
+The input values must be in strictly increasing order but the transfer function
+does not have to be monotonically rising. The point @code{0/0} is assumed but
+may be overridden (by @code{0/out-dBn}). Typical values for the transfer
+function are @code{-70/-70|-60/-20}.
@item soft-knee
-Set amount for which the points at where adjacent line segments on the
-transfer function meet will be rounded. Defaults is @code{0.01}.
+Set the curve radius in dB for all joints. Defaults to 0.01.
@item gain
-Set additional gain in dB to be applied at all points on the transfer function
-and allows easy adjustment of the overall gain.
-Default is @code{0}.
+Set additional gain in dB to be applied at all points on the transfer function.
+This allows easy adjustment of the overall gain. Defaults to 0.
@item volume
Set initial volume in dB to be assumed for each channel when filtering starts.
-This permits the user to supply a nominal level initially, so that,
-for example, a very large gain is not applied to initial signal levels before
-the companding has begun to operate. A typical value for audio which is
-initially quiet is -90 dB. Default is @code{0}.
+This permits the user to supply a nominal level initially, so that, for
+example, a very large gain is not applied to initial signal levels before the
+companding has begun to operate. A typical value for audio which is initially
+quiet is -90 dB. Defaults to 0.
@item delay
-Set delay in seconds. Default is @code{0}. The input audio
-is analysed immediately, but audio is delayed before being fed to the
-volume adjuster. Specifying a delay approximately equal to the attack/decay
-times allows the filter to effectively operate in predictive rather than
-reactive mode.
+Set delay in seconds. The input audio is analyzed immediately, but audio is
+delayed before being fed to the volume adjuster. Specifying a delay
+approximately equal to the attack/decay times allows the filter to effectively
+operate in predictive rather than reactive mode. Defaults to 0.
+
@end table
@subsection Examples
+
@itemize
@item
-Make music with both quiet and loud passages suitable for listening
-in a noisy environment:
+Make music with both quiet and loud passages suitable for listening in a noisy
+environment:
@example
-compand=.3 .3:1 1:-90/-60 -60/-40 -40/-30 -20/-20:6:0:-90:0.2
+compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
@end example
@item
-Noise-gate for when the noise is at a lower level than the signal:
+Noise gate for when the noise is at a lower level than the signal:
@example
-compand=.1 .1:.2 .2:-900/-900 -50.1/-900 -50/-50:.01:0:-90:.1
+compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
@end example
@item
-Here is another noise-gate, this time for when the noise is at a higher level
+Here is another noise gate, this time for when the noise is at a higher level
than the signal (making it, in some ways, similar to squelch):
@example
-compand=.1 .1:.1 .1:-45.1/-45.1 -45/-900 0/-900:.01:45:-90:.1
+compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
@end example
@end itemize
@code{1}.
@end table
+@section dejudder
+
+Remove judder produced by partially interlaced telecined content.
+
+Judder can be introduced, for instance, by @ref{pullup} filter. If the original
+source was partially telecined content then the output of @code{pullup,dejudder}
+will have a variable frame rate. May change the recorded frame rate of the
+container. Aside from that change, this filter will not affect constant frame
+rate video.
+
+The option available in this filter is:
+@table @option
+
+@item cycle
+Specify the length of the window over which the judder repeats.
+
+Accepts any interger greater than 1. Useful values are:
+@table @samp
+
+@item 4
+If the original was telecined from 24 to 30 fps (Film to NTSC).
+
+@item 5
+If the original was telecined from 25 to 30 fps (PAL to NTSC).
+
+@item 20
+If a mixture of the two.
+@end table
+
+The default is @samp{4}.
+@end table
+
@section delogo
Suppress a TV station logo by a simple interpolation of the surrounding
Compute and draw a color distribution histogram for the input video.
-The computed histogram is a representation of distribution of color components
-in an image.
+The computed histogram is a representation of the color component
+distribution in an image.
The filter accepts the following options:
It accepts the following values:
@table @samp
@item levels
-standard histogram that display color components distribution in an image.
-Displays color graph for each color component. Shows distribution
-of the Y, U, V, A or R, G, B components, depending on input format,
-in current frame. Bellow each graph is color component scale meter.
+Standard histogram that displays the color components distribution in an
+image. Displays color graph for each color component. Shows distribution of
+the Y, U, V, A or R, G, B components, depending on input format, in the
+current frame. Below each graph a color component scale meter is shown.
@item color
-chroma values in vectorscope, if brighter more such chroma values are
-distributed in an image.
-Displays chroma values (U/V color placement) in two dimensional graph
-(which is called a vectorscope). It can be used to read of the hue and
-saturation of the current frame. At a same time it is a histogram.
-The whiter a pixel in the vectorscope, the more pixels of the input frame
-correspond to that pixel (that is the more pixels have this chroma value).
-The V component is displayed on the horizontal (X) axis, with the leftmost
-side being V = 0 and the rightmost side being V = 255.
-The U component is displayed on the vertical (Y) axis, with the top
-representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value
-of a pixel of the input clip. So the graph can be used to read of the
-hue (color flavor) and the saturation (the dominance of the hue in the color).
-As the hue of a color changes, it moves around the square. At the center of
-the square, the saturation is zero, which means that the corresponding pixel
-has no color. If you increase the amount of a specific color, while leaving
-the other colors unchanged, the saturation increases, and you move towards
+Displays chroma values (U/V color placement) in a two dimensional
+graph (which is called a vectorscope). The brighter a pixel in the
+vectorscope, the more pixels of the input frame correspond to that pixel
+(i.e., more pixels have this chroma value). The V component is displayed on
+the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
+side being V = 255. The U component is displayed on the vertical (Y) axis,
+with the top representing U = 0 and the bottom representing U = 255.
+
+The position of a white pixel in the graph corresponds to the chroma value of
+a pixel of the input clip. The graph can therefore be used to read the hue
+(color flavor) and the saturation (the dominance of the hue in the color). As
+the hue of a color changes, it moves around the square. At the center of the
+square the saturation is zero, which means that the corresponding pixel has no
+color. If the amount of a specific color is increased (while leaving the other
+colors unchanged) the saturation increases, and the indicator moves towards
the edge of the square.
@item color2
-chroma values in vectorscope, similar as @code{color} but actual chroma values
+Chroma values in vectorscope, similar as @code{color} but actual chroma values
are displayed.
@item waveform
-per row/column color component graph. In row mode graph in the left side represents
-color component value 0 and right side represents value = 255. In column mode top
-side represents color component value = 0 and bottom side represents value = 255.
+Per row/column color component graph. In row mode, the graph on the left side
+represents color component value 0 and the right side represents value = 255.
+In column mode, the top side represents color component value = 0 and bottom
+side represents value = 255.
@end table
Default value is @code{levels}.
Allowed range is [0, 40].
@item step
-Set step for @code{waveform} mode. Smaller values are useful to find out how much
-of same luminance values across input rows/columns are distributed.
+Set step for @code{waveform} mode. Smaller values are useful to find out how
+many values of the same luminance are distributed across input rows/columns.
Default value is @code{10}. Allowed range is [1, 255].
@item waveform_mode
@table @samp
@item parade
Display separate graph for the color components side by side in
-@code{row} waveform mode or one below other in @code{column} waveform mode
-for @code{waveform} histogram mode. For @code{levels} histogram mode
-per color component graphs are placed one bellow other.
-
-This display mode in @code{waveform} histogram mode makes it easy to spot
-color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom of each waveform.
-Since whites, grays, and blacks are characterized by
-exactly equal amounts of red, green, and blue, neutral areas of the
-picture should display three waveforms of roughly equal width/height.
-If not, the correction is easy to make by making adjustments to level the
-three waveforms.
+@code{row} waveform mode or one below the other in @code{column} waveform mode
+for @code{waveform} histogram mode. For @code{levels} histogram mode,
+per color component graphs are placed below each other.
+
+Using this display mode in @code{waveform} histogram mode makes it easy to
+spot color casts in the highlights and shadows of an image, by comparing the
+contours of the top and the bottom graphs of each waveform. Since whites,
+grays, and blacks are characterized by exactly equal amounts of red, green,
+and blue, neutral areas of the picture should display three waveforms of
+roughly equal width/height. If not, the correction is easy to perform by
+making level adjustments the three waveforms.
@item overlay
-Presents information that's identical to that in the @code{parade}, except
+Presents information identical to that in the @code{parade}, except
that the graphs representing color components are superimposed directly
over one another.
-This display mode in @code{waveform} histogram mode can make it easier to spot
-the relative differences or similarities in overlapping areas of the color
+This display mode in @code{waveform} histogram mode makes it easier to spot
+relative differences or similarities in overlapping areas of the color
components that are supposed to be identical, such as neutral whites, grays,
or blacks.
@end table
Simple interlacing filter from progressive contents. This interleaves upper (or
lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
+halving the frame rate and preserving image height. A vertical lowpass filter
+is always applied in order to avoid twitter effects and reduce moiré patterns.
@example
Original Original New Frame
@item scan
determines whether the interlaced frame is taken from the even (tff - default)
or odd (bff) lines of the progressive frame.
-
-@item lowpass
-Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
@end table
@section kerndeint
reference file @file{ref_movie.mpg}. The PSNR of each individual frame
is stored in @file{stats.log}.
+@anchor{pullup}
@section pullup
Pulldown reversal (inverse telecine) filter, capable of handling mixed
projects / ffmpeg / blobdiff