@section decimate
-This filter drops frames that do not differ greatly from the previous
-frame in order to reduce framerate. The main use of this filter is
-for very-low-bitrate encoding (e.g. streaming over dialup modem), but
-it could in theory be used for fixing movies that were
-inverse-telecined incorrectly.
+Drop frames that do not differ greatly from the previous frame in
+order to reduce framerate.
-It accepts the following parameters:
-@var{max}:@var{hi}:@var{lo}:@var{frac}.
+The main use of this filter is for very-low-bitrate encoding
+(e.g. streaming over dialup modem), but it could in theory be used for
+fixing movies that were inverse-telecined incorrectly.
-@table @option
+The filter accepts parameters as a list of @var{key}=@var{value}
+pairs, separated by ":". If the key of the first options is omitted,
+the arguments are interpreted according to the syntax:
+@option{max}:@option{hi}:@option{lo}:@option{frac}.
+A description of the accepted options follows.
+
+@table @option
@item max
Set the maximum number of consecutive frames which can be dropped (if
positive), or the minimum interval between dropped frames (if
Default value is 0.
-@item hi, lo, frac
+@item hi
+@item lo
+@item frac
Set the dropping threshold values.
-Values for @var{hi} and @var{lo} are for 8x8 pixel blocks and
+Values for @option{hi} and @option{lo} are for 8x8 pixel blocks and
represent actual pixel value differences, so a threshold of 64
corresponds to 1 unit of difference for each pixel, or the same spread
out differently over the block.
A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of @var{hi}, and if no more than @var{frac} blocks (1
-meaning the whole image) differ by more than a threshold of @var{lo}.
+than a threshold of @option{hi}, and if no more than @option{frac} blocks (1
+meaning the whole image) differ by more than a threshold of @option{lo}.
-Default value for @var{hi} is 64*12, default value for @var{lo} is
-64*5, and default value for @var{frac} is 0.33.
+Default value for @option{hi} is 64*12, default value for @option{lo} is
+64*5, and default value for @option{frac} is 0.33.
@end table
@section delogo
Draw a colored box on the input image.
-The filter accepts parameters as a list of @var{key}=@var{value} pairs,
-separated by ":".
+The filter accepts parameters as a list of @var{key}=@var{value}
+pairs, separated by ":". If the key of the first options is omitted,
+the arguments are interpreted according to the syntax
+@option{x}:@option{y}:@option{width}:@option{height}:@option{color}:@option{thickness}.
-The description of the accepted parameters follows.
+A description of the accepted options follows.
@table @option
@item x, y
Set the thickness of the box edge. Default value is @code{4}.
@end table
-If the key of the first options is omitted, the arguments are
-interpreted according to the syntax
-@var{x}:@var{y}:@var{width}:@var{height}:@var{color}:@var{thickness}.
-
Some examples follow:
@itemize
@item
Default is @code{row}.
@item display_mode
-Set display mode for @code{waveform}.
+Set display mode for @code{waveform} and @code{levels}.
It accepts the following values:
@table @samp
@item parade
-Display separate waveforms for the color components side by side in
-@code{row} mode or one below other in @code{column} mode.
-
-In this display mode it is 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
+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 height.
+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.
@item overlay
Presents information that's identical to that in the @code{parade}, except
-that the waveforms representing color components are superimposed directly
+that the graphs representing color components are superimposed directly
over one another.
-This display mode can make it easier to spot the relative differences or
-similarities in overlapping areas of the color components that are supposed
-to be identical, such as neutral whites, grays, or blacks.
+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
+components that are supposed to be identical, such as neutral whites, grays,
+or blacks.
@end table
Default is @code{parade}.
@end table
@item harddup
@item ilpack
@item ivtc
-@item kerndeint
@item mcdeint
@item ow
@item perspective
@item rgb
If set to 1, force the filter to accept inputs in the RGB
color space. Default value is 0.
+
+@item shortest
+If set to 1, force the output to terminate when the shortest input
+terminates. Default value is 0.
@end table
Be aware that frames are taken from each input video in timestamp
ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
@end example
+@item
+Compose output by putting two input videos side to side:
+@example
+ffmpeg -i left.avi -i right.avi -filter_complex "
+nullsrc=size=200x100 [background];
+[0:v] setpts=PTS-STARTPTS, scale=100x100 [left];
+[1:v] setpts=PTS-STARTPTS, scale=100x100 [right];
+[background][left] overlay=shortest=1 [background+left];
+[background+left][right] overlay=shortest=1:x=100 [left+right]
+"
+@end example
+
@item
Chain several overlays in cascade:
@example
Specify the size of the original video, the video for which the ASS file
was composed. Due to a misdesign in ASS aspect ratio arithmetic, this is
necessary to correctly scale the fonts if the aspect ratio has been changed.
+
+@item charenc
+Set subtitles input character encoding. @code{subtitles} filter only. Only
+useful if not UTF-8.
@end table
If the first key is not specified, it is assumed that the first value
projects / ffmpeg / blobdiff