@item
Invert phase of the second channel:
@example
-eval=val(0)|-val(1)
+aeval=val(0)|-val(1)
@end example
@end itemize
the output audio will be silence. Default is 44100.
@item start_time, st
-Specify time for starting to apply the fade effect. Default is 0.
-The accepted syntax is:
-@example
-[-]HH[:MM[:SS[.m...]]]
-[-]S+[.m...]
-@end example
-See also the function @code{av_parse_time()}.
-If set this option is used instead of @var{start_sample} one.
+Specify the start time of the fade effect. Default is 0.
+The value must be specified as a time duration; see
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
+If set this option is used instead of @var{start_sample}.
@item duration, d
-Specify the duration for which the fade effect has to last. Default is 0.
-The accepted syntax is:
-@example
-[-]HH[:MM[:SS[.m...]]]
-[-]S+[.m...]
-@end example
-See also the function @code{av_parse_time()}.
+Specify the duration of the fade effect. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
At the end of the fade-in effect the output audio will have the same
volume as the input audio, at the end of the fade-out transition
the output audio will be silence.
-If set this option is used instead of @var{nb_samples} one.
+By default the duration is determined by @var{nb_samples}.
+If set this option is used instead of @var{nb_samples}.
@item curve
Set curve for fade transition.
@section apad
-Pad the end of a audio stream with silence, this can be used together with
--shortest to extend audio streams to the same length as the video stream.
+Pad the end of an audio stream with silence.
+
+This can be used together with @command{ffmpeg} @option{-shortest} to
+extend audio streams to the same length as the video stream.
+
+A description of the accepted options follows.
+
+@table @option
+@item packet_size
+Set silence packet size. Default value is 4096.
+
+@item pad_len
+Set the number of samples of silence to add to the end. After the
+value is reached, the stream is terminated. This option is mutually
+exclusive with @option{whole_len}.
+
+@item whole_len
+Set the minimum total number of samples in the output audio stream. If
+the value is longer than the input audio length, silence is added to
+the end, until the value is reached. This option is mutually exclusive
+with @option{pad_len}.
+@end table
+
+If neither the @option{pad_len} nor the @option{whole_len} option is
+set, the filter will add silence to the end of the input stream
+indefinitely.
+
+@subsection Examples
+
+@itemize
+@item
+Add 1024 samples of silence to the end of the input:
+@example
+apad=pad_len=1024
+@end example
+
+@item
+Make sure the audio output will contain at least 10000 samples, pad
+the input with silence if required:
+@example
+apad=whole_len=10000
+@end example
+
+@item
+Use @command{ffmpeg} to pad the audio input with silence, so that the
+video stream will always result the shortest and will be converted
+until the end in the output file when using the @option{shortest}
+option:
+@example
+ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
+@end example
+@end itemize
@section aphaser
Add a phasing effect to the input audio.
The shown line contains a sequence of key/value pairs of the form
@var{key}:@var{value}.
-It accepts the following parameters:
+The following values are shown in the output:
@table @option
@item n
The number of the first sample that should be dropped.
@end table
-@option{start}, @option{end}, @option{duration} are expressed as time
-duration specifications, check the "Time duration" section in the
-ffmpeg-utils manual.
+@option{start}, @option{end}, and @option{duration} are expressed as time
+duration specifications; see
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}.
Note that the first two sets of the start/end options and the @option{duration}
option look at the frame timestamp, while the _sample options simply count the
is 1024. Only used if plugin have zero inputs.
@item duration, d
-Set the minimum duration of the sourced audio. See the function
-@code{av_parse_time()} for the accepted format, also check the "Time duration"
-section in the ffmpeg-utils manual.
+Set the minimum duration of the sourced audio. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
Note that the resulting duration may be greater than the specified duration,
as the generated audio is always cut at the end of a complete frame.
If not specified, or the expressed duration is negative, the audio is
@end example
@end itemize
+@section silenceremove
+
+Remove silence from the beginning, middle or end of the audio.
+
+The filter accepts the following options:
+
+@table @option
+@item start_periods
+This value is used to indicate if audio should be trimmed at beginning of
+the audio. A value of zero indicates no silence should be trimmed from the
+beginning. When specifying a non-zero value, it trims audio up until it
+finds non-silence. Normally, when trimming silence from beginning of audio
+the @var{start_periods} will be @code{1} but it can be increased to higher
+values to trim all audio up to specific count of non-silence periods.
+Default value is @code{0}.
+
+@item start_duration
+Specify the amount of time that non-silence must be detected before it stops
+trimming audio. By increasing the duration, bursts of noises can be treated
+as silence and trimmed off. Default value is @code{0}.
+
+@item start_threshold
+This indicates what sample value should be treated as silence. For digital
+audio, a value of @code{0} may be fine but for audio recorded from analog,
+you may wish to increase the value to account for background noise.
+Can be specified in dB (in case "dB" is appended to the specified value)
+or amplitude ratio. Default value is @code{0}.
+
+@item stop_periods
+Set the count for trimming silence from the end of audio.
+To remove silence from the middle of a file, specify a @var{stop_periods}
+that is negative. This value is then threated as a positive value and is
+used to indicate the effect should restart processing as specified by
+@var{start_periods}, making it suitable for removing periods of silence
+in the middle of the audio.
+Default value is @code{0}.
+
+@item stop_duration
+Specify a duration of silence that must exist before audio is not copied any
+more. By specifying a higher duration, silence that is wanted can be left in
+the audio.
+Default value is @code{0}.
+
+@item stop_threshold
+This is the same as @option{start_threshold} but for trimming silence from
+the end of audio.
+Can be specified in dB (in case "dB" is appended to the specified value)
+or amplitude ratio. Default value is @code{0}.
+
+@item leave_silence
+This indicate that @var{stop_duration} length of audio should be left intact
+at the beginning of each period of silence.
+For example, if you want to remove long pauses between words but do not want
+to remove the pauses completely. Default value is @code{0}.
+
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+The following example shows how this filter can be used to start a recording
+that does not contain the delay at the start which usually occurs between
+pressing the record button and the start of the performance:
+@example
+silenceremove=1:5:0.02
+@end example
+@end itemize
+
@section treble
Boost or cut treble (upper) frequencies of the audio using a two-pole
must be equal to the number of specified expressions.
@item duration, d
-Set the minimum duration of the sourced audio. See the function
-@code{av_parse_time()} for the accepted format.
+Set the minimum duration of the sourced audio. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
Note that the resulting duration may be greater than the specified
duration, as the generated audio is always cut at the end of a
complete frame.
@end example
@end itemize
+@section codecview
+
+Visualize information exported by some codecs.
+
+Some codecs can export information through frames using side-data or other
+means. For example, some MPEG based codecs export motion vectors through the
+@var{export_mvs} flag in the codec @option{flags2} option.
+
+The filter accepts the following option:
+
+@table @option
+@item mv
+Set motion vectors to visualize.
+
+Available flags for @var{mv} are:
+
+@table @samp
+@item pf
+forward predicted MVs of P-frames
+@item bf
+forward predicted MVs of B-frames
+@item bb
+backward predicted MVs of B-frames
+@end table
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Visualizes multi-directionals MVs from P and B-Frames using @command{ffplay}:
+@example
+ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
+@end example
+@end itemize
+
@section colorbalance
Modify intensity of primary colors (red, green and blue) of input frames.
Denoise frames using 2D DCT (frequency domain filtering).
-This filter is not designed for real time and can be extremely slow.
+This filter is not designed for real time.
The filter accepts the following options:
Default is @code{0}.
@item overlap
-Set number overlapping pixels for each block. Each block is of size
-@code{16x16}. Since the filter can be slow, you may want to reduce this value,
-at the cost of a less effective filter and the risk of various artefacts.
+Set number overlapping pixels for each block. Since the filter can be slow, you
+may want to reduce this value, at the cost of a less effective filter and the
+risk of various artefacts.
If the overlapping value doesn't allow to process the whole input width or
height, a warning will be displayed and according borders won't be denoised.
-Default value is @code{15}.
+Default value is @var{blocksize}-1, which is the best possible setting.
@item expr, e
Set the coefficient factor expression.
The absolute value of the coefficient can be accessed through the @var{c}
variable.
+
+@item n
+Set the @var{blocksize} using the number of bits. @code{1<<@var{n}} defines the
+@var{blocksize}, which is the width and height of the processed blocks.
+
+The default value is @var{3} (8x8) and can be raised to @var{4} for a
+@var{blocksize} of 16x16. Note that changing this setting has huge consequences
+on the speed processing. Also, a larger block size does not necessarily means a
+better de-noising.
@end table
@subsection Examples
dctdnoiz=e='gte(c, 4.5*3)'
@end example
+Violent denoise using a block size of @code{16x16}:
+@example
+dctdnoiz=15:n=4
+@end example
+
@anchor{decimate}
@section decimate
@item expr_int_format, eif
Evaluate the expression's value and output as formatted integer.
-First argument is expression to be evaluated, same as for @var{expr} function.
-Second argument specifies output format. Allowed values are 'x', 'X', 'd' and
-'u', they are treated exactly as in printf function.
-Third parameter is optional and sets the number of positions taken by output.
-Effectively this allows to add padding with zeros from the left.
+The first argument is the expression to be evaluated, just as for the @var{expr} function.
+The second argument specifies the output format. Allowed values are 'x', 'X', 'd' and
+'u'. They are treated exactly as in the printf function.
+The third parameter is optional and sets the number of positions taken by the output.
+It can be used to add padding with zeros from the left.
@item gmtime
The time at which the filter is running, expressed in UTC.
@end example
@item
-Shwo text fading in and out (appearing/disappearing):
+Show text fading in and out (appearing/disappearing):
@example
#!/bin/sh
DS=1.0 # display start
@end example
@end itemize
+@section lenscorrection
+
+Correct radial lens distortion
+
+This filter can be used to correct for radial distortion as can result from the use
+of wide angle lenses, and thereby re-rectify the image. To find the right parameters
+one can use tools available for example as part of opencv or simply trial-and-error.
+To use opencv use the calibration sample (under samples/cpp) from the opencv sources
+and extract the k1 and k2 coefficients from the resulting matrix.
+
+Note that effectively the same filter is available in the open-source tools Krita and
+Digikam from the KDE project.
+
+In contrast to the @ref{vignette} filter, which can also be used to compensate lens errors,
+this filter corrects the distortion of the image, whereas @ref{vignette} corrects the
+brightness distribution, so you may want to use both filters together in certain
+cases, though you will have to take care of ordering, i.e. whether vignetting should
+be applied before or after lens correction.
+
+@subsection Options
+
+The filter accepts the following options:
+
+@table @option
+@item cx
+Relative x-coordinate of the focal point of the image, and thereby the center of the
+distrortion. This value has a range [0,1] and is expressed as fractions of the image
+width.
+@item cy
+Relative y-coordinate of the focal point of the image, and thereby the center of the
+distrortion. This value has a range [0,1] and is expressed as fractions of the image
+height.
+@item k1
+Coefficient of the quadratic correction term. 0.5 means no correction.
+@item k2
+Coefficient of the double quadratic correction term. 0.5 means no correction.
+@end table
+
+The formula that generates the correction is:
+
+@var{r_src} = @var{r_tgt} * (1 + @var{k1} * (@var{r_tgt} / @var{r_0})^2 + @var{k2} * (@var{r_tgt} / @var{r_0})^4)
+
+where @var{r_0} is halve of the image diagonal and @var{r_src} and @var{r_tgt} are the
+distances from the focal point in the source and target images, respectively.
+
@anchor{lut3d}
@section lut3d
The shown line contains a sequence of key/value pairs of the form
@var{key}:@var{value}.
-It accepts the following parameters:
+The following values are shown in the output:
@table @option
@item n
The number of the first frame that should be dropped.
@end table
-@option{start}, @option{end}, @option{duration} are expressed as time
-duration specifications, check the "Time duration" section in the
-ffmpeg-utils manual.
+@option{start}, @option{end}, and @option{duration} are expressed as time
+duration specifications; see
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
Note that the first two sets of the start/end options and the @option{duration}
option look at the frame timestamp, while the _frame variants simply count the
ffmpeg -i in.avi -vf "vflip" out.avi
@end example
+@anchor{vignette}
@section vignette
Make or reverse a natural vignetting effect.
"25".
@item duration, d
-Set the video duration of the sourced video. The accepted syntax is:
-@example
-[-]HH:MM:SS[.m...]
-[-]S+[.m...]
-@end example
-See also the function @code{av_parse_time()}.
+Set the duration of the sourced video. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
If not specified, or the expressed duration is negative, the video is
supposed to be generated forever.
Some examples:
@example
-testsrc=t=dc_luma
+mptestsrc=t=dc_luma
@end example
will generate a "dc_luma" test pattern.
Set the sample aspect ratio of the sourced video.
@item duration, d
-Set the video duration of the sourced video. The accepted syntax is:
-@example
-[-]HH[:MM[:SS[.m...]]]
-[-]S+[.m...]
-@end example
-Also see the the @code{av_parse_time()} function.
+Set the duration of the sourced video. See
+@ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1) manual,ffmpeg-utils}
+for the accepted syntax.
If not specified, or the expressed duration is negative, the video is
supposed to be generated forever.
@table @option
@item volume
-Specify the transform volume (multiplier). Acceptable value is [1.0, 100.0].
-Default value is @code{16.0}.
+Specify transform volume (multiplier) expression. The expression can contain
+variables:
+@table @option
+@item frequency, freq, f
+the frequency where transform is evaluated
+@item timeclamp, tc
+value of timeclamp option
+@end table
+and functions:
+@table @option
+@item a_weighting(f)
+A-weighting of equal loudness
+@item b_weighting(f)
+B-weighting of equal loudness
+@item c_weighting(f)
+C-weighting of equal loudness
+@end table
+Default value is @code{16}.
+
+@item tlength
+Specify transform length expression. The expression can contain variables:
+@table @option
+@item frequency, freq, f
+the frequency where transform is evaluated
+@item timeclamp, tc
+value of timeclamp option
+@end table
+Default value is @code{384/f*tc/(384/f+tc)}.
@item timeclamp
Specify the transform timeclamp. At low frequency, there is trade-off between
@item fontfile
Specify font file for use with freetype. If not specified, use embedded font.
+@item fontcolor
+Specify font color expression. This is arithmetic expression that should return
+integer value 0xRRGGBB. The expression can contain variables:
+@table @option
+@item frequency, freq, f
+the frequency where transform is evaluated
+@item timeclamp, tc
+value of timeclamp option
+@end table
+and functions:
+@table @option
+@item midi(f)
+midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
+@item r(x), g(x), b(x)
+red, green, and blue value of intensity x
+@end table
+Default value is @code{st(0, (midi(f)-59.5)/12);
+st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
+r(1-ld(1)) + b(ld(1))}
+
@item fullhd
If set to 1 (the default), the video size is 1920x1080 (full HD),
if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
@end example
+@item
+B-weighting of equal loudness
+@example
+volume=16*b_weighting(f)
+@end example
+
+@item
+Lower Q factor
+@example
+tlength=100/f*tc/(100/f+tc)
+@end example
+
+@item
+Custom fontcolor, C-note is colored green, others are colored blue
+@example
+fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
+@end example
+
@end itemize
@section showspectrum
@code{640x512}.
@item slide
-Specify if the spectrum should slide along the window. Default value is
-@code{0}.
+Specify how the spectrum should slide along the window.
+
+It accepts the following values:
+@table @samp
+@item replace
+the samples start again on the left when they reach the right
+@item scroll
+the samples scroll from right to left
+@item fullframe
+frames are only produced when the samples reach the right
+@end table
+
+Default value is @code{replace}.
@item mode
Specify display mode.
@item line
Draw a vertical line for each sample.
+
+@item p2p
+Draw a point for each sample and a line between them.
+
+@item cline
+Draw a centered vertical line for each sample.
@end table
Default value is @code{point}.
Set the (approximate) output frame rate. This is done by setting the
option @var{n}. Default value is "25".
+@item split_channels
+Set if channels should be drawn separately or overlap. Default value is 0.
+
@end table
@subsection Examples
projects / platform / framework / web / crosswalk.git / blobdiff