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author | Paul B Mahol <onemda@gmail.com> | 2018-01-01 15:34:02 +0100 |
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committer | Paul B Mahol <onemda@gmail.com> | 2018-01-04 12:26:19 +0100 |
commit | 89bbf5c7ec18a3dff2e2505883a662d182ca6c3a (patch) | |
tree | f9a4d472de455b25d11ac3556b7b23b9e09bbe59 /doc | |
parent | 695b1d81117d6708a5db2d7115b73ef7c6e1a090 (diff) | |
download | ffmpeg-streaming-89bbf5c7ec18a3dff2e2505883a662d182ca6c3a.zip ffmpeg-streaming-89bbf5c7ec18a3dff2e2505883a662d182ca6c3a.tar.gz |
avfilter: add hilbert source FIR filter
Signed-off-by: Paul B Mahol <onemda@gmail.com>
Diffstat (limited to 'doc')
-rw-r--r-- | doc/filters.texi | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 477f833..73537c5 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -926,6 +926,7 @@ afftfilt="1-clip((b/nb)*b,0,1)" @end example @end itemize +@anchor{afir} @section afir Apply an arbitrary Frequency Impulse Response filter. @@ -4873,6 +4874,33 @@ anoisesrc=d=60:c=pink:r=44100:a=0.5 @end example @end itemize +@section hilbert + +Generate odd-tap Hilbert transform FIR coefficients. + +The resulting stream can be used with @ref{afir} filter for phase-shifting +the signal by 90 degrees. + +This is used in many matrix coding schemes and for analytic signal generation. +The process is often written as a multiplication by i (or j), the imaginary unit. + +The filter accepts the following options: + +@table @option + +@item sample_rate, s +Set sample rate, default is 44100. + +@item taps, t +Set length of FIR filter, default is 22051. + +@item nb_samples, n +Set number of samples per each frame. + +@item win_func, w +Set window function to be used when generating FIR coefficients. +@end table + @section sine Generate an audio signal made of a sine wave with amplitude 1/8. |