aphaser¶Watch on youtube.com
The description in the official documentation:
Add a phasing effect to the input audio.
A phaser filter creates series of peaks and troughs in the frequency spectrum. The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
Each segment of the uploaded video was created with the following script:
#! /bin/sh ffmpeg -hide_banner -y -filter_complex " amovie=wolframtones_01.wav ,atrim=0:15,afade=t=out:st=14.5:d=0.5 ,aphaser= in_gain=0.4 :out_gain=0.74 :delay=3.0 :decay=0.4 :speed=0.5 :type=t ,aformat=sample_fmts=u8|s16:channel_layouts=stereo ,asplit=3[out1][a1][a2]; [a1]showfreqs=s=$((1280/5*3))x720:fscale=log:cmode=separate[v1]; [a2]showwaves=s=$((1280/5*2))x720:mode=cline:split_channels=1[v2]; [v2][v1]hstack ,format=yuv420p [out0]" -map '[out0]' -map '[out1]' out.mp4
The effect of this is so obvious that I won’t say anything.
- see also