[FFmpeg-user] Documentation and feature request

Carl Eugen Hoyos ceffmpeg at gmail.com
Sun Apr 28 20:32:40 EEST 2019

2019-04-28 18:25 GMT+02:00, Michael Koch <astroelectronic at t-online.de>:
>>> Feature request:
>>> -- Decay filter, makes short flashes of light appear longer, with an
>>> exponential decay curve. Like on an analog oscilloscope screen with long
>>> persistence time. Could be used for videos of the night sky to make fast
>>> meteors appear longer. Should work as follows:
>>> For each pixel do:  Multiply the RGB values from the previous output
>>> frame with a decay constant in the range [0..1], for example 0.95. Use
>>> these RGB values for the next output frame. But if the RGB value from
>>> the next input frame is brigher than this, then use the brighter value.
>> Implemented as lagfun filter.
>> See ffmpeg-devel mailing list.
> Tested and working very good. Here is an example of a meteor in real
> time, left side without and right side with lagfun filter:
> https://www.youtube.com/watch?v=Bc_lLGOHjjM

Thank you for the demonstration!

Carl Eugen

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