[FFmpeg-user] exponential decay, is it possible?

[Michael Koch]

>>
>> Every time when the input becomes brighter than the last output frame,
>> the output is set to the input value. If input is below the last output
>> value, then exponential decay.
>> I have a timelapse video of the night sky with meteors. Each meteor is
>> visible only in one frame. I'd like to make them visible a little
>> longer, decaying over several frames.
>>
>> Example:
>> Input   Output
>> 0     0
>> 1     1            // set to input value
>> 0     0.95      // exponential decay begins
>> 0     0.90
>> 0.50     0.86
>> 0.50     0.81     // until here
>> 0.90     0.90     // now set again to input value, because input is
>> brighter
>> 0.90     0.90     // keep at the same level
>> 0.60     0.86     // exponential decay begins
>> 0.60     0.81
>> 0.60     0.77
> If it is calculating global luma instead of local one, it can be added
> to deflicker filter.
> Otherwise you will need to write new video filter.

I need it local for all pixels.

Michael