[FFmpeg-user] asubboost and asupercut

Michael Koch astroelectronic at t-online.de
Fri Nov 27 23:40:37 EET 2020

Am 27.11.2020 um 20:50 schrieb Paul B Mahol:
> On Fri, Nov 27, 2020 at 8:24 PM Michael Koch <astroelectronic at t-online.de>
> wrote:
>> Am 27.11.2020 um 19:25 schrieb Paul B Mahol:
>>> On Fri, Nov 27, 2020 at 7:09 PM Michael Koch <
>> astroelectronic at t-online.de>
>>> wrote:
>>>> Hello,
>>>> I have a few questions about the asubboost and asupercut filters.
>>>> -- In asubboost it's not yet clear how the block diagram of the filter
>>>> looks like. Especially the "decay" and "feedback" options are unclear.
>>>> What's the input of the the delay line? Before or after the low pass
>>>> filter? Where does the feedback go to? Before or after the lowpass
>>>> filter? I have attached a sketch of a possible block diagram, but it's
>>>> only a wild guess.
>>> This filter just adds delayed sub frequencies set by cut off frequency
>> back
>>> to output. Decay sets decay of old sub echo in buffer and feedback sets
>> how
>>> much
>>> new sub frequencies are added to the delay buffer.
>> Sorry, I didn't understand it. I think this filter could be explained
>> much better with a block diagram.
>>>> -- Is it correct that the "slope" parameter effectively changes the
>>>> cutoff frequency, but doesn't change the steepness (dB / octave) of the
>>>> filter?
>>> It changes steepness, not cutoff.
>> What's the unit of the "slope" option?
> 1 / octave, can be set as dB unit, eg. -20dB, 0dB or 1 is max value.
> Use mentioned mpv command for the reason, as it displays curve.

The command does not work on my computer. I did download mpv.exe and run 
the command line. mpv exits immediately, no output, no error message. 
When I run mpv without any options, then a mpv window opens.


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