[FFmpeg-user] asubboost and asupercut

[Paul B Mahol]

On Sat, Nov 28, 2020 at 1:35 PM Michael Koch <astroelectronic at t-online.de>
wrote:

> Am 28.11.2020 um 12:57 schrieb Paul B Mahol:
> > On Sat, Nov 28, 2020 at 12:41 PM Michael Koch <
> astroelectronic at t-online.de>
> > wrote:
> >
> >> 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.
> >> I did try to reverse engineer the asubboost filter from its output
> >> signal. Is the attached sketch correct?
> >> It seems the "feedback" parameter is unnecessary because it does exactly
> >> the same thing as "wet".
> >>
> > No, your reasoning is invalid.
> >
> > I do not have time to draw graphs or do consulting for free.
>
> When you swap the values of "wet" and "feedback", the output does always
> remain the same.
> If you think that I'm wrong, please show an example to prove the opposite.
>

Make sure that you take into account decay parameter, delay buffer is still
used.

I do not want to lost more time in such pointless discussions.
As better time is spent developing code more then teaching someone to
properly read and understand source code.



> Michael
>
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