[FFmpeg-trac] #9461(avfilter:new): Showpectrumpic: scale doesn't work anymore (was: Showpectrum scale doesn't work anymore)

[FFmpeg]

#9461: Showpectrumpic: scale doesn't work anymore
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             Reporter:  RKleinert   |                    Owner:  (none)
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avfilter
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Changes (by RKleinert):

 * summary:  Showpectrum scale doesn't work anymore => Showpectrumpic: scale
     doesn't work anymore


Old description:

> == Summary of the bug: ==
> In https://trac.ffmpeg.org/ticket/8919 I had adressed a bug that would
> mess up the scaling of the frequency-axis in showspectrum() and
> showspectrumpic() when choosing a starting-frequency that is not zero.
> This bug is now supposedly fixed.
>
> Now after the "fix" both functions won't work anymore at all when used
> with my prevousily used arguments. Especialy defining an output size
> (which is crucial) seems to lead to a never ending loop where ffmepg
> doesn't get anywhere. My batch-script doesn't end and no output is
> written.
>
> Secondly I noticed, that the argument "legend" doesn't default to 0 (as
> it states in the doc) but to 1 - so the legend and axes are always
> enabled if not actively disabled.
>
> == How to reproduce: ==
> {{{
> #!div style="font-size: 80%"
> The Sample Code:
>   ffmpeg -i input.wav -filter_complex
> "showspectrumpic=size=700x400:mode=combined:color=rainbow:scale=sqrt:fscale=log:legend=1:start=500:stop=20000"
> output.png
>
> leads into an endless loop. Whereas the code without the size-argument:
>   ffmpeg -i input.wav -filter_complex
> "showspectrumpic=mode=combined:color=rainbow:scale=sqrt:fscale=log:legend=1:start=500:stop=20000"
> output.png
> does the trick (although it takes quite some time to run)
> }}}
> {{{
> ffmpeg version 2021-10-18-git-d04c005021-full
> built from gyan.dev
> }}}
>
> I supplied the input.wav file which is a test-sample with a 1kHz-Sinewave

New description:

 == Summary of the bug: ==
 In https://trac.ffmpeg.org/ticket/8919 I had adressed a bug that would
 mess up the scaling of the frequency-axis in showspectrum() and
 showspectrumpic() when choosing a starting-frequency that is not zero.
 This bug is now supposedly fixed.

 Now after the fix Showspectrum() seems to work just fine. On  the other
 hand '''showspectrumpic() won't work anymore at all''' when used with my
 prevousily used arguments. Especialy defining an output size (which is
 crucial) seems to lead to a never ending loop where ffmepg doesn't get
 anywhere. My batch-script doesn't end and no output is written.

 Secondly I noticed, that the argument "legend" doesn't default to 0 (as it
 states in the doc) but to 1 - so the legend and axes are always enabled if
 not actively disabled.

 == How to reproduce: ==
 {{{
 #!div style="font-size: 80%"
 The Sample Code:
   ffmpeg -i input.wav -filter_complex
 "showspectrumpic=size=700x400:mode=combined:color=rainbow:scale=sqrt:fscale=log:legend=1:start=500:stop=20000"
 output.png

 leads into an endless loop. Whereas the code without the size-argument:
   ffmpeg -i input.wav -filter_complex
 "showspectrumpic=mode=combined:color=rainbow:scale=sqrt:fscale=log:legend=1:start=500:stop=20000"
 output.png
 does the trick (although it takes quite some time to run)
 }}}
 {{{
 ffmpeg version 2021-10-18-git-d04c005021-full
 built from gyan.dev
 }}}

 I supplied the input.wav file which is a test-sample with a 1kHz-Sinewave

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Ticket URL: <https://trac.ffmpeg.org/ticket/9461#comment:1>
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