Re: SF2: bsefextract produces -inf

[Tim Janik <timj gnu org>]

On 09.03.2017 17:33, Stefan Westerfeld wrote:
>    Hi!
>
> On Thu, Mar 09, 2017 at 04:01:00PM +0100, Tim Janik wrote:
> > with current wip/soundfont, I'm getting -inf on some audio tests.
> >
> > Here's a test case for -inf results from bsefextract:
> >
> >   http://testbit.eu/~timj/.tmp/sum-diff-test.wav
> >
> > (temporary URL, will be removed at some point in the future)
> >
> > tools/bsefextract sum-diff-test.wav --cut-zeros --channel 0 --avg-spectrum \
> >   --spectrum --avg-energy
> >
> > gives:
> >
> > avg_energy = -inf;
>
> Not here (with your file):
>
> $ ../tools/bsefextract --cut-zeros --channel 0 --avg-spectrum --spectrum --avg-energy sum-diff-test.wav
> # this output was generated by bsefextract 0.10.1~wip from channel 0 in file sum-diff-test.wav
> #
> # --spectrum: generate 30ms sliced frequency spectrums
> spectrum[0,0] = {
> };
> # --avg-spectrum: average frequency spectrum
> avg_spectrum[0] = { };
> # --avg-energy: average signal energy in dB
> avg_energy = -5.61784072;

Ah, ok, that was the file from a different run then.

Please download again, I've updated the file with one that has just zeros.

> Note that it will return -inf if the input sample is completely silent,
> basically because average energy is measured in dB, and db(0) -> -inf.

Right, but that still leaves this warning unfixed:

../../tools/bsefextract sum-diff-test.wav --cut-zeros --channel 0 --avg-spectrum
--spectrum --avg-energy  > sum-diff-test.tmp
../../tools/bsefcompare ./sum-diff-test.ref sum-diff-test.tmp --threshold 99.99
sum-diff-test.tmp:9: error: unexpected identifier 'inf', expected number (float)

I.e. either you change the output to say something like "0" if there's no
energy,or bsefcompare should be prepared to handle +inf and -inf.

> In any case I'd recommend finding a strategy
> that reliably reduces the number of zeros produced before the actual output to
> a minimum.

Yes, but that's a different topic/bug.

>    Cu... Stefan

-- 
Yours sincerely,
Tim Janik

https://testbit.eu/timj/
Free software author.