[opus] Antw: Re: Antw: Re: Possible bug in Opus 1.3

[Jan Stary]

On Nov 05 18:00:06, hans at stare.cz wrote:
> On Nov 05 11:32:49, hans at stare.cz wrote:
> > On Nov 05 11:05:34, hans at stare.cz wrote:
> > > > Did you also try to listen at the beginning, shortly before the real tone appears in the audible spectrum? While significantly larger, Opus had produced significant ghost noise (much less than Vorbis did)...
> 
> I experience the "same" low level noise even in a wav file,
> even on frequencies a bit higher, when playing on shitty enough speakers.
> I don't think it is a relict of the compression (it cannot be, here).
> 
> Every speaker (or headphones) is designed for a certain frequency range.
> Outside of that range, all bets are off. I wouldn't bother with what you
> "hear" outside of the audible spectrum.
> 
> My current bet is that the very low frequencies are correctly
> represented in the Opus file, but your speaker/headphones
> are not capable to play them properly (which is no wonder).

Attached I send the spectrogram (vic SoX) of the first 20 seconds
for the wav file and the opus file. Indeed, there is extra noise
for the low frequencies, but somewhere around -100 dB.

	Jan

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