Thread: What is that?
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Old 04 March 2009, 08:22 am   #3
dev
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Join Date: Mar 2009
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Quote:
Originally Posted by Shy View Post
1. your "graphs" are undetailed, to say the least.

2. it can't be simply explained in one sentence or even many. You should learn how various forms of audio processing, and specifically, audio coding formats work if you want to understand exactly what you can see in graphs.

3. In short, with a sine wave sweep, more than with any other audio content, you will see lots of interesting "artifacts" when you apply any form of audio processing. Be it dividing the audio into bands (as Musepack does, among many other things), applying simple filtering, various forms of FFT processing, resampling, etc. etc.
What you see in a graph (and especially one of a processed pure sine wave), doesn't necessarily reflect what you hear.

Suggestion: try to generate a sawtooth tone or sweep, then look closely and ask yourself how come while what you're hearing is a sawtooth wave, the actual graphical representation of it looks more like a swirly ramp.

1. Yes, I wanted to put it simply, but to correct that; on my spectrum analizer original PCM is shown above, the "Musepack" graphs, I wanted to show that added sinwave in slideshow, as it goes from left to right and gets biger... .

2. Problem is that there is not much specification on Musepack from what I could find, and from technical point of view I`m intreested as to why this sinvawe goes louder and louder as sweep goes up on frequency, I`m not asking as "why the hell it`s there? :evil: ", simply what for what that gives, some ath, noise normalization... ?

3. "What you see in a graph (and especially one of a processed pure sine wave), doesn't necessarily reflect what you hear." - I know they don`t
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