[vorbis] MP3/Vorbis comparision

[Frank Grotelueschen]

Giuliano Pochini wrote:

>The tests show strange ripples and pre/post-echo in -q4 encoded
>sine of 4410Hz. Vorbis file at -q4 is about 24Kbps and .mp3
>is 64Kbps. The spectral analysis show that the ogg file is better
>the mp3 even if in time domain it doesn't look so. The strange
>thing is the ripple. I tried several frequencies and all quality
>levels and there is always a tremolo effect for free.

I can see this ripple in your files too. The mp3-files has no ripple.
And the pre/post echos are much lower as ogg. But it is audible?
I have generated a sinus tone sweep from 20Hz up to 22KHz at -6dB with
30sec length. After encoding with ogg q4, the ripple is always visible,
but it is not audible. At every frequency, i can not hear this ripple.
Maybe a test with pure sine tones is a test, which is too hard for
lossy encoding with mp3 and ogg. In normal music, pure sine tones and
abrupt level changes from digital silence to -6dB should never occur.
Ogg's main problem is the high frequency boost, but besides this,
music encoded with ogg sounds very well.

Frank

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