Re: [Vorbis] Vorbis at first place in "Public, Multiformat Listening Test @ 128 kbps"

Fabio Pedretti fabio.ped at libero.it
Tue Jan 17 08:18:13 PST 2006


> The relevant summary of the test is that all codecs (except Shine) 
> perform similarly well at ~128kbps and are very close to transparent 
> encoding. I didn't see any of this mentioned in your first message.

Yes, you are right. Anyway it is good to see that Vorbis is still with the
best encoders.

> They don't really explain why they've _chosen_ different bitrates. I 
> haven't read the entire discussion, but their explanation seem to be the 
> difficulty of using VBR quality settings and obtain comparable bit 
> rates. That is an explanation why they were not _able_ to use same bit 
> rates and not an explanation why they _chose_ to use different bit 
> rates.

Seems they used this quality value because with a larger test sample the
bitarate of all codecs were similar. The samples used in the test have
different bitarate thought.

> It is of course not reasonable to compare perentual differences 
> in the quality score and the sample bit rates, but considering that the 
> Vorbis encoder scored only 1% better than iTunes' AAC encoder and 2% 
> better than WMA, the 7-8% bit rate difference may very well have impact 
> on the strict (and irrelevant) result order.

Seems that at this bitrate a slight different bitrate doesn't change a lot
the quality. Also the quality is a subjective measure, so we can't say that
a codec is X% better than another if it gets a value X% higher.



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