[vorbis] Spectrum duplication (2)

[Headless]

Tuesday, June 17, 2003, 01:55, you wrote:

> Yes, the implementation is done to remain backward compatible. This,
> however, is hardly related to the technique itself, which is 
> duplicating part of the spectrum using some auxilary data.

>> Ogg doesn't need that sort of nonsense.

> The backward compatibility stuff, no. But a technique that can maybe 
> improve percieved quality? Would make sense to consider it at least. 
> IMHO.

For me Ogg V1 equaled the performance of MP3Pro at low bitrates when I
compared some 70 sound samples. So imo there's nothing to fix.

>> There is nothing to "fix" for MP3Pro at higher bitrates, which is why
>> proper MP3Pro encoders only allow encoding up to a certain bitrate.

> Right.. but none the less, they made AACpro or whatever it's called, 
> which apparently employes the same "technology", viz. the spectrum 
> duplication stuff, to improve on AAC's quality in low bitrates.

AAC suffers for the same problem that MP3 suffers from, it's an old
format that isn't efficient enough by modern standards. Thus it
performed badly when compared to modern encoders, hence it needed a
similar sort of "fix" for it to remain competitive.

Ogg does not fall in this old inefficient encoder category.

<p>Headless

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.