[vorbis-dev] comparison of beta2 and beta3 encoder quality

[Marshall Eubanks]

Michael Smith wrote:
> 
> >Will vorbis never support 24 bit ( or more ) input and/or output ?
> 
> Vorbis doesn't use integer samples internally at all - so it doesn't care.
> It'd be easy to change an encoder/decoder to use 24 bit samples.
> 
> However, vorbis is a perceptual audio codec. As such, you can't,
> realistically, get 24 bits of precision anyway. It'd internally treat it
> the same as it does 16 bit samples (though the original input data would
> have more precision, so the results might have slightly better precision).
> 
> Michael

But it would get you more dynamic range, which is I think the more
fundamental reason for having these extra bits to begin with. 
Compression techniques that use floating point offer near infinite
dynamic range, so Vorbis should be able to make use of the extra bits.

16 bits - dynamic range is 1 to 65,536 or ~ 96 dB (in power) 
24 bits - dynamic range is 1 to 16.8 million or ~ 144 dB (in power).

I don't think that the ear can hear 24 bits of precision as a general
rule :)
It does, however, have a dynamic range of over 120 dB at 4 kHz. So if
you were going to record something that went from a whisper to ear splitting
rock and roll you could use those extra bits.

                                   Regards
                                   Marshall Eubanks

   Multicast Technologies, Inc.
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