[vorbis-dev] slightly different audio output

[Owen Emry]

Segher Boessenkool wrote:
>Adrien Beau wrote:
>> 
>> On Monday 8 April 2002 14:51, Owen Emry wrote:
>> >
>> > >Some slight differences will be unavoidable, I think.  But
>> > > nothing bigger than off-by-one.
>> >
>> > Off by one what?  One in the LSB of a 16-bit integer sample?
>> > Nonsense.  :) Think about it:  Take an original piece of PCM
>> > data, encode it with Vorbis, and then decode it again using
>> > the reference libvorbis.  Certainly you would expect the
>> > vorbis step to inflict more than an "off-by-one" effect on
>> > each sample.
>> 
>> I think Segher perfectly knows this.
>> 
>> > Thus perhaps the real question is whether or not a given
>> > libvorbis delivers results that are at least as "lossless" as
>> > the reference library.
>> 
>> Thus perhaps Segher meant that he expects nothing bigger
>> than off-by-one between the output of a given libvorbis and
>> the output of the reference library.

Whereas what I meant is that this seems unrealistic, given that the
difference introduced by the codec is an order of magnitude greater.

>Exactly.  Which was exactly what the original post was about.  And
>errors of more than 1% seem way too big, to me.  But the exact
>requirements should be set in the formal spec, which doesn't exist yet.

I thought you were talking about a difference of 1, not 1%.  Anyway, you're
correct; there ought to be a spec for tolerable variance, but I still
maintain it's a more complicated analysis.

-Owen

<p>--- >8 ----
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