[vorbis-dev] slightly different audio output
Owen.Emry at corp.palm.com
Mon Apr 8 16:11:04 PDT 2002
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.
<p>--- >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-dev-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.
More information about the Vorbis-dev