[vorbis-dev] end-user mode for a moment (side-by-side tests)

[Jelle Foks]

Ralph Giles wrote:
> 
> On Wed, 13 Sep 2000, Kenneth Arnold wrote:
> 
> > Thanks, Ralph, for the Ogg todo sent a while ago. I've only now got to really
> > studying it and looking at what to do. Looks like video is it. So a couple
> > questions for the list:
> 
> Glad it was helpful. If anyone's interested, I've put up a version at
> http://snow.ashlu.bc.ca/ogg/todo.html
> 
> > 1. Where's the Tarkin source anyway?
> 
> Jack's still sitting on it?
> 
> The wavelet part wouldn't be hard to re-create I think. A good exercise
> anyway (where have you heard that before?) Just look for a basic tutorial
> on the web. The quantization is probably trickier.

The quantization is mostly a matter of tuning (subjective) unless you
want to use nonuniform quantization (I like that idea)

And I'd also say finding the order in which it's most efficient to
encode/transmit the wavelet coefficients (zerotree is popular).

> > 2. I am aware that Tarkin uses wavelets. MPEG uses object detection and
> > motion estimation. What other methods are out there? Does anybody know
> > of any new, cool methods for compressing video? Or, failing that, does
> > anybody know [of] anyone who does?
> 
> Aren't wavelets new? Especially as a 2+1 dimensional transform. If you
> want a larger space for the encoder to play in, Monty has pointed out
> Steve Mann's work on chirplets. My understanding in that direction pretty
> much stops at a hunch it might by fruitful. :-)

Wavelets are pretty new. MPEG4 allows objects to be described in the
wavelet domain, H.26L or it's followup will probably support wavelets,
and, of course, we have JPEG2000 which is fully based on wavelets. All
2d wavelets though.

> http://wearcam.org/chirplet.html
> 
> Note that including a series of frames (time) in the transform domain is a
> form of motion compensation, and a sophisticated one.
> 
> Hope that helps,
>  -r
> 
> --
> giles at ashlu.bc.ca
> 
> --- >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.

--- >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.