[theora] A comparison of VP3, and two MPEG-4 variants

Colin Mckellar blibblelibby at black-market-babies.com
Tue Mar 25 06:56:40 PST 2003

On Monday, March 24, 2003, at 06:00  PM, Christoph Lampert wrote:
> Hi,
> interesting indeed. But it would be more useful for others if you
> could test again a standardized test set of sequences like
> standard MPEG's CIF/QCIF sequences, for download e.g. at
> http://delboy.ucd.ie:9997/Files/Downloads/
> also, there is a mirror of VQEG sequences at
> http://media.xiph.org/vqeg/TestSequences/Reference/
> Unfortunately they are all interlaced, but a real challange for video
> encoding routines.

Interesting. I will look at those. However, since they are interlaced, 
that is a serious limitation. None of the codecs that I used support 
interlaced video.. so testing them with interlaced video is unrealistic.
I believe that interlacing in this day and age is unnecessary. 
Interlacing really only has a place on old school TVs.

> Without preprocessing, scaling, cropping those ckips should give
> PSNR numbers that can be compared to others codecs, e.g. from DivX and
> XviD or ffmpeg.

The version of VP3 that I have includes a de-noise filter prior to 
encoding. I am too unskilled to be able to edit the source to remove 

> If there isn't a possibility to encode raw YUV or RGB with quicktime
> codecs, you really should create one. I can't think of developing a 
> codec
> without it.

QT can give YUV, or RGB data to codecs, depending on how they declare 
what colourspaces they accept. (3ivx, for example, has advertised a 
great deal, that it can accept YUV video directly)


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