Re: YUV format

Ed Okerson wrote:
> On Sat, 21 Dec 2002, Holger Waechtler wrote:
> 
> 
>>Yes, you can modify tarkin.c to use lower resulution for U and V.
> 
> 
> OK, I have a working encoder that reads YUV4MPEG2 file format now.  It is
> somewhat slow, it took 711 minutes to encode a clip with 3636 frames.  I

well, IIRC I was able to encode and decode about 20 frames/sec at CIF 
resolution on a Duron with 800 MHz at decent bitrates (about 3-8kBytes 
per frame). Without any optimisation.

> also modified the tarkin_sdl_player to use YUV overlays so it can handle
> the native YUV12 format.  Playback appears to be at 1 frame every 1 - 2
> seconds, and after a few frames the image degrades into random patterns.

?!?

> Have I really messed something up, or is this the current state of the
> codec?  I am running the encoder as
> 
> tarkin_enc_yuv stream.yuv 100000 2 2

Why do you want to use such high bitrates?


> I also tried with 3000 instead of 100000 and it just made larger Moire
> patterns.

you have to deinterlace your movies before encoding.

After all you should remember that this code is for research, it 
compresses oonly in statial domain and does not exploits any temporal 
coherence.

So you have to compare it to still image comression algorithms, not to 
video codecs unless you add a motion compensation scheme before.

Holger

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