Hi,

> Right.  Input is broadcast (cable) and output is to a television.
>
> > 2 fps does not
> > sound unreasonable for an Athlon 800Mhz considering that disk I/O and
> > lav2yuv are going to slow things down.
>
> So it seems.  It's just so disappointing.  I mean considering mp1e can
> encode mpeg1 realtime @ 640x480 on this hardware, I was just hoping
> for (a sight!) better than 2-4fps from mpeg2enc.  

There are two main reasons for the big performance difference.

1.  MPEG-2 simply requires more work (lots more motion estimation modes to 
choose between).

2.  mp1e is really really optimised.   However, some of things it does (like 
combined DCT/Quantisation) make it harder to support really high quality 
encoding.   One big unnecessary defect in the way mpeg2enc works is that it 
basically does each phase of MPEG encoding a frame at a time rather than a 
macro-block at a time.  This does bad things to the data cache.  The other 
"defect" is that there is no way to switch out the optimised-for-high-quality 
motion estimator in favour of a quick-and-dirty motion estimator for 
speed-critical applications.

I'm currently starting work restructuring mpeg2enc.  This should 
significantly improve maximum encoding speed as an early side-effect.
  
Andrew

> Boy do I wish we North Americans were not so lame so as to suck up
> whatever proprietary systems the cable and satellite vendors throw at
> us.  DVB would be soooooo nice.

Toys for the new year are going to be a DVB-Sat card and a DVD burner ;-)


Andrew
PS
The Brits are nicely locked into Rupert Murdochs proprietary Sky Satellite 
technology.  No DVB cards there... not even the option to by decent quality 
set-top boxes at sane prices...


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