[mythtv-users] Suggested Encoding Rates

[Alexander Varakin]

Output of PVR-?50 at 6-8Mb/s is as good as uncompressed.
It is also a good idea to apply slight temporal filter of PVR-?50 if your 
singnal is noisy.  

As for realtime encoding idea, I've been there and don't want to go back.
Encoding is not all what you want to do while recording, you also want to 
deinterlace and apply denoising filter. Denoising and deinterlacing are very 
important because they allow much better compression.  You need  a good 
horsepower to do this, at least 2GHz.  Such hardware is noisy (or expensive) 
and consumes about 150W of power, so you have to pay about $10 for 
electricity bill each month if you run backend 24x7.  Also raw capture cards 
often have issues with audio sync. One more thing:  obviously it is not 
possible to  do multipass encoding  in real time.
On the other hand, PVR-?50 can be run on older hardware (e.g PIII) which 
consumes only 30W and can be easily made silent.


> >
> > If you're reencoding already encoded files it's too late.
>
> To some extent.  But I think if you record 720x480 at a high bitrate
> (8mbit) on your pvr-250, you can then reduce that to something lesser like
> 480x480 mpeg4 without doing too much worse than having done it from the
> raw.
>