[mythtv] encoding vs decoding

[Joseph A. Caputo]

On Monday 13 October 2003 05:06 pm, Michael J. Hammel wrote:
> According to the docs, a Celeron 450 takes about 2% CPU to encode a
> stream but takes about 80% to decode.  Is that a typo or is that about
> right?  

Um, sounds like a typo to me.  A Celeron 450 is probably not even enough to 
encode a stream at any reasonable quality, and is probably barely enough to 
play one back.  The docs do state that "A dual Celeron/450MHz is able to view 
a 480x480 MPEG-4/3300kbps file created on a different system with 30% CPU 
usage."  Note the use of the word "dual" before "Celeron".

If you have a PVR-250 (which I'd guess you don't), you can encode with a 
Celeron-450, as it won't require much/any CPU to encode.  But then you'll 
still be pushing that machine really hard to try and play back the recorded 
MPEG-2 stream.

Bottom line:  a Celeron 450 is grossly underpowered to serve as a combined 
backend/frontend for Myth, unless you've got hardware that does both encoding 
and decoding (say, a PVR-350).


...which brings up a good question for someone (Isaac):  How little CPU could 
I get away with (for recording and for playback) with various hardware 
encoding/decoding options?  i.e., how little CPU could I get away with to run 
mythbackend with a hardware MPEG-2 encoder, and how little could I get away 
with to run mythfrontend w/full-screen playback using a hardware MPEG-2 
decoder (i.e., PVR-350).  I've got a Pentium-150 lying around, and may soon 
have an extra PII-333...


-JAC