[mythtv] Trading CPU for disk (capture using low cpu codec?)

Ray mythtv-dev@snowman.net
Tue, 10 Dec 2002 13:01:35 -0700


On Tue, Dec 10, 2002 at 01:53:48AM -0800, kevin thayer wrote:
> Has anyone experimented with the trade-offs between
> CPU usage and disk size?
> 
> I have a dual celeron setup, at 500mhz each, they
> aren't terribly powerful, but I have heard tales of
> people using inefficient codecs and getting decent
> performance out of their slow pcs using a "really
> light weight encoder" (RAW?) and then compresing it
> during off hours.

Rtjpeg which is already supported by Myth is pretty light weight so if you
can get the quality you want from that....   There are also lossless
compression codecs out there which should have equivalent quality to raw yuv
but I have no idea what the speed is like.  IMHO doing uncompressed capture
isn't worth it due to the massive storage space and storage bandwidth
required.  I know disk space is cheap but it isn't THAT cheap, especially
compared to cpu.  

Personally, I think a better question is which compression codecs will hurt
quality least if you want to do manipulations of the resulting files
(denoising, commercial cutting, etc).  My gut feeling is that frame based
compressors such as rtjpeg/mjpeg/dv? would be best but it really depends on
what tools are out there to do the manipulations and formats it works with.    

-- 
Ray