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

Isaac Richards mythtv-dev@snowman.net
Tue, 10 Dec 2002 15:26:47 -0500


On Tuesday 10 December 2002 04:53 am, kevin thayer wrote:
> Can anyone comment on the feasability of using a
> really space-inefficient but cpu friendly codec to do
> time-shifting tv watching (pause/ff/etc live tv)?
> (would disk throughput become *the* factor?)

Disk speed pretty quickly becomes a factor then, yeah, at least with watching 
live-tv.

> What would rock is a table of codecs and max seamless
> record/watch resolution for various cpu's.. That's a
> TALL order though :)
>
> This may be a dumb question, but using software, can
> you specify an arbitrary resolution and thereby
> squeeze the maximum SOFTWARE performance out of your
> cpu? (ie. increase the size till it chokes) I know
> there is a size setting, but not sure how configurable
> it is.

It'll only capture to what the tuner card will output..   Doing any 
cropping/resizing in software is relatively expensive, so I don't think you'd 
see any gains by doing it.

> Can you use other (untested?) codecs for
> record/playback by changing that line of the config
> file to other libavcodec supported codecs?

Yup.  I've tested with their mjpeg and huffyuv encoders..  I don't think that 
using the mpeg1 encoder works right, though.  

Isaac