[mythtv-users] Hardware resrouces required for s/w encode

James Crow james at ultratans.com
Thu Feb 4 14:23:35 UTC 2010

> Since I've got a 2.3GHz X4 CPU, I'm assuming that s/w MPEG-4 (or 
> RTjpeg) encode can easily be taken care of by the CPU.
> Am I correct? Or have I overlooked something?
> I'm also assuming that the GHz performance of a single core is not the 
> determining factor in whether or not s/w encode is possible, and that 
> codecs are multi-threaded to share the load across cores. If not, I'm 
> concerned (given Hauppauge's min. requirement of a 3GHz P4) that a 
> single 2.3GHz core won't be man enough for the job.
I don't know about the HVR-4000, but if it lacks HW mpeg2 encoding chips 
then you will need software encoding for the analog inputs (composite, 
RF or coax, etc). I have two analog software encoders on my Myth setup.

Under Mythbuntu 9.04/Myth 0.21 I was able to use RTjpeg. With Mythbuntu 
9.10/Myth 0.22 I am unable to use RTjpeg and can only use MPEG4. For me 
RTJpeg gave a slightly better picture in the finished recording. I am 
now using MPEG4 with the high quality options turned on, bitrate of 
3200, and the Max Quality settings at 1. This is the best I have found 
for my setup with MPEG4. The picture is a little softer (i.e. slightly 
blurred) than the picture I got with RTJpeg, but the best I can 
currently get.

I have a Phenom II x4 3.0 GHz. A single software encoding takes 
approximately 30% of one core. Your 2.3 GHz Athlon should have no 
problem with software encoding. I have no proof, but I would think a 
modern Athlon would soundly beat a P4 on a clock per clock comparison.


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