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

Michael PARKER michael.parker at st.com
Thu Feb 4 14:27:04 UTC 2010


James,

That's just the info/reassurance I needed - many thanks.

Mike 

> -----Original Message-----
> From: James Crow [mailto:james at ultratans.com] 
> Sent: Thursday, February 04, 2010 2:24 PM
> To: michael.parker at st.com; Discussion about mythtv
> Subject: Re: [mythtv-users] Hardware resrouces required for s/w encode
> 
> 
> >
> >
> > 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.
> 
> Cheers,
> James
> 



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