MPEG Hardware Acceleration & Digital TV Cards

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

Hi,

I'm planning to build a HTPC with a digital TV card, and I'd like to
do this on a GNU/Linux - EPIA mini-itx based system.

I currently have a Nebula Electronics DigiTV card in my desktop and
would like to use this, but their support tells me that current EPIA
systems are not powerful enough as their card uses software decoding.

What I don't understand is this - the EPIA M series boards have some
form of MPEG hardware acceleration, and are sufficiently powerful to
play back DVDs, so why can they not play digital tv?

Is the digital tv broadcast in a different flavour of MPEG to the DVD
stuff, and requires conversion? I was under the impression that the
terrestrial digital signal (in Australia) was broadcast in MPEG2
format and could be recorded to disk directly, and then played back -
hopefully using the motherboards hardware decoding. For direct play,
just decode and play the signal directly.

Is the Nebula card just unable to access the hardware decoding on the
EPIA board?

Would I be better off using a hardware enabled card (such as the
Hauppage Nexus-T - if I can find one!) and a less powerful motherboard
without hardware acceleration?

Surely I don't need hardware acceleration on both the TV card and the
motherboard!

Any thoughts on this, or references to web resources much appreciated.

Barney

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

barney.b@iname.com (Barney Barumba) wrote in message news:<696a5dea.0405172108.1091e262@posting.google.com>...
> Hi,
>
> I'm planning to build a HTPC with a digital TV card, and I'd like to
> do this on a GNU/Linux - EPIA mini-itx based system.
>
> I currently have a Nebula Electronics DigiTV card in my desktop and
> would like to use this, but their support tells me that current EPIA
> systems are not powerful enough as their card uses software decoding.
>
> What I don't understand is this - the EPIA M series boards have some
> form of MPEG hardware acceleration, and are sufficiently powerful to
> play back DVDs, so why can they not play digital tv?
>
> Is the digital tv broadcast in a different flavour of MPEG to the DVD
> stuff, and requires conversion? I was under the impression that the
> terrestrial digital signal (in Australia) was broadcast in MPEG2
> format and could be recorded to disk directly, and then played back -
> hopefully using the motherboards hardware decoding. For direct play,
> just decode and play the signal directly.
>
> Is the Nebula card just unable to access the hardware decoding on the
> EPIA board?
>
> Would I be better off using a hardware enabled card (such as the
> Hauppage Nexus-T - if I can find one!) and a less powerful motherboard
> without hardware acceleration?
>
> Surely I don't need hardware acceleration on both the TV card and the
> motherboard!

Are you sure the DigiTV is capturing the MPEG2 stream directly and
using no resources in doing so?

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.video (More info?)

nil_einne1@email.com (Nil Einne) wrote in message news:<3bafcd2d.0405210656.679b7144@posting.google.com>...
> barney.b@iname.com (Barney Barumba) wrote in message news:<696a5dea.0405172108.1091e262@posting.google.com>...
> > Hi,
> >
> > I'm planning to build a HTPC with a digital TV card, and I'd like to
> > do this on a GNU/Linux - EPIA mini-itx based system.
> >
> > I currently have a Nebula Electronics DigiTV card in my desktop and
> > would like to use this, but their support tells me that current EPIA
> > systems are not powerful enough as their card uses software decoding.
> >
> > What I don't understand is this - the EPIA M series boards have some
> > form of MPEG hardware acceleration, and are sufficiently powerful to
> > play back DVDs, so why can they not play digital tv?
> >
> > Is the digital tv broadcast in a different flavour of MPEG to the DVD
> > stuff, and requires conversion? I was under the impression that the
> > terrestrial digital signal (in Australia) was broadcast in MPEG2
> > format and could be recorded to disk directly, and then played back -
> > hopefully using the motherboards hardware decoding. For direct play,
> > just decode and play the signal directly.
> >
> > Is the Nebula card just unable to access the hardware decoding on the
> > EPIA board?
> >
> > Would I be better off using a hardware enabled card (such as the
> > Hauppage Nexus-T - if I can find one!) and a less powerful motherboard
> > without hardware acceleration?
> >
> > Surely I don't need hardware acceleration on both the TV card and the
> > motherboard!
>
> Are you sure the DigiTV is capturing the MPEG2 stream directly and
> using no resources in doing so?

I believe so - the average cpu of the DigiTV process on my desktop
machine (2.4GHz/512MB) is:

Play live TV: 35%
Play & record: 35%
Record only: 7%
Play recorded TV: 31%

so it's not doing much to the signal it records.

Barney