[mythtv-users] Capture cards

Brian Wood beww at beww.org
Fri Jan 12 16:26:17 UTC 2007

On Jan 12, 2007, at 8:54 AM, Rich West wrote:

> I was asked by a neighbor to help finalize a setup for his son's
> computer before he went back to college.  When I got over there,  
> one of
> the things on his list of "I can't get this to work" was the video
> capture card.  Apparently, he wanted to set up the machine as a dual
> purpose school computer/television and the card he bought wasn't
> functioning.
> Being Windows (ugh), I checked and quickly got the card functioning
> properly, but, as I was doing that, I looked at the card
> specifications.  Apparently, the card records in either MPEG-2 or
> MPEG-4, all via hardware.
> I thought the reception was horrible, but apparently my neighbor is
> having problems with their cable, so all of their TV's have horrible
> analog cable reception.  Anyhow, this card was a "Powercolor Real  
> Angel
> 330" that his son picked up for ~$40.
> It *seems* like it would be a great alternative to the Hauppauge card
> which, as we all know, does hardware MPEG-2 encoding.  Does anyone  
> have
> any experience with this card?  If so, any news as to the quality  
> of the
> card and the compatibility of it with MythTV?

As was stated here it looks like that card relies on software to do  
the encoding.

I would have guessed that just from the price, unless you meant  
"picked up" literally.

The only product that does hardware MPEG-4 encoding that I have tried  
is the Plextor 402 series. It can do MPEG-2 or MPEG-4 but only the  
latter is supported by Myth (at least in 0.19), and it costs  
considerably more than $40.

Also, the chip used in the Plextor was originally designed for  
security systems and thus does not embed audio into the MPEG stream,  
you have to handle audio yourself, though that's not a big problem.

The obvious advantage to MPEG-4 is reduced space requirements, the  
disadvantages include more CPU power required to play it back, and  
the inability to get any help from XvMC. You also have to transcode  
to MPEG-2 if you want to burn the program to DVD.

As time goes on slow CPUs will become rarer, and I think we will  
start to see video cards that can do some sort of hardware MPEG-4  
playback. The satellite companies are going to move to MPEG-4  
eventually to save bandwidth, and the BBC HD tests are an MPEG-4  
variant. Some hardware chips exist in proprietary STBs, and some of  
the players for the latest Windows media codecs (aka VC-1) are pretty  
good. As to whether VC-1 is an MPEG-4 variant or has actually moved  
far enough away to be a separate entity, that depends on who you talk  
to :-)

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