[pvrusb2] high latency

[Michael Krufky]

Mathieu Bouchard wrote:
> Hi,
> 
> I tried to plug a video game console into the wintv pvr usb 2 to play some 
> games with my laptop screen while my girlfriend is watching the tv. 
> Unfortunately, there is a latency of about 2-3 sec. between input and image, 
> so the games are unplayable.
> 
> Is this a limitation in the hardware or a software problem? I didn't tried the 
> device on windows yet and I'm using the module provided with the 2.6.19 
> kernel. I tried with xawtv and mplayer. The image is 720x480 and my laptop is 
> a pentium M 1.4 ghz with 512 mb of ram.

An mpeg encoder is not the best choice of a video capture device for use with
an interactive system, such as a video game.

By design, as the hardware receives the video, it is encoded into mpeg, which is 
sent to the pc over the usb bus, only to be decoded in software to produce the
video that you see.  Naturally, there will be somewhat of a delay, and this cannot
be avoided.

This delay can be reduced if you have a hardware mpeg decoder, however, the delay
will still be present -- just a bit less.  Still, this is no solution for a video
game console.

If you want to use your computer as a display device for a video game console, I
recommend that you use a raw analog "dumb" framegrabber, instead of an mpeg encoder.

Hope this helps,

Michael Krufky