[mythtv-users] PVR-350 Slow video on Tv Out

[Tim Harvey]

> -----Original Message-----
> From: mythtv-users-bounces at mythtv.org [mailto:mythtv-users-
> bounces at mythtv.org] On Behalf Of Jason Donahue
> Sent: Sunday, January 18, 2004 5:37 PM
> To: Discussion about mythtv
> Subject: [mythtv-users] PVR-350 Slow video on Tv Out
> 
> So, I finally got my 350 working with inputs AND outputs. I am using
the
> latest snapshot ivtv drivers from CVS, Myth 0.13, and a 2.2GHz Celeron
> with 512MB Ram
> 
> 
> Why is my video slow on TV Out???
> 
> Video plays fine on the Monitor, but not on the TV. I saw a thread
where
> someone had the same problem and fixed it by moving the 350 to a
> different PCI slot. I tried every slot in my box...no go.
> 
> 
> Any Ideas?

I'm guessing that your talking about the video from 'mplayer' (or
MythVideo which simply launches mplayer) being slow.  This is because
the ivtv driver is still in development and there are some hardware
capabilities of the PVR-350 which may speed up the video that are not in
use yet.  I'm 'hoping' that there is enough hardware support in that
card that can be taken advantage of to make it a viable output device
for mplayer + XWindows.

Your hardware is plenty enough to 'decode' the audio/video fast enough,
but MPEG decodes to YUV colorspace (luminance/chrominance) and it's a
heavy load to convert this to RGB and scale the image to fit the screen.
Both of these capabilities have therefore been provided by hardware
support in videocards (starting perhaps in the mid 90's cards started
supporting this for this reason).  The PVR-350's support that ivtv is
using was designed for OSD so I'm hoping that it has the capabilities.
Apparently it has the colorspace conversion but I'm not sure about the
hardware scaling.

If you configure MythTV to use the PVR-350 for output (it's a checkbox
in one of the setup dialogs), then MythTV sends raw MPEG to the device
to decode/display.  This can only work for the MythTV features (live TV,
watching of 'non transcoded' shows).

Changing slots won't help at all (and in fact, this will may very likely
require a change to 'BusID' in the XF86Config for the ivtv
framebuffer?).

Tim