[mythtv-users] Slight Pauses in Playback/Live TV

[Brion Swanson]

On Thu, 2007-12-20 at 11:10 +0000, Tim Sawyer wrote:
> Hi Folks,
> 
> I've just built my first MythTV box, and it almost works perfectly.  Love the 
> functionality when compared to a commercial solution.  I just have a couple 
> of small issues left to iron out.  I'm using Mythbuntu.
> 
> My hardware:
> 
> Jetway J7F2 mini-itx motherboard, no fan, 1.2Ghz
> Hauppauge Nova-T-500 dual DVB-T card
> Brand New 500Gb Seagate IDE drive, ext3 for root and xfs for video partition
> Connected via svideo from the motherboard to a panasonic wide screen TV (CRT)
> 
> My main problem is one of slight pauses when watching live TV or playing back 
> recorded programmes.  I hardly noticed it myself, my other half pointed it 
> out.  It's particularly noticeable when there is scrolling text, like you 
> sometimes get at the bottom of the screen on the shopping channels.  It seems 
> to that some frames are being dropped and there's a slight pause in the 
> movement of the text.  Our commercial PVR is definitely smoother.
> 
> Can anyone point me towards recommended settings for my hardware?  Or suggest 
> where I start looking to work out what the problem is?
> 
> Also, when in mythfrontend (and backend setup) the left hand side of the 
> screen is missing, so I sometimes can't see checkboxes.  Not a big deal this 
> one, but would be nice to sort if anyone has any pointers.  I'm using a 
> widescreen theme.
> 
> Many thanks for any pointers,
> 
> Tim.

As far as the left-hand side of the screen gone missing, you simply need
to go into the frontend settings and adjust the appearance such that the
width (and usually position) of the screen is smaller than the default.
It starts at 0 (which is auto-fill the screen) and you must raise it
slowly (holding the right arrow on the keyboard is fastest -- don't know
why we can't type in a value) until you get to a number that is less
than your known resolution.  From then on, it's a matter of continuously
shrinking that number, applying the settings, waiting for Myth to
rescale the images, and repeat until you can see what you need to.  

You may also need to adjust the horizontal position of the screen as you
shrink it.

The reason you have to do this is because most televisions "overscan"
the image, so while it claims to to 1280x720 (720p for example), it's
actually displaying a smaller area than the full resolution (though it
is displaying at that resolution.  I believe this is primarily so you
will never see the "edge" of the screen and any garbage that hangs out
there.  But it does make reading the edges of Myth a bit more difficult.

There are ways to tune the overscan on your TV but it's not recommended
and you can actually damage your television (not to mention they way to
do it involves a service menu that is "hidden").  Using Myth is much
easier.

Brion