[mythtv-users] MHEG issues (UK) - flickering, video resizing, mind the gaps!

[David Matthews]

Sam Jacobs wrote:
> On Sun, Apr 6, 2008 at 12:14 PM, John Veness
> <John.Veness.myth at pelago.org.uk> wrote:
>>  Yes, I've seen these things too, although 0.21 was an improvement on
>>  0.20.2. There are some rendering errors on the GameCentral letters page
>>  too (page 809 on ITV1). To help the devs I'd like to be able to provide
>>  screenshots - what's a good way to make a screenshot of an MHEG screen?
> 
> I would just take them in the normal way for whatever platform you're
> on. I took a few from BBCi, Teletext on 4 and The Hits, and put them
> online: http://picasaweb.google.com/fluffybunnypoos

Thank you both for pointing these out.  I don't always read the user 
list so it's usually best to create a ticket when there's a definite bug.

There has been little change in the MHEG code for quite a while but 
there have been changes in various other areas which could be affecting 
the MHEG display.  I need to find some time to look at these more 
closely.  I do have a few changes in the pipeline related to MHEG on 
Freesat.

I've had a look at your screenshots.  The text layout problem on page 
809 was a bug and I'll include a fix in my next update.

I suspect the problem with the "gaps" is due to rounding issues in the 
OSD code.  The MHEG code generates multiple OSD images but if these 
don't exactly fit then there will be gaps.

> For some reason the text doesn't look very good in the screenshots, it
> looks better on-screen - smoothing appears to have been applied at
> some level. Note that I modified MythFrontend to use
> TiresiasScreenfont for rendering MHEG text (I also have the rest of
> the interface using it, and it looks fantastic).

The UK MHEG profile specifies the Tiresias screen font but as far as I 
am aware this is still not freely available.  That's why the current 
Myth code uses FreeSans.  I guess it could check to see if Tiresias is 
installed and fall back to FreeSans otherwise.

> I want to take some more screenshots, specifically of Sky Text, NHS
> Direct on Sky Text and NHS Direct on Teletext. I'm unable to take
> screenshots of the radio channels because they're crashing the
> frontend (as are off-air channels, which is *really* annoying). 

There were some initial problems with MHEG on off-air channels when the 
multirec branch was first merged, actually not with the multirec code 
itself but the removal of the old "dummy" video stream.  There weren't 
any crashes, it just didn't display anything until it was fixed.  I'm 
not aware of anything in the off-air or radio channels that could cause 
a crash and they certainly work for me with the 0.21 fixes branch.  If 
you're getting crashes you probably need to get a gdb traceback and 
investigate further.  What version of Myth are you running?

David.