[mythtv-users] Aspect ratio problems

[papenfuss at juneau.me.vt.edu]

	Hello all.  I've got a bit of an issue that I can't make sense of.  How 
does mythtv decide to do its aspect-ratio scaling?  Here are the details:

mythtv-0.14 compiled from source
PVR-250r1, OEM as #0 card
BT878-based #1 card
Rage128 VGA card to custom hardware converting to SVideo 
	(no scanline conversion)
Resolution is 720x480, 15.7 kHz Horiz, 29.97 Hz Vert, interlaced
GATOS r128 driver, since the stock XFree86 r128 driver appears to have a bug 
	with Xv on interlaced modelines.

	Mythtv seems puts black bars on both sides of the TV (and squishes the 
picture), unless I cycle through the aspect ratios until 16:9 is selected.  
It looks like it's only using around 640x480 or so of the horizontal 
resolution.  To get around doing this all the time, I can set the PVR-250 to 
set the aspect-ratio of its recording at 16:9.  The BTTV-based card has no 
such option.

	I normally capture at 480x480, but changing the capture resolution  
doesn't seem to affect anything.  Also, I've played with over/underscan.  It 
will "overscan" in the underscanned window is all.  I'm actually suspect that 
mythtv is cropping the top of the picture when I cycle through to 16:9, since 
I'm running 1.5 AR on the screen, not the 1.78 of 16:9.

	The other problem is now that I'm archiving some shows via SVCD, 
the mpeg stream from the PVR-250 is tagged as 16:9, confusing my DVD player 
into squashing it.

	So, the big question is where's the error?  Is it mythtv trying to
auto-detect/assume aspect ratios?  Granted, computer monitor resolutions are
*almost* always 4:3 ratio (except, for example, the weirdo 1280x1024).  Given 
that we're doing TV here, assuming square pixels on a 4:3 screen doesn't seem 
like a good assumption.  Perhaps adding a user-definable aspect ratio from 
within the GUI setup?

Thanks,
-nothing_is_ever_easy_Cory

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