Understanding screen resolution ..
#1
I am trying to work out if xbmc is outputing video to my tv at the best resolution/interlace etc.

My Sony TV is connected through an HDMI cable and has 1366x768 pixels and will accept 1080/24p, 1080p, 1080i, 720p etc but I think as it's not full HD will downsample 1080 to 720. I am running a minimal Unbuntu intrepid install and xbmc r19947 and nvidia the driver is 185.19 on a zotac mobo which has an intel E5200 and a 9300 igp.

When I play what I believe is a 720p video the info button reports yuv420p and 1280x520 - is that what ffmpeg interprets the file as being or is it the best that it thinks it can play the content on my TV? If the latter, is it the best?

xbmc.log is here http://pastebin.ca/1449053

Xorg.0.log is here http://pastebin.ca/1449054

randr is here http://pastebin.ca/1449056

Not sure if there's any other log/conf which is relevant.

I know Xorg reports a conflict in the EDID data but I am not sure whether it's relevant or if I have a screen setting wrong somewhere in xbmc. TIA.
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#2
yuv420p is the colorspace, nothing to do with the resolution. The resolution you're seeing is the actual content size. The AR was one of the anisotropic ones (wider than 16:9), so black bars were cropped at encode time giving you the shorter height. Long story short, you're worrying about nothing. Everything is as it should be.
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#3
Thanks
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#4
Hmm, I have also a general question in this context.
It is not even 100% XBMC related, but generic understandig of X11 and LCD TV screens.

1) My TV is a Toshiba 37" HD-ready LCD TV, also with 1366x768 px.
(according to the manual)

2) I captured the EDID information, and it reports "native backend timing: 1920x1080 @ 50Hz"

3) A first modeline works with 1080i, but does have overscan:
modeline "1920x1080i_50" 74.25 1920 2448 2492 2640 1080 1084 1094 1124 +hsync +vsync Interlace

3) I created a somehow weird modeline according to [1]:
modeline "no_overscan" 74.25 1824 2400 2444 2640 1020 1054 1064 1124 +hsync +vsync Interlace


To get this modeline compiled, I created my own 1920x1080px GDM backbround image with colored lines to identify the amount of overscan. Big Grin
I tweaked the H2,H3 and V2, V3 values of this modeline to death, and now I have a perfectly fitted screen.


Question:
Does this make sense at all? - Can XBMC scale to this modeline?
Or should I accept the overscan because this is intended. (On videos, I may be ok, but for the desktop, this is better now).

And Im just wondering if it would make more sense to force the LCD to its native 1366x768px resolution Huh


Regards,
Marcus


[1]: http://ubuntuforums.org/showthread.php?t=1003099&page=2
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#5
marcusfischer Wrote:And Im just wondering if it would make more sense to force the LCD to its native 1366x768px resolution Huh

Just answering this question to myself.
Actually, I wasn't able to tweak my modeline to 1366x768px.
The size of this image is two small.

I fixed it to 1366x768, which works.
Then, I corrected the upper left (0,0) coordinate, where the image begins.
But it does not fit the screen with this size.

Somehow, the pixel size of the image and the pixel size of the LCD TV do not match Huh


What does this mean at all, when these LCD TVs are sold with 1366x768 px ? - I mean, this is a rather typical screen resolution for HD-ready LCDs, not?


I really don't get it. I feel that a 1:1 pixel mapping is impossible at all.



Just wondering if these "HD-ready 1080p" displays with 1:1 pixel mapping are much superior for PC-based media centers or if this doesn't matter at all.
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#6
Just pushing this one here...
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#7
when your LCD doesn't have the option to pixelmap the HDMI input, you could play around with the FlatPanelProperties option in the screen section of your xorg.conf

I'd try "Scaling = Native" first

this is for the proprietary nvidia driver of course
OpenElec Standalone --> Asus Chromebox 'Panther' --> Onkyo TX-NR709 --> Sony 55" X85C Android TV (also with Kodi!)
Asus Chromebox EZ Script
Kodi on Sony Bravia Android TVs
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#8
I'm not 100% sure how this will help me according to what I've read in the Nvidia readme about that option right now.


Also, I'm wondering that I have two options now:
a) my custom modeline and no scaling in XBMC defined
b) a regular 1920x1080 pixel modeline and doing the scaling inside XBMC


I'm more than confused about a very multi-dimensional challenge, and I completely lost the overview about what is possible (and more important, what makes sense!).

Thanks for your hint, I'll add that option to my test scenarios in the next days.
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