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Author Topic: Wrong screen size with Sony Bravia  (Read 9998 times)
jpconley
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« on: February 21, 2010, 12:53:11 pm »

Hi Everyone,

I just unpacked my new link.  I got it working and in general I am impressed.  I have two issues that I can't get quite right however.

1. The link seems to want to send an image to my Sony Bravia that about 10% too large (both top to bottom and side to side).  This creates difficulties as it cuts off important parts of the Linux interface and webpages like top and bottom menus, and confirmation buttons. I have tried turning on the link first and also the TV first, but it comes up the same.  I also tried seeing if I adjust the setting in administration/display, but they were set to the right 16-9 aspect ratio.  I tried all the display setting on the Bravia also with no luck.  As far as I can tell,  the link is sending a correct HD signal (1920X1080), but it is just blown up somehow to overflow the TV screen.

2. I get significant judder when I play any video.  The content looks to be high res (and the Bravia light that comes on when it thinks it is getting HD content is on), but it has lots of non-smooth movement.  It is not the internet connection as it happens even when there is a significant buffer and also with downloaded content.  The bravia works fine with HD content not from the link. To me this seems like a problem with the Video card in the link not being able to keep up.

Update: March 30, 2010

I have been working with support for the last month and basically have my problems resolved.

1. Overscaning: seems to be a Bravia problem.  The solution was to choose the "one to one pixel" setting on the screen menu.  I have a W series, so YMMV.

2. The judder seems to be due to Adobe's lack of support for hardware acceleration in Flash.  I am not sure they will support it in for Linux even in there 10.1 release.  However, I reduced the screen resolution to 1080720.  This worked fine, and since Hulu, etc only steam at  480 anyway.

It took a while to get there, but it all works now.


What do you think?  I wonder if I have a wrong driver, or some of the driver setting wrong.  Could it be the video card is having to work too hard to translate HD into HD +10% size and this is cause of both problems?  Maybe the Bravia is taking good HD signal from the link and upsizing it and this is causing the judder.  This seems less likely as it is able to upsize other content without similar problems.

Any ideas or help would be appreciated.

Best,

JPC

« Last Edit: March 30, 2010, 08:37:51 pm by jpconley » Logged
ChadV
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« Reply #1 on: February 21, 2010, 07:21:25 pm »

The "too large" is called overscan, and it could be an issue with the LINK or with the TV.  Generally it's a sync issue, try turning on vsync and/or changing refresh rates on the LINK.

The LINK shouldn't be changing resolutions at all, so your HD "Bravia" light should always be on...  What is the source of your video?  HD Flash playback?  H.264 Files?  MPEG/AVI files?
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braddock
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« Reply #2 on: February 28, 2010, 05:55:43 pm »

Same problem here.  Sony Bravias and Nvidia cards don't play well together.  Everything I've read puts the blame on the Bravias not providing the correct resolution info to the Nvidia chip.  I have tried many different suggested fixes with no success.  The issue would be easily remedied if my Bravia had a pixel by pixel setting in the menu...it doesn't.  I'd also be in good shape if the Linux Nvidia driver had overscan adjustment for HDMI...a no on that one too.   It would be really helpful if someone at Neuros put some time in on this issue.  A search on Sony, Nvidia, and overscan shows there are a lot of people suffering with this problem.  The only thing functional like this is XBMC which somehow automatically adjusts for the overscan.  I'm stumped.
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greyback
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« Reply #3 on: March 03, 2010, 03:38:29 pm »

Hey,
do you have this option on your TV:
"Settings / Set-up / Screen settings / Display Area" and select the "Full pixel" mode

This is 1:1, and might stop overscan?
-G
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braddock
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« Reply #4 on: March 04, 2010, 11:36:12 am »

As I stated above if you have this setting on your HDTV you'll be fine.  If you don't you could be in for a big disappointment when you fire up your Neuros Link and its pretty much unusable due to a missing inch of screen real estate on all four sides.  Nvidia has ignored the overscan issue with its Linux drivers for going on three years now.  Still hunting a fix here...maybe someday.
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greyback
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« Reply #5 on: March 06, 2010, 04:48:32 pm »

Hey,
there are hacks, but none are pleasant.

I've been looking into this. At first I thought that the absolute latest nVidia driver (195) and settings util has an overscan compensation option, but while it works for VGA, HDMI people don't seem to get this option:(

The primary hack I can find on this stems from the EDID data that the TV sends the nVidia driver. It appears that the driver misinterprets this data (or the data is flawed somehow). Successful hacks I've found either
1. over-ride the EDID settings on the driver completely, and manually set up X for the display
2. capture the EDID data, edit it to be correct, and instruct X to use this new EDID instead. (See here for an example.

Neither of these are easy to do however, especially since there are so many different types of Bravia set with different capabilities. I can confirm that Neuros are trying to establish some kind of fix for this problem, but it might take time.
-G

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braddock
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« Reply #6 on: March 08, 2010, 10:31:15 pm »

I found a stop gap fix...certainly not a solution.  If you create panels on all four sides of the screen and increase the the width of the panels bit by bit you can push your desktop back within the viewable area.  This isn't my fix.  I just found it somewhere in the sea of complaints about this overscan issue.  A hacked EDID seems like the solution for HDMI...that just looks like a project I'm going to have to spend a whole weekend on.  I got nowhere with a custom modeline in my xorg.conf.  It's hard to decide if I hate Sony or Nvidia more right now.
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greyback
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« Reply #7 on: March 09, 2010, 07:24:15 am »

Yeah, we're fighting with this too.

Some Bravia sets have the 1:1 mode, and that works fine. But those which don't all experience this overscan issue. the 195 driver has an overscan compensation feature, but this doesn't seem to apply to HDMI.

This is proving hard to deal with.
-G
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braddock
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« Reply #8 on: April 03, 2010, 01:02:20 am »

I finally gave up trying to find a way to fix the overscan issue in Linux with the Link's Nvidia chip.  For the hell of it I decided to load Windows 7 on the Link and give it a go.  It's just not fair...the windows version of the Nvidia software lets you freely resize the desktop to any size you choose.   In my case...to make the Link usable...Windows is my only solution.
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mstieb
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« Reply #9 on: April 11, 2010, 08:41:26 pm »

Sadly, I'm in the same boat - Win7 is what I had to resort to
(IDE hard drive) in order to be able to:

1) re-size my desktop to fit on the screen (Toshiba 42")
2) stream Netflix (IE8)
3) use a USB DVR I already own to record TV.
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ChadV
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« Reply #10 on: April 11, 2010, 10:25:12 pm »

Sadly, I'm in the same boat - Win7 is what I had to resort to
(IDE hard drive) in order to be able to:

1) re-size my desktop to fit on the screen (Toshiba 42")
2) stream Netflix (IE8)
3) use a USB DVR I already own to record TV.

I'm using a Toshiba 42" and didn't have to do anything but change the zoom settings to get rid of overscan.  And mine is an almost 3-year-old model...
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