Author Topic: Video Cropping  (Read 9555 times)

Orphus

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Video Cropping
« on: March 25, 2009, 09:10:58 am »
Hi All.

I am a total Linux newbie but am a little downhearted that the installation of MCE was not a straightforward as I'd hoped.

I have an nVidia 8500gt card and following installation, after displaying the Kubuntu screen etc correctly, the AV wizard starts and the image is off centre with about 25% of the screen dissappearing off the right edge of the screen.   On the cetering options screen I cant move the screen to fill the gap on the left of the screen as it thinks this is already at the edge of the screen.

I am using the DVI output of the card and outputting to a 42'' LCD.

Any ideas anyone?

Thanks in advance.

J

colinjones

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Re: Video Cropping
« Reply #1 on: March 25, 2009, 09:21:07 am »
Your first task, should you choose to accept it, is to install the latest nVidia drivers as described in the wiki under Display Drivers.

If that does not fix your problem, turn EDID to true (in both places) in your /etc/X11/xorg.conf file. Go to a command line, then edit this file (the text editor I use is joe, install using "sudo apt-get install joe", then "sudo joe /etc/X11/xorg.conf", to save and exit ^Kx)

This will cause the system to talk to your display to find out its parameters, in some instances this allows it to adjust properly and give a good image, but many displays don't conform with the correct communications specification.... no matter, at the least it will mean that the details of the display will be logged in the /var/log/Xorg.0.log file and that may mean we can construct a custom modeline to drive the display properly...

But I think the newer drivers are the best option at this point as your 8500 is newer than the standard drivers supplied.

Orphus

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Re: Video Cropping
« Reply #2 on: March 25, 2009, 09:24:24 am »
Wow!

That was quick.

Thanks a lot, I'll try this later.  I also have a problem with sound, I'll post this under a new topic, although basically I have no sound output at all using a SB Live! 24 bit external with SPDIF.

J

colinjones

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Re: Video Cropping
« Reply #3 on: March 25, 2009, 09:27:01 am »
go to a shell and type

alsamixer

you will see all the mixer levels. Look for IEC958, it is probably muted, you can unmute it from there, that should enable SPDIF....

Orphus

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Re: Video Cropping
« Reply #4 on: March 25, 2009, 11:42:08 am »
Thanks again!

I will try all of this out tonight.  Will be doing a clean install 1st.

J

krys

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Re: Video Cropping
« Reply #5 on: March 25, 2009, 04:04:54 pm »
A trick on the SPDIF, do as Colin says with alsamixer but also make sure that it is at 100% volume if that is an option. Also if that doesnt work, I had one instance where I had to set all the volume options to 100% for SPDIF to work.

totallymaxed

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Re: Video Cropping
« Reply #6 on: March 25, 2009, 04:59:42 pm »
Wow!

That was quick.

Thanks a lot, I'll try this later.  I also have a problem with sound, I'll post this under a new topic, although basically I have no sound output at all using a SB Live! 24 bit external with SPDIF.

J

I'm not sure that updating the nVidia driver will correct Overscan, which is what you are describing, as we see exactly the same effect with Intel/nVidia/ATI GPU's. The AVwizard generates a common modeline that is used universally for all GPU/Drivers so we suspect that the 'fix' is in customising the modeline and possibly adjusting some of the other parameters like "FlatPanelProperties". I'll post some modelines or complete xorg.conf files here if we have any success with this.

All the best

Andrew
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colinjones

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Re: Video Cropping
« Reply #7 on: March 25, 2009, 08:51:09 pm »
Wow!

That was quick.

Thanks a lot, I'll try this later.  I also have a problem with sound, I'll post this under a new topic, although basically I have no sound output at all using a SB Live! 24 bit external with SPDIF.

J

I'm not sure that updating the nVidia driver will correct Overscan, which is what you are describing, as we see exactly the same effect with Intel/nVidia/ATI GPU's. The AVwizard generates a common modeline that is used universally for all GPU/Drivers so we suspect that the 'fix' is in customising the modeline and possibly adjusting some of the other parameters like "FlatPanelProperties". I'll post some modelines or complete xorg.conf files here if we have any success with this.

All the best

Andrew

No, probably not, but as I say it is still the first step before messing around with other stuff. My next step is to turn on EDID, and get some feedback from that. We can also look in the modeline database for something appropriate.... but first things first!

totallymaxed

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Re: Video Cropping
« Reply #8 on: March 25, 2009, 10:17:46 pm »
Wow!

That was quick.

Thanks a lot, I'll try this later.  I also have a problem with sound, I'll post this under a new topic, although basically I have no sound output at all using a SB Live! 24 bit external with SPDIF.

J

I'm not sure that updating the nVidia driver will correct Overscan, which is what you are describing, as we see exactly the same effect with Intel/nVidia/ATI GPU's. The AVwizard generates a common modeline that is used universally for all GPU/Drivers so we suspect that the 'fix' is in customising the modeline and possibly adjusting some of the other parameters like "FlatPanelProperties". I'll post some modelines or complete xorg.conf files here if we have any success with this.

All the best

Andrew

No, probably not, but as I say it is still the first step before messing around with other stuff. My next step is to turn on EDID, and get some feedback from that. We can also look in the modeline database for something appropriate.... but first things first!

We've already explored all those ideas Colin... so I can definitely say that there is nothing quite right in the mode line db at present. As I say we should have a good handle on this fairly shortly and will post an update here and on the Wiki when we do ;-)

Andrew
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colinjones

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Re: Video Cropping
« Reply #9 on: March 25, 2009, 10:30:39 pm »
Andrew - sorry, I'm not following, do you already know what screen Orphus is using, and you have looked for an appropriate modeline? Or are you saying that this is unrelated to the screen? If the latter, what is this related to, as he seems just to be using a normal nVidia chipset with DVI output, plenty of people are doing that, surely, and not having this issue?

In the past, this seemed related to getting the porch timings right for a specific screen, and using a custom modeline to do so. But I seem to be missing something here, did I miss a thread related to this somewhere? Generally, you can solve overscan and displacement with the timing values, is this what you have confirmed doesn't work for his screen?

Orphus

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Re: Video Cropping
« Reply #10 on: March 25, 2009, 10:46:11 pm »
This is going straight over my head guys, but I really appreciate the help.

I'm just busy trying to update the drivers now.  I'm getting a message pop up on terminal every few seconds, does this make any sense to you?

(some numbers which change) ALSA /root/R/alsa-driver/acore/oss/pcm_oss.co:466: BUG? (v >= 0)
                                             as above                                                 457: BUG? (max >=0)
                                             as above                                                 963: BUG? (err >= 0)

I assume that the mention of PCM it is referring to an audio issue?

J

totallymaxed

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Re: Video Cropping
« Reply #11 on: March 25, 2009, 11:41:18 pm »
Andrew - sorry, I'm not following, do you already know what screen Orphus is using, and you have looked for an appropriate modeline? Or are you saying that this is unrelated to the screen? If the latter, what is this related to, as he seems just to be using a normal nVidia chipset with DVI output, plenty of people are doing that, surely, and not having this issue?

In the past, this seemed related to getting the porch timings right for a specific screen, and using a custom modeline to do so. But I seem to be missing something here, did I miss a thread related to this somewhere? Generally, you can solve overscan and displacement with the timing values, is this what you have confirmed doesn't work for his screen?

Colin at present the modeline added when the AVwizard runs is essentially the same regardless of what screen you have attached for a given resolution ie say 720p. Below are two example modelines from one our test systems;

MM600 (nVidia 9300 onboard GPU attached to a 42" LG LCD TV @ 720p);
Modeline        "1280x720" 74.250 1280 1390 1430 1650 720 725 730 750 +hsync +vsync

MM220 (Intel GMA950 onboard GPU attached to a 22" LG LCD @ 720p);
Modeline        "1280x720" 74.250 1280 1390 1430 1650 720 725 730 750 +hsync +vsync

MM300 (Intel GMA950 onboard GPU attached to a 32" Panasonic LCD @ 720p);
Modeline        "1280x720" 74.250 1280 1390 1430 1650 720 725 730 750 +hsync +vsync

MM400 (nVidia 9400 PCi-e card attached to a 38" LG LCD TV @ 720p);
Modeline        "1280x720" 74.250 1280 1390 1430 1650 720 725 730 750 +hsync +vsync

As you can see the Avwizard does not 'craft' a modeline at all... and this is the cause of a number of problems beyond overscan. So currently it does not make any difference what screen you attach at all... we are trying to make sure that xorg setup and modelines are crafted to exploit the maximum performance from a given screen. In 0810 of course this changes as 'out of the box' it does not use modelines but relies on closely matching/capturing the EDID from a screen.

Andrew


Andy Herron,
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colinjones

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Re: Video Cropping
« Reply #12 on: March 25, 2009, 11:48:28 pm »
Andrew, then I think we were talking at cross pusposes. I wasn't talking about using the AV Wizard at all to correct the overscan problem. I was talking about correcting the xorg.conf file manually with a more appropriate, custom modeline. I imagine Orphus would like to get this working now rather than waiting for 0810. Which is why I asked him to turn on his EDID so that we could capture more information.

BTW, what is changing in 0810 around this? You mentioned going to EDID by default... that could be a little scary considering so many TVs have badly brain-damaged EDID info :) It would be nice if something was exposed in the AV Wizard that let you choose either a preset (like the static modelines used now) or explicitly say "Detect my screen automatically" ... do you think?

Either way, Ophus, turn on your EDID for now - either it will fix the problem, or it will log some extra info that might let us craft a custom modeline for you....

Orphus

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Re: Video Cropping
« Reply #13 on: March 26, 2009, 12:02:34 am »
I have tried to do this as instructed but when trying to install "joe" I get an error message saying this is not available.

Apologies if I am a little green in this area.

J

colinjones

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Re: Video Cropping
« Reply #14 on: March 26, 2009, 12:14:56 am »
I have tried to do this as instructed but when trying to install "joe" I get an error message saying this is not available.

Apologies if I am a little green in this area.

J

Are you typing

sudo apt-get install joe

? And you have access to the internet?