Question about Screen Sharing with Virtual Display

[ozthegweat]

Hi there,
as I have not yet upgraded to Lion, could someone answer the following question for me? I read that you can remotely log in to a Mac via Screen Sharing, even if another user is already using that Mac. In that case, what screen resolution would be used? Does it have to be the same as the already logged in user, which uses the real display of that Mac?

I ask because of this: I'd like to hook up a Mac mini to my TV, which obviously would have a resolution of 1080p. At the same time, I would like to log in as a different user with my MBP to use the Mac mini for other non-media-center tasks (Handbrake encodings, downloading etc.). There, I'd prefer a smaller resolution, as a scaled down 1080p picture would be very hard to interact with on my MBP.

Is that possible?

 

[nsayer]

It's apparently not even possible with the resolution being the same. Every time I try to use virtual display screen sharing on any of the 5 macs I've upgraded to lion, the target machine winds up with a login window on the physical screen that is completely wedged an non-functional (complete with the beach ball of despair).

 

[ozthegweat]

It's apparently not even possible with the resolution being the same. Every time I try to use virtual display screen sharing on any of the 5 macs I've upgraded to lion, the target machine winds up with a login window on the physical screen that is completely wedged an non-functional (complete with the beach ball of despair).

Sounds great :-/

Screen Sharing wasn't bug free in Snow Leopard either, it took a few 10.6.x updates until it worked... let's hope they fix it!

 

[canisbos]

In my experience, using Lion screen sharing to connect to a 2009 Mac mini that is connected to a 1080p HDTV using a DVI cable, from a 2009 13" Macbook Pro, these are the resolutions that are available in the Displays prefpane of the virtual desktop:

1680 x 1050
1280 x 1024
1280 x 720
1024 x 768
800 x 600
​

However, I have no reason to believe these are the resolutions the virtual desktop will offer to anyone else. The particular list of resolutions you get may be determined by various factors, including the resolution of the client display, the amount of free memory on the server, Steve Jobs's mood, etc.

I'm happy with 1280 x 720, because it fits on the MBP's screen without scaling, as long as you hide Screen Sharing's toolbar or use fullscreen mode.

 

[kocoman]

Does anyone know how to add more custom resolutions to the virtual display? SwitchResX does not let you add it

Does anyone have any idea how to debug it? I tried the

/System/Library/Displays/Overrides/DisplayVendorID-756e6b6e/DisplayProductID-76697274

mods but it does not work

I found its called a "VirtDisplay0" in com.apple.windowserver.plist, but can't find anyone reference to that in google

 

[notsofatjames]

I'm curious with this too. I run a headless server that serves media to other computers (& PS3) on my network. I only ever connect to it via screen sharing on my MBP but the screen resolutions available in Sys-Prefs are 800x600, 1024x768 and 1280x1024.. all 4:3 resolutions!

With Lion you can full screen your screen-sharing window.. and it's like being actually plugged in to that machine! But because I can't get the resolution to match my macbook's 1280x800 I get bars down the side. Only a minor annoyance I suppose though.

 

[kocoman]

Its in the virtual framebuffer setup.. but I have not been able to attach gdb debugger to screensharingd. it seems to be tied to launchd

I was able to get CoreGraphics Debug statements to show in the log via "bindings" patching of the NIB file in Quartz Debug, but to actually see what code gets executed, I need to run it through gdb. I was also able to get debug statements for ARD, ie: screensharingd.log, etc via a defaults write string..

I am trying to get an SSE2/leopard only widescreen laptop to Remote Desktop into a Lion Desktop, so I can "run" lion on laptop and not have to sit on the desk all day.

 

[notsofatjames]

Its in the virtual framebuffer setup.. but I have not been able to attach gdb debugger to screensharingd. it seems to be tied to launchd

I was able to get CoreGraphics Debug statements to show in the log via "bindings" patching of the NIB file in Quartz Debug, but to actually see what code gets executed, I need to run it through gdb. I was also able to get debug statements for ARD, ie: screensharingd.log, etc via a defaults write string..

I am trying to get an SSE2/leopard only widescreen laptop to Remote Desktop into a Lion Desktop, so I can "run" lion on laptop and not have to sit on the desk all day.

I'm normally pretty good at understanding technical terms, but this all just went right over my head! Is there a defaults for ARD or screensharingd to amend the default screensharing resolution?

 

[kocoman]

I'm normally pretty good at understanding technical terms, but this all just went right over my head! Is there a defaults for ARD or screensharingd to amend the default screensharing resolution?

I think its hardcoded by Apple

I tried to attach gdb on the newly "launchd" screensharingd, but it does not let me do it.