poor playback performance -m171

[samsc]

hi Richard,
you may have already fixed this but,

Regards
Paul

do you have any other HUD elements on the other screens such as layers displays? etc?

you should try to minimise these too.

I have noticed in the past you have had large HUD screens open as well as playback.

[samsc]

Paul

There were also some murmurings about quicktime versions recently - Im still running QT7.3.1 - Apple did something in QT7.4, not sure if its fixed in recent QT version - check with Richard.

S

nothing to do with quicktime.
nothing to do with m171.

when a refresh rate says its 75hz its not - its 75.02, or 75.03 - and its slightly different at every single monitor resolution - and different between dvi and vga- ( even at the same resolution ) ( connecting one monitor with vga and the other with dvi - i have seen this not work well )
and these slight timing differences can cause problems.
its something that needs testing on end users system - as its not always something that is a problem.

[SourceChild]

when a refresh rate says its 75hz its not - its 75.02, or 75.03 - and its slightly different at every single monitor resolution - and different between dvi and vga- ( even at the same resolution ) ( connecting one monitor with vga and the other with dvi - i have seen this not work well )
and these slight timing differences can cause problems.
its something that needs testing on end users system - as its not always something that is a problem.

One of the things I have been researching is DVI to 5-Wire BNC connectors. Since obviously we all have a more common tendency to drive our projectors with 5-Wire BNC I figured the would be one less connection in the path to troubleshoot.

What I found is something from Gefen which has a Male DVI which 'Y's out to 5 BNC plugs and a Female DVI plug. I didn't know why they did this. It didn't make sense to me. The explained it would allow a user to attach a DVI screen and run a 5-wire signal simultaneously.

Surprising what I found!
Apparently many video cards can drive DVI and VGA simultaneously through the same port. In this case, a user can attach one of these DVI BNC Y-adaptors and view an analog and digital signal simultaneously on two different output devices.

(Basically, I can setup my racks to output DVI and BNC simultaneously without needing a converter.)

I have been researching the video cards in MACs. They perform this function. I am reading into the Quartz specs to see how this is controlled and if it produces signal overhead. What I am thinking is that perhaps a command key can be entered by a user into the terminal which will disable either the DVI or the VGA.
(~"PLEASE NOTE THIS IS VERY DANGEROUS UNLESS YOU KNOW HOW TO HACK IN UNIX"~)

The hope in this discovery is to determine if some of the overhead issues can be alleviated by using this fix. I will report further as I find out.

[samsc]

the 3 different types of DVI doesnt make things easy. DVI-A DVI-D DVI-I
http://www.datapro.net/techinfo/dvi_info.html

5 wire bnc doesnt do EDID-

so it will default to standard resolutions. and might cause troubles.

---
dvi/vga enabling - this happens in the hardware - its not related to 'quartz'.

One of the things I have been researching is DVI to 5-Wire BNC connectors. Since obviously we all have a more common tendency to drive our projectors with 5-Wire BNC I figured the would be one less connection in the path to troubleshoot.

What I found is something from Gefen which has a Male DVI which 'Y's out to 5 BNC plugs and a Female DVI plug. I didn't know why they did this. It didn't make sense to me. The explained it would allow a user to attach a DVI screen and run a 5-wire signal simultaneously.

Surprising what I found!
Apparently many video cards can drive DVI and VGA simultaneously through the same port. In this case, a user can attach one of these DVI BNC Y-adaptors and view an analog and digital signal simultaneously on two different output devices.

(Basically, I can setup my racks to output DVI and BNC simultaneously without needing a converter.)

I have been researching the video cards in MACs. They perform this function. I am reading into the Quartz specs to see how this is controlled and if it produces signal overhead. What I am thinking is that perhaps a command key can be entered by a user into the terminal which will disable either the DVI or the VGA.
(~"PLEASE NOTE THIS IS VERY DANGEROUS UNLESS YOU KNOW HOW TO HACK IN UNIX"~)

The hope in this discovery is to determine if some of the overhead issues can be alleviated by using this fix. I will report further as I find out.

[SourceChild]

Did some looking. The problem is that when render data is sent to the GPU, the GPU will only render one display space. Since the graphics card might see an analog and a digital device at the same time, the analog device actually receives precedence. So using these DVI to DVI Y BNC 5-Wire cables means that if the final analog device is outside the scan range of the DVI viewing device, then the DVI device will not scan correctly.

Incidentally, I tend to always use 1024x768@75 (for 25fps) I got a few of these cables with the DVI Y BNC and they seem to work fine with my projectors and DVI monitors.

It's a good cheap solution when I can't justify the cost of having a half dozen Image Pros in a rack with me.

[samsc]

sounds like trouble to me.

Did some looking. The problem is that when render data is sent to the GPU, the GPU will only render one display space. Since the graphics card might see an analog and a digital device at the same time, the analog device actually receives precedence. So using these DVI to DVI Y BNC 5-Wire cables means that if the final analog device is outside the scan range of the DVI viewing device, then the DVI device will not scan correctly.

Incidentally, I tend to always use 1024x768@75 (for 25fps) I got a few of these cables with the DVI Y BNC and they seem to work fine with my projectors and DVI monitors.

It's a good cheap solution when I can't justify the cost of having a half dozen Image Pros in a rack with me.