From: Kevin in Fort Davis <fsm79734@gmail.com>
Date: July 8, 2015 3:56:25 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Naming Cameras?
Hi Milton, sorry it took me a while to respond. I should have been more descriptive of what "video preview screen freezing" means, but I mean the former - the app still functions, it's just that the video in the preview screen freezes in place. This happens after the Astro IIDC have been launched and the cameras are recognized and video is started. Our solution to that is, as you suggested, to simply stop and then restart the video.
We have three copies of Astro IIDC, and run one of those for each of our three cameras by starting them all up manually.
As frequently happens for those of us in the IT world, this "freezing" issue hardly ever happens to me, but rather happens to my staff when they're doing public programs. It's sometimes difficult to troubleshoot after the fact when someone just tells me "it froze", "it did something weird", or "an error message popped up" (and of course they couldn't be bothered to do a screen shot or write it down).
I've told my staff to please run the cameras at 7.5 fps, as that seems to work pretty well, but if they experience the "freezing" thing, to run them at 3.750 fps. However, I'm not sure that running them at a lower frame rate has, thus far, prevented the "freezing". The other option is not to run all three cameras at the same time, since there's no need to do that most of the time.
It occurred to me that I've probably never sent you examples of what I do with our solar imaging setup. I attached a few minimally processed pictures. Most of the time we're using the setup to show the live Sun to ~75,000 people a year, but when I have time, I like to do some imaging of my own. Enjoy!
-Kevin
On Sat, Jul 4, 2015 at 2:26 PM, Milton Aupperle maupperl@gmail.com [Astro_IIDC] <Astro_IIDC@yahoogroups.com> wrote:
Hi Kevin;
On 2015-07-04, at 9:22 AM, Kevin in Fort Davis fsm79734@gmail.com [Astro_IIDC] <Astro_IIDC@yahoogroups.com> wrote:
Thanks so much for that analysis, Milton, I appreciate it! I've somewhat verified that empirically, and have found it safer to sometimes run at 3.750 fps. Would the video preview screen's freezing be a likely effect of a lack of FireWire bandwidth? Also, is there any advantage of using the FMT7 modes of the camera in terms of bandwidth?
Just to be clear, by "video preview screen freezing" do you mean the app works (i.e. move windows around, change camera controls, switch to a different app etc.) but the video doesn't change in the preview window or do you mean the app itself freezes?
If its the first case, then the camera did not start up when send it the start transmit command, so hitting the start stop button would get it running again. That should be caught and reported as an error, unless of course either the camera doesn't report a FireWire error code or Apple is getting it and not passing it back to us (which happens pretty frequently now - especially under Coca which I avoided with Astro IIDC and stayed with C & Carbon). There were also some pThread contention issues too where Apples threads would just go dead (stop responding) from sleep wake states - and I had to make some really skanky code to detect and work around this too.
I'm not sure how your launching the apps either, because your running 3 copies of Astro IIDC at the same time. Are you starting them up individually and giving them time to get each camera running or are you using some Apple Script or other script method to launch the apps at the same time?
With 2 cameras, I've never had the contention issues, but usually one is running at absurdly slow frame rates and the other is maybe running 15 fps for tracking. So bandwidth wasn't an issue in my case and I had them daisy chained together too - meaning I had no hubs in the mix either.
HTH..
Milton Aupperle