[QLab] Issues I've Run into while Building a Show with QLab

[Christopher Ashworth]

Hi Matt,

Thank you much for the feedback!  Comments and (attempts at)  
clarification below:

> 1. Documentation the Help section of Qlab is minimal at best. Sure  
> it describes what each thing does, but it does not answer some  
> basic questions of functionality. Which leads me to my next issues

I agree that a stronger set of help resources is important.  For  
example, I really want to offer some downloadable "demo workspaces"  
that allow people to see an example rather than try to create one on  
their own.  I also want to add a lot more step-by-step examples.

Anyone who has a hankering to help in this regard, please have at it!:

http://figure53.com/wiki/index.php?title=Step-by-step_examples

As for the documentation, I absolutely welcome suggestions on  
particular topics that you feel are insufficiently covered!

> 2. Patching in the sound cue preferences. When do they take effect?  
> After you close the preference window or does it do it on the fly?

When you close the preferences window all cues are told to update  
themselves with the new assignments.

> Also how does that work if I am using 3 out puts on a motu 828 do I  
> need three patches heading to the 828 device?

No, you do not need three patches.  The patches represent entire  
physical devices.  So if you want a cue to go to the 828, you assign  
it the patch that is assigned to the 828.

The outputs of a device are represented entirely by the output  
channels of the cue.  So to use the first three outputs of the 828  
you will need to route the audio to the first three outputs (i.e. the  
first three columns) in the sound cue levels tab.

> 3. Why won't QLab remember my patch settings? I will connect an  
> 828mk1 to my laptop program a lot of cues through the day then pack  
> up, leaving my 828. When I come in the next day I get all red X's  
> in front of the cues and they will not go away until I setup my  
> patch yet again. Even though my 828 is already connected and seen  
> by OS X.

QLab saves patch settings using the kAudioDevicePropertyDeviceUID  
property for each device as supplied by CoreAudio.

This property is described in the CoreAudio headers as:

//	a CFStringRef that contains a unique identifier for the device.
//	This ID is persistent and can be used from run to run of a process
//	and across boots.

If a device is a properly behaved CoreAudio device, this ID will  
remain persistent.  I don't know off the top of my head if this ID  
should remain the same between sessions if a device is disconnected;  
it may not be.  But one way or another, this is the only universal ID  
that CoreAudio provides for devices, so if it disappears or changes  
between sessions there is very little I can do to compensate.

> 4. Why won't the title of the cue update when I change the file of  
> said cue? For example if I have a cue called 100 lion and I update  
> the cue to be 100 lion V2 the name of the cue in the list is still  
> 100 lion. This is very confusing.

Originally it did update, but a number of people requested I change  
it to the current behavior.  The reason for this is that often the  
filename will be a good default cue name to start with, but the cue  
name is often changed later so resetting the cue name when a new file  
was assigned was frequently erasing the name that people wanted.  So  
I changed it to only use the filename if the cue name was not already  
set.

> 5. Why does the buffer not actually load some cues? It will say it  
> does but when the go button is pressed QLab still takes a 1/2 a  
> second or so.  The only solution found is to delete the entire cue  
> and rebuild it from scratch. (on MOTU hardware)

I don't have an answer for this one--I'd need more information.  It  
may be a bug or it may be something going on with your particular  
configuration, it's hard to say.  For what it's worth this is the  
only case so far of this behavior that has been reported.  I hope  
that anyone else who has experience this will let me know so that I  
may investigate the problem.  Matt, if you would supply some more  
details of this behavior off list that will help.  e.g. Do you see  
any warning messages logged to the console, can you make it do this  
consistently with some cues and not others, are there any common  
factors when it happens, etc.

> QLab is great and lit the fire under a lot of developers. So lets  
> keep the pressure on huh?

For what it's worth, I'll be the first to tell you that I feel no  
lack of pressure to keep improving QLab.  :)

Mr. Lee sent me a thoughtful and excellent list of suggestions today,  
I know that Leon is compiling his own extensive list, and every day  
more and more people are sending in comments and constructive  
criticism and feature requests.  And I love getting it!  QLab has  
only achieved what moderate success it has because of the excellent  
feedback I receive from you and everyone else.  I have more TODOs on  
my plate now than I have ever had.

So believe you me, the "pressure" is not waning in any way.

Thanks again for the feedback--it is very valuable.

Cheers,
Christopher