Audio functions and QLC+ command line parameters ??

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Freddy_H
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Joined: Mon Apr 13, 2015 11:40 am
Location: Belgium
Real Name: Freddy Hoogstoel

Audio functions and QLC+ command line parameters ??

Post by Freddy_H » Sun Mar 06, 2016 10:51 am

Hello,

I ran into some weird behavior with QLC+ audio functions, this seems to be influenced on how QLC+ is started.

My configuration: OS= Linux Mint 17.3 64 bit ; QLC+ = 4.10.2.b

I setup a workspace for a theatre production I'm doing sound&light for. Basically it contains some fixtures, some scene functions + chaser and some audio functions + chaser and a virtual console with 2 cue lists and some individual sliders. When I had everything set up and working to my likings, I decided to make a shortcut to run VC only in kiosk mode (-k command line parameter) ... and all of a sudden my audio functions no more played ... opening the same workspace by clicking on it (without making any change to the audio functions) makes them play again ...

As I modified the workspace XML for another issue (post will follow later), I decided to start from scratch and experimented with various command line parameters (-k , -f, ...). After a while I got audio functions 'broken' again, but now only some ...

Today (for writing this post) I started again from a scratch with some sample audio files, but as I did not write down all the command line tests I did previously, I have not been able yet to reproduce the behaviour in this third workspace file..

Analysis of the 3 different workspace files (joined) shows that:
- in my original workspace (Produktie_2016.qxw) all audio functions have <Source>..</Source> tags that contain paths relative to my user home directory.
- in the scratch workspace (P2016.qxw), some audio functions have <Source>..</Source> tags that contain paths relative to my user home directory and other audio functions have <Source>..</Source> tags that contain paths relative to the workspace directory (which is a subdiretory of my user home directory).
- in the test workspace (Audio_2.qxw) all audio functions have <Source>..</Source> tags that contain paths relative to the workspace directory

My conclusions are that:
- some operation in QLC+ (my first thoughts go to opening workspaces with command line options, but it can be something else) causes audio functions 'Source' attribute to change from 'relative to workspace directory' (what it should be ?) to 'relative to user home directory'.
- an audio function with a Source relative to the workspace directory plays well, both in 'regular' and kiosk mode.
- an audio function with a Source relative to the user home directory directory plays well in 'regular' mode but will not work in kiosk mode.

As we went live with our performance this weekend, my workaround is not to run in kiosk mode, which is fine as I do the operating. It would be nice, however to have this issue resolved so that anyone can operate a performance (using kiosk mode).

Thanks for any assistance,

Freddy

O, by the way, this was my first 'live' performance with QLC+ and it did his job perfectly. Thanks to everyone maintaining this great software.
Attachments
Audio_2.qxw
(3.78 KiB) Downloaded 28 times
P2016.qxw
(11.33 KiB) Downloaded 27 times
Produktie_2016.qxw
(30.02 KiB) Downloaded 30 times

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mcallegari
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Location: Italy
Real Name: Massimo Callegari
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Re: Audio functions and QLC+ command line parameters ??

Post by mcallegari » Sun Mar 06, 2016 12:59 pm

Here's the explanation:
when you create a project and add audio/video files, QLC+ stores paths relative to the project in the qxw file. If I remember correctly, "relative" in this case means: same directory or sub folder of the qxw.
When you launch QLC+ from command line, the internal path used is no more the project one, but the path where the QLC+ executable is stored (most likely /usr/bin), so all the relative paths get broken

My suggestion is to change the paths in your qxw files to be absolute.

When I have some time I'll investigate this specific case. Probably it's not that difficult to solve

Freddy_H
Posts: 21
Joined: Mon Apr 13, 2015 11:40 am
Location: Belgium
Real Name: Freddy Hoogstoel

Re: Audio functions and QLC+ command line parameters ??

Post by Freddy_H » Sun Mar 06, 2016 6:41 pm

Hi Massimo,

I've done some more testing, only to get more confused :

1) with the Audio_2.qxw workspace (which only contains some audio functions, a chaser and a VC cue list):
Whatever I do to open the workspace (clicking on it, from command line, from shell script, from .desktop), with or without extra command line parameters, audio sources are always saved "correctly" (i.e. relative to the workspace directory).

2) with the P2016.qxw workspace (which next to audio, also contains fixtures, scenes, etc ...):
I open the workspace by clicking on it, then I remove the 3 audio functions that had sources with paths relative to my user home directory, then save and close the workspace.
-> Inspection with leafpad shows that the 3 audio functions are no longer in the workspace (the remaining audio functions keep their original function ID).
Then I open the workspace again by clicking on it and add the audio functions again that I removed before, save and close the workspace.
-> Inspection with leafpad shows that the 3 audio functions are present again (with the same function ID as before), and with source paths that are relative to my user home directory again ...
Next I edit the workspace with leafpad and change the soure path for the 3 audio functions to be relative to the workspace directory (like the other audio functions), save and close the workspace.
Then I open the workspace againg by clicking on it, make some changes (but not to any audio function) and save and close the workspace again.
-> Inspection with leafpad shows all audio functions with correct source paths (to workspace directory).
Then I open the workspace by clicking on it again, delete 1 of the 3 previously mentioned audio functions, save, close, open again by clicking on it, add deleted audio function again, save, close ... and
-> Inspection with leafpad shows the just added audio function with it's original function ID, and source path relative to my user home directory again ...

So to me it looks like if audio functions are the first to be put in your workspace (and no more touched afterwards) they work OK, whatever way you open the workspace; but as soon as "something" (a fixture? a scene? a specific combination of certain functions ... ?) gets added to the workspace, then the 'save audio function' decides to act up and saves audio functions with source paths to the user's home directory ...

Hope this helps you with your investigations.

Kind regards,

Freddy

Freddy_H
Posts: 21
Joined: Mon Apr 13, 2015 11:40 am
Location: Belgium
Real Name: Freddy Hoogstoel

Re: Audio functions and QLC+ command line parameters ??

Post by Freddy_H » Fri Mar 11, 2016 8:25 am

Hello,

I had some reflections on the test results I described in my previous post and came up with this:

Maybe, the cause for the issue is not how qlc+ is started (with or without command line parameters), but in the "select audio file" module that, under specific conditions (to be establshed), does not return paths relative to the workspace directory ... (to be investigated by someone familiar with the source code).

Workaround: once all required functions are present in your workspace (or before you want to start using command line parameters), save workspace & close QLC+ and open workspace file with editior (like leafpad), where necessary modify audio functions <Source>..</Source> paths to be relative to your workspace directory. After saving your changes, the workspace can be opened with command line parameters (like -k for kiosk mode) and audio functions will work (play) correctly.

Grtz,

Freddy

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