Show Cue System

I recently made a show using SCS 10 and found I got fairly frequent glitches. What happens is that the playback seems to stutter and replay the last half a second or so of audio. I never had this with SCS 9 and so I thought is might have been something to do with the laptop I was using.

I had to do the show with internal soundcard from headphone jack, as there was no budget for an external one. I never managed to solve it despite turning off all background tasks and fancy visual windows stuff. This was a Dell laptop running Vista home premuim.

I just updated my own SCS system to 10 and have now found that I am getting the same problem on it. This is a purpose built audio laptop with an Edirol FA-101 soundcard, there are no background tasks running other that necessary drivers and almost no other software installed, Running XP SP2. This laptop never had this problem with SCS 9.

The glitching is reasonable frequent, in a 1 hour show it would always happen three to four times, but not at all consistent as to where in the show it would happen. If it happened on a cue and I reset and play that cue again it would be fine. I am planning on trying to increase the audio buffer size to see if that helps, will report on the results.

limitedheadroom wrote:I am planning on trying to increase the audio buffer size to see if that helps, will report on the results.

That's what I would suggest. One of the significant differences between SCS 9 and SCS 10 is that SCS 10 uses a mixer component of the audio library. This has been added to support some functionality that wasn't available in SCS 9, such as panning when speaker assignments are selected, and downmixing stereo (or higher) audio files to single speaker outputs. A disadvantage of using the mixer component is that pan and level changes are applied pre-buffering, so can get delayed audibly by the length of the playback buffer. The default playback buffer size in SCS 9 was 5000ms (5 seconds) which is obviously not suitable when using the mixer. So in SCS 10 I reduced the default buffer size to 200ms (0.2 second). A larger playback buffer size will help deliver a smoother playback if there are interruptions to the disk transfers.

If you increase the size of the playback buffer I suggest you also increase the update period, up to the maximum value of 100ms. The developer of the audio library recommends the update period should be no more than 1/3 of the playback buffer size, which is why in 10.2.0 I reduced the default update period to 50ms.

I've been running some tests today on my HP Compaq laptop (1Gb RAM, 1.6GHz AMD processor, Vista Business).

I now have a suggestion that may solve the audio glitches.

The suggestion is to pre-load whole files into memory. To do this, go to the Editor and tick the Pre-Load Whole File checkbox for each audio file cue.

In the General Options / Permanent Options, on the General tab I suggest you keep the Max. No. of Audio Files to Pre-Open at the default setting of 5 because pre-loading whole files takes a lot of memory.

On the Audio Driver tab I left all buffering at the defaults (200ms for buffers, and 50ms for the update period) and had the three checkboxes clear.

I then ran some tests using cue files that played stereo music tracks, typically of 4-5 minutes duration each.

I had Task Manager open and visible during the tests to monitor memory usage (primarily). All tracks played perfectly - sometimes I played 2 or 3 tracks together as well as the occasional hot key. With the files I used, the memory usage and commit size of scs10.exe were never more than about 205Mb, and the Physical Memory percentage never exceeded 65%. CPU Usage was generally around 8% while playing one file; slightly more when playing two; and briefly jumped to about 15% on starting a file. It also jumped to about 30% on opening a file.

If you find pre-loading whole files into memory solves the audio glitching problem, and that the extra memory requirement at runtime is not an issue, then I'll add a new option to enable users to pre-load whole files by default, instead of having to set this property on every audio file cue.

Have just returned from a tour where we experienced the same glitching problem. We use a laptop with an ESI Quatafire hanging off it and had no problems with version 9. I'll experiment with your ideas Mike and report back . . . all other functions appear to be running well.

As promised I've run some further tests and followed up on Mike's suggestions.
For the information of other SCS users my particular use for SCS is running ‘multi-track’ audio, MIDI and video for live music productions. For this test I’m running Cues consisting of 5 Audio Sub-Cues (3 x Stereo and 2 x Mono) and a MIDI file Sub-Cue. All of these cues are starting together and should remain in sync. Other productions require more tracks.
Laptop: Dell Inspiron 1525, Processor Intel Pentium Dual CPU T2370 @ 1.73GHz, RAM 1014 MB running VISTA Home Premium.
As a follow on from the previous threads I first checked ‘Preload Whole File’ checkbox for all Cues and Sub-Cues. The following occurred . . . Random glitching . . CPU usage 10% . . Physical Memory 94% . . Very unstable . . even opening and switching tabs in Task Manager causes glitches. Navigating within the main screen is very slow – 10secs to load.
I then disabled the ‘software mixer’ . . which showed me a small improvement: CPU usage around 6% - 15% . . Physical Memory 72% - 85% . . but a cue can now take as much as 5 secs to load and also the screen redraw can take as much as 9 seconds before the display is refreshed.
This seems to have overcome glitching at the start of a cue but some is still occurring at random times within a cue. This seems to increase as more cues are played. Hitting ESC prior to playing a cue does seem to decrease the amount of glitching.
When glitching now occurs all the tracks remain in sync with each other. Prior to disabling the software mixer they lost sync with each other.
I tried increasing both buffers to 2000ms . . this didn’t seem to help the glitching problem but made navigating really slow (e.g. 35 secs to load a Cue after navigating to it) . . it then crashed when I tried to hit play before the file had loaded. Reset back to SCS default (200ms).
I've reloaded version 9.4 back on my other laptop to get me through the next gig and it's only when you do that that you realise all the great advances that version 10.2 has to offer . . . I'm sure that Mike will be able to fix this issue as he always does . . .

Just an update on this topic: Martin's been running some tests for me (we're in the same timezone which helps!) and we are making progress. A 'non-mixer' version of SCS 10 is now playing files perfectly on all machines, and the 'mixer' version plays files correctly on desktop machines but not laptops. I've asked Martin to check some settings in the Windows Control Panel for the laptops.

Any progress to report on getting audio files to play correctly on a laptop?

Bruce

There's some progress but I still working on some mods. First of all, we found that on Martin's laptop a process named mcshield was frequently running and having a devastating affect on SCS. mcshield is a McAfee process, and the process was running even though McAfee had been disabled. Since the laptop is not connected to the Internet we uninstalled McAfee, so that got rid of mcshield.

Another matter I'm concerned about is that on this laptop it is very obvious that the disk spins down after a few seconds of inactivity. I don't know if this is a complete spin down to idle, or whether the speed of spin is just lowered, but you can hear the drive spin down. All the power settings are set to keep the machine running, so I haven't found any way to prevent that spin down. The laptop is a Dell Inspiron.

The main SCS issue I'm working on regarding this forum topic is that when starting 'linked' files, one of the files sometimes starts out of sync with the others. To 'fix' this I'm implementing a non-mixer option. This will bypass the audio library's mixer, which was added in SCS 10. There will be some restrictions in functionality when selecting the non-mixer option, but this may be necessary for some users, and the audio performance should be the same as for SCS 9. The default buffer sizes when selecting the non-mixer option will be 5000ms (as they were for SCS 9).

I' m having the same (or similar) problem on my "Theatre desktop PC" (it's an old PC of course). A "click" sound at the start of cues, wich is happening randomly. On my laptop, clicks plus stutters. I went back to version 9 just to be able to work. Is it possible to send me the link to the "non mixer " version, please, so I can give it a try?
Thanks.

I've emailed you details, Fanis.

I am also experiencing the random glitches when changing from one active sound cue to the next one. SCS repeats some miliseconds of the sound file that is being playing before switching to the next one. I am using a Laptop with Roland Edirol UA101 connected to an USB2.0 port. I have extended the UA101 buffer to the maximum lenght but that had no effect on the glitches.

Could it be due to the mixer problem you mentioned in the previous appends? I am new user of SCS and I have no V9 to compare with.

I stopped all the background processes I could stop, disabled firewall and antivirus (Symantec) auto-protect option, and preloaded all the files I could in memory. However, I have some files inside the performance in Playlist cues. As far as I saw, they cannot be preloaded. Should I move them to standard sound cues?

Please, help! We have our first performance this Saturday!

Best regards.
Antonio.

Antonio,

Please try the option in SCS 10.3.0 to not use the SCS Internal Mixer. If you have not yet installed 10.3.0 then you will need to do that first because this option is not available in earlier SCS 10 versions. See the forum topic SCS 10.3.0 now available for information, and also the SCS Help for Permanent Options / Audio Driver, and read the info under SCS Internal Mixer.

With this option selected (to not use the internal mixer) I recommend you clear your checkboxes for 'preload whole file', because that causes delays in opening files and can take a significant amount of memory. Leave your playlist cues as playlists.

One other thing - what processor speed and RAM do you have on your laptop? I had problems with my UA101 on an old low-spec laptop, and that was with SCS 9, but it runs perfectly on my current laptop (HP Compaq Persario, 1.6GHz, 1GB RAM, Vista Business).

Finally, for audio applications it is recommended that you set Processor Scheduling to Background Services. You can get to that setting via the Windows Control Panel / System / Advanced.

Thank you very much, Mike. I will try 10.3 asap. I have a good laptop, not top-of-the-market, but with 1.5 GHz CPU and 1GB RAM. I also have the option of Processor Scheduling to Background Services set, as it is recommended by Roland.

Anyway, thanks for this excellent program!
Antonio.