Troubleshooting FAQ



Q. When I scrub In Pro Tools, VVTR doesnt follow.

A. Make sure you have set the following:
- In Pro Tools, turn on 'Send Midi Machine Control' send this to VVTR
- In Pro Tools Preferences -> Operations, turn ON 'machine follows insertion/scrub'
- In VirtualVTR check your Midi / OMS Settings. In some cases with OMS, you will need to choose a different OMS source for MMC and MTC. This is a quirk of OMS. For example with Emagic MT4, select MT4 for MTC, and Port 1, for MMC. You will need to have devices created on your interface ports in OMS Setup.


Q. I am in Timecode Master or slave mode and my movie starts when I play in ProTools but the sync is very bad and it jumps all the time.

A. You probably have the frame rate set differently in Pro Tools and in VirtualVTR. Check the setting in ProTools session setup window and also in the 'Reset Timecode Reference' in VirtualVTR. The same issue applies when you are in slave mode.
A. Other things to check - some cards like Aurora Igniter MUST have an audio track (even silence) in the movie in order to run at an accurate speed or be genlocked. Under OS9, set the Sound Out to use the Igniter hardware. In OSX, do NOT set Igniter as sound output from the System prefs, VVTR does this itself.
A. Make sure your computer and disk are fast enough to ensure smooth playback
A. In some cases, the MTC coming from Pro Tools may be wrong or off-speed. Check your USD clock references. Try switching to using the MTC from the PT timeline through OMS rather than from the USD, and vice versa. In some cases, Pro Tools sends out different things....


Q. I am in Timecode Master mode and My movie starts when I play in ProTools but the sync is very bad and it jumps all the time.

A. You may have the 'Send MTC to Port' checked in Pro Tools and feeding VVTR in which case Pro Tools is sending out MTC to Virtual VTR at the same time as VTR is getting MTC from the Video Syncman. You should stop sending MTC from Pro Tools to VVTR when in Timecode Master mode.


Q. I get a jump in the picture every few seconds

A. (OS9) You may have the Mac's RAM Cache set too high. The Default setting for machines with alot of RAM is not good for real time applications. You should set the Ram Cache to 1MB or less in the Memory Control Panel. Note that in some cases, this can cause problems with Digitising, so in general, just experiment with different size caches, large or small. Also see the first question about poor sync

A. There are 2 types of 'jump'.
1) A Resync - this occurs when the sync of the timecode and picture are more than the sync tolerance specified in the prefs. When this occurs, you will see the 'Resync' LED light up in the VirtualVTR status window. A Resync shows that you need to examine your sync. There are 2 common causes, either sync drift, or sync instability. Sync drift shows that your picture and workstation are playing at slightly different speeds. In a pro environment you should ensure that your audio workstation and your VirtualVTR video card are both genlocked to a common Video reference (in some cases using genlock REQUIRES you to have an audio track in the movie, especially Aurora Igniter Systems). For non-genlocked setups, ensure you have an audio track in your movie, even silence (often the timing is derived from the audio hardware/track). Check that you have the same frame rate in VirtualVTR's timecode reference, movie, and your audio workstation. Sync instability suugests the incoming timecode is irregular (lumpy), although it may be linear over a long period. It is possible that short term timing lumps are pushing the sync out of tolerance. In this case, increase the value of the Sync Tolerance preference. If this solves the problem, great. if this merely lengthens the time between resyncs, then you have a drift problem, see above.

2) Dropping Frames - this occurs when the VirtualVTR Computer subsystem is not performing fast enough to play all frames. In this case, you will see dropped frames in the playback, but you will NOT see the 'Resync LED' light up. At this point you should check everything which affects system performance, try faster (or just different) hard discs, quit all unused apps, extensions etc, check your video monitors (spreading a window across 2 monitors can hurt performance), see the section below covering performance on Digitising - many of the same factors apply


Q. I am having problems Digitising picture.

A. Try any / all of the following:
- (OS9) Set your Ram cache to 1MB or less (Memory control Panel)
- (OS9) Set your Ram cache to 5MB or more (Memory control Panel)
- Try a different destination disk
- (OS9) Turn Virtual Memory OFF
- Turn Appletalk / filesharing OFF
- Use the latest versions of Virtual VTR, QuickTime, PCI / video card driver, Mac OS
- Energy saver features disabled
- Processor Cycling off (laptops)
- Airport Extensions off
- Small Preview Window
- try with an alternative Grabbing app to verify the problem
- Certain combinations of OS and Video Card drivers are incompatible. check with the card maker.


Q. I am having problems Digitising. I make a recording, but afterwards it will not open.

A. This is a common problem with users of Igniter in OSX. It is because you have not set things up correctly (probably selected built-in sound connection for input). Follow the instructions below:
- Select 'Built In' for the sound input in the System Preferences SOUND panel (not in VVTR)
- Select the correct Igniter audio input in the 'Sound Settings' in VirtualVTR (from E-E Mode)


Q. I get a jump in the picture every few seconds, and the sound on the movie is the wrong pitch or is wobbling

A. Sounds like your system clock on the Pro Tools system isnt right. Make sure that the Sample rate of your session and your sync device (USB, SSD, VSD etc) match, the frame rate matches, and that whatever is providing master sync is present (video, house sync etc). If in doubt set the master clock to internal sync.


Q. I have a Midisport 2+2 USB Interface, and I get a big jump in the picture every minute or so.

A. We have tested the Midisport 2+2 USB with a G4, and we experience a Midi transmission failure every 30 seconds to 1 minute when receiving MTC. This seems to be a bug in the Midisport driver, or a fault with the hardware. The same problem occurs with any software receiving MTC from the Midi sport. Dont use the Midisport 2+2 with VirtualVTR. We have tested the Unitor 8 Mk II (USB) with VirtualVTR with good results, and we recommend this product. Also the Emagic MT4 is recommended.


Q. When I scrub In Pro Tools, VVTR doesnt follow very well, and when I release the mouse button, midi continues to flow out of the Pro Tools mac, and hence VVTR keep on trying to scrub.

A. We see this problem only with USB Midi interfaces on the Pro Tools machine. It seems like Pro Tools sends too much midi data for the USB Midi to handle, and it gets buffered up, flowing on even after you release the mouse. The solution is to have a proper Serial Midi interface on the Pro Tools machine (although on some systems you may still see the problem, in which case you should switch to 9-pin instead of MMC). Digidesign are aware of the problem and have fixed in in Pro Tools 6.0.


Q. When I send MTC to VVTR, I see a white screen. I have checked the timecodes and everything matches up.

A. There are 2 possible solutions. 1- you have the 'Online' menu item turned OFF. In this case, VVTR will not chase MTC at all. Turn it back on and all should be well. Alternatively its possible that you have incorrect values in the 'Video Head Disengage Threshold and Max Shuttle Speed parameters. These should both be quite a bit more than 100%, typically several hundred percent, depending on your CPU. Max Shuttle speed is typically double or higher than the Disengage threshold.


Q. I am using 9-pin in VVTR and controlling it from another system. I see serial errors on my controller screen.

A. Some 9-pin controllers are very fussy about how devices behave. You will need to play with the 9-pin preferences in VirtualVTR to find the optimum setup. 9-pin control in OSX is much more responsive and reliable for most situations than OS9. For any kind of complex 9-pin setup, you MUST use OSX. OS9 9-pin is only supported for very simple control from Pro Tools. Contact Gallery for more advice on configuring VirtualVTR with 9-pin for mix stages etc. For the simplest 9-pin implementation, or for complex 9-pin setups with VirtualVTR in OS9, use the Gallery P2Plus hardware interface box, available from our web store, although in most cases this is not necessary, since similar performance can be acheived by setting up the 9-pin parameters in VirtualVTR (OSX) carefully.