Slow audio scrubbing on MC6 and MX02Mini

Niels Koopman · Joined: 04 Jul 2005 Posts: 12

I recently upgraded from MC5.5 to 6, and from snow leopard to Lion.
Before that I was working on MC5.0.3 in combination with MX02, and it worked perfect.
But since my upgrade to MC5.5 and MX02 Version 2.3.3.0016 (and now MC6 and MX02 V. 3.0.0.0071) I have a huge delay in audio playback when I have caps lock turned on for audio scrubbing.
I use audio scrubbing a lot, since I do a lot of syncing and perf slipping. I don't have this problem when I switch the Matrox off, but in MC6 it isn't possible to toggle anymore.
Did anyone encounter the same problem, and solved it?

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Can you confirm what resolution and frame rate is your sequence in Avid MC6?

Do you have Fast Scrub enabled or disabled?
_________________
Regards,
Sam
Matrox Video Technical Support

Niels Koopman · Joined: 04 Jul 2005 Posts: 12

I'm not working in a sequence, but with subclips in my preview monitor. I sync separate audio & video by timecode, which creates a subclip. When I want to perfslip this subclip, to correct the offset in sync, I step back and forth at the sync-clap. When doing this (with capslock turned on), there's a huge delay in sound. When I edit the clip in a sequence, the problem stays the same.

At first I tried it with "use fast scrub" enabled, when I disable it it only gets worse. Both my preview monitor in Avid, and my external monitor go black.
In my Avid preview monitor I get the message "Audio Underrun".
I'm working in a 1080P/25 (film) project, with XD CAMEX 35Mbits MXF resolution.
I also work in 1080/24, same problems!

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Hi Niels Koopman,

We seem to have reproduced a slight delay of audio while scrubbing with MXO2 when compared to native Avid.
Can you confirm how much of a delay you are seeing?

We also have not reproduced the Audio Underrun error message. It seems this may be due to bandwidth or performance issue with the system.
See this Avid link for more information: http://community.avid.com/forums/t/81848.aspx

Here are some other helpful posts: http://forums.creativecow.net/thread/45/869072
http://www.geniusdv.com/weblog/archives/audio_video_underuns_in_avid_xpress.php

Hope this information is helpful.
_________________
Regards,
Sam
Matrox Video Technical Support

Niels Koopman · Joined: 04 Jul 2005 Posts: 12

the delay I'm having here is somewhere near a second, when I step back and forth. I think I'm going to reformat my system drive and make a clean install of Lion, Avid 6 and the latest Matrox firm-&software.

Thanks for your time!

Grtz,
Niels

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Thanks for the update Niels. We will address the scrubbing delay to our engineering department and hope to have a solution or update in the near future.
_________________
Regards,
Sam
Matrox Video Technical Support

d_di_francesco · Joined: 04 Jul 2005 Posts: 4

I have had the same problem. I have updated to the proper firm and software version of the MXO2 Mini and am running Media Composer 6.0.

If I try to enable Audio Scrubbing (Caps Lock), I get an Audio Underrun error message in my preview window when I try to go frame by frame and hear the audio. I was running Media Composer 5.5.3 for some time with the previous Matrox version and had no problems so long as I disabled the 'Use Fast Scrub' functionnality in Media Composer. Now I've tried it every which way, no way of getting a workable audio scrub.

Any news on this from the Matrox team ? This is a rather basic and important functionality. I can't imagine editing properly without it.

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Hi,

What are your system specs? What version of MXO2 drivers are you running?
Have you tried the underrun suggestions in the posts from previous reply? ie Different media drive, removing audio effects, or changing/matching audio sample rates from project settings with clip settings?

d_di_francesco · Joined: 04 Jul 2005 Posts: 4

None of the tips apply to my situation. It's not a drive problem, I am working with 1080p23.98 DnX36 encoded media and my drive is more than capable of read/write at up to 76MB/sec according to a disk speed test. It is not a corrupt render file, there are no effects applied to the clips I am working on. And the problem is really only present when I attempt to have audio scrubbing enabled (Caps Lock). It is not an on and off problem, I can recreate it at any time. If I enable 'Use Fast Scrub' and recreate the problem, I get the following error message (but only with Use FastScrub enabled. If its disabled, I get Audio Underrun messages.):

Exception: BlipPlayer::NonThreadedPlayBlipField: Timed out waiting for single frame player to stop. If scrubbing a complex sequence of unrendered effects, consider rendering them for better performance

If I disable the Matrox hardware and run Media Composer in software only mode, I have no problems.

I am running Media Composer 6.0 on an Early 2008 MacPro 8-core, 2.8Ghz system with OS X 10.7.2 and Matrox software v.3.0.0.xxx, 8GB of RAM.

Niels Koopman · Joined: 04 Jul 2005 Posts: 12

good to know that I'm not the only one having this problem! Although I experienced the same troubles in 5.5.3, but never tried switching "use fast scrub" on or off.
At that time I got the following message in my preview window and also in my console, when caps lock turned on and stepping through a clip (just a sub-clip in my preview monitor).

PlayerHostThread::CheckForExceptions: Exception: PMS_NOT_READY_TO_START
Exception caught in APlayer::Play - Exception: PMS_NOT_READY_TO_START

As said in a previous post; I'm planning a clean install of OSX 10.7.2, MC6 and Matrox next week, to see if it makes a difference.

I'll keep you posted

N.

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Hi Niels,

Please let us know your results after your clean install whenever possible.
_________________
Regards,
Sam
Matrox Video Technical Support

Niels Koopman · Joined: 04 Jul 2005 Posts: 12

Hi,

a clean install didn't do it.
Same problem, same delays and audio underrun message;

Exception caught in APlayer::Play - Exception Audio Underrun.

I'm out of options now, and forced to work with my MX02 offline!

Grtz,
Niels

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Hi Niels,

The audio delay issue is a reported issue and has been sent to our engineering department for further investigation.

Have you tried the suggestion regarding Audio Sampling Rates? Verify you do not have mismatched sampling rates.
http://www.geniusdv.com/weblog/archives/audio_video_underuns_in_avid_xpress.php

Would it be possible to send us a sample clip of the Avid MXF file? Since we are not able to reproduce in house, your file may be able to help us troubleshoot the issue. I can send you the ftp information to upload the file.
_________________
Regards,
Sam
Matrox Video Technical Support

Niels Koopman · Joined: 04 Jul 2005 Posts: 12

Hi Sam,

the sample rates of the clips in my project are all the same.
I've send my private adres for you to send me the FTP details, so I can upload a couple of my files and a copy of the project I'm working in for further investigation.

Grtz,
Niels

Matrox_Support_Sam · Site Admin Joined: 04 Jul 2005 Posts: 6881

Hi Niels,

Thanks for the update. I sent a PM with ftp instructions. Please verify your inbox for more information.
_________________
Regards,
Sam
Matrox Video Technical Support