leopard latency & the IoHD…

[Bob Zelin]

eric –
PLEASE do this for me, and post back your results.
Open the same project that you were seeing the audio/video sync offset (and that is now in perfect sync) –

take your mouse, and AGGRESIVELY scrub on the time line (move the mouse around fast on the timeline). Hit play – is it still in sync ?

Please let me know.

Bob Zelin

[E. Eric johnson iii]

bob-

i’ll do it first thing in the morning and post with the results.

-eric

e. eric johnson iii
eric@lillmonster.net
LILL MONSTER MOTION PICTURES
principal, producer-director-camera

now in post production – START 2 FINISH: What It Really Takes to Race A Bike

[E. Eric johnson iii]

hi bob-

you might be on to something… here’s the results of what you asked and another interesting deal:

for starters, the aggressive scrubbing did in fact change the sync significantly. which makes some sense because in my prior frustration i did move the mouse back & forth in a less than happy fashion. i checked the frame offset & it did not change numerically. also, if you waited a few minutes, the sequence played back closer to sync, but not on.

in addition, upon opening the sequence and initially playing the sequence (before scrubbing aggressively), it began playing short loops (my guess is about 30-60 frames) in an exponential fashion. this lasted about five seconds then the sequence played normally. BTW the timeline showed no sign of movement during this looping activity.

just to make sure, i went back and restarted FCP & the sequence again. everything occurred the same as above, sans the wacky, exponential looping thing. though on prior days this did happen.

the added thing i noticed is that the setups for IoHD & KONA 3 apparently cannot co-exist in FCP. originally i was going to use a K3 with this machine (MP Tower), but i had to wait on using it, so the IoHD got put into use. when i added the setups for the IoHD, the K3 setups disappeared. i thought nothing of it since i wasn’t going to be using the K3 immediately anyway.

so you know, prior to this test i added my K3 card (with b-box) and reloaded the setups. for this test, i reloaded the IoHD setups, which in turn removed the K3 setups. BTW, there have been no sync issues with the K3 (offset at 4 frames).

this is all done on the MP 8-core tower running leopard.

hopefully this helps you in your research and if there’s anything else i can do, let me know.

-eric

e. eric johnson iii
eric@lillmonster.net
LILL MONSTER MOTION PICTURES
principal, producer-director-camera

now in post production – START 2 FINISH: What It Really Takes to Race A Bike

[Gary Adcock]

[e. eric johnson iii] “so you know, prior to this test i added my K3 card (with b-box) and reloaded the setups. for this test, i reloaded the IoHD setups, which in turn removed the K3 setups. BTW, there have been no sync issues with the K3 (offset at 4 frames).
“

WHOA….
you need to uninstall the drivers FIRST then restart- not just overwrite the older/ alternative driver as that does not remove all of the proper components.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD

[E. Eric johnson iii]

thanks gary… will do and post back with the results.

-eric

e. eric johnson iii
eric@lillmonster.net
LILL MONSTER MOTION PICTURES
principal, producer-director-camera

now in post production – START 2 FINISH: What It Really Takes to Race A Bike

[E. Eric johnson iii]

hi gary-

thanks for the help.

now back to square one: i did an uninstall, restarted, reinstalled the IoHD setups, restarted and, only after aggressive scrubbing in the timeline, is there a change in sync. however, if you wait 15-20 seconds the sync appears to return.

other than that, it now all seems to work fine.

again thanks for the reminder on the uninstall… D’OH!

-eric

e. eric johnson iii
eric@lillmonster.net
LILL MONSTER MOTION PICTURES
principal, producer-director-camera

now in post production – START 2 FINISH: What It Really Takes to Race A Bike

[Gary Adcock]

hey everyone

I want everyone that has seen this issue to know that it was one of the people working with BobZ that found what we think to be the root of the issue regarding “the Audio Latency when scrubbing with the IoHD”

it seems that the when there are more than 4 tracks of audio only / audio not connected or linked to the video / or that the soundtrack might be composed of small audio or short audio and video clips that go out of sync with fast scrubbing of the timeline.

there are a couple of issues here first off – turn off HQ audio monitoring- all this does is tax the audio playback and induce delay do to the increased processing needs of the computer CPU and that delay is exacerbated by the FW latency and the CPU cycles taken up with the I/O functions using the IoHD rather than a Kona card ( do to its internal location on the PCIe buss)

Secondly – if the are a number of smaller clips – the nature of audio file makes them more read/ write intensive do to the small size and sheer number of them. – Video is one really big file, however audio sweetening is a large number of small files strewn all over parts of your computer – and if those files are not stored on the same array as your video there can be delays when the disks need to spin up to speed when doing a fast scrub.

Try your timelines again – making sure that you check the audio settings

UNCHECKING THE SCRUB HIGH QUALITY checkmark in

FCP system settings -> playback control.

and

User Settings > General > Audio setting < LOW > – faster playback>

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD

[David Perry]

Hi,

I’ve just read this thread and was noticing that you turned on your machine and then the IO HD. I was told by AJA that you should turn on the AJA first in order for everything to work correctly.

Just thought you might like to know.

David Perry

David Perry
Carmen Productions

[E. Eric johnson iii]

thanks david…

i ended-up trying it with the IoHD on and off prior to starting the cpu. strangely enough, it made no difference with the latency issue. i just have to remember to take a breath or two before i playback after a good scrubbing. not too mention taking gary’s advice and uncheck the HQ audio in FCP.

thanks for the input.

onward & upward,

eric

e. eric johnson iii
eric@lillmonster.net
LILL MONSTER MOTION PICTURES
principal, producer-director-camera

now in post production – START 2 FINISH: What It Really Takes to Race A Bike