Serious Audio related issue with AJA IoHD

[Carsten Orlt]

have you tried to use AJA TV (little app you get with the driver installation) to play your QT clips? By using AJA TV you’ll force the audio of your clips through the ioHD, and this way you don’t need a mixer or dual inputs on your speakers.

The problem with audio latency or in this case better called delay is that the video has to go through through the ioHD and gets delayed due to processing. If the audio doesn’t go via the ioHD and gets synchronized within the ioHD the audio arrives basically not synchronized with the picture.

Because of firewire the delay is noticeable. So give Aja TV a try. (little tip: if your client wants to double click his files to always open them in AJA TV rather then QTplayer, you can set file(s)/type of files to always open with a certain app = contextual menu>hold option and the open with command changes to ‘always open with’

Carsten

[Jeremy Garchow]

See, that’s where I was going about the file types, but this won’t work without standard video codecs.

[Woody Bass]

I had forgotten about the AJA TV app, but that just might do the trick. All of the codecs in use are standard, so I don’t think using this app will be problematic….I’ll give it a spin tomorrow.

Thanks for all the feedback guys….we’re still relatively new to the game, so some things that are obvious to most of you isn’t that obvious to me :-). Any other feedback re: best practices with the IoHD are more than welcome….

Woody

[Ravi Sockalingam]

Hi

UNCHECK SCRUB HIGH QUALITY – does not have any effect..the issue remains unsolved… Aja support also suggested this setting but it does not work..

[Gary Adcock]

[Ravi Sockalingam] “The audio follows video delayed when scrubbing through the timeline of preview window.. Is there any other way which could solve this latency issue???
“

Ok thats a Different Issue
Turn off high quality scrubbing and set your audio quality to Low inside of FCP.

there is no need to monitor audio at a quality setting higher than you bring it into FCP at, the Low setting allows the system to monitor the audio with out converting or resampling.

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

[Ravi Sockalingam]

yes this i have done after it was suggested by Aja support team… However even after this the problem persists…

[Woody Bass]

Gary, et al.,

Not trying to beat a dead horse here, but can someone clarify why this weird audio “echo, loop” issue only happens when the System audio out is set to use the IoHD?

Maybe I’m just missing something obvious here, but since the audio that’s coming from FCP to the IoHD is also traveling over the Firewire bus, how is it that it can “bypass” this issue? Does FCP interact with the AJA software in a different way than does the Core Audio layer of the OS/Quicktime?

I understand the workaround, i.e. using FCP or the AJA TV to play QT files, but it just seems to be that if you can play audio from within FCP through the IoHD w/o any “echo”, then the same should hold true for any audio traveling over the Firewire bus.

Again, I apologize if I’m asking something that’s obvious to the rest of your more seasoned gurus out there :-).

Woody

[David Perry]

I haven’t read the whole thread recently but the “bypass” is going out of the line output of the MAC directly to the audio device you are listening to it on. You are not going out of the FW to the IO HD and then to your speakers.

Change your System Settings in FCP to Audio – Line Output instead of the AJA output for audio.
Then change your MAC System Prefs and choose the Sound icon and change the output to Line Output. Then connect a mini stereo cable to your MAC line output and run it to your speakers.

Certainly not an ideal situation but I think AJA has a handle on the problem and will fix it by NAB. (I might be wrong).

I hope this is right and helps.

David Perry
Carmen Productions

[Mazaltarim Marcel]

Hi Ravi
I am trying to find the sofware can you help me
Regards
Marcel M

[David Bispham]

We have the same issue of audio delay / latency / lip slip on two systems.
AJA Io HD 5.1.1
FCP 6.0.2
MAC OS X 10.4.11 2×3 Quad core Intel Xenon
16 GB 667 MHz DDR2 FB-DIMM
Sonnet 8TB
AJA Gen 10 Sync generator

The echo problem has been resolved by System Line out switched to Built in Line out instead of the AJA out which makes sense.

We have made the changes within FCP….
Setting audio quality to LOW which is 48KHz.
Setting video quality to HIGH.
Setting frame rate to FULL
Unchecking high quality scrub.

I did have luck hooking up the audio out of the Mac to a second input on the speakers so I can get system sound when playing DVDs or video clips on the desktop. This works nicely.
This may be obvious to most, but when I play a DVD using this setup the audio is dead on, but when system audio is pumped thru the AJA the sync is way off.

So, this is a known issue I am told, the rapid scrubbing and audio sync, but we get it with basic timeline navigation, which makes it a little difficult to edit and find audio que points. Can / will the issue be resolved? Is there a time frame? Should we get Kona cards? Could we be doing something wrong?
David