FORUMS: list search recent posts

a couple questions

COW Forums : AJA Video Systems

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
bruce alan greene
a couple questions
on Dec 2, 2008 at 5:46:15 am

I've been using the I/O HD to record 720p Varicam to Pro Res HQ using a Macbook Pro and e-sata raid. We record to QT using the AJA VTR exchange software.

I have a couple questions:

1. When playing back to the HDSDI monitor using FCP it seems to drop partial frames. Is there a way to avoid this?

2. When the VTR exchange is used to play back a clip on the computer screen, the HDSDI monitor goes wacky. Is this normal?

3. One more...I captured a tape played back in the camera and the QT clip is like every other frame of video and the sound loses sync. What causes this? I did it once before with the incorrect TC setting in the AJA software, but it happened again with the usual setting.

Thanks experts in advance!



Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


Return to posts index

Jeremy Garchow
Re: a couple questions
on Dec 2, 2008 at 6:17:18 am

[bruce alan greene] "1. When playing back to the HDSDI monitor using FCP it seems to drop partial frames. Is there a way to avoid this? "

What do you mean? What's the evidence?


[bruce alan greene] "2. When the VTR exchange is used to play back a clip on the computer screen, the HDSDI monitor goes wacky. Is this normal? "

Wacky how? Does it do this with AJA TV?


[bruce alan greene] "3. One more...I captured a tape played back in the camera and the QT clip is like every other frame of video and the sound loses sync. What causes this? I did it once before with the incorrect TC setting in the AJA software, but it happened again with the usual setting. "

Sounds like you have captured the wrong frame rate or you didn't use an easy setup with a 'VFR' tag on it.

Jeremy


Return to posts index

bruce alan greene
Re: a couple questions
on Dec 2, 2008 at 8:46:30 am

thanks Jeremy.

What is AJA TV?

When playing back through fcp, some frames have flashes of digital giberish, usually in the bottom of the frame.

I think I've set up the frame rates correctly...




Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


Return to posts index


Jeremy Garchow
Re: a couple questions
on Dec 2, 2008 at 3:56:47 pm

AJA Tv is an application that plays out qualified Quicktime movies through the AJA. Right click on a QT file and choose Open With > AJA TV. It's a simple playback application.

[bruce alan greene] "When playing back through fcp, some frames have flashes of digital giberish, usually in the bottom of the frame"

Does the digital giberish happen at the same time in the file or does it happen sporadically?

Is the digital giberish apparent if you watch the Quicktime movie in Quicktime on your computer monitor?

Do you have reference running to the io, if so how? If not, how is your reference setup? Have you tried free run?

Jeremy


Return to posts index

bruce alan greene
Re: a couple questions
on Dec 3, 2008 at 7:34:13 am

[Jeremy Garchow] "Does the digital giberish happen at the same time in the file or does it happen sporadically?

Is the digital giberish apparent if you watch the Quicktime movie in Quicktime on your computer monitor?

Do you have reference running to the io, if so how? If not, how is your reference setup? Have you tried free run?
"


The digital digiberish happens at random times and not twice in the same place. The QT files play fine on the computer screen.

What's a "reference"? I'm just playing back through the fcp timeline or viewer to the AJA/HD monitor.

I've found that adding a filter to the clip will make for smoother playback at slightly reduced resolution, but I changed some setting in fcp and now it always tries to playback at full res and drops frames when a filter is applied. I guess I screwed with the RT settings and can't get them to change resolution for the non-rendered clips anymore. It seems like I need a little faster mac or there is a bottle neck in the data bus somewhere. I'm using an e-sata bus adapter and e-sata raid so that only the IO is on the firewire bus.

Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


Return to posts index

gary adcock
Re: a couple questions
on Dec 3, 2008 at 12:19:59 pm

"The digital digiberish happens at random times and not twice in the same place."

this sounds like a playback error- like you machine does not have the horsepower to playback the file as recorded. --What computer? what sata storage? how much RAM?


"What's a "reference"? " it's genlock to you camera guys...

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




Return to posts index


Ken Botelho
Re: a couple questions
on Dec 4, 2008 at 1:17:39 am

"The digital digiberish happens at random times and not twice in the same place."

Try to capture and playback uncompressed to see if its a codec issue.



Return to posts index

bruce alan greene
Re: a couple questions
on Dec 4, 2008 at 8:39:26 am

Gary,

I have a MB pro with 2.2 ghz core 2 duo and 2gb ram. The drive is a g-tech e-sata raid through the e-sata bus adapter. The I/O is firewire 800 connection.

Do I need a reference for playback through fcp? I wouldn't think so.

Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


Return to posts index

gary adcock
Re: a couple questions
on Dec 4, 2008 at 11:31:47 am

[bruce alan greene] "Do I need a reference for playback through fcp? I wouldn't think s"

NO. it is not a reference issues

[bruce alan greene] "I have a MB pro with 2.2 ghz core 2 duo and 2gb ram. "

this is the bare minimum config for an IoHD. It will always be right on the edge for its ability to handle the data particularly for playback of HQ content.

try capturing and playing back plain ProRes - you will see that it works like a charm and you will see noticeably less errors

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




Return to posts index


bruce alan greene
Re: a couple questions
on Dec 6, 2008 at 1:57:58 am

[gary adcock] "his is the bare minimum config for an IoHD. It will always be right on the edge for its ability to handle the data particularly for playback of HQ content.

try capturing and playing back plain ProRes - you will see that it works like a charm and you will see noticeably less errors "


Thanks Gary,

Is the processor the bottle neck? Or, will more RAM help?

And, If I have AJA VTR exchange set to abort on dropped frames, can I assume I'm having only a playback issue if the capture does not abort?

I really want to capture 10 bit HQ if possible for color grading, and I've already captured 1/3 of the movie in this format. I've played back 1080P ProResHQ before without issue, so I thought that 720P wouldn't be a problem.

Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


Return to posts index

Jeremy Garchow
Re: a couple questions
on Dec 6, 2008 at 2:05:47 am

A 2.33 GHz machine in the recommended lowest common denominator. What frame rate are you working in? If you are working in 24p and the ioHD needs to add pulldown, I have seen this gibberish happen in that scenario. You can get around it by putting your 24p (or 30p) movie in a 720p60 timeline and rendering. Surprisingly, FCP will add proper pulldown to these 720p formats when rendering. The gibberish will go away.


Return to posts index

gary adcock
Re: a couple questions
on Dec 6, 2008 at 2:42:25 pm

[bruce alan greene] "
Is the processor the bottle neck? Or, will more RAM help?

And, If I have AJA VTR exchange set to abort on dropped frames, can I assume I'm having only a playback issue if the capture does not abort? "


Based on your message here - the processor is the bottleneck on the output- if it was dropping frames on capture you would know it.

"I really want to capture 10 bit HQ if possible for color grading, and I've already captured 1/3 of the movie"
You will see no difference between the 2 versions of prores.- none whatsoever


gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




Return to posts index


bruce alan greene
Re: a couple questions
on Dec 10, 2008 at 7:49:33 am

Now, the picture is playing back fine, but the audio seems to be recorded at a different speed. How does this happen?

Varicam/Steadicam Owner
Los Angeles, CA
http://www.brucealangreene.com


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]