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Best Settings to Avoid Artifacts in OnLocation Capture

Feb 19, 2011 12:28 PM

On Harm Millaard's advice, I am reposting this question here.

 

I would like to ask what are the best settings using an HVX-200P with a 1394 firewire to the following PC (CS4):

 

 

Motherboard

Asus P6TSE

Processor

Intel Core i7 2.66GHz

RAM

OCZ Platinum 12GB DDR3 1333 (PC3 10666)

Boot Drive

Western Digital WD5001AALS 500GB   SATA2 7200rpm 32MB Intellipower Hard Drive

Projects/Scratch

Seagate ST3750528AS 750GB SATA2   7200rpm 32MB Hard Drive

Media

Seagate ST3750528AS 750GB SATA2   7200rpm 32MB Hard Drive

Case

Cooler Master Centurion 534   RC-534-KKN2-GP No PS ATX Mid Tower Case (Black)

Power Supply

CORSAIR CMPSU-750TX 750W

Graphics Card

MSI ATI Radeon HD4850 OC 1GB   DDR3 2DVI PCI-Express Video Card

OS

Windows 7 Pro 64-bit

 

 

I've been getting sporadic artifacts when capturing at 720p30. I'm shooting an interview format against a green screen. My OL settings are:

Visible Lines - Odd

Monitor Aspect Ratio and Letterbox - 16:9

MPEG Decompression - Resolution=Half and Frames displayed=I+P

 

I pretty sure my memory and other hardware and BIOS settings are in good shape (no overclocking), so I'm wondering if I'm not getting the OL settings right. I know there can be almost infinite reasons why artifacts show up, but I want to rule out OL setting mistakes.

 

Any suggestions would be greatly appreciated.

 
Replies
  • Currently Being Moderated
    Feb 21, 2011 10:32 AM   in reply to Paul Stark

    No settings in OnLocation affect the quality of what's recorded. OL records the video stream direct-to-disk, without decoding/re-encoding it, so there's no opportunity for the application to introduce problems. The artifacts could be coming from the camera or they could be a product of an issue writing to disk--for instance, if fragmentation is so bad that the app has to cached too many frames while looking for open sectors, then you could end up with dropped frames. In that particular instance, the message bar below the field monitor would warn you that RAM is dangerously full.

    To test whether the problem is on the camera's side, you could record both to the P2 card and to OL. Then when you encounter an artifact in OL's recording, check the same frame in the P2 clip. A triple-check would be to point the camera at OL's field monitor while recording both to the P2 card and direct-to-disk. Then you could see whether an artifact that exists in the clip that OL recorded is also evident in the decoded video that OL displayed live.

     

    What's the nature of the artifacting?  Can you post a frame?

     
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  • Currently Being Moderated
    Feb 23, 2011 12:39 PM   in reply to Paul Stark

    Okay, this is going to be a bit of a scattergun response...

     

    We have seen frames with artifacts much like yours and have a bug on the books about it, dating back to 2008. That bug is closed as a 3rd party issue, with the following note: "These "glitch" frames are not unique to OnLocation. There are many documented cases of such frames coming from the HVX 200. Anecdotal evidence points to a hitch in the data transfer, with the Firewire cable being the main suspect."

     

    Here's a related thread on DVXUser.com: http://www.dvxuser.com/V6/showthread.php?77384-Let-s-solve-this-glitch -once-and-for-all&highlight=the+glitch. The artifacts they're discussing are similar to what your frame shows, but OnLocation was not in the mix.

     

    Anyway, my recommendation is that you try another cable--and keep it under the 4.5 meter limit. Also, it might be worth downloading the trial of Premiere Pro CS5 and seeing if you get the artifacts in that version of OL. I don't recall seeing any "glitch" frame in the CS5 cycle, but I wouldn't testify to that. And even if my memory is right, that doesn't mean that we fixed anything in the app--it could just be that I had scrapped the bad Firewire cable...

     

    Since my memory is shaky on this, I consulted a couple of colleagues. One suggested testing with anti-virus disabled. The other pointed to high RAM usage or a pegged CPU--given how beefy your system is, I'd be a little surprised if either of those proved to be factors, but as far as RAM goes, keep in mind that OL is a 32bit app, so it's not able to access memory addresses beyond the 4GB threshold.

     

    Unrelated to this issue, since you mention only that you're running CS4, I urge you to patch to OL 4.0.3 if you haven't already done so. We fixed a boatload of bugs in the patches.

     
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