jerky video

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jonny
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Joined: Mar 23 2002

I have an MSI K7T Turbo motherboard (VIA KT133A chipset based) with a 1.2 GHz AMD Athlon processor, 256 MB of RAM, and an ATI DV Wonder firewire card.

I can capture DV video from my camcorder to my computer just fine, but when I send it back to my camcorder the video and audio are jerky. What is the problem? Are there known issues with this motherboard?

[This message has been edited by jonny (edited 23 March 2002).]

foxvideo
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Joined: Sep 9 1999

A drive for video/audio data separate to the system drive, pref 7200rpm & with DMA enabled would probably solve the problem.

See the FAQ: http://www.dvdoctor.net/cgi-bin/ubb/Forum3/HTML/000024.html

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Dave Farrants
Producer/Editor
Fox Video Productions

[This message has been edited by foxvideo (edited 23 March 2002).]

Dave Farrants Fox Video Editing

jonny
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Joined: Mar 23 2002

Would partitioning my hard drive and using one drive solely for video solve the problem, or do you mean getting an entirely separate hard drive? Is a separate hard drive better than just a partitioned one?

Does anyone have any experience with the ATI DV Wonder firewire card? Have you been able to import and export DV with no problems? What motherboard do you have?

[This message has been edited by jonny (edited 24 March 2002).]

foxvideo
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quote:Originally posted by jonny:
Would partitioning my hard drive and using one drive solely for video solve the problem, or do you mean getting an entirely separate hard drive? Is a separate hard drive better than just a partitioned one?

Partionining is not the answer, most video users have a separate, dedicated hard drive for video storage/playback.

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Dave Farrants
Producer/Editor
Fox Video Productions

Dave Farrants Fox Video Editing

Trevor Page
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Joined: Oct 4 1999

And, if using IDE preferably that seperate hard drive is on a separate IDE controller.

jonny
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Joined: Mar 23 2002

Are you pretty sure a separate hard drive would resolve this issue? It has also been suggested that my motherboard might conflict with my firewire card. Do you think this is a possibility? By the way, is there a way to export analogue video, without connecting tv out and playing the movie, to save processing power and make the movie play back smoother?

foxvideo
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Joined: Sep 9 1999

Don't know of any conflicts of board and FW card, try the ATI site for info if your convinced there's a problem

Do you have the latest VIA drivers (4.38) and DirectX 8.1?

No. You have to play the movie!

------------------
Dave Farrants
Producer/Editor
Fox Video Productions

Dave Farrants Fox Video Editing

Trevor Page
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Joined: Oct 4 1999

When Capturing from video, The data stream coming from your DV camcorder is a constant 3.6MB/second. The PC is able to buffer this stream prior to writing to the Hard drive. This means that other demands placed on the hard drive by say the OS using the swap file (page file) can - to a certain extent be tolerated - without dropping frames. However, when writing back to tape (DV output) the camera cannot buffer large amounts of data. So the DV output stream has to maintain the constant 3.6MB/sec needed. If it can't (as is nearly always the case with single drive systems) then frame dropping occurs. (Jerky video/audio) Fragmented hard drives will make the problem worse. Your disk could have a transfer rate in excess of say 20MB/sec, but it needs to sustain a constant 3.6MB/sec all the time.

Conflicting IRQ's usually result in dropped frames during capture and record to tape. Firewire/motherboard conflicts would more likely result in crashing, BSOD or abnormal program termination.

Trev

[This message has been edited by Trevor Page (edited 25 March 2002).]

jonny
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Joined: Mar 23 2002

The separate hard drive did solve the problem. Any other suggestions? Does anyone have any experience with the ATI DV Wonder firewire card? If so what motherboard do you have?

foxvideo
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Dave Farrants
Producer/Editor
Fox Video Productions

Dave Farrants Fox Video Editing

pettitj
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Joined: Jan 7 2001

Did you mean "did not solve the problem". I think you must have as you go on to ask more questions. The Fox video reply with a smiley although well intentioned may have put off other replies to help solve you query.

I had this problem and it turns out that soundblaster cards can cause this. I now have a Yamaha card with no more jerkiness when playing the video back to the camera.

Jim Pettit

Jim Pettit