Digital Audio Drift

Bryan Beasleigh · May 30th, 2004, 03:35 PM

Wouldn't it be easier to just buy a star wars DVD.

Jeff Donald · May 30th, 2004, 03:50 PM

My experience is that all of these devices add or subtract a frame or two error to the process. The manufacture doesn't tell you about this delay (or advance) figuring you'll never see or hear it. But in reality, when you start adding up all the delays, it can be quite noticeable.

My case in point would be the DVX100, which in some modes has a several frame delay. Compound this with the delay in the playback device and the display device (say LCD Screen) and all of a sudden you have a, say, 6 to 8 frame delay.

Peter Moore · May 30th, 2004, 04:19 PM

Is not the cameras since the delay is different on different cards.

Douglas, yes TerraTec. Sorry I couldn't remember the exact name. :) In general I've been very pleased with the EWX 24/96, until now. Sounds like I should just get a better sound card for the future.

Jeff Donald · May 30th, 2004, 05:07 PM

Sorry, I wasn't clear on my point. I wasn't trying to single out a camera or one specific device. Rather, I was trying to point out the drift in the mix of the analog and digital world.

In the past, the analog world was linked via SMPTE timecode if you needed frame accuracy. Digital has thrown a curve into the formula. Display devices (LCD, plasma screens, digital projectors etc.) have a frame buffer, or delay, that can be a problem. Capture devices that incorporate A/D and D/A convertors, generally use frame buffers that can contribute to the frame error. Playback devices, such as DVD players, DV video decks, computers, can add a delay also. Some cameras (DVX100 for example) record with a frame or two delay in some modes.

If you view the signal through just one or two device the delay or advance in most cases is not noticeable. However, add a capture device and a digital display device and the effect will surely be noticeable.

Peter Moore · May 30th, 2004, 05:22 PM

how about this:

http://www.newegg.com/app/viewProductDesc.asp?description=29-121-105&depa=0

Should this give me no audio drift?

May 30th, 2004, 03:35 PM	#16
Bryan Beasleigh Trustee Join Date: May 2002 Location: Barrie, Ontario, Canada Posts: 1,922	Wouldn't it be easier to just buy a star wars DVD. __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ".......holy smokin rubber lips...what a ride!"

May 30th, 2004, 03:50 PM	#17
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	My experience is that all of these devices add or subtract a frame or two error to the process. The manufacture doesn't tell you about this delay (or advance) figuring you'll never see or hear it. But in reality, when you start adding up all the delays, it can be quite noticeable. My case in point would be the DVX100, which in some modes has a several frame delay. Compound this with the delay in the playback device and the display device (say LCD Screen) and all of a sudden you have a, say, 6 to 8 frame delay. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

May 30th, 2004, 05:07 PM	#19
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Sorry, I wasn't clear on my point. I wasn't trying to single out a camera or one specific device. Rather, I was trying to point out the drift in the mix of the analog and digital world. In the past, the analog world was linked via SMPTE timecode if you needed frame accuracy. Digital has thrown a curve into the formula. Display devices (LCD, plasma screens, digital projectors etc.) have a frame buffer, or delay, that can be a problem. Capture devices that incorporate A/D and D/A convertors, generally use frame buffers that can contribute to the frame error. Playback devices, such as DVD players, DV video decks, computers, can add a delay also. Some cameras (DVX100 for example) record with a frame or two delay in some modes. If you view the signal through just one or two device the delay or advance in most cases is not noticeable. However, add a capture device and a digital display device and the effect will surely be noticeable. __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

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May 30th, 2004, 04:19 PM	#18
Peter Moore Trustee Join Date: Oct 2002 Location: Arlington VA Posts: 1,034	Is not the cameras since the delay is different on different cards. Douglas, yes TerraTec. Sorry I couldn't remember the exact name. :) In general I've been very pleased with the EWX 24/96, until now. Sounds like I should just get a better sound card for the future.

May 30th, 2004, 05:22 PM	#20
Peter Moore Trustee Join Date: Oct 2002 Location: Arlington VA Posts: 1,034	how about this: http://www.newegg.com/app/viewProductDesc.asp?description=29-121-105&depa=0 Should this give me no audio drift?