Audio Sync issue addressed by Panasonic at DVinfo.net

Taro Beckwith · January 10th, 2003, 03:50 PM

Here's Stuart English's comment:

http://2-pop.5thavehosting.com/cgi-bin/discussion/forums/panasonicAGDVX100camera.cgi?noframes;read=37154

Frank Granovski · January 10th, 2003, 04:06 PM

So what he's saying is that there is no problem and no fix. Ha! I bet.

Jeff Donald · January 10th, 2003, 06:53 PM

Well, there is a fix, but not on a camera at that price point. An audio delay is needed and that doesn't fit their pricing of the DVX100.

Jeff

Nick Kerpchar · January 10th, 2003, 07:52 PM

Jeff,
I read through Stuart English's posting on 2-Pop about the "aduio sync" problem on the DVX100 and have a question. Stuart stated that the XL-1, and other cams, have the same problem (characteristic). Do you know if any XL-1s owners have reported the audio sync problem to the extent that the Panny DVX-100 owners have?

The message that they don't intend to do anything about it came through loud-and-clear. Wow. That is a real show-stopper for me.

Nick

Jeff Donald · January 10th, 2003, 08:11 PM

A couple of us are getting together this weekend to try to determine if the the delay is present on the Sony PD150 and Canon XL1S. We are also going to re-measure his DVX100 so that we can do an accurate comparison. I'll be posting the results here Monday or Tuesday as my schedule permits.

I've not heard the level of complaints about a sync delay in the XL1 as the DVX100. So, if it is present, it typically may fall with the 1 field delay that is visually difficult to notice. I believe the 1 field delay is present in all camcorders in this price range. His explanation makes perfect sense. But the figures I'm hearing and seeing are more like the DVX100 is 1.5 to 2 Frames out of sync (or 3 to 4 fields). It's not a terribly hard fix in post, you just slip the audio 2 frames.

Jeff

Nick Kerpchar · January 10th, 2003, 10:07 PM

Jeff,
Thanks a million. Look forward to hearing what you find.

Nick

January 11th, 2003, 10:32 AM

My tests have shown that capturing in 24pN and 24pA ,audio is 1 frame ahead.

My previous tests were captured in a 30 frame project so pulldown would push sync arounf an extra frame (or field) to get somewhere between 1 and 1.5.

All tests done in 24 frame projects have been consistent with 1 frame. Also considering that sync may fall somewhere between the "sync" frame and the previous frrame depending on velocity of the clap, this would put the sync issue at ~.5-1 frame ahead.

I don't consider this a huge issue at all as much of the film dailes that are synced in telecine display the same amount of precision.

There is also a cadence issue as to frame alignment and audio going between 24 and 30 - picture frame boundaries change whereas audio does not. So a clap falling exactly on an "A" frame will have a different audio to picture relationship than claps falling on other pulldown cadence frames.

I will update a white paper I wrote in this years ago to my website.

I have seen other posting where tests have been done with other cameras, I believe that true sync on all cameras is not exact and most will show some basic offset.

Michael

January 10th, 2003, 03:50 PM	#1
Taro Beckwith Regular Crew Join Date: Oct 2002 Location: Portland, OR Posts: 27	Audio Sync issue addressed by Panasonic Here's Stuart English's comment: http://2-pop.5thavehosting.com/cgi-bin/discussion/forums/panasonicAGDVX100camera.cgi?noframes;read=37154

January 10th, 2003, 04:06 PM	#2
Frank Granovski Outer Circle Join Date: May 2002 Location: Hope, BC Posts: 7,524	So what he's saying is that there is no problem and no fix. Ha! I bet.

January 10th, 2003, 06:53 PM	#3
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Well, there is a fix, but not on a camera at that price point. An audio delay is needed and that doesn't fit their pricing of the DVX100. Jeff

January 10th, 2003, 07:52 PM	#4
Nick Kerpchar Major Player Join Date: May 2002 Location: Texas Posts: 211	Jeff, I read through Stuart English's posting on 2-Pop about the "aduio sync" problem on the DVX100 and have a question. Stuart stated that the XL-1, and other cams, have the same problem (characteristic). Do you know if any XL-1s owners have reported the audio sync problem to the extent that the Panny DVX-100 owners have? The message that they don't intend to do anything about it came through loud-and-clear. Wow. That is a real show-stopper for me. Nick

January 10th, 2003, 08:11 PM	#5
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	A couple of us are getting together this weekend to try to determine if the the delay is present on the Sony PD150 and Canon XL1S. We are also going to re-measure his DVX100 so that we can do an accurate comparison. I'll be posting the results here Monday or Tuesday as my schedule permits. I've not heard the level of complaints about a sync delay in the XL1 as the DVX100. So, if it is present, it typically may fall with the 1 field delay that is visually difficult to notice. I believe the 1 field delay is present in all camcorders in this price range. His explanation makes perfect sense. But the figures I'm hearing and seeing are more like the DVX100 is 1.5 to 2 Frames out of sync (or 3 to 4 fields). It's not a terribly hard fix in post, you just slip the audio 2 frames. Jeff

January 10th, 2003, 10:07 PM	#6
Nick Kerpchar Major Player Join Date: May 2002 Location: Texas Posts: 211	Jeff, Thanks a million. Look forward to hearing what you find. Nick

January 11th, 2003, 10:32 AM	#7
Michael P Posts: n/a	My tests have shown that capturing in 24pN and 24pA ,audio is 1 frame ahead. My previous tests were captured in a 30 frame project so pulldown would push sync arounf an extra frame (or field) to get somewhere between 1 and 1.5. All tests done in 24 frame projects have been consistent with 1 frame. Also considering that sync may fall somewhere between the "sync" frame and the previous frrame depending on velocity of the clap, this would put the sync issue at ~.5-1 frame ahead. I don't consider this a huge issue at all as much of the film dailes that are synced in telecine display the same amount of precision. There is also a cadence issue as to frame alignment and audio going between 24 and 30 - picture frame boundaries change whereas audio does not. So a clap falling exactly on an "A" frame will have a different audio to picture relationship than claps falling on other pulldown cadence frames. I will update a white paper I wrote in this years ago to my website. I have seen other posting where tests have been done with other cameras, I believe that true sync on all cameras is not exact and most will show some basic offset. Michael