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Old Aug 17, 2004, 12:19 AM   #21
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Beverly W wrote:
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Just how long is a nine frame lag?
If we assume the camera is shooting 30 frames per second, then the nine frame lag is 9/30 of a second = 0.3 s.

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They saw no time lag and suggested that I update my sound drivers.
I think it's true that sound drivers and any of many other factors could impact the playback of videos and their associated audio files. I have a more noticable audio delay when I play back through Windows Media Player as opposed to Adobe Premiere.

It is hard to quantify the time lag just by watching the video. It's even harder when one cannot immediately detect the correlation between a video image and the sound that should be heard. Watching someone speak is a difficult condition to measure sound delay. Do you have a metronome? Try dropping a marble on a countertop. Make sure the lighting conditions cast a distinct shadow so you can visually identify the moment the sound should be made (when the shadow "touches" the bouncing ball).

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Could the tests have been a case of finding a problem because you are expecting a problem?
When you play a video and audio file in Premiere, you can see the images of the video in one window and the audio track displayed as an amplitude waveform in another. With an experiment like the pen test, the audio track is pretty distinctive... a bunch of spikes corresponding to when the pen taps the table. In Premiere I play the video frame by frame until the pen's shadow indicates contact has been made (if the pen has a push top, you can also detect when the spring is depressed :sad. I then look at the same frame number in the audio file and I should see that the frame corresponds to a spike on the graph. It doesn't. I must advance eight or nine frames forward to reach the corresponding audio spike.

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Also there is the speed of light vs speed of sound issue to deal with here (speed of sound through air 340 meters per second vs 300 million meters per second for light).
:-) :-) :-)

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Okay so how do we explain the finding no difference in the high vs low speed cards on the tapping test?
When you say there is no difference in performance, it's the case that they both generate equally bad delays, right?
If the camera hardware/software is the weakest link, then even the slower memory might be good enough to keep up.

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Could that be because I had updated my drivers? Would just updating the drivers alone have help in my case? Did the drivers have anything to do with this? I really don't know.
There are so many things that are optimized to accomplish multimedia playback on a PC that anything is possible. I'm skeptical that this was your problem. If the audio driver were slow, then the audio would continue playing after the video stopped. Again, this might be hard to detect, but I doubt it's the case. I don't know what other software to recommend using to debug other than Premiere. I think you might find the dropping ball test pretty informative. Remember if you find a ball with the right coefficient of restitution, you can drop it from a good height and get a progressively quicker "beat." You'll probably get your own sense of the rhythm and be able to spot misalignments pretty easily.

-Dave
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Old Aug 17, 2004, 3:56 AM   #22
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I have a more noticable audio delay when I play back through Windows Media Player as opposed to Adobe Premiere.
I suppose that Apple's Quiktime is the best for watching Nikon's videos.
(Because the video format is .mov)

Download QuikTime:
http://www.apple.com/quicktime/products/qt/
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Old Aug 18, 2004, 12:41 AM   #23
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mc_cool wrote:
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I have a more noticable audio delay when I play back through Windows Media Player as opposed to Adobe Premiere.
I suppose that Apple's Quiktime is the best for watching Nikon's videos.
(Because the video format is .mov)

Download QuikTime:
http://www.apple.com/quicktime/products/qt/
Oh yes, sorry about that. Quicktime is what I use to playback the MOV files. But I do believe that I have more audio delay with the quicktime player. I haven't checked this carefully, though. It's just a recollection I have from a few weeks ago.

-Dave
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Old Aug 22, 2004, 10:32 PM   #24
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I bought the Kingmax 256mb card too because of its high rated speed, plus Newegg.com sells it for a very good price of $34.

But something doesn't look/sound right when I watch the video I recorded. (I just record a news show watching the reporters mouth move on the TV).

Perhaps this is why Nikon has their $100 rebate.

It would be nice if there was a program that we could use to edit it, and put it into sync.
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Old Aug 23, 2004, 12:11 AM   #25
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I just tried converting the .mov file to .avi using a program called "Rad Video Tools".

Then used the free program VirtualDub and in its "audio" menu, under the option "interleaving" it has an option to change the "Audio Skew Correction". First I unchecked the option "enable video/audio interleaving" (mainly because I'm not sure about that), then I changed the "Audio Skew Correction" to -300ms and it improved the sound/video sync greatly.

(the sound was coming very slightly after I see their mouth move)

Not sure if -300ms is exact or anything, but it looks right to me now. I would hate to have to do that to every video file though. Not sure if I'm losing video quality by all the conversions also.

I would think Nikon could adjust/resync the audio themself. I doubt this has to do with having a highspeed card because it does it on the lower resolutions also. Or if someone could make an automated program to change the sync.
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Old Aug 25, 2004, 9:19 AM   #26
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My experiences to date with the Coolpix 3700 movie mode sync problem, firmware version 1.2, using subjective finger tap and speaking tests. All cards formatted prior to testing. Replayed on camera and on TV.

Sandisk 16MB card (came with camera):
- 640x480 30fps: Noticeable (unacceptable) audio lag
- 320x240 15fps: Noticeable (unacceptable) audio lag

Sandisk 256MB card:
- 640x480 30fps: Noticeable (unacceptable) audio lag
- 320x240 15fps: Noticeable (unacceptable) audio lag

Sandisk 256MB Ultra II:
- 640x480 30fps: Noticeable (unacceptable) audio lag
- 320x240 15fps: Noticeable (unacceptable) audio lag

Panasonic 256MB 80x super fast:
- 640x480 30fps: card ordered, will update soon
- 320x240 15fps: card ordered, will update soon

I hope the Panasonic card fixes the problem - 640/30fps movie mode is one of the main reasons I was willing to pay A$500 for a 3 megapixel auto-only point-and-shoot. Very good camera otherwise, for what it is.

Mark

PS When I asked 5 different leading Sydney digital camera retailers about this issue, what do you think they said? "We've never heard of it."

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Old Oct 13, 2004, 7:36 PM   #27
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well marke we r still waiting for ur reply for ur new panasonic high speed SD card .i hope that it will end ur audio sync problem that most of the users are facing with this 3700 coolpix.
faisal sheraz
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Old Oct 14, 2004, 10:20 AM   #28
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Update re Panasonic high speed 10Mbps card: made no difference to sync problem.

I got annoyed with the 3700, returned it for a Sony P100, which also has 640/30fps video mode Sony calls VX Fine or something. Got the Sony home and started using it, no sync problem, and nice smooth rendering of high speed motion, but........gee, that image looks softer than 640x320...........do some sniffing around on the web, found a comment by someone who claimed VX is just a marketing gimmick, and is merely interpolated 320x240.

Could this be true? Such deception from a "It's a Sony"? Well, yes - I compared the SonyVX with some Coolpix 640* and it's chalk and cheese. Sony VXlooks like320. Unbelieveable. And the clincher? The P100 does not offer a 320x240video resolution optionat all, only 640 and 160. How telling.

So, I got even more annoyed with the Sony camera (AU$200 more) and swapped it back for the 3700 (understanding shop). I'll live with the the sound sync problem, which can be fixed as required with editing.

Another thing, the 3700 640video at times shows really obvious (i.e. distracting) compression artifacts under certain conditions, e.g. areas of low image detail--I understand why, but Mini DV it certainly is not.

Has this movie mode quest become an obsession? Well yes :-), but having just returned from a 2 week family holiday armed with 3700, 2 batteries, 2 256MB cards and laptop for nightly download, I can pronounce with grand authority that VIDEO MATTERS. At least for us,1/3 ofthe stuff we captured were just little moments which wereintrinsically dynamic, movement and sound, situations where still images would be meaningless. Mind you, we got plenty of great stills too. Reviewing the day on the laptop each night was not a chore but rather part of the fun of the trip.

Anyway, I'm waiting for better convergence of video and stills (and phones/PDA etc), but for now the 3700 will do us.

Mark








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Old Oct 14, 2004, 5:44 PM   #29
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well if the panasonics cant work then only the card left is Simple Tech pro high seed cards.lets hope that it works.Other option which i m thinking is to replace the unit with another ,maybe there is a production fault with this camera as some of the users are not experiancing audio/video sync at all.they only have to buy a high speed card to get 30 FPS with no problem.
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Old Nov 19, 2004, 12:50 AM   #30
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:arrow: STATUS: I just picked up the Nikon 3700. I captured several movies and noticed the 270ms lag when playing them in Quicktime. I'm using a generic Kingston 512MB card (mere 3MB/sec write speed) and captured 180 seconds of tapping a table.

THE GOOD NEWS: It turns out there really isn't a problem. The audio & video are in sync (close enough) if you play it with the program

mplayer

which luckily is free and open source and works on XP and linux. Download it from

http://www1.mplayerhq.hu/MPlayer/releases/win32-beta/

There are also several nice GUIs which use it.


MORE GOOD NEWS: If you love your movie, you can use the associated program mencoder to convert the movie to the compression (i.e. Divx5.1 or Xvid) of your choice and it will be in-sync on MediaPlayer or the DivX Player or probably any AVI player program.

If you have questions, email me at [email protected]

Mike
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