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Old December 27th, 2009, 10:13 PM   #1
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MiniDV 60min recording plays in 10secs?

Greetings. I'm new to the forum, and found you guys while doing a search for info on a perplexing issue.

I have a MiniDV recording of a vacation trip from a few years back, recorded on a Panasonic PV-GS9. When I finally got around to transferring the recording recently to my Mac via iMovie, the resulting file plays back at super high speed; the whole hour or so plays back in a jumble over about 10 seconds.

When I play back the same tape on the camera, the full length of the video is present, but the sound cuts in and out. There's usually no sound, but sometimes just brief moments of sound.

I don't know enough to more than guess, but I'm thinking the recording is damaged and that the time encoding and sound are the damaged parts.

Is anyone familiar with this type of problem? Is there anything I might try to at least save the video, if not the audio? If I could at least get the video to playback at a normal speed, I could still enjoy seeing my trip and maybe even set it to music. As it is, it's unplayable after transfer to the computer, and I'm worried the recording will further degrade on the tape considering what has happened so far.

Thanks for any thoughts on this issue.
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Old December 28th, 2009, 01:24 AM   #2
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I'd try borrowing a second DV cam and making a digital tape to tape dub, and if that doesn't work, try analog, followed by a capture to Mac of the new tape. Even if you dub via FW, the new tape should have new timecode rather than transferring the old. It certainly would with an analog dub.
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Old December 28th, 2009, 05:33 AM   #3
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i would bet that the edge of the tape is damaged, probably was maligned on head wrap and crunched the edge the lenght of the tape that it was in that position.
when the edge is damage audio goes first, i analised why a long time ago, if i remember right within the diagonal scans of data, the audio is part of that same data scan, and is at the edge of the tape. the sync signals are also on the edge.
Carefully Flip up the door on the tape by releacing the tiny lever, and look at the tape, then close it safely and carefully, and you should be able to see anything wrong with the tape.

it moves faster because without sync, it is probably going to SP instead of its recorded LP or it just isnt getting a sync at all.

What to do, its ruined, if it was in LP it really needs to be played back with the cam that recorded it, although another camera aligned well might also play it back.
if its over in 10 seconds of tape, then it probably wasnt moving well either to begin with.
IF it was in SP a device that does not even DO LP will sync it better when unsynced.

other Stuff when dealing with unruely DV.
FFWD the tape to the end, then back again WITH the tape position laying flat, meaning turn the camera so the top of the FLat Top part of the tape is up. then do that again

tight Reels on DV tapes can be so bad that the motors cant move the reels , which would usually result in a tape jam ALSO.
When Lesser tape is recorded in Horizontal positions the tape wrapping on the reel can sway from side to side, forming a binding in the whole reel item (it can actually push the reels against the case). by laying the tape down flat, and moving it back and forth a few times, the tape will all align against one side of the reel (the bottom of the reel preferably).

AS LONG AS the tape mechanism isnt just JAMMING the tape up again, this process of moving it back and forth and rolling it over the head, can pull out some of the creacing.
If it is still jamming up though, everything on both sides, the tape and the machine will get worse and worse, to the point of not even being able to eject the tape itself.

that is all i know, i repair stuff like that for others, but your symptoms sound like the tape itself is now crunched.
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Old December 28th, 2009, 05:49 AM   #4
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Anytime we re-use any tape, we always roll the reel back on flat, back and forth, because of the issues of horizontal recording , and tiny tiny stuff that is thin and weak.
that way after the one horizontal recording nothing much can go wrong.
when feeding to the computer, or playing it or whatever else, we always try and set the tape to flat again too.

anytime a tape comes out of Storage, we do the same process of sending the tape fully foreward and back to loosen it up a bit from any contraction and expansion that occured over time. Prior to playing the tape.

You should see how much 8MM film shrinks over time :-)
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Old December 28th, 2009, 10:24 PM   #5
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Quote:
Originally Posted by Marty Welk View Post
...FFWD the tape to the end, then back again WITH the tape position laying flat, meaning turn the camera so the top of the FLat Top part of the tape is up. then do that again...
I'll certainly give this a try. Just to make sure I understand, when laying the tape flat in the camera the label side of the tape will be oriented up, and the hub/camera interface will be down?

Thanks.

-Dan
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Old December 28th, 2009, 10:40 PM   #6
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yes , the holes in the hub down flat, the reels laying horizontal, the tape trying to align to the hub side of the internal reels.
(never had to descibe that in text)
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Old December 28th, 2009, 10:57 PM   #7
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The fast video playback (as fast as your computer can pump the data through) is a codec issue on your Mac.

Try capturing / recording to another device.

Andrew
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