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-   -   Corrupt Quicktime file - Help! (https://www.dvinfo.net/forum/open-dv-discussion/126226-corrupt-quicktime-file-help.html)

Nate Haustein July 18th, 2008 10:21 AM

Corrupt Quicktime file - Help!
 
While recording a play last night, (a 3 hour long one at that) my hard drive that I was capturing footage to lost power because someone switched off the circuit it was on after the show was over. When I started it back up, I got a "The movie could not be opened: The file is not a movie file." dialog box. I have tapes, but there are about 2 minutes when I was switching tapes, not to mention my camera had all the sound going into it.

The file showing on the hard drive is 0kb, however, after entering a terminal command to show hidden files, I found a 38GB file still on the drive. Opening it with a Hex Editor, I compared it to a good quicktime movie, and found that the header and footer information is different or nonexistent on the corrupt file.

Does anyone know something about altering headers in quicktime movies? I've tried for hours now, and have come up with the following results with different methods:

Open with MPEG Streamclilp: "Can't find video or audio tracks"

Open with VLC Player: mp4: "MP4 plugin discarded (no moov box)
ffmpeg: Seeking too far : EOF?"

FileJuicer: No usable results, only a black screen

It seems as if the movie has no reference to what is used to play it, and I'm all for lost on how to add that information with Hex Edit, Text Editor or otherwise. Any help would be greatly appreciated.

Dean Sensui July 18th, 2008 03:15 PM

Nate...

Hopefully you were recording to tape as well?

Check out this website. Maybe it might help. The demo is free and could be of some value. Make sure you're working on a copy of the file, and not the original.

http://www.imagineproducts.com/products_mac.htm

Recording to a hard drive via a computer is risky because of the likelihood of crashes. I've heard of people doing that when recording audio and losing everything when the system locked up during a lengthy recording session.

While it's troublesome, you might consider having a UPS to provide backup power to the recording system in case of a glitch or other power problem. At least the computer has a battery. But having backup power to the hard drives would be nice in that it allows a proper shutdown in case of a power failure.

Good luck. Hope it turns out OK. If I find anything else I'll post it here.

Robert Martens July 18th, 2008 05:53 PM

I wish I could say I actually have the solution, but I'm still digging through all the Quicktime files I've got and picking them apart according to the file format spec: http://developer.apple.com/documenta.../QTFF/qtff.pdf

Seems to me the good stuff starts on page twenty-nine and goes from there; info about the various "atoms" in .mov files, their size, what data they contain, and so on. I've got some files I've intentionally damaged with a hex editor (copies of the originals, of course) that I'll try and repair, fingers crossed.

I have a suspicion it may be worth using Quicktime Pro to export reference movies of known good files for comparison with their originals. Perhaps the process of elimination will reveal what's actually video and what's just metadata? I'm grasping at straws, really, but it seems worth a shot.

I'll keep digging in to this and let you know if I find anything. Best of luck to you!

Nate Haustein July 23rd, 2008 01:03 PM

I really appreciate all the help you guys.

That hex edit stuff is pretty dense. Yes I do have tape backups (always), as well as 2 other camera angles with adequate sound that will work for the 2 minutes I was changing tapes.

Don't worry about sleuthing too much more for my sake, I'll just make do with what I have. Just wanted to know if there was a relatively easy fix for the problem.

Thanks-


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