Need help with captured HDV footage - please.

Terry Esslinger wrote on 3/15/2009, 3:46 PM
I think this is a camera (FX1) or a tape problem rather than Vegas but I know no better group of professionals to ask.

I captured about 25 minutes of video (HDV) with scene detection turned on. It appeared to capture fine.
But:
I had a couple of glitches in the capture, I thought. When I reviewd the captued footage there was a glitch (for lack of a better term) at about 5 minutes and another one at 9-10 minutes. The rest played fine. At first I thought it was a capture problem but Vegas (8.1 on i7 Vista 64 box) did not report any dropped frames. The 'glitch' consisted of a freeze frame (like video paused) and sound loss that lasted less than one second at the first spot and between 1 and 2 seconds at the second spot. When I went back to view the tape on the camera LCD I noticed the same thing. So I figured that this ruled out Vegas and left either the camera or the tape. I realize that drop outs can be a major problem with HDV (because of the GOP thing) but I did not think that this was what it would appear like. I had taped a school play a couple of months ago that consisted of ne long 58 minute video where the camera was not paused. One long scene. I noticed a couple of spots where this occured in that project also but didn't have time to track down what the problem might be. I guess I hoped it would go away.

So I guess that I have a camera that is recording with problems or I have tapes that are of dubious quality. That it happened on two different tapes under different circumstances make me think it might be the camera. But I used the same brand of tape. Have always used Sony Premium DVM60PRL and nothing else.

Can any of you brains (and that means all of you) give me some ideas on sorting this out?

Comments

blink3times wrote on 3/15/2009, 4:17 PM
I suppose you've done the obvious (head cleaning).... but what I have found (as a GENERAL rule anyway) is that tape drop outs occur mostly on really old, well used tapes..... or the brand new ones that haven't been used yet. On important projects I will always use a tape that has been already run once or twice.
apit34356 wrote on 3/15/2009, 4:37 PM
Blink, one would think the digital signal would be not affected by new or once-used tape vs analog. Little off topic blink, but your investagation into wavs on Bluray was interesting.
Terry Esslinger wrote on 3/15/2009, 4:55 PM
Blink, Thanks for the reply. I kknow its easy to overlook the obvious things. Been there done that. But yes I have cleaned the heads. I would not suspect taht it was a head cleaning problem anyway since the 'glitch' occurs at the same time code in the tape. BTW the TC freezes for the amount of time that the video is paused also.

Does this sound like a drop out problem?? Never noticed any problems with these tapes before, but was always doing SD where it is not such an obvious problem.
blink3times wrote on 3/15/2009, 5:05 PM
"Blink, one would think the digital signal would be not affected by new or once-used tape vs analog. Little off topic blink, but your investagation into wavs on Bluray was interesting.

I'm not sure it has much to do with the digital signal as it is simply breaking in the tape and brushing off any foreign matter left behind in the manufacturing process (just a wild stab in the dark guess)

wav on blu ray.... Thanks. Don't know how much I'll actually use the uncompressed pcm on blu but it's a viable alternative.
blink3times wrote on 3/15/2009, 5:08 PM
"Does this sound like a drop out problem?? Never noticed any problems with these tapes before, but was always doing SD where it is not such an obvious problem."

I'm just playing guessing games Terry. I would try some alternatives ( using slightly used tapes....etc) before bringing it in. It's always expensive to even say "hello" to a camera repair shop
Tim L wrote on 3/15/2009, 5:23 PM
Terry,

I had a similar experience with my FX7 using Sony Premium tapes. I've mainly just been recording in SD mode, but decided to do HDV for a band concert. My 40 minute recording had three breaks in it due to dropouts. (I always use brand new tapes.)

I went back to check the tape in the camcorder itself -- just viewing on the LCD display -- to see if it was just a capture problem or actually a problem with the tape, and confirmed the problem was evident in the camcorder itself. But... sometimes it DID play through a problem section.

I ran a head cleaning tape, a couple times, and it didn't really seem to "fix" things, but if I played through the problem spots sometimes it would still glitch and sometimes not.

In the end, I was able to successfully recapture two out of the three glitch spots. One of the dropouts never did play back successfully, while the other two had maybe a 50/50 chance of doing so.

I simply captured about 10 seconds before a glitch to 10 seconds after, then synched on the timeline and "cut" in the replacement footage. (Obviously you have to leave a gap in the original footage to leave room for the "missing" footage -- use timecode to align things.)

Tim L
Terry Esslinger wrote on 3/15/2009, 5:40 PM
Tim, Thanks for helping. I have tried playing through the glitch sections several times. They always glitch, never play through. If this is a problem inherent in the camerathen the cam is worthless on 'critical' projects as you would never know when it was going to glitch. If it is a problem with the tapes, what tape would you recommend to try and compare it against to test it.
Porpoise1954 wrote on 3/15/2009, 7:10 PM
I think you might find it is something to do with the GOP. i.e. If the scene finishes in the middle of a GOP rather than at a keyframe, it doesn't have sufficient data to put the subsequent frames together, so you get the "freeze-frame" effect. I've noticed that when editing sometimes as well, so it's not necessarily camera induced and I think we can safely say it's nothing to do with the tape or the heads.
Terry Esslinger wrote on 3/15/2009, 8:04 PM
Thats a good idea but the problem is that it isn't at the end of a scene its in the middle of a scene. I don't think that would apply. Thanks for the reply.
Himanshu wrote on 3/16/2009, 7:02 PM
Admittedly I know nothing about the FX1 cam. I have a Sony HDR-HC3 which captures HDV and Sony reccommends, and I always use, HDV tapes not their regular Mini DV tapes (even if Premium). On my very first tape a few years ago I remember running into a dropout, but since then I haven't had any that I can recall.

Before calling the camera a dud I'd use an HDV tape - Sony, Panasonic & JVC make them so you have a choice. Unfortunately they are quite pricey, but I stocked up on a few in the recent Circuit City liquidation sale.
winrockpost wrote on 3/16/2009, 7:23 PM
play it back in the cam, look for hits. If none try turning off scene detection .... and dont use old tapes.... wow blink .... imho

edit ... don't use used tapes or old or borrowed or blue