DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Open DV Discussion (https://www.dvinfo.net/forum/open-dv-discussion/)
-   -   Weird glitches and junk when playing back a pro-duped DV tape (https://www.dvinfo.net/forum/open-dv-discussion/101441-weird-glitches-junk-when-playing-back-pro-duped-dv-tape.html)

Eric Shepherd August 15th, 2007 09:01 PM

Weird glitches and junk when playing back a pro-duped DV tape
 
1 Attachment(s)
Hi all,

So I got a DV tape mailed to me from a resort's video department. They shot the footage themselves and made me a tape to use on a project (stock footage of theirs).

The slate says 16:9 Anamorphic on the beginning of it.

I'm playing it back in my XL2 and it shows up widescreen, but occasionally bounces to 4:3 in the viewfinder. The audio is stuttering like crazy, and when watching playback on my tv, the viewfinder, or during capture, it appears to have MPEG artifacts (like jellyfish) around some high contrast changes, or moving parts of the image. There is tearing when there are pans at anything above super slow speed.

I exported a few seconds of a water park segment and you'll see there are real artifacts all over the place here. Not jellyfish-looking things that are just weird looking, but actual color and checkerboarded glitches.

Is this a problem with their duplication process or my camera? I've only mainly played back my own recordings in my camera so far, using TDK tapes almost exclusively. Yes, I know about the tape switching debate. I'm guessing there's maybe 30 hours on my heads? This tape is a 'Sony Digital HD Video' DVM63 tape. White in a darkened case with gold trim. Looks expensive. Says 'for HDV/DV' on the tape.

Should I request another tape or try to play this on a different machine? I'd like to think I can receive and play any miniDV tape mailed to me, as the easiest other miniDV machines I have access to (GL2's, JVC decks, etc) are at a studio 75 miles away, unless I want to bother friends with cameras.

Thanks in advance!
Eric

Jonathan Jones August 15th, 2007 10:50 PM

Quote:

Originally Posted by Eric Shepherd (Post 729697)
Hi all,

So I got a DV tape mailed to me from a resort's video department. They shot the footage themselves and made me a tape to use on a project (stock footage of theirs).

The slate says 16:9 Anamorphic on the beginning of it.

I'm playing it back in my XL2 and it shows up widescreen, but occasionally bounces to 4:3 in the viewfinder. The audio is stuttering like crazy, and when watching playback on my tv, the viewfinder, or during capture, it appears to have MPEG artifacts (like jellyfish) around some high contrast changes, or moving parts of the image. There is tearing when there are pans at anything above super slow speed.

I exported a few seconds of a water park segment and you'll see there are real artifacts all over the place here. Not jellyfish-looking things that are just weird looking, but actual color and checkerboarded glitches.

Is this a problem with their duplication process or my camera? I've only mainly played back my own recordings in my camera so far, using TDK tapes almost exclusively. Yes, I know about the tape switching debate. I'm guessing there's maybe 30 hours on my heads? This tape is a 'Sony Digital HD Video' DVM63 tape. White in a darkened case with gold trim. Looks expensive. Says 'for HDV/DV' on the tape.

Should I request another tape or try to play this on a different machine? I'd like to think I can receive and play any miniDV tape mailed to me, as the easiest other miniDV machines I have access to (GL2's, JVC decks, etc) are at a studio 75 miles away, unless I want to bother friends with cameras.

Thanks in advance!
Eric

For the bulk of the work they sent you, my guess is that they didn't know what they were doing - in a wide variety of ways....but as far as the clip you shared, my first impression was that you are looking at the result of dirty heads, either on your end in importing the footage, or on their end with exporting the footage.

Is the tape brand they sent you very different from the one you typically use in your machine? Have you tried to run a head cleaner and then re-import? If so, and the problem persists, then you or someone else who knows what they are doing may need to pay the facility a consultation visit to show them how to do this stuff correctly.

From my end, I have had a few situations in which I have had a client outfit ask me to do post of content they capture in house...(they say - "yeah, we got a video guy in house who knows all about that stuff...he's got a camera and everything"...which means "we got a minimum wage employee in the back who got a camcorder for Christmas. He'll do everything...we just need you to make the DVDs", and then they proceed to hand over a box full of the worst raw footage you've ever seen and expect you to turn it into an Oscar winning showpiece in two days.

-Jon

Eric Shepherd August 15th, 2007 11:05 PM

Thanks for the reply, Jonathan,

I don't know how to tell if the tapes are 'much different'? I use TDK's normally and this is a Sony, as I mentioned.

My heads aren't dirty. I played this tape the other day for 2 mins and saw the problems (I think I've seen this referred to as sparkly things in other posts maybe?). I put in a tape and shot 3 mins of test stuff today and then captured it, no problems with that. Put this tape back in, full of junk again.

The resort has pretty good looking footage. Helicopter flyovers, slow motion stuff (I assume with a 60 frame/sec camera), smooth tilts and pans, similar to my Miller DS-10 head. So whomever shot it had some gear and knew their stuff. The guy who FedEx'd the tape works in their video department, but as I've never been there, that could be a fancy title as you said but I doubt it.

So it sounds like it's a case of dirty record heads. I don't have a head cleaning tape yet (not sure which to buy), but my XL2 works fine before and after running this tape through it, and it's a nice quality tape case/shell design, so I don't think it's cheap media.

From what I understand, they have many different format machines there and asked what format I wanted it on, etc. As I only have miniDV, that's what I went with. Maybe he's just not aware the record heads are dirty on that unit.

So it's not a matter of my camera not playing nicely with stuff recorded on another machine then, right?

Glenn Davidson August 15th, 2007 11:12 PM

I was just viewing the clip in Quicktime Player. To me it looks like the problem is on every third frame. Is that right?

Eric Shepherd August 15th, 2007 11:21 PM

Looking at the glitch file I uploaded, it appears that way here too. But I deleted the original capture. I'll grab some more again. Does that indicate something specific?

Jonathan Jones August 15th, 2007 11:31 PM

Quote:

Originally Posted by Eric Shepherd (Post 729734)
So it's not a matter of my camera not playing nicely with stuff recorded on another machine then, right?

Can't say for sure. I would try to re-import a clip, and check to see if the anomalies are identical from one capture to the other. If they are the same, then the tape is recorded (or duped) that way, and if they are different from one capture to the next, then it is likely happening in playback from your deck.

The fact that they are using Sony tapes, and you've typically run TDK tapes may contribute to the problem. Sony uses a composite to make their tape that is different than most other brands, and it has been noted by alot of folks (myself included) that changing to and from Sony tapes to other brands can result in residue buildup on the heads. (The chemical compounds between contrasting brands are speculated to interact with each other in a way that results in a compound breakdown causing residue to be left on the heads.) This is why alot of folks stick with the "pick a brand and stick with it" method of running tape.

BTW: this has been an issue of much contention in these forums as there has been little or no verifiable data upon which to base this premise. However the amount of anecdotal evidence is staggering. Personally, I do alot of work on other people's footage, and I get tapes from them on just about every brand you can name. But yeah, I routinely get dirty head glitches after using Sony tapes also, basially because I don't use them as my standard tape of choice (although the Sony Premium tapes are said to be among the best.) Either way, folks who argue that there is no validation to the switched tape dilemma are just plain wrong....and that's just way it is.


When working with other people's footage on different brands, I just simply advise that you really should have a cleaning tape on hand (I tend to run it for 5 seconds after every 15 to 20 hours of tape run.) Canon specifies using the 'dry type' cleaning tape. I understand Sony cleaning tapes are of a wet variety - (yes even the little single cassette ones -forum lurkers, don't get me started on this...I'll just ignore the posts), so maybe consider getting either a Canon cleaning tape (if you can find them - good luck) or a Maxell or Panasonic cleaning tape that specifies 'dry type'.

-------------
I also just sas Glenn's post about every third frame...good eye, Glenn, I just checked it and you're right. Weird. I wonder if they shot to the original footage on digibeta or something and had some incompatiblity with sending it on to the mini-dv deck. Hard to say.

-Jon

Eric Shepherd August 16th, 2007 12:42 AM

1 Attachment(s)
Okay, so I tried to capture again, here are my results:

Vegas now has a constant tempo stuttering when I open the capture window. With the camera plugged in or not. I don't get this one.

Premiere Pro 2 froze my computer a couple times trying to capture, but this has happened before, not sure why. The picture jumped back and forth between 16:9 and 4:3 a LOT on this section of footage. Before freezing one time, it told me no datecode was present, so scene detection would not work. Does this indicate something? Would a DV deck not record a datecode as an option, or is this a further tape glitch?

So my last resort was Windows Movie Maker, which has frozen in the past during capture. This time it didn't freeze though. I was able to run the same capture twice on the footage. The playback rate appeared normal during the capture, but as you can see from this attachment, both are at high speed, and they don't match one another, speed-wise.

I matched the beginning of the clips (though one starts later), with the upper track at 55% opacity. You'll see it start dim and then the solid track appears, and they lock and then separate. The switch to the panning shot is on the tape, so it should appear at the same time on both clips.

Findings:
* One of the tracks is loaded with glitches, the other has no glitches.
* The glitches are in the 100% opaque track.
* The glitches are every 2 frames now ;)
* Both are playing back too quickly, but at different speeds from one another.
* There's a datecode missing.
* The camera flashes CH 1/2 and 16 bit during playback in the viewfinder.
* It switches between 16:9 and 4:3 in the viewfinder but the computer doesn't switch.

The firewire cable is new. I'm capturing to my internal drive which is running fine currently on all my other projects. Nothing else major is running, all the usual bases are covered. Yes, I've rebooted (when the computer completely froze 2 or 3 times in Premiere).

Thoughts? :)

Bruce Foreman August 16th, 2007 12:55 AM

I would send them a blank tape (whatever you use in your gear) and ask them to redo it, explaining that what they sent you won't give clean playback.

Suggest they run a cleaning tape through their transport mechanisms before making the new copy.

Eric Shepherd August 16th, 2007 01:04 AM

Quote:

Originally Posted by Bruce Foreman (Post 729755)
I would send them a blank tape (whatever you use in your gear) and ask them to redo it, explaining that what they sent you won't give clean playback.

Suggest they run a cleaning tape through their transport mechanisms before making the new copy.

I could do that, but my concern is that tapes are supposed to be 'universal', no? I mean, I don't want to send tapes out to people every time I need footage from them.

I don't know the original tape format this was shot on. I would assume something high-end.

The place is probably 45 minutes from here. I've never been there, just had my new business venture partner contact them and request a stock footage tape in miniDV format. He's done business with the resort in the past. I wonder if just saying "I'm unable to play back your tape properly here, it's full of dropouts and timecode errors (which would explain the speed up and slowdown problem), can you clean your heads and record another copy for me?" would do the trick instead? Sending a tape isn't a big deal, but it will add another few days to the project and seems like it shouldn't be necessary. But then the fact that my camera deals with the same footage differently each time is interesting.

I don't know if this indicates anything, but the color bars and white text on black both have this same jittery glitchy problem too.

Jonathan Jones August 16th, 2007 01:40 AM

Quote:

Originally Posted by Eric Shepherd (Post 729756)
I don't know if this indicates anything, but the color bars and white text on black both have this same jittery glitchy problem too.

hmmm, not good. You don't happen to have a second cam you can use to capture the tape do you? (for future reference, this might be a really good suggestion as it will save unnecessary wear on your XL2 heads.)

If you don't, try capturing through a different firewire cable and/or ensure you don't happen to have a new wifi rounter or cell phone sitting right next to your firewire cable while you are capturing.

Any chance you can try capturing to a second system just in case your graphics card is going on the fritz?

Try to cancel out all possibilities before going back to them, to ensure that the problem is not on your end first. (wouldn't do much for client confidence).

Then, when you are sure your end is holding up fine, you can feel pretty confident that it might be something on their end that should be brought to their attention.

-Jon

Heiko Saele August 16th, 2007 04:18 AM

Is it SD material or is it supposed to be HDV?
Because if it's SD it could be DVCAM and not DV. Most Sony DV camcorders can play back DVCAM, but other brands such as Canon usually won't play DVCAM correctly.

DVCAM can be recorded to any DV tape, but it uses more space on the tape (so on a 60 minutes DV tape you can fit 40 minutes of DVCAM material). The codec on the other hand is the same as DV (the difference between DVCAM and DV is basically the same as the difference between SP and LP recording mode)

The only solution for DVCAM would be to get a Sony camcorder that plays DVCAM or, even better, a DVCAM recorder like a DSR-11.

Glenn Chan August 16th, 2007 09:30 AM

I have a Panasonic camcorder that will play back DVCAM. :D It is similar enough that some cameras will play it back... though it could be a problem, since the different tape speed can be a problem.

For example, if you play back a DVCPRO tape (Panasonics pro version of DV) in a DVCAM deck, the deck takes a while before it plays the tape at the right speed and without dropouts.

2- Different head alignments could be a problem too. Some tapes play back best in the camera that recorded the tape.

3- What is with blaming the other side?
A- You do not know if it is their fault.
B- It is not a good way of getting help.

Eric Shepherd August 16th, 2007 11:37 AM

Yup the firewire cables are new.

My router is 8 or 10 feet away from me (though I did install a new third party firmware yesterday on it ;)

I think you guys found the problem. The guy emailed me and said "I FedEx'd the dvcam tape and you should have it Monday" (this was on friday). And I immediately though "I can't play the wide tapes, just the minidv's here". And then I thought about the tapes labeled 'dvcpro' and all the other variations when you go to the stores to buy tapes. So I assumed he meant one of the wide, 3 hour dv tapes. Then when it arrived and I saw HD on the tape, I wondered if it was even possible to play HD tapes in an SD machine. I figured with using an entirely different codec, it would be possible. ;)

It can't be a bad firewire cable if the camera on its own can't play this tape back properly. It must be dvcam like his email said. I'll contact him now and request DV format. It'll be cheaper than buying a deck just to play his tape back once ;)

Thanks for all your help guys, I'll keep you posted on this.

Eric

Ervin Farkas August 16th, 2007 12:46 PM

Some camcorders will play back DVCAM properly (Sony Z1 for example). Ask around your local friends and save some time... just an idea.

Eric Shepherd August 16th, 2007 01:05 PM

I would if I knew of anyone with something better than a Sony Handycam (TRV-900 I think it is) and a few other lesser camcorders. :)

I don't know a lot of people in the Orlando area. I requested for the video person to send a regular DV format tape to me. That should be fine. This isn't a next-day urgency thing, but if I can begin working on it next week, that'd be great. I just wanted to make sure the problem wasn't with my gear, which apparently it's not, which makes me feel better. :)


All times are GMT -6. The time now is 08:02 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network