Need Help Timecode Breaks at DVinfo.net

Chris Korrow · February 25th, 2006, 02:55 PM

I'm doing a shoot on top of a building and am getting interference from all the dishes up there. It gives some beeps in the sound and weirds the video occasionally but the real problem is time code breaks. I've got a lot of them on every tape. Could these dish signals be causing them? Can they screw up my camera? And is the best way to deal with these breaks by dubbing them to a new tape?
Thanks,
Chris

Running FCP 4.5
2ghz powermac G5
XLs
OS 10.4.5
Quicktime 7.0.1

Bob Hart · February 25th, 2006, 08:30 PM

Chris.

The dishes could well be your problem.

Most video camcorders seems to have all-plastic casework, which is not a good RF shield.

If you really must shoot at that location, you might try wrapping the camcorder in cooking wrap and grounding with a lead to an earthing point on the building.

Microwave frequencies are able to reflect into some tight places when lower frequencies might be shielded out so I don't know how well this would work. You can't mask over the lens itself.

Random tripping of the steadyshot in camcorders has also been attributed to RF interference.

Wraping the cam up in foil may cause other issues depending on how well designed the electronics are. Stray capacitances within the camera the system can live with may be altered enough to send something off.

If you are using a mike on an unblanced lead, this may also be contributing to your problem.

Take little heed of my comments. I am no expert. I held a novice amateur radio operator's licence but really know only enough to realise the vastness of what I don't know.

Chris Korrow · February 25th, 2006, 11:32 PM

"know only enough to realise the vastness of what I don't know"

Well isn't that all of us.

I was getting random tripping of the steadyshot.
I am using a balanced mic.
The video & sound are for the most part fine, it's the number of time code breaks that's disturbing, I'm even getting breaks on footage shot on the ground and breaks on one tape that was used for narration on another project (so it had the time code written on it).
I'll try wrapping the Cam & will probably wrap it in paper first. I'll be able to tell right away because I'm only using one channel but you can see bars on the other channel when there's interference.

Can I just make a dupe of the tapes to get rid of the time code breaks or is there another way to deal with it?
Thanks Bob

Chris

Bob Hart · February 26th, 2006, 09:56 AM

Chris.

Whatever you wrap the camera in is going to have to be electrically conductive material. I suggested the cooking foil only because you can form it fairly easily around the camcorder and secure it with stickytape or elastic bands.

A foil lined "take-away" roast chicken or turkey bag might be just as good.

Duping to tapes may restore a usable timecode but you may need to pre-record timecode to the tape as the timecode breaks may simply copy across or cause the receiving recorder to make its own breaks in its own timecode.

There are timecode options in camcorders, "make" or "run" are defnitions I have seen. One apparently creates continuous timecode, another starts and stops. I'm out of my league here however as I have simply not done the research and have operated the camera on trust alone - not very professional I know.

Hopefully someone who knows what they are talking about will chime in soon and we can both learn something.

If you will be using the camera again in that environment, I suggest trying to plug another mike into that other unused channel if your camera has multiple inputs as well as multiple tracks.

If that unassigned socket is open circuit, there might just be some unterminated conductors within the cam similar enough in length to work as antenna for microwave frequencies.

For best efficency, antennas (I know - should be antennae) must be of a tuned length or associated with other parts which in combination produce a tuned circuit.

Because there is interference getting in, some part of the camera is possibly functioning as a antenna or tuned circuit. Upset that magic combination and the problem may go away or be reduced.

You might try plugging a headphone in to your headphone-out socket as well.

Beyond trying these backyard fixes, the only other solution is to identify within the camera circuits, what is picking up the microwave signal or perhaps a harmonic of it. That is the realm of engineers and would involve designing some internal shielding and perhaps alteration of some circuits.

Being close to the source means you may be getting interference at frequencies other than that being intentionally transmitted.

These should be of a much lower order of power than the frequency in use. If not, then your FAA or non USA equalivent should perhaps be interested.

You may therefore discover by experimenting, various places on the building where the interference is less.

In any event, I should try to avoid getting directly in front of any dishes or arrays which are used for transmitting as they are not all that good for living things to be in the way of for any length of time.

Glenn Chan · February 26th, 2006, 05:02 PM

Quote:

Duping to tapes may restore a usable timecode but you may need to pre-record timecode to the tape as the timecode breaks may simply copy across or cause the receiving recorder to make its own breaks in its own timecode.

I've found that most consumer miniDV equipment will record their own timecode, and pick up where the last timecode left off (equivalent to TC RUN I believe). This is what you want in this situation.

More advanced / "professional" cameras will have more timecode options. i.e. the DVX100 can start timecode at a user defined time (i.e. it doesn't have to be 00:00:00;00), and it can use timecode that's coming over firewire.

Chris Korrow · February 26th, 2006, 08:31 PM

"I've found that most consumer miniDV equipment will record their own timecode, and pick up where the last timecode left off (equivalent to TC RUN I believe). This is what you want in this situation."

So what your saying Glen, is that dubbing the tapes should take care of it?
Thanks,
Chris

Jason Varner · February 26th, 2006, 08:36 PM

You can use Mpeg-Streamclip to repair the timecode breaks. Just drag the affected clips into the viewer and select repair timecode breaks from the pulldown menu. Then export as quicktime movie using dvcpro-ntsc codec and that should do it. You may experience some loss of resolution due to recompression but then again you might not. It's probably better than doing an analog dub in either event. The official score is Mpeg-Stramclip 3, Problem Video 0. Good Luck, Jason.

Glenn Chan · February 27th, 2006, 01:24 AM

Quote:

So what your saying Glen, is that dubbing the tapes should take care of it?

Yep. You should also have the same video quality, since the video is copied over as a bunch of 1s and 0s (assuming you use firewire... i.e. a 4pin firewire-firewire cable).

Quote:

You can use Mpeg-Streamclip to repair the timecode breaks. Just drag the affected clips into the viewer and select repair timecode breaks from the pulldown menu. Then export as quicktime movie using dvcpro-ntsc codec and that should do it. You may experience some loss of resolution due to recompression but then again you might not. It's probably better than doing an analog dub in either event. The official score is Mpeg-Stramclip 3, Problem Video 0. Good Luck, Jason.

Cool, didn't know it could do that.

Ideally it wouldn't recompress the video... I wouldn't know myself whether or not it does this.

Chris Korrow · February 27th, 2006, 10:31 AM

Is Mpeg-Streamclip in FCP?
Thanks a lot guys, your really helping me out.
Chris

February 25th, 2006, 02:55 PM	#1
Chris Korrow Major Player Join Date: Aug 2002 Location: Whidbey Is, WA Posts: 326	Need Help Timecode Breaks I'm doing a shoot on top of a building and am getting interference from all the dishes up there. It gives some beeps in the sound and weirds the video occasionally but the real problem is time code breaks. I've got a lot of them on every tape. Could these dish signals be causing them? Can they screw up my camera? And is the best way to deal with these breaks by dubbing them to a new tape? Thanks, Chris Running FCP 4.5 2ghz powermac G5 XLs OS 10.4.5 Quicktime 7.0.1 Last edited by Chris Korrow; February 25th, 2006 at 04:32 PM.

February 26th, 2006, 08:36 PM	#7
Jason Varner Major Player Join Date: Aug 2005 Posts: 119	Timecode Repair You can use Mpeg-Streamclip to repair the timecode breaks. Just drag the affected clips into the viewer and select repair timecode breaks from the pulldown menu. Then export as quicktime movie using dvcpro-ntsc codec and that should do it. You may experience some loss of resolution due to recompression but then again you might not. It's probably better than doing an analog dub in either event. The official score is Mpeg-Stramclip 3, Problem Video 0. Good Luck, Jason.

February 25th, 2006, 08:30 PM	#2
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Chris. The dishes could well be your problem. Most video camcorders seems to have all-plastic casework, which is not a good RF shield. If you really must shoot at that location, you might try wrapping the camcorder in cooking wrap and grounding with a lead to an earthing point on the building. Microwave frequencies are able to reflect into some tight places when lower frequencies might be shielded out so I don't know how well this would work. You can't mask over the lens itself. Random tripping of the steadyshot in camcorders has also been attributed to RF interference. Wraping the cam up in foil may cause other issues depending on how well designed the electronics are. Stray capacitances within the camera the system can live with may be altered enough to send something off. If you are using a mike on an unblanced lead, this may also be contributing to your problem. Take little heed of my comments. I am no expert. I held a novice amateur radio operator's licence but really know only enough to realise the vastness of what I don't know.

February 25th, 2006, 11:32 PM	#3
Chris Korrow Major Player Join Date: Aug 2002 Location: Whidbey Is, WA Posts: 326	"know only enough to realise the vastness of what I don't know" Well isn't that all of us. I was getting random tripping of the steadyshot. I am using a balanced mic. The video & sound are for the most part fine, it's the number of time code breaks that's disturbing, I'm even getting breaks on footage shot on the ground and breaks on one tape that was used for narration on another project (so it had the time code written on it). I'll try wrapping the Cam & will probably wrap it in paper first. I'll be able to tell right away because I'm only using one channel but you can see bars on the other channel when there's interference. Can I just make a dupe of the tapes to get rid of the time code breaks or is there another way to deal with it? Thanks Bob Chris

February 26th, 2006, 09:56 AM	#4
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Chris. Whatever you wrap the camera in is going to have to be electrically conductive material. I suggested the cooking foil only because you can form it fairly easily around the camcorder and secure it with stickytape or elastic bands. A foil lined "take-away" roast chicken or turkey bag might be just as good. Duping to tapes may restore a usable timecode but you may need to pre-record timecode to the tape as the timecode breaks may simply copy across or cause the receiving recorder to make its own breaks in its own timecode. There are timecode options in camcorders, "make" or "run" are defnitions I have seen. One apparently creates continuous timecode, another starts and stops. I'm out of my league here however as I have simply not done the research and have operated the camera on trust alone - not very professional I know. Hopefully someone who knows what they are talking about will chime in soon and we can both learn something. If you will be using the camera again in that environment, I suggest trying to plug another mike into that other unused channel if your camera has multiple inputs as well as multiple tracks. If that unassigned socket is open circuit, there might just be some unterminated conductors within the cam similar enough in length to work as antenna for microwave frequencies. For best efficency, antennas (I know - should be antennae) must be of a tuned length or associated with other parts which in combination produce a tuned circuit. Because there is interference getting in, some part of the camera is possibly functioning as a antenna or tuned circuit. Upset that magic combination and the problem may go away or be reduced. You might try plugging a headphone in to your headphone-out socket as well. Beyond trying these backyard fixes, the only other solution is to identify within the camera circuits, what is picking up the microwave signal or perhaps a harmonic of it. That is the realm of engineers and would involve designing some internal shielding and perhaps alteration of some circuits. Being close to the source means you may be getting interference at frequencies other than that being intentionally transmitted. These should be of a much lower order of power than the frequency in use. If not, then your FAA or non USA equalivent should perhaps be interested. You may therefore discover by experimenting, various places on the building where the interference is less. In any event, I should try to avoid getting directly in front of any dishes or arrays which are used for transmitting as they are not all that good for living things to be in the way of for any length of time.

February 26th, 2006, 08:31 PM	#6
Chris Korrow Major Player Join Date: Aug 2002 Location: Whidbey Is, WA Posts: 326	"I've found that most consumer miniDV equipment will record their own timecode, and pick up where the last timecode left off (equivalent to TC RUN I believe). This is what you want in this situation." So what your saying Glen, is that dubbing the tapes should take care of it? Thanks, Chris

February 27th, 2006, 10:31 AM	#9
Chris Korrow Major Player Join Date: Aug 2002 Location: Whidbey Is, WA Posts: 326	Is Mpeg-Streamclip in FCP? Thanks a lot guys, your really helping me out. Chris