PDA

View Full Version : Tricaster Broadcast - issue when cutting



Daniel H
07-12-2011, 10:54 AM
Hi Guys

Please can you have a look at what is happening between every other cut when using a Tricaster Broadcast...

http://www.danielharrison.tv/tricaster.png

This is a black and white one, but some have a flash of red on them - there quite noticeable when you watch the clip back.

I've got a series of recordings to do later this week and can't afford for this to happen on the programmes.

I have had the same issue happen at a different studio which used a Tricaster Studio, funny though that it doesn't appear to have live as your cutting the cameras, but only when I import the MPEG file recorded on the Tricaster into Adobe Premiere.

bbailey
07-13-2011, 09:52 AM
I do football with 4 cameras and a slo-mo tape deck and other than sometimes experiencing a slight delay when punching directly on the Program buss, I never have any problem. I'm told that if I use the Take button and set the next camera shot on preview instead of punching directly on Program, I shouldn't have ANY delay.

Are you setting the correct odd and even field dominance when you import?

Daniel H
07-16-2011, 03:16 AM
Hi bbailey

Thanks for your reply, did my shoot yesterday and still having the same issue :(

Please have a look at this more prominent example...

http://www.danielharrison.tv/grab.jpg

It by no means does it on every cut but it is really noticeable to have a frame of that every so often.

How do you got about setting the right odd and even field dominance? Sorry maybe a basic question, but I'm just importing the files straight into Adobe Premiere.

Our cameras aren't genlocked either but then I thought that was the benefit of the Tricaster that they didn't have to be, I'm using S-Video out on the camera to 2 x BNC into the Tricaster Broadcast.

brwainer
07-16-2011, 05:46 AM
I believe what you're seeing is the luminance from one camera combined with the chroma of the other (which, of course, is how S-Video carries the video). If I remember correctly, it is just a function of how the signals are timed coming into the Tricaster. Quality and length of the cables used are the biggest factors in timing. I remember this issue coming up before, maybe in regards to another SD Tricaster such as the Studio or the original, so try to search the forums.

Daniel H
07-16-2011, 06:38 AM
Hi brwainer - thanks for your reply.

I've actually had this same issue before, but with a Tricaster Studio, again not genlocked but the cameras were connected using 3 x BNC's each (component).

I used this same setup many times after and didn't really replicate the problem.

What I used this week was a short S-Video adapter then ran 2 x 5m BNC cables into the Tricaster, so not that long I didn't think?

brwainer
07-16-2011, 07:35 AM
Actually, as long as all cameras go through the same length, their timings should be delayed by the same amount. I'm not sure if that actually plays into this issue, but I wanted to mention it just in you case had different length cable runs.

ghoneycutt
07-16-2011, 08:58 AM
There are other threads on here about not directly cutting on the program bus. Preview the next camera then take it. That gives the system a chance to sync the previewed camera before the "take"

Daniel H
07-16-2011, 10:13 AM
Hi Guys

Thanks for your replies, really appreaciate your advice...

After initially having this issue during testing, I did read posts about hot cutting on the program bus, so did as you've said, previewied everything then 'take'd it but still I've had this problem.

Do you think the fact that some of the BNC cables from the cameras are 75-Ohm and some are 50-Ohm maybe causing the issue?

brwainer
07-16-2011, 10:22 AM
That may be a factor. The only way to check is to use all the same cords.

Daniel H
07-16-2011, 10:41 AM
OK will try this on Monday - is 50-OHM prefered or 75?

Also another thing I forgot to mention was that every so often when I change what camera I'm previewing, a strange jerk goes across the preview / program monitor on the Tricaster monitor - it doesn't appear in the recorded footage, but at the time of recording it does make a crackle sound through the speakers (again this isn't recorded on the recorded file).

Don't seem to be having much luck which is strange as I used a Tricaster Studio at a TV Channel for a few years, hot cutting cameras, and very little issues...

brwainer
07-16-2011, 11:02 AM
On the 50 Ohm vs. 75Ohm issue, I don't think it matter much, especially for SD. On the tearing/jerking issue, I have no idea, but that deserves a separate topic.

ghoneycutt
07-16-2011, 12:08 PM
is the same power outlet used to supply power to the TC and the cameras?

Daniel H
07-16-2011, 12:24 PM
Hi ghoneycutt

Yes, its the same power supply - to be honest were a bit short on power points at the minute so a lot is coming off the same plug socket, could this be a possible cause?

Thinking about it, I don't think it is to do with the BNC cables causing the strange frame between some cuts, as I did have the same thing happen when I first connected the cameras using a single composite cable.

bbailey
07-18-2011, 09:07 AM
Be sure to use 75 Ohm cables.

You said you don't see the problem at the Tricaster but you do after importing into Premiere? Try looking at the same clip in another program...AVID or Final Cut... and see if the problem appears there.

If you don't already have it, download MPEG Streamclip, it's free, and drop the clip into it's window and see if the problem is still there.

Be sure your odd and even fields are set correctly when exporting/importing.

PIZAZZ
07-18-2011, 09:37 AM
Video should only be use with 75Ohm cables. I would change all your cables to the correct ones first and foremost. Then do another test.

PIZAZZ
07-18-2011, 09:40 AM
Another thing to check is the PCI Latency setting in the TriCaster's BIOS. This should be set to 128. I have seen sometimes the BIOS get reset from factory defaults and this little timing setting can throw all kinds of issues into the mix.

Daniel H
07-18-2011, 04:40 PM
Hi Guys

Thanks again for your further replies.

I checked the Latency today - 32 it was set on :|

I changed this to 128 and there is some improvement! The stutter / tearing that was happening across the preview and program monitors on the Tricaster seems to have stopped - yay!

Had hoped it would sort the issue of the strange frame flashes between some cuts, having looked back at my footage from last week it was happening a lot more often that I first realised, a test recording today after up'ing the latency seems to have reduce it a lot less but it is still there.

Did try resetting config but no luck, I will change to all 75 OHM cables when I'm back in the office / studio later this week, many thanks again for your help so far!

Daniel H
07-24-2011, 02:09 PM
Hi Guys

Thanks again for your advice and suggestions, I've changed all the video cables to be equally 75ohm, all same length etc, but still having the same issue of strange frames between cuts - its like a crossfade between the 2 sources with a splash of red in them.

I've tried powering the Tricaster from a different power socket but still the same.

Also whist I'm editing I've come across something which makes the issue even more stranger, here is a grab from a Tricaster recording: http://www.danielharrison.tv/tricaster2.jpg - this is the playback of a VT which was prepared in Adobe Premiere and exported as a MEPG2 to play on the Tricaster.

The clip here cuts from one shot to another (it's the same VT playing back) and the red splash you can see is showing part of the next shot, in Adobe Premiere and Windows Media player, these clips play fine with no jump, or strange frame between different shots, nor do they show up when the Tricaster is recording - it's just afterwards.

My Adobe Premiere project is all setup correctly and in fact the dodgy frame is 100% on the recorded file as it shows up when watching the clip back in Media Player.

Getting slightly fustrated now as I'm having to spend a lot of time going through each scene cut to take out the flash and slow down the previous frame to fill the space.

bob anderson
07-26-2011, 12:55 PM
As far as the jerk on the preview monitor, that's an easy one. NewTek designed the TriCasters ( you actually see this more often on the HD models than the SD ) so that the actual Video outputs always look good, and will often sacrifice the computer monitor Program, and Preview monitors appearance if the system is being overly taxed. I guess you could say this is a feature, not a bug.

Bob Anderson