Delay in Tricaster Studio

[zonuna]

I was doing a live switching with my New Tricaster Studio with 3 cameras and 3 video projectors.
People are complaning a delay on the screen with what happened on the stage plus an audio out of sync, can anyone solve this problem ?:help:

[John Perkins]

Any digital device will have a slight delay as frames are digitized, processed and then output, but in TC alone, this is very minimal, about 2 frames.

What usually causes a noticeable delay is the projector and any scalers that may be connected to the output of the TC. The delay in each device is compounded, so optimizing the path to the projector is very important. A 2-3 frame delay in each device could easily add up to 8 or more frames without proper planning.

To minimize the delay, make sure that the VGA output matches the native resolution of the projector and that any scalers are turned off. If the projector is 1280x1024 native, don't feed it 800x600 or 1600x1200. Sending it the correct native resolution will also improve the clarity of the image.

I'm not sure how you are driving the three simultaneous projectors, but that could also be a big variable in your setup that needs to be addressed.

Also note that most projectors use a digital scaler to do 16:9.

I hope this helps,

[zonuna]

Thanks for a reply, I`ll try to explain my connections, I simply connected 3 projectors through a Tricaster`s composite output via an AV splitter (1 input to 4 outputs) A video clips that I played from Tricaster is ok sync perfectly.

Maybe, if a Line out from an Audio Mixer (Hall Sound system) is connected to Tricaster`s Audio IN Then A Line OUT from Tricaster goes to Power Amp. to sound system the problem of Out Of Sync might be solve.

Delay itself is no prob. as long as Recording is ok, But Audio Out Of Sync with the picture on a Projector while Live switching is very bad

[wadeace]

Are you running the live sound from the mixer to the tc then to amp/speakers. If so that delay is extremely noticeable, especially to the speaker(s). a good solution for that would be to split the mix from the oudio board between tc and live sound through the board mains and controle room outs

[Jim Brown]

The best way to connect the audio is:

1. Connect a feed from the live audio (mixer) to the input of the Tricaster. This provides audio for your Tricaster record of your program.
2. Connect a feed from the live audio directly to your amplifiers. DO NOT ROUTE THROUGH THE TRICASTER as that would introduce delay and disrupt your performers.
3. Connect from the headphone output of the Tricaster to your amplifier. The proper way to do this is through a direct box. Any music store should be able to supply. You will have to adapt from the 1/8" stereo to whatever your mixer board requires as an input.
4. VERY IMPORTANT. Select the "solo bus" for the VCR in the Tricaster audio section. This will allow only Tricaster VCR audio to be routed to the mixer via the headphone jack. If you do not do this you will get an electronic loop in the mixer. That is not a good thing!

As to the delay which started this thread. There is a 2 frame delay between the video and live audio. It is barely discernable unless you are on the front row and are looking at the screen and speaker at the same time. The further back you go the less it will be noticed. At about 75ft, the effect will disappear.

If you are in a situation where the stage people cannot hear the audience sound (ie they listen to monitors) you can introduce some delay to the house feed via effects processors in the sound system. You have to be very careful here to keep from getting echo and disrupting your performers and I would only recommend to be done by very experienced audio personnel. We have done this on shows where we have deep audiences with delayed speakers halfway back that are already being delayed. We then will experiment with the front speakers.


Hope this helps.

Jim

[zonuna]

The best way to connect the audio is:

3. Connect from the headphone output of the Tricaster to your amplifier. The proper way to do this is through a direct box. Any music store should be able to supply. You will have to adapt from the 1/8" stereo to whatever your mixer board requires as an input.

Jim

Thank you guys, I think I`ll give No.3 a try, What I have done previously, the Audio System does not goes through TC, I only input Audio mixer line out for recording.

[rally1]

Nice idea on the solo trick. We have announcers that need to hear program audio, so we pull that off the mixer before the tricaster to eliminate the delay/echo. But they couldn't hear the VCR clips, now they can. Only caveat is the switcher will now need to listen from the external mixer too, not the Tricaster itself.

[Scrut]

I have measured the delay through the Tricaster and in PAL mode it is 5 frames. This makes it unusable as production switcher were you have a on stage presenter displayed on a screen with a PA. Our experience so far is that this delay is unacceptable particularly when combined with the added delay of projectors ect. It is just too off putting for a presenter to hear himself 200ms after he has spoken.
Our Tricaster was replaced by an MX70 on it's first job as the client would not put up with the delay.
For comparison a MX50 has one frame of delay and a Sony DFS500 has 2 frames.

[ACross]

I have measured the delay through the Tricaster and in PAL mode it is 5 frames. This makes it unusable as production switcher were you have a on stage presenter displayed on a screen with a PA. Our experience so far is that this delay is unacceptable particularly when combined with the added delay of projectors ect. It is just too off putting for a presenter to hear himself 200ms after he has spoken.
Our Tricaster was replaced by an MX70 on it's first job as the client would not put up with the delay.
For comparison a MX50 has one frame of delay and a Sony DFS500 has 2 frames.

Scrut,

The latency of a TriCaster on video output (not quite the same as VGA output) is between 2 and 3 frames depending on the timing relationship between TriCaster and the camera inputs. The range of latencies is caused simply by the fact that every input has a TBC to bring all video inputs into timing alignment so that they can be switched between.

To get the very lowest latency, you can genlock your video inputs to your video output; if your cameras are capable of this.

If you are still not seeing the same results as me do not hesitate to email me (across@newtek.com), this is how we measured the latency :

TimeCode -> TriCaster -> CRT monitor (it is important that it is a CRT)
--------------> CRT monitor

We now place the two CRT monitors side by side, one with timecode coming through the TriCaster, the other without. We then take a photo of the outputs and go through and compare the time codes that we see.

Andrew

[Sledgehammer]

I was wondering how y'all measured that.