HD-SDI Switching and Genlock/Timecode

[TheReverendDave]

AW-HS50
www2.panasonic*DOTCOM*/webapp/wcs/stores/servlet/prModelDetail?storeId=11301&catalogId=13251&itemId=406589&modelNo=Content04082010011427274&surfModel=Content04082010011427274

This guy has frame syncing, but no genlock.

If i had cameras genlocked together using the aja, and these inputed into the HS50, all the sources are frame sync'd coming in and the HS50 would handle those signals internally (with internal frame syncing). I am getting that this wouldn't be frame perfect syncing, but it would have to be dang close because the camera feeds are all in line.

[bladeaudio]

The issue is that the SWITCHER needs to know when the signals are timed so that it can make cuts and fades without "glitching." So, the genlock needs to be tied to all your cameras AND your switcher for "genlock" to work.

[TheReverendDave]

Originally Posted by bladeaudio

The issue is that the SWITCHER needs to know when the signals are timed so that it can make cuts and fades without "glitching." So, the genlock needs to be tied to all your cameras AND your switcher for "genlock" to work.

Makes sense.
Thanks for that clarification!

[tdangelo]

Reverend Dave,

Before you give up note that some switchers in this class will genlock to the input signal of a particular input. There is not enough information on the HS50 to know if it supports this.

- Tom D'Angelo
NYC

[Newbie Kelly]

Reverend Dave - As my user name suggests, I'm no veteran of this biz... but am studying as much as possible. Don't know what your budget is or what real costs are, but I have been studying closely switchers from For-A and Ross. Ross seems to offer a product built with you and I in mind, available in various frame sizes. Their Vision Octane is available with SD/SDI or HD/SDI ins and outs, frame correction, rescaling engine for inputs of multiple resolutions, and best of all... onboard configurations that enable "IMAG" productions without additional gear.
I'm not permitted to post URL's yet, but the Ross Video website will lead you to the info easily.

One of the big criteria for me is the ability to control several screens from one operator, yet expand in the future. Ross' product allows one control desk to be used, yet add more desks in the future if two, three or more video operator persons were needed. Why use 3 switchers if only one person was the operator? Also, a single engine is needed if "screen spanning" (one image stretched accross multiple screens) was desired *without* additional outboard gear.
The company seems to be VERY dedicated to working with the user every step of the way. Seems to be worth looking into. Best wishes on your big new steps.

[manu4jc]

Hate to be the barer of bad news but even with nice GENLOCK HD cameras and a GENLOCK HD Mixer there is still very noticeable delay in HD IMAG... here is my setup:

4 CANON XH-G1 cameras (HD-SDI with GENLOCK)
1 Datavideo SE-2000 (HD-SDI mixer) also tried the FOR-A 300 mixer (with GENLOCK)

and I still get the same problem... the output from the camera through the mixer and out to the projectors even GENLOCKED still has a good 150-200ms delay... noticible lipsink issue between the live audio from the Yamaha M7 mixer and the live video on the Benq 16:9 HDMI projectors...

I used BELDEN 1694A (expensive) cables, AJA HI5 / HA5 converter boxes (expensive) and still have the same problem... even going camera directly to output device there is a noticeable lag... so conclusion is... I hope to find a fix (possibly a lower latency camera... in the next month if not we are going back to SD ... )

Hope this helps.

[TheReverendDave]

That's rough. You said you are using AJA convertors, right?

It could be the XH-A1. But, lemme ask what do you have the cameras set at? 1080p30? Or 720p60? On the Panasonic HPX170, the recording format drastically affects the HDSDI output. Often we use the cam at 720p/30fps or 720p/24fps and if you hook that up, it appears much more laggy. This could easily the same type of issue. HIGHLY recommend you insure that the HDSDI output is 720p/60fps and test again. Check your manual for details on the HDSDI output.

Other than that, I don't know much about genlock, but you are sure that the cams are "talking" via the genlock? My understanding is it should be one as master others as slaves, but I could be wrong. Hope some of this nonsense helps!

[petereit]

I suspect it's the scaler in your Sony Bravia TV introducing most of that delay. I also know from spending many, many hours in professional broadcast video forums that Datavideo products are universally scorned in the professional video industry.

[TheReverendDave]

Originally Posted by petereit

I suspect it's the scaler in your Sony Bravia TV introducing most of that delay. I also know from spending many, many hours in professional broadcast video forums that Datavideo products are universally scorned in the professional video industry.

He did say he was getting delay without the datavideo switcher... Though I would agree with you about datavideo.

I would HIGHLY recommend the Panasonic HS50. The multiview is worth it's weight in gold. And the price is so good at under $3999.

[manu4jc]

Hey guys... the cameras are XH-G1 (with hd-sdi and genlock) not A1's the AJA boxes are used to convert the signal out of the mixer going to the projectors.

Soo this Sunday I was able to take the Datavideo mixer and 2 of the cameras over to a local church that has the For-A a HD mixer and some JVC HD-SDI cameras... outputing to some very nice HD projectors....I saw their setup and there was practically no delay between the sound and video... we hooked up the datavideo mixer with the canon cameras and went out to their projectors and it was just as good.

This leads me to believe that the culprit was the Sony TV in my living room adding delay and also the fact that I was about 3 feet from the TV did not help... in a church setting where the projection screens are a good 50-100 feet away and the delay is not as noticible... The sound also has to travel further in a church then it needs to in my living room so therefor the difference between the speed of light and speed of sound helped with the "percieved reduction in delay"

I am going forward with the setup and will take pictures of it all once installed. Thanks for the help and God Bless

[TheReverendDave]

That makes sense. I thought that you had said you tried it with the projectors. Glad to hear you got it worked out!