Issue with A/V Syncronization

[Shawn Jones]

I have a 6000MXP system running F6.2, that I use for our corporate large-scale, up-to CEO level meetings where I integrate the unit with an outside vendor's broadcast quality cameras, switchers, and other accessories.

We are utilizing the VCR Video input on the unit (400p), and Audio input 4 (RCA), and Audio output 1, and Single monitor Composite out (Sometimes the DVI out), and are experiencing sync issues with A/V coming from this codec. Our production company has yet to update to HD video, although, I will most likely purchase the TVS in the next few months to allow for HD video transmission from our production company.

Is anyone else experiencing or has experienced this issue, and the resolution?

The system is in service contract, but if it is a configuration issue, I would rather not call. :mad:

Thanks in advance.

[tonyi]

Could you define Sync issues? Do you mean your switcher doesent see signal? If so what resolves the issue?

[Shawn Jones]

Lip Synchronization.

[tonyi]

Ah ok i thought you were talking Genlock sync with the switcher or something. So are the video and audio streams going the same path? Aka is the video going to the same switcher as the audio on the same inputs?(channel) Or could you just run down what the actual switching gear or signal path is thats involved?

[stian123]

Lip Synchronization issues was one of the tings corrected on the F6.3 soft ware. First of all I would try to upgrade the system.

[Shawn Jones]

The audio and video paths are separate, I have not noticed this much of a discrepancy in the past. I get the video in through the VCR input, and out through the Single Monitor Composite out. The audio is input through the Audio #4 RCA, and out through the Audio #1 RCA.

This issue occurs whether it is an H.320 or H.323 call.

The A/V equipment used at each meeting (Grass Valley Switcher, Barco Switcher, Yamaha digital audio consoles, etc.). I utilize the codec in this way usually at the beginning of the financial quarter for our different brand's quarterly briefings, and special announcements where I have to broadcast to multiple sites.

What I have done so far:

Contacted my service provider, indicating this problem.

Delay the audio via the audio console usually 40-60mS to line up the audio with the video.

Downgraded the software to F5.4 to see if this is a possible resolution, as I have not noticed this when I was running F5 versions. (Suggested by my service provider)

I am also going to make a couple of calls with my TB HD Camera / Mic and see if there is an issue there. (Suggested by my service provider)

I have a couple more of these setups to do this month, so I will see what comes about.

Your thoughts are appreciated.

[Tallman2]

Shawn
I do not know the Tandberg set up, however on Polycom there are dedicated VCR audio input I do not know if Tandberg has this...
The reason why I say this on Polycom the VCR input go threw compressor and a delay built into the codec's. If Tanberg is the same way the adudo input you are using maybe a line level input which does not go threw these devices.

Either fine the dedicated inputs or see if in the menu if there are setting to set the input your ion to (VCR).

Hope this helps.

[VCT]

Hi Shawn,
Do you mean the farend video and audio not in sync? Do you have another system that you can test? Firstly, you should remove the audio delay that you created.

[Shawn Jones]

This 6000MXP is not permanently installed, I utilize it instead of moving carts from one end of a building to another. All of my twenty-one of my 6000MXP's are running F6.2, the portable was downgraded to F5.4 for testing that I plan to do early this week.

I have had reports from the Far-End participants of lip sync being out, and have seen it recently from a Far-end 6000MXP that was set up in the same manner using the VCR Video, and Audio 4 inputs, with the Single monitor out RCA, and Audio 1 out being utilized at both ends.

To solve this issue, I have had to delay the input or output to sync the moving mouth.

Update: I found that the video scan converter that the production company was utilizing to knock the signal down from VGA to Composite was causing the issue. When replaced with another unit by a different manufacturer, all was good.

The unit in question is a Folsom/Barco ImagePro. The unit was replaced by a GrassValley switcher output that was just aquired by the supplier.