Best options for video output/playback with PTHD?

[zboy2854]

Hi All,

I've been tasked with creating a more robust video playback/output setup for the studio's PTHD system, and I admit I'm pretty ignorant about the video side of things.

Currently we've been playing back QT video by going firewire out to a Canopus ADVC 500, but have noticed that there is some noticeable latency and I read that in general it is not a very robust solution.

Can anyone recommend what other hardware or setup options there are that work really well for video output/playback with a PTHD system without latency issues, etc.? Thanks.

[Craig F]

What HD do you have and are you going to be upgrading to 11 if you are not there?
old Mojo is better if your on an old system
a Blackmagic card is good middle aged system (having problems with 64 bit currently)
AJA is good for new 11 system

[Chief Technician]

Originally Posted by zboy2854

Can anyone recommend what other hardware or setup options there are that work really well for video output/playback with a PTHD system without latency issues, etc.? Thanks.

Before I answer your question, lets consider the points where latency is introduced.

• Before video output
• Inside video display

For example, if you are using a BlackMagic DeckLink HD Extreme 3(D), and you turn on downconversion, it adds latency!

If you are not using a CRT display, then you have latency inside your video display. Even CRT displays could have up to 1 frame of latency! Wait, it gets worse (or better)! The plasma displays I have used have over 2 frames of internal latency (deinterlace, scale, etc.). High quality (aka Grade A) LCD displays can have even more than this!

I digress, if only slightly, to say that recommending a solution without latency issues is not really possible.

Now the solution that will give you minimal latency issues is either the Mojo or Mojo SDI. These peripherals are accurate to within a few samples up to the point where the video leaves the Mojo. Past that point, you need to account for the latency in your video display device.

Now there is a catch with both Mojo and Mojo SDI. The minimal latency only applies when using Avid MXF video. While you can playback QuickTime wrapped media (.mov) with either Mojo, you will also have to deal with up to +/- 1 frame of slop each time you press play.

Both Mojo and Mojo SDI will not work with Pro Tools 11. Don't even bother trying to make them work.

With Pro Tools 11, the +/- 1 frame slop is supposed to be gone. I haven't tried it myself. Apparently AJA hardware works well with 11, and there are mixed reports on the DeckLink card. Some people say the latest DeckLink driver (v10.1.1?) solved their problems. Others say they still have latency issues, primarily with the amount of time between you pressing play and playback actually starting.

[reichman]

Jonathan is more experienced than I am, but I will add that you should be more concerned about "slop" or the term I use instead, "jitter" than overall latency. If the latency is consistently the same amount every time you hit play, who cares how long it is, as long as you buy a Syncheck, measure it and compensate for it in the video offset settings.

Put Syncheck into your budget, and remember that you get what you pay for with video hardware.

[zboy2854]

Originally Posted by Craig F

What HD do you have and are you going to be upgrading to 11 if you are not there?
old Mojo is better if your on an old system
a Blackmagic card is good middle aged system (having problems with 64 bit currently)
AJA is good for new 11 system

Hi Craig, thanks for your response. We're running HD8 on OSX 10.6.8 with legacy HD Core/Accel cards. No plans to upgrade anytime soon.

So it sounds like we should be looking into the Mojo or Blackmagic interfaces, yeah?

[zboy2854]

Originally Posted by Chief Technician

Before I answer your question, lets consider the points where latency is introduced.

• Before video output
• Inside video display

For example, if you are using a BlackMagic DeckLink HD Extreme 3(D), and you turn on downconversion, it adds latency!

If you are not using a CRT display, then you have latency inside your video display. Even CRT displays could have up to 1 frame of latency! Wait, it gets worse (or better)! The plasma displays I have used have over 2 frames of internal latency (deinterlace, scale, etc.). High quality (aka Grade A) LCD displays can have even more than this!

I digress, if only slightly, to say that recommending a solution without latency issues is not really possible.

Now the solution that will give you minimal latency issues is either the Mojo or Mojo SDI. These peripherals are accurate to within a few samples up to the point where the video leaves the Mojo. Past that point, you need to account for the latency in your video display device.

Now there is a catch with both Mojo and Mojo SDI. The minimal latency only applies when using Avid MXF video. While you can playback QuickTime wrapped media (.mov) with either Mojo, you will also have to deal with up to +/- 1 frame of slop each time you press play.

Both Mojo and Mojo SDI will not work with Pro Tools 11. Don't even bother trying to make them work.

With Pro Tools 11, the +/- 1 frame slop is supposed to be gone. I haven't tried it myself. Apparently AJA hardware works well with 11, and there are mixed reports on the DeckLink card. Some people say the latest DeckLink driver (v10.1.1?) solved their problems. Others say they still have latency issues, primarily with the amount of time between you pressing play and playback actually starting.

Thanks Jonathan, sounds like there's a lot more to consider than I originally figured. Also sounds like I'm going to have to deal with video latency no matter what I do. I guess I'll have to look into the Syncheck with whatever solution I go with. Thanks all.

[seanmccoy]

Originally Posted by Chief Technician

Now there is a catch with both Mojo and Mojo SDI. The minimal latency only applies when using Avid MXF video. While you can playback QuickTime wrapped media (.mov) with either Mojo, you will also have to deal with up to +/- 1 frame of slop each time you press play.

I also am looking into adding video distribution for my PT10/11 HD Windows setup for ADR and Foley work. While I'm aware of the various places latency can be introduced (I already own a Syncheck), are you saying the latency amount might be inconsistent based on the video filetype?

[Craig F]

Originally Posted by seanmccoy

I also am looking into adding video distribution for my PT10/11 HD Windows setup for ADR and Foley work. While I'm aware of the various places latency can be introduced (I already own a Syncheck), are you saying the latency amount might be inconsistent based on the video filetype?

yes, different codecs take different amounts of processing power/time
best thing is to have Syncheck test files for the codecs you use and addjust the QT offset in PT if/when changing codec types

[Craig F]

Originally Posted by zboy2854

Hi Craig, thanks for your response. We're running HD8 on OSX 10.6.8 with legacy HD Core/Accel cards. No plans to upgrade anytime soon.

So it sounds like we should be looking into the Mojo or Blackmagic interfaces, yeah?

Mojos are SD video only
Blackmagic can be temperamental about the codec/size, I've had them 3:4 crop a 16:9 QT file

[Chief Technician]

Originally Posted by seanmccoy

I also am looking into adding video distribution for my PT10/11 HD Windows setup for ADR and Foley work. While I'm aware of the various places latency can be introduced (I already own a Syncheck), are you saying the latency amount might be inconsistent based on the video filetype?

When setting up your video distribution, you want to be using the same video signal transport (HDMI, SDI, etc.) to all of your displays. You also want all of your displays to be from the same model line. When it comes to video delay, screen size doesn't matter. What does matter is the electronics inside the chassis. If you have a two Samsung displays, and one is model ABC and the other is XYZ, chances are high that their electronics are different, and the end result will be that each display has a different latency value. Try doing ADR or Foley work where your displays are not in sync.