Low latency capture card

Fred

A reasonable way to measure latency requires a few tools.

2 monitors with a known latency or the same model with the same latency

Some kind of video playback device with pre recorded timecode

1 camera

Play timecode from the playback device with a splitter 1 signal direct to the monitor and 1 to the capture device, take the output of the computer and plug it into the second monitor and use your software to display the capture input onto the monitor (both monitors should be identical and connected with the same connection type ie SDI or composite). Film both monitors at once with a camera whilst the timecode is playing back. You can then read the timecode and subtract the number of frames difference between the 2 monitors and you get your latency. You can try and check the latency of your monitor the same way by displaying timecode on your laptop and mirror the output to your monitor (LCD monitors still have delay and large beamers can have a lot).

If you want to get really specific you can read the pulses on the video signal with an oscilloscope but I don't think that much detail will help you.

Don't worry so much about the eye, we are used to that delay we deal with it every day and the world is not our of sync.

dbengali

About to do a small project with live off-stage actor on camera via isadora, and live sound, which will not be running through the same computer.

Knowing that there will be at least some latency in the video, even if we use a fast capture card, are there affordable solutions anyone might recommend to get the audio in sync with the video?

-David

MatthewH

Any decent digital mixer will have per input channel delay precisely for those sorts of applications.

Armando

Thanks for the answer Fred. No software solution then isn't it?

vanakaru

I have Matrox MXO2 that will capture live video good for lip-sync similar to PS3. There are many versions of this card depending what connections to your mac you have.

I have read that BlackMagic Intensity will do the same.

http://www.blackmagicdesign.com/products/intensity/

http://www.matrox.com/video/en/products/mxo2/

fifou

Thanks Vanakaru,

That's exactly what I meant by talking about "latency" : I'd like a good "lip-sync" when live filming my actors on stage.
I'm about to test the blackmagic Intensity Usb3.0 (someone is going to lend me one).

Best
Philippe

keftaparty

Hi Fifou,

I think the usb3 shuttle from blackmagic is not compatible with mac osX. It's a windows only device.

Mehdi

fifou

You're right Mehdi, but drivers for Intensity Shuttle USB3.0 on mac just arrived !
http://forum.blackmagicdesign.com/viewtopic.php?f=11&t=3518
But if I buy one, I'll buy the thunderbolt one.
Do you think an Intensity shuttle thunderbolt and a Matrox Tripplehead thunderbolt can work together on the same port ? (With a thunderbolt hub of course) ?

Philippe.

nick

I don't think there is such a thing as a thunderbolt hub - you need a device with two connections (a through connection) to be able to have more than one device connected to a computer with a single thunderbolt port

Skulpture

There is the Thunderbolt dock but don't know too much about it if i'm honest.

http://store.apple.com/uk/product/HB865B/A/belkin-thunderbolt-express-dock?afid=p219%7CGOUK&cid=AOS-UK-KWG-PLA-PLA_UK_BTB

I would love the Intensity Shuttle USB3.0 to work on Mac; would save a few quid! Not just for the device but also the expense of the thunderbolt cable!

Skulpture

From BM forum:

"I can confirm that the USB 3.0 Intensity Shuttle works with the Macbook Pro in Mac OS X 10.8.4\. Use driver 9.7.9."

MatthewH

I have a Belkin Thunderbolt Dock and can answer any questions about it. That being said, it doesn't give you any more thunderbolt ports than your computer already has so I don't know what good it would do in this instance.

fifou

I just tried, It works !
Blackmagic Intensity Shuttle USB3.0 works on mac OSX 10.8.4. Install osx drivers, plug the card, driver asks for online update, update, it works !
Latency in composite capture is much more acceptable. Is still have some issues with deinterlacing. This card is supposed to deinterlace but it seems it doesnt work... For the moment Isadora does it.
I'll choose this USB3.0 card and save my only thunderbolt port for my forthcoming Matrox Tripplehead..

Thanks all for your comments.
Best
Philippe

Skulpture

Hmmmm interesting! Thanks for the update!

jgastonraoul

Just sharing my own experience :

I've just bought an Intensity Shuttle USB3 and it works on my mid 2012 (non retina) MBP on OSX 10.8.5.

But I had to test every single input settings before to find which one was the good for my GH3 and my Gopro (so if you have a black screen while trying to input video from this card, just test other input settings).

I was thinking it would discover itself what are the right ones... (like my TV do...)

And I can't input signal at 1080/25p (I had to change my GoPro record settings to 24p...).

I hope that BlackMagic will fix that in their next driver release...

fifou

I had to search right settings too.
And it seems deinterlacing doesnt work.. for the moment I hope.

vanakaru

jgastonraoul

I wonder how you Gopro works. I have stayed away from using it for live and not testing actually. Do you go HDMI out and do you get clean frame without any icons? I have HD2 sitting araound that I do not use much, but for live there would be a life for it.

jgastonraoul

@vanakuru

I did a quick test with my Gopro HD Hero 3 black HDMI out yesterday and it seems to work !

To remove icons, I had just to set OSD option to Off. And for the settings, I selected 1080/24p on GoPro and Intensity shuttle.

If you can't make it work clean, just tell me and I'll give another try.

vanakaru

OK! I got the mini(micro) HDMI adapter and was able to hook my idle GoProHD2 to Matrox MXO2. Great quality 1080p PAL 25fps. I have a project requiring closeup lens camera and this is absolutely perfect. Now when new HD3 is about to come out I see HD2s selling for 100EUR. It would be great camera for live capture - latency with MXO2 is about 1/3 of a sec, picture is very good on daylight and not too bad with poor lighting(gets grainy) and as a great bonus you can record what the camera sees while broadcasting live. Powering via USB mini connection works fine. And it is a small camera.

jgastonraoul

The Hero3 black edition is far more expensive, but really better in low light conditions if you need to use it on stage.