View Full Version : Real-time HD video capture?


Geoffrey Cox
December 6th, 2012, 02:04 PM
Hi,

I'm looking for a solution to capture HD video streaming from my Mac laptop, probably via the HDMI output (or perhaps component) of the connected Matrox Mini, or possibly straight out of the Mac mini-display port itself. I use software (Jitter) to process video in real-time for live performance but would like to be able capture this in high quality. I've yet to get Jitter to talk to the Matrox properly but am hopeful this can solved, otherwise it will have to be from the mini-display port.

I've tried screen capture software but it's not really up to the job (frames dropped continually) as it is so taxing on the CPU of the computer, which is already working pretty hard with the video processing. I can do it by using a scan converter connected to the display port, down-resing to SD composite and recording to an HDV/DV player / recorder, but obviously the quality drops through the floor.

I've looked at a few things online but am not really sure what I'm looking for apart from a piece of hardware that can cope! The video material itself is all 1920x720, JPEG at 50% quality.

Can anyone suggest anything?

Kevin Spahr
December 7th, 2012, 09:04 PM
I would bet your problem is the hard drive on your MacBook it would be too slow to capture full HD.
An external Thunderbolt raid MIGHT work. Blackmagic has free software on the Apple App Store that can show you what your hard drive is able to capture in for different FPS, frame size, and various compression rates.

Blackmagic also has a new product family called UltraStudio that might be of some use in this application.

I recently purchased the UlltraStudio Recorder so I could use my 17" MBP as a field monitor. I know it is not a real field monitor but I'm trying to cut down on carrying extra stuff.

Seth Bloombaum
December 8th, 2012, 01:36 AM
There are all these HDMI recorders out there, Atomos Ninja and Convergent Designs Nanoflash come to mind. I'd be interested to try one of these on an hdmi output from a laptop, I'd guess that it will work at at least some resolutions/refresh rates.

Geoffrey Cox
December 8th, 2012, 02:54 AM
Thanks for the tips Kevin - the free Blackmagic software sounds useful - is it this one?

https://itunes.apple.com/us/app/blackmagic-disk-speed-test/id425264550?mt=12

Seth, yes those are the type of drives I'd been looking at. They seem very varied in price and as you say they could work ... some of the time. Advice from the makers / sellers might be the only way to find it if they are suitable I guess.

Keith Dobie
December 14th, 2012, 01:51 PM
Geoff -- wondering what kind of quality and recording time you are looking for. Is it just for archiving or are you planning to edit it? Can you describe what your video sources are — Is it just material that's already on your computer and you're sending to Ustream or something similar?

Geoffrey Cox
December 14th, 2012, 02:12 PM
Thanks for the response Keith.

The QT material is already on my computer (or an external Firewire drive). It is processed live by the software (Jitter) on the same machine and the results viewed on my external HD screen (basically the software randomly selects clips from banks and I control the speed of selection, how much of a clip is played and bank choice, live i.e. in real time, but many other forms of image processing are possible). At present it is simply sent out of the display port but I'm hoping to get it sent via the Express card port to Matrox mini hardware but I need to re-program the software to do this (this would have the advantage of HDMI or component output from the Matrox hardware as well as dealing with interlaced material).

I'm looking for the same quality that it displays at (1920x720, JPEG codec at 50% quality) or as near as possible. I guess in terms of time that could be flexible but 5-10 minutes would be OK. I then need to be able to import the recorded file into FCP for further editing and / or combination with other material.

Sorry not sure what Ustream is but don't think it is relevant.

Geoff

Geoffrey Cox
January 30th, 2013, 12:28 PM
After further research, the Atomos Ninja 2 (suggested by Seth) looks like it would work:

Atomos Ninja 2 Portable 10 bit Smart Production For DSLR?s & HDMI Cameras at Markertek.co.uk (http://www.markertek.co.uk/Catalog/Digital-Hard-Disk-Recorders-DVRs/Atomos-Ninja-2-Portable-10-bit-Smart-Production-For-DSLRs-HDMI-Cameras)

Anyone used this / any experience yet?