Homemade Direct-to-Disc on the cheap

[Sean Schult]

Originally Posted by Ron Arrivillaga

I did use a pretty beefy cpu for this test (Core2 Duo, 2GB RAM), but CPU usage hovered around only 10% and memory usage never exceeded 256MB.
...
If anyone is interested in this "investigation", I'll post my progress in this thread (or perhaps start another?).

Ron,

I would definately be interested in your findings and anything you may develop along the way. When you did the dual capture, were you previewing either of the streams? If not then I can understand the low CPU usage -- a simple transfer of data from one interface to another shouldn't be too tough on it. I would be curious what the usage would be if there was a scaled-down (25% maybe?) preview of both streams displayed on the screen.

-Sean

[Ron Arrivillaga]

Originally Posted by Sean Schult

Ron,

I would definately be interested in your findings and anything you may develop along the way. When you did the dual capture, were you previewing either of the streams? If not then I can understand the low CPU usage -- a simple transfer of data from one interface to another shouldn't be too tough on it. I would be curious what the usage would be if there was a scaled-down (25% maybe?) preview of both streams displayed on the screen.

-Sean

I agree - for simple capture the limitation shouldn't be the CPU. Bus speed and hard drive speed maybe. Which is why I was thinking it should be possible to capture using a handheld WindowsCE device (no preview of course). I think drivers may be an issue on WinCE though, so I'm going to work the WinXP dual capture angle first. I'll see what I can do about adding preview for both streams.

[Ted OMalley]

Ron,

That's very interesting information - good work. After playing around with a stylistic 3500 (which was quite impressive for older hardware), I decided to back off - I'd still like a smaller capture device than that. So, instead, I've decided to sell mine on eBay.

I'll keep checking up on the great work you guys are doing over here, it sure sounds cool.

Thanks,

[Anmol Mishra]

I am trying to do something similar but to make a portable 4:2:2 colorspce and 3:1 compression MJPEG recorder. DV gives us 4:1:1 with 5:1 compression so 4:2:2 would be a step up.
There is a Linux MJPEG page
mjpeg.sourceforge.net

Initially I am planning to get Y/C S-video input and then later use SDI/HDMI for a HD recorder.
Any ideas for the initial SD version ??

[David Suthers]

Here's an update for anyone thinking about building your own portable capture rig running Linux....

dvgrab has been updated to version 3.0

The new version allows capture of HDV video and also allows DV capture via USB.

Since I don't have an HDV camera, I can't attest to how well the new features work. But for standard def I just keep plugging away with mine without any problems. Since August I've captured over 700GB of video directly to my tablet. The only dropped frames happened one night when I used a retractable firewire cable (no shielding) too close to some two-way radios.

David

[David Suthers]

FYI to anybody who visits this thread...

While I don't visit the boards very often, I still use my Fujitsu tablet for capturing video. I used it filming 88 sporting events during the 2007-2008 school year and have already filmed over 30 events this year. All without lost frames or other issues. That's over 1.7 TERABYTES of video files in the past 15 months.

The proof is obviously in the results and I have been nothing but pleased with how the system works. If I had it to do over, would I? Absolutely!

- David

[Bryan Daugherty]

David- thank you for posting this. It was quite a long read and I am happy to have learned so much. I actually was looking for Direct to DVD articles (and I may seek your advice when I find the right thread) when i came across this jem of an article. Thanks for sharing!