View Full Version : Some questions about Cineform, 10-bit YUV, and the AJA Xena LHe


Charles Moxie
May 7th, 2007, 05:25 PM
Hello, I'm going to be purchasing an AJA Xena LHe soon, and I had a couple of questions that I'm hoping someone can help me with. The thing that particularly concerns me is having adequate writing speed with my RAID 0 array. If I read correctly, YUV is mathematically the same as RGB. Is there any reason why someone would choose RGB over 10-bit YUV capture? I have also read about the Cineform codec which seems to be (near?) lossless. If I purchase Cineform Aspect HD, will that allow me to capture directly from my source to the Cineform codec? I've also read about HuffYUV which seems to be lossless as well, but I'm not sure if the AJA Xena LHe will work with it. All of these codecs affect the datarate greatly and can save me money because I wont be buying as many hard drives. If someone could answer my questions, I would really appreciate it. Thanks.

Salah Baker
May 7th, 2007, 05:50 PM
After you get your AJA test/demo the CineForm Prospect line...
You’ll love the size to array / quality ratio.
Plus as you grow you if you get a reatail AJA you can dual boot between the 2, and run Machina

David Newman
May 7th, 2007, 08:19 PM
Charles,

YUV 10-bit is 4:2:2 and RGB 10-bit is 4:4:4, so RGB is 50% bigger than YUV. 10-bit YUV at 30p is about 150MBytes/s and RGB 225MBytes/s. Compressed to CineForm, these data rate would average only 20MB/s and 40MB/s (RGB is a little less efficient to compress,) yet the quality is so high people can't pick to source for the CineForm compressed (http://cineform.blogspot.com/2007/03/quality-results-and-green-screen.html.) HUFFYUV is a lossless codec, but it will only half the data rate of average, and it doesn't have a 10-bit mode, nor any integration with Xena cards. So 7:1 compressed 10-bit will out perform all practical ways 2:1 compressed 8-bit.

For 10-bit YUV 4:2:2 you will need Prospect HD ($999) not Aspect HD ($499), as AHD is only an 8-bit 1440x1080 application. Prospect HD also include timeline intergration of the Xena cards, whereas Aspect doesn't. For RGB 4:4:4 you will look at a more expensive system, Xena 2K, Prospect 2K Ingest.