Red unexpectedly demoed the RedRay, their 4K player, to an unsuspecting audience at the recent Red Party in Las Vegas. I, unfortunately, was on the other side of the country, but reports are the results were impressive.
The player can output 4K, 2K and 1080p. The Red demo was a reel (material shot on the Red One, of course) compressed with a new RGB codec designed for the RedRay, with a data rate of just 10 Mb/s. That’s 4K at 1/3 of the bit rate of a typical Blu-ray disc, which would be a substantial advance in compression technology. Sufficiently substantial that there has been a fair bit of skepticism about it, in fact.
I’d like to address a bit of that here. As I pointed out in this post over on Cinematography.com, while the advances embodied in RedRay are quite impressive, they’re technically plausible. Blu-ray runs at around 30 Mb/s, but this is mostly because it can; Blu-ray discs offer room to spare. Respectable 1080p video can be delivered with the H.264 codec at as little as 10 or 11 Mb/s. See Apple’s trailer site for many examples. 4K is around 4x the number of pixels of 1080p (just a little more, actually), so this means Red’s new codec is perhaps 4x as efficient. That’s about the same improvement factor that H.264 offers over MPEG-2, the codec for standard-definition DVD. The upshot is, we’ve seen codec improvements on this scale before.
There is, of course, no such thing as a free lunch. And in the case of dramatically improved video quality at a given bit rate, the cost comes in the form of computational overhead. H.264 requires much more processing power to decode than MPEG-2, and I suspect that the RedRay codec requires so much that real-time software decoding will be impossible for the next several years, and you’ll have to use a dedicated hardware device with an appropriate ASIC (a specialized processor) to play the footage.
Fortunately, the RedRay, which is precisely such a device, is supposedly going to be priced under $1000, making it a very handy tool for Red productions and post facilities, and probably of considerable interest on film festival circuits and to art house theaters.
Can you recommend a specific trailer at 10 or 11 Mbps which you consider to be a good example of quality? In my experience, fast motion never looks good (in the sense of truly HD) at that bitrate.
Chris …wasn’t the Redray demo at 10bit though? If it was then it is even more impressive because Blu-ray would struggle to show h.264 video without artifact at 8-bit 10mbps IMO. I guess time will tell regarding the pros and cons of REDs solution.
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