The Retailing of HD-DVD and Blu-ray
September 1, 2006,
Is Blu-ray faster, and is it relevant?
On our retail tour, several of the sales reps we met said that Blu-ray has a higher bit rate, and the ability to read and transfer data more rapidly makes it a better solution for high quality video. They are correct that maximum bit rates on Blu-ray are higher than HD-DVD. The maximum bit rate on HD-DVD is 36.55 million bits per second, whereas it is 54 Mbps on Blu-ray. To people reading the spec sheets that sounds like a big technical advantage for Blu-ray. And in theory, the more data you can move and process in a given period of time, the better the picture and sound will be.
However, this is true only to a point. Given the fixed limitations of other elements in the video system like film size, 1080p scans, and 24 frame per second film exposure rates, one cannot simply continue to increase bit rates and gain ever-increasing picture quality. Eventually you get to the point where the limits of the source and the displays are reached, and further increases in bit rates become irrelevant. And as far as 1080p/24 video material with the advanced codecs is concerned, if that point has already been reached with a maximum 36.55 Mbps bit rate, then incremental bit rates beyond that will not contribute to perceptible increases in image quality.
So how fast is fast enough? Transfer rates on standard DVD average about 5 Mbps and max out at 9 Mbps. Standard HDTV broadcast is at 19.4 Mbps. Clearly in the range of performance defined by DVD and HDTV as encoded in MPEG-2, more data and higher bit rates produce better images. Today's HDTV broadcasts on high resolution video displays look extremely good, and certainly they are head and shoulders above DVD.
Now, HD-DVD's maximum bit rate of 36.55 Mbps is about double that of broadcast HDTV. That by itself is enough to enable it to deliver spectacular picture and sound, the likes of which we have not yet experienced. But on top of HD-DVD's virtual doubling of HDTV's bit rate, there is the huge kicker in performance that is derived from the advanced codecs: HD-DVDs being made today are in VC-1 and MPEG-4, whereas HDTV is in MPEG-2, so with HD-DVD a lot less data needs to be read and transferred in order to deliver a magnificent HD picture. HD-DVD can run circles around HDTV even when loping along at bit rates far below those of HDTV's 19.4 Mbps.
Therefore, as with the storage issue, HD-DVD's maximum bit rate of 36.55 Mbps is not likely to be a limiting factor in the quality of the home theater experience, at least as far as 1080p/24 film transfers are concerned. Many other factors have as much or more influence in setting the limits of picture quality including the physical limitation of film size, the condition and restoration of the film, the 24 frame-per-second exposure rate, the 1080-line scan format, the precision of the advanced codecs, and the non-transparency of today's 1080-line digital video displays. These limitations are equally inherent in both HD-DVD and Blu-ray. It is for these reasons that we maintain that once HD-DVD and Blu-ray are delivering their maximum potential (and neither one is there yet), the consumer will notice no difference between the two in terms of image and sound quality.
Yet, rather than debating the merits of the technical specifications to determine whether Blu-ray or HD-DVD is the better value, we'd be a lot better off if consumers could simply be allowed to see these two technologies side by side on identical 1080p flat panel monitors with comparable source material. This is ultimately where many retailers are failing the public. They have the opportunity to help consumers get a real feel for the differences, or lack thereof, between HD-DVD and Blu-ray. But instead, many of them are staging skewed demos to upsell the customer to the higher priced product.
They cannot be blamed for this. After all, the retailer's primary objective is to maximize profit and revenue per square foot, not educate the public. Nevertheless, it is unfortunate that consumers are not able to see the merits of these two impressive technologies in demos that show them both side by side on an equal footing.
But on second thought, even that might not make a difference. In one remarkable retail store we found both HD-DVD and Blu-ray being demo'd on equivalent 1080p flat panel monitors. The Blu-ray demo was playing a movie and the HD-DVD was running a loop from the DVD Forum demonstration disc that had been taken with a 1080p video camera. As anyone would guess, the HD-DVD picture was smoking the Blu-ray due to the higher quality source. I asked the sales rep, "Correct me if I am wrong, but the picture on this HD-DVD actually looks better than the Blu-ray, wouldn't you agree?" He said, "No it isn't. It can't be, because it is only 1080i. The other one is 1080p." In the strange world of video marketing, specs trump the picture before your eyes.