Thursday, July 06, 2006

HD DVD vs. Blu-ray (Pt. II)

HD DVD and Blu-ray are new, competing video disc formats. They're both high-definition, and they've both hit the stores over the last few months, after nearly a decade in which DVDs were all standard definition (480i, raised to enhanced definition 480p by "progressive" players). The players for each new hi-def format cannot play the other new format, even though both player types use a new blue laser. Both formats' players play standard, red-laser DVDs.

Officially, Blu-ray discs are exactly that: "Blu-ray discs," BDs for short. They are not DVDs, since the DVD Forum has not endorsed this format. BDs can't be played in standard DVD players or in HD DVD players.

HD DVDs are DVDs, endorsed by the forum ... but they can't be played in standard DVD players or in Blu-ray players.

Toshiba has been first out of the starting gate with its HD-XA1 ($799.99) and HD-A1 ($499.99) HD DVD players. Now the introductory Blu-ray players have arrived: Sony's BDP-S1 ($999.95) and Samsung's BD-P1000 ($999.99). Sony is expected to release a less-pricey PlayStation 3 gaming console in the fall that also plays Blu-ray discs.

The Toshiba entrants have received mostly positive media reviews, including: Sound & Vision's HD-XA1 review, Home Theater's HD-XA1 review, Ecoustics.com's HD-A1 review, and Ultimate AV's HD-A1 review.


In general, most reviewers have been blown away by the picture quality of the initial spate of HD DVD titles when played on a Toshiba player
  • through a HDMI digital connection
  • at a 1080i scan rate
  • into a 1080p-native HDTV
but not at a 720p scan rate, a problem seemingly due to a poor 1080p-t0-720p internal scaler in the players. Component video output at 1080i is likewise excellent — not down-rezzed to 480p as had been feared. (These two Toshiba models share the same basic innards and yield the same overall performance.)

The HD DVD video-quality improvement over standard DVD is said to include
  • greater picture clarity and resolution
  • an absence of compression artifacts such as mosquito noise
  • super-punchy contrast
  • subtle shadow detail, and
  • eye-popping colors that are nonetheless not at all oversaturated (due presumably to the wider color gamut)
Spurious edge enhancement, long the bugbear of DVD cinemaphiles, has been deep-sixed, at least for the initial HD DVD titles.

Some reviewers have noted that HD DVD beats cable and broadcast HD quality(!), owing to higher bit rates and better codecs (see Pixel-Perfect 1080p from DVD?).

Sound quality has also drawn raves. But some of the initial movie releases have been mastered with sound levels way too low.


Also impressing reviewers has been an interactive menu capability that lets you select from most options while the disc continues to play. But some reviewers don't like the players' sluggish response to commands from the remote control.

Most reviewers, moreover, have disliked how long it takes these first HD DVD player models to boot up (they're actually special-purpose, 2.5-GHz Pentium 4 computers) or to begin playing a newly inserted disc. The wait times can easily exceed one minute and can approach twice that long.

There have been widely reported minor playback glitches of the type that will probably be addressed by firmware updates from Toshiba later on. (The players can be updated through their Ethernet ports.) Other playback woes such as the inability to stop and restart a disc without going back all the way to the beginning have been laid at the doorstep of early disc-mastering miscues and will unfortunately not resolve themselves as easily via firmware updates.


Ecoustics.com's reviewer unearthed a pair of subtle video performance issues with the Toshiba player.
  1. "Using the HDMI output, the luma values are being clipped. Above white and below black information are missing from the image, so dynamic range is not preserved." (Luma is the black-and-white or Y portion of a YCbCr digital video signal. Clipping its above-white and below-black values — removing them entirely — can theoretically cause digital signal processing errors later on in the TV that might wind up degrading actual whites and/or blacks on the screen. That could eliminate subtle detail in very bright or very dark parts of the image.)
  2. " ... the player is using the wrong color space for HD material if HDMI is converted to DVI at any point. Instead of using the proper REC 709 spec that HD is mastered in, it is being converted to REC 601, which is for standard definition sources. So if your display has a DVI input and you are using an HDMI to DVI cable, the color space used is for SD material, not HD. If you go HDMI to HDMI, it does not have this problem. With standard DVDs, the color space stays correct at 480p." (So DVI conversion of the players' HDMI digital outputs yields hue and saturation errors from HD DVD discs, but not from standard DVDs.)

I have yet to see any editorial reviews of the brand new Blu-ray players from Sony and Samsung. But a posting at TheDigitalBits.com gives a cautionary note about the Samsung BD-P1000's 1080p HDMI-output video quality: too little detail, contrast, and color, compared with Pioneer's yet-to-be-introduced Elite BDP-HD1 Blu-ray player. All of the problems that were complained of at the Digital Bits disappeared with a switch to using the player's component-video output at 1080i.

Bill Hunt, the proprietor of the Digital Bits website, also complained that with his Panasonic projector at the other end of an interconnecting HDMI cable, his Samsung BD-P1000 didn't "handshake" correctly and consequently didn't scale properly from one scan rate to another — or (I'm not clear on this) was it from one aspect ratio to another?

There have also been consumer complaints logged online that the video quality of the first Blu-ray titles has been uneven, with some looking superb and some looking less so. Check out the customer ratings for the Blu-ray titles listed at Amazon.com. (The equivalent list of HD DVD titles is here.)


It is obviously too soon to draw meaningful, once-and-for-all comparisons between what HD DVD actually delivers as one of two new hi-def home video disc formats that will surely be with us for quite some time vs. what the other one, Blu-ray, does. Clearly, both formats' first players and disc releases are beset by startup woes that obscure long-term judgments.

I note also that the roster of initial releases from the two camps is both abbreviated and less than prepossessing, with no real "must have" titles. Moreover — and this could ruin both sides' chances at dominance — neither format is supported yet by all the major studios. (A rundown on which studios are releasing what titles in these two hi-def disc formats can be found here, at the Digital Bits site.) One can only hope that the various studios will gradually come to follow two of their number's, Paramount's and Warner Bros.', stated intention to release all titles in both formats.

Moreover, there is a pricing gap that surely hurts Blu-ray. You can get a HD DVD player for $500, while the current entry-level Blu-ray machine is twice that. (The Sony PlayStation 3 that is due in November and will play Blu-ray discs will reportedly cost $500.) HD DVD discs seem to cost between $20 and a figure a bit north of $30 at Amazon, while BDs (Blu-ray discs) are debuting at roughly, I'd say, $5 more.


As I indicated in HD DVD vs. Blu-ray (Pt. I) and Pixel-Perfect 1080p from DVD?, Blu-ray is providing true 1080p output over HDMI. With that output scan rate, the best possible picture on a 1080p-native HDTV that also supports 1080p input can theoretically be obtained. HD DVD has missed that particular boat, with 1080i output the best scan rate its initial players offer. But HDTVs with first-rate 1080i deinterlacers can fully offset that drawback.

Future HD DVD players will, it has been promised, include the full 1080p output capability.

I also said before that Blu-ray has missed an entirely different pair of boats. In practice, HD DVD uses advanced AVC and VC-1 codecs to compress the video bitstream, then stores it on dual-layer discs. Blu-ray, on the other hand, has chosen (for now) stodgy, less-efficient MPEG-2 encoding on single-layer discs. The combination of those two choices may make for disc-to-player-to-TV bit-delivery rates too low to ward off compression artifacts.

Both of those questionable choices on the part of Blu-ray will surely be superseded on future disc releases, once the necessary authoring tools and disc-manufacturing facilities are in place.


I see that this discussion has gotten much more long-winded than I originally intended. More is to come on the HD DVD/Blu-ray format war in later posts.

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