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A Statistical Comparison of HD DVD & Blu-Ray Reviews
An anonymous reader writes "Gizmodo today posted a statistical comparison of over 300 HD DVD and Blu-ray reviews published at High-Def Digest since the start of the high-def format wars last Spring. Their findings? Overall video quality between the two formats is nearly identical, however Blu-ray titles were slightly, but definitely superior in audio playback, while HD DVD titles had far superior standard def features and moderately superior high-def features."
HD DVD supports both Dolby and DTS. Much like a normal DVD, whether or not it has DTS is entirely up to the studio mastering the disc. Dolby mandatory, and I believe DTS is optional (just as it is with standard def DVD's). HD DVD also supports both Dolby and DTS lossless formats, should the studio master the disc to use it. (Again, Dolby TrueHD decoding is mandatory, DTS-HD is optional)
The reason why Blu-ray is credited with 'sounding better' is because many Blu-ray discs use raw PCM encoding for audio, rather than any sort of compression (lossless or not). Some purists believe they can hear the difference between compressed, lossless and lossy compression.
While many HD DVD titles use lossless compression, not all of them do.
When an HD DVD title does have lossless compression, its audio is ranked as good as Blu-ray's (and it had better, given that the decoder should be seeing an identical bitstream).
To be honest, I'm a believer in lossy compression; at the bitrates used in HD DVD, I seriously doubt anybody could tell the difference between lossless and lossy in a double-blind test on identical equipment; the bitrate is well above the level of transparency.
-- Sometimes you have to turn the lights off in order to see.
Nope, that's not it.
On DVD, your 5.1 audio codecs are DTS or Dolby Digital up to 448 Kbps. HD DVD supports Dolby Digital Plus up to 1.5 Mbps. Even professional film mixers tell me they feel that DD+ north of 1.2 Mbps is pretty much transparent to them.
Note that Blu-ray doesn't make DD+ mandatory, nor does it require players to have built-in compression for TOSLink output, which is why the Sony discs use AC-3 @ 640 Kbps (the BD max) AND PCM 5.1 48 KHz 16-bit simultaneously. So it takes more than 5 Mbps to provide the audio experience that HD DVD does in 1.5 Mbps.
My video compression blog