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Father of DVD Interviewed
An Anonymous Coward writes "Interview with Koji Hase. Talks about some of the interesting history behind the DVD format, copyright protection, and competing formats for audio."
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The 'logic' behind region encoding is to allow the motion picture industry to phase the release of movies across the globe.
Not all movies are released at the same time in all countries. They usually are released in the US first, Europe and Japan next, etc. A movie may actually be released on DVD or VHS in the US before it hits the theatres in some countries.
Regional playback controls are thus an attempt to keep DVD sales from eating into theatre revenues in countries where theatre release is significantly later in time than it is in the US.
I don't agree with it, but that's the reason.
What if the hokey-pokey really is what it's all about?
One word: compression. Five hours in 500 Mb is 800 Mbits/hr, or just over 220 Kbit/sec. A well encoded MP3 at 320VBR averages less than that, and I can't tell the difference between that and the original CD.
Even truly lossless (bit-for-bit reproduction) can be achieved with better than 2:1 compression, which would make 5 hours of CD music (just under 1.5 Mbit/sec bitrate) take 1.5 Gb, so reaching 6:1 shouldn't be a huge problem IMO.
The worst thing I find about DVD is region encoding. Why is it there?
The original idea was to prevent importing movies on DVD from other regions before they actually hit cinemas locally. The point has become somewhat vague, because many discs are released only on some region, so many people have to resort to importing to get all the stuff they like. Interestingly, lately many blockbusters have opened at cinema almost simultaneously worldwide, which is definitely a good development. I wouldn't be surprised if this was at least partly because of the DVD importing still being possible despite region codes.
It seems they wanted to put something to replace the PAL/SECAM/NTSC barrier.
That barrier still exists on DVDs, but it's easier to overcome than with VHS. There are PAL and NTSC discs. Every PAL player can also play NTSC discs, but only some NTSC players can play PAL discs. If component signal is used (RGB is very common in Europe) you don't have to bother with color encodings, only whether your television can sync to 50/60Hz and display all the lines needed.
Is the NTSC stuff encoded on the DVD or is it an artifact of the conversion from digital to analong of the image?
Picture on DVD is fully digital MPEG-2, hence it has no NTSC, PAL or SECAM color encoding. Picture resolution and FPS still match either NTSC or PAL (SECAM has same specs as PAL, so there are no SECAM discs), because almost every display device used with DVDs still uses them. NTSC resolution on DVD is 720x480, while PAL is 720x576. Player handles 2:2 (PAL) or 3:2 (NTSC) pulldown on film material, and is also responsible for generating actual NTSC/PAL/SECAM color encoding if something else than component signal is used in connecting player to the display device. Needless to say, using component signal gives the best image quality you can achieve without going progressive, because it requires no additional signal format conversions after DA-conversion.
It's also good to note that because of the slight differences between NTSC and PAL discs, well-encoded PAL disc has better picture and smoother movement than well-encoded NTSC disc.
They do store the film at 24fps on the disc. The difference between a PAL disc and an NTSC disc is the resolution. PAL is 720x576 and NTSC is 720x480. The player converts the 24fps MPEG stream into 50fps or 60fps for the telly.
Be aware there's an incredible problem with the frame rate conversion. NTSC is 3:2 (odd frames twice, even frames thrice) which converts 24 fps into 60fps neatly. PAL is 2:2 (show each frame twice) which converts 24fps into 48fps. But PAL TVs are syncing at 50fps! So PAL DVD players actually show the movie a little bit fast to keep the frames syncing. This pitch shifts the audio track enough to be irritating, especially if you are playing DVD music (meaning music on DVD, not DVD-A).
Fortunately if you know the problem you can work around it. Some DVD players can output a bastardised format called PAL60. This is the PAL colour encoding at 60Hz. Almost any modern Australian TV supports this bastardised format.
Though an even better solution would be consumer-grade multisync TVs. Then you could sync the TV at 24fps and ignore the upsampling process. I don't know if any consumer-grade DVD player can output 24fps.