I wonder if the hd-dvd (or blu-ray) disks are bit-for-bit identical with the original digital film? If they aren't what is the original bitrate (both for audio and video) of movies that shot on HD?

I wonder if the hd-dvd (or blu-ray) disks are bit-for-bit identical with the original digital film? If they aren't what is the original bitrate (both for audio and video) of movies that shot on HD?

I heard Uncompressed without audio a Movie would take up to 400GB. So no not even close.

400GB didn't sound right to me, so I did the math...
1920 horizontal pixels x 1080 vertical pixels = 2,073,600 pixels per frame
2,073,600 pixels per frame x 12 color bits per pixel = 24,883,200 bits per frame
24,883,200 bits per frame / 8 bits per byte = 3,110,400 bytes per frame
3,110,400 bytes per frame x 24 frames per second = 74,649,600 bytes per second
74,649,600 bytes per second x 60 seconds per minute x 60 minutes per hour = 268,738,560,000 bytes per hour
268,738,560,000 bytes per hour / 1024 bytes per kilobyte / 1024 kilobytes per megabyte / 1024 megabytes per gigabyte = 250.28 Gigabytes per hour (!!!)

That is of course assuming 12 color bits (or bits per pixel or bpp).
8bpp = 165GB/hr.
12bpp = 250GB/hr.
16bpp = 333GB/hr.

If you're filming a movie and want the highest quality I'd expect to use at least 12bpp (AKA 36 bit color). HDMI now supports this after all.

Personally I think the movie industry is foolish for clinging to the 24 frames per second standard. If you go to 60 frames per second (fps) like video, then things get even higher still: 625GB/hr for 1080p60 @ 12bpp (1080 resolution, 60 frames per second, 12 bits per pixel).

Remember all of these numbers are uncompressed and without audio (!!!).