Audio/Video Specifications for BD-ROM (1 Viewer)

[Richard Paul]

The BDA website has just been completed and if you go here you can download the specifications for Blu-ray. Besides the already announced additions of VC-1 and MPEG-4 AVC HP there is also the surprising news that DTS++ will be one of the mandatory audio codecs. DTS++ can go up to 7.1 channels with 24 bits and 192 kHz sampling. Currently the BDA is still deciding on the maximum bit rate for DTS++.

BD-ROM will support 1080p at 24 fps, but currently does not support 1080p at 30 fps (or 25 fps). I know that most Japanese companies are big supporters of interlace but not including 480p at any frame rate and not including 1080p at 30/25 fps seems a pretty odd decision. Hopefully this will be corrected before the BD-ROM 1.0 specification is made. Also the supported video formats for VC-1 have not yet been finalized.

 

[Dan Rudolph]

THose specs sound great for film, but there are plenty of TV/video titles as well. Hopefully this will change.

 

[ChristopherDAC]

I'm not sure what you're talking about. Television material in the U.S. and Japan is either a 24fps film source, which would get a 1080p24 transfer, or a 480i30 video source, or a 1080i30 video source. What I'm worried about is that they specify "1080*1920i59.94". This is TOTALLY WRONG. Firstly, the HD standard frame rate is 30 per second, NOT the 29.97 of NTSC colour, and secondly that 29.97 is technically 30Hz [that is, the legal standard frame rate for NTSC monochrome is 30Hz +/- 1%, and all colour transmissions have that 0.1% "fudge factor" applied]. The field rate for 480i and 1080i should just be specified at 60hz and left there. This all comes from pushing multiple-frame-rate support, the question of which one is correct gets ignored and the wrong rates get implemented.

 

[Dan Rudolph]

True, but there are European shows shot on 25 fps film.

The hardwarre needs to be able to deal with 480P anyway for backward compatibility purposes, so you might as well work it into the spec.