TOSHIBA HD-A20 is really a 1080I player with problems. BLU-RAY is better quality

[phloyd]

Part of the problem, as noted earlier with no clarification, is that the HD DVD standard does not support 24 (or 23.976) 1920x1080 progressive. It supports 29.97 fps interlaced. That is all.

HOWEVER, it should be noted that the files on the discs are stored using progressive frames, but with special flags that indicate how those frames should be converted to interlaced 30 fps pictures. This way the decoder will output the correct 29.97 1080i as required by the standard.

If you look at the header of one of the files (I have done this with AVC HD DVD files) the frame rate is specified at 29.97 fps.

So, for the player to not mess with the 24 fps encoding, the decoder would have to violate the standard and ignore the flags that instruct it to create interlaced frames at 29.97 fps and create progressive frames at 23.976 fps instead. This would require the decoder as well as the rest of the system to actually be able to go into the stream and determine if the underlying data is really progressive or interlaced, and change what it does based on this. All of the information that the headers have indicates that the streams are interlaced, as this is what the HD DVD standard requires.

This information was first revealed (iirc) by Rich at RBFilms when he encoded Chronos.