Between The Lions...

I must admit, this is something that I do not fully understand as it applies to digital media. I had been under the impression that interlacing was strictly the function of the display device used to watch video. I had no idea at all that a video source could be encoded as interlaced or progressive. I assumed that all sources were progressive by default and that the display device simply did its best to adapt as needed.

So I do have a few questions... Why are video sources interlaced on DVD to begin with? I mean, NTSC television sets are interlaced by standard, with 30 frames per second, 60 fields per second, refreshing each display line at 60 Hz. I don't see how interlacing the video data on disc would improve quality...

If anything it would seem to be a way to degrade it instead, as all the data for a single frame would be divided in two. Is this done as a security measure to prevent the playing of these DVDs in different (PAL) territories? Aren't PAL television sets all (or mostly) progressive scan? Is it done to conserve disc space? Is there any technical advatange to be gained from having the DVD source interlaced, or is this just a means to hide Macrovision within the display signal?

Also, what is the difference between YPbPr and YCbCr component video signals? Why does one of them work with my Brother's new APEX projection screen and Sony DVD player, while the other does not?

Ali, Bumaye!

Akai Rounin, The Cyber Sage