Originally Posted by jjmixman
This is quite informative:http://www.hdtvmagazine.com/forum/viewtopic.php?t=5317
a) SD material is REC609 (normal)
b) HD material is REC701 (wide)
c) The RGB range thing is definitely for computers. RGB or Component signals for video should use the 16-235 range. So I guess I should turn that setting back off on my HDDVD player...
It also states that there is a problem playing upscaled SD material because the display cannot know that the source is SD (at least not if you are connected by a component video cable) In other words, if your projector is set to 1080p, it will tend to assume the wide space... unless it is a VW60 and gives you a button with which to choose
I suspect that a couple of different Rec. 601 vs. Rec. 709 distinctions might be getting conflated here.
One is about the primary chromaticities, or the meaning of R, G, and B. Rec. 709/HD specifies a wider color gamut than has been used for Rec. 601/SD. This roughly corresponds to the Pearl's Wide vs. Normal "Color Space" control, at least in its function. According to gregr's review, the VW60's Normal setting works well for Rec. 601, although the Wide setting is a bit oversaturated for Rec. 709. But many people (not all, and I'm not trying to make a value assertion here
) consider this a relatively
subtle issue and don't bother adjusting primary chromaticities based on whether the source is SD/601 or HD/709.
The other distinction is about the coefficients used in the matrix transform to encode/decode RGB to/from YCbCr. Rec. 709 defined significantly different coefficients than were used for Rec. 601 (and many other previous standards). This is the higher-order distinction of concern when doing things like upscaling an SD source before feeding it to an HD display. If the source video is SD YCbCr, encoded with the 601 coefficients, then in addition to the geometric scaling it should be transformed to 709-encoded YCbCr for 1080i/p output because that is what the display will be expecting to decode for such an HD-resolution input. It is conceivable for a display to support manual configuration of whether a YCbCr input at any resolution is encoded with 601 or 709 coefficients, but that's not a common feature. I have a VW50 and it doesn't have such a control, and I'm pretty sure that gregr's review of the VW60 explicitly states that it doesn't have one either (along with a wish that more displays would support manual control of this behavior). So, if you're feeding the VW60 an HD-resolution YCbCr signal (1080i/p or even 720p), Rec. 709 encoding is assumed.
This leaves an interesting question which I'm hoping someone here will know the answer to. If an upscaling DVD player or HDDVD player plays an SD disc, does it, or does it not translate from the SD to the HD color space? My current observations would suggest not, in which case viewing SD material with Wide Colour enabled on the VW60 is a definite no-no.
It depends on the player, but I think that newer upscaling players are likely to do the right thing with respect to transforming the encoding for YCbCr output. I can say that my Oppo DV-970HD and my Toshiba HD-XA2 do the right thing for their YCbCr outputs with all combinations of output resolution and SD or (in the case of the XA2) HD source video.
Disclaimer: I am not a video professional, this is all just based on my personal understanding and experience.