From: David Tetzlaff (email suppressed)
Date: Mon Dec 06 2010 - 06:41:08 PST
Brook notes that some source material will stress any compression system more than others. And Pip holds DVD to be an inappropriate form for experimental work because of intraframe compression problems — problems that do not show up on typical narrative or doc stuff.
So my question is: are there any short works in distribution, for SD and HD, that would serve as an acid test of any display method? Since the test piece would have to be available, that would mean it would have to already be in some optical disc form, but of course some are better than others. The idea would be to start from some technically challenging piece with the best available encoding, rip from the disc into ProRes 422 as a baseline, and then recompress using different schemes and compare artifacting and other possible problems.
So does anyone have a suggestion for something that would be useful for this? Especially if you can note specific points in the footage where problems would show themselves. Are there specific pieces on the By Brakhage releases, for example, that would work?
Although I'm looking for both SD and HD, given the discussion the HD is more important. So I guess I'm mainly looking for some source material that has been transferred to Blu-Ray with great care and success, but would likely show problems if, you know, you or I had encoded it with the tools we have available.
Of course, if someone has original work that poses a proper technical challenge, and is willing to share a tricky segment of same (a minute or so?) in the form of a ProRes file, that would be fab.
(To share my own choices for practical tests on another issue: There are two DVDs I use to check the contrast range of projectors, and problems with monochrome reproduction and color-wheel moires: In the original Texas Chainsaw Massacre, when the first young man enters the house, looks around, and gets surprised by Leatherface who whacks him in the head, there actually is some shadow detail you can see on a good monitor, and how badly it all goes to mud on a projector is a fair test of the contrast range, generally confirming that DLP has it way over LCD. The first few minutes of the Following DVD (Christopher Nolan) have the kind of contrasty edits that spike the moires, especially in the close-ups of the objects in the box. Since it's B&W it will also reveal any of the uneven tinting that tends to plague monochrome on LCDs. Parts of Puce Moment kick up the moires pretty well, too).
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