From: Brook Hinton (email suppressed)
Date: Sun Dec 05 2010 - 16:13:02 PST
On Sun, Dec 5, 2010 at 3:18 PM, David Tetzlaff <email suppressed> wrote:
> I'm not talking about Blu-Ray.
> I have no idea what you mean by "NOT blu-ray quality, though it is a BD
> spec." There is no fixed 'Blu-Ray quality'. Blu-Ray discs can be authored
> with different resolutions (e.g. 720P or 1080P), different bit-rates, even
> different codecs (MPEG-2). Within any specific set of these parameters,
> different technologies used to achieve them will yield different results.
> 'Bandwidth' (by which I assume you mean bit-rate) is only indicative of
> quality if all other things are constant, which they aren't, and besides,
> there's a point of diminishing returns and the maximum rates are defined to
> provide cushion for the future and so are impractically high. E.g. if you
> set your DVD to encode at the maximum bit-rate available within the DVD
> spec, it will almost certainly skip in any common player. If you check the
> presets in Compressor or iDVD or any other software package that generally
> produces acceptable results, you'll see they're quite conservative.
David you are preaching to the choir here, and in a condescending tone to
boot. OF COURSE all other things aren't equal. I work with this stuff on a
daily basis and until recently it was how I paid the rent. Anyway,
everything you say in that paragraph is true except that in my experience
reliable playback across devices of HD on a DVD-R means using a bitrate well
below the 18mb/s Aaron helpfully looked up as the supposed max for this
workflow. On 1080p material with significant motion and detail it's not
great, but again, the artifacting isn't as bad as it is on SD DVDs.
Actually the Compressor DVD presets aren't quite conservative enough in my
book, but they're close. Nothing - even increased quality - is worth the
risk of the comically common "gallery freeze'" or skpping you see on those
8mb/s dvd loops in the cubes.
> If you put a limited amount of HD on a DVD-5, and it looks noticeably worse
> than a commercial Blu-Ray, that is due either to the fact that the
> commercial disk started with a better quality source, or you made the DVD-5
> the wrong way. For example, you can create a Blu-Ray on DVD-5 disc from
> pretty much any HD Quicktime file in Toast, but it is likely to have lots of
> artifacts. This is a product of the method Toast employs, not the limits of
> the Blu-Ray format, or the max data rates of recordable DVD5s.
It is also a function of the encoder you use, the encoding method, the care
taken with prepping the source, in some cases the reduced bitrate mentioned
above, and a host of other factors, but that's the same for any of these
> Uh, I said it makes no sense to trash DVD sui generis for problems created
> by bad encoding, bad media, bad burning and bad players. If you are going to
> screen 16mm prints, you need to know whether your projector is working
> properly or not. If you are going to screen DVD+/-R discs, you need to know
> if your player can handle properly prepared discs. But, again, here is
> something people don't know. If they have some device that plays commercial
> DVDs, they figure they should be able to pop any old disc they get sent in
> there and have it play. It doesn't work that way.
People will always do this with that type of media. I believe it is wishful
thinking to hope such habits will dissipate with education.
Also the ratio of good to bad 16mm projectors is significantly higher than
the ratio of good to bad disposable plastic dvd and blu ray players. That's
not counting professional equipment though, which is out of range for many
of the folks we're talking about.
16mm can also often be serviced in-house in many cases.
> In acknowledging that HD video can be written to standard DVD blanks, you
> added the caveat, "assuming a dead-compatible player". Well, why would any
> screening venue have anything BUT a "dead-compatible player"?
Because it happens. Because people don't think things through. Because they
got a player from ebay that worked with two discs and then realized the
night of the program that three pieces would not play on it, and money and
time were so tight they couldn't do anything about. Because few venues that
show experimental work can afford professional decks. Because many are
begging and borrowing whatever they can to get the show running.
All that said, I applaud your efforts to do something about this, and I do
think you are on the right track.
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-- ____________________________ Brook Hinton Moving Image and Sound Maker www.brookhinton.com Associate Professor / Assistant Chair Film Program at CCA California College of the Arts www.cca.edu/film
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