> On Wed, 10 Dec 2003 [EMAIL PROTECTED] wrote:
>
> Well, it does use the -B switch to transcode (fast resize) not the -Z for
> regular resize. Would fast resizing result in halos/artifacts? In any case,
You bet it would. From the pointer to dvdrip you provided:
"Fast resizing is a special algorithm for resizing the frame which is much
faster than high quality resizing. The quality isn't that good,..."
What I wonder though is how they're doing the resizing - is it
clipping from 720 to 704 before doing a 2->1 downscale or is it
doing a 720->354 (wrong).
> accomodate this peak, wont mplex fail with frame underruns? The fact that
> mplex succeeds is proof that my -r is sufficient, isnt it?
It's working now? There was mention of overruns still happening.
> > Um..what is VBV? The buffer size? That is -B, right?
From mplex's usage:
--video-buffer|-b num [, num...]
Specifies decoder buffers size in kB. [ 20...2000]
No, -B is the non-video bitrate and is used with the encoder mpeg2enc.
> and a poorly authored disc might account for your bad experience!
That was part of it, but no, the video quality was not good. The
fellow didn't have the highest resolution/quality original material
and should have created the DVD at half "D1" to make the most of things
rather than zooming up the source to full size. The typical
packages don't offer that as an option.
> True. Forget VCD. If you have a DVD writer, do they really let you copy a
> commercial DVD to another, byte-for-byte without re-encoding?
No, I don't believe they do since consumer drives can't write certain
areas on the media where key information is stored. Also, sectors
on commercial DVDs aren't 2048 bytes - there's an extra 6 bytes per
sector for the CSS information and consumer recorders can't write that
information.
>I read somewhere that DVD-R blanks have a opaque ring right where the CSS
>code is written, just as a copy-protection measure? If thats so, making a
>identical copy of a DVD is impossible, right?
You might be able to if you spend the $3k for a "Authoring" drive
and use authoring media (so you can write the BCA = Burst Cutting
Area) but for a $20 DVD that's a bit overkill I'd say ;)
> What is defined as "clean material"?
From a miniDV, Digital8, or similar source or a DVD that was shot
using recent film or digital technology.
> Is anything on a commercial DVD clean material? Even if it is a 1960s movie?
You'll probably have noise from the original film and possibly from
degradation of the film before it was digitized. DVDs get around that
by using lots of bits of course ;) When recoding that material a
bit of denoising or other filtering can be beneficial.
> But a 1960s movie on DVD, with the same settings generated a 1500MB mpeg
> file! Is this because one source material is "noisier" than the other?
The original was noisy so the DVD was likely at a very high bitrate
to compensate. Recoding that means you'll have to either settle for
lower quality (by filtering for example) or use a higher bitrate
than you might prefer (might be a 2 VCD/SVCD set instead of 1).
Steven Schultz
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