Z
On Tue, 9 Dec 2003 [EMAIL PROTECTED] wrote:
> I am using the dvd::rip 4:3 NTSC preset on the 'Clip & Zoom' tab, which,
> I guess maps to the standard NTSC framesize of 352x240?
Ok - sounds like it is doing the right thing.
> So you are saying that -K kvcd and -N 1.0 actually work against each other.
No, rather they are each doing the same thing and as the old
saying goes "Too much of a good thing is not good".
> Use one or the other?
Unless you know what you're doing of course ;)
-N at one time was the only way to modify the quantizers' high
frequency entries. Later (moderately recently) additonal quantizer
tables were added and those contain precomputed HF de-emphasis
builtin. It is possible to further modify the tables by specifying
-N but that falls into the "don't try this at home" or "unless you
know what you're doing" classes.
> Not sure what dvd::rip calls to scale the data. I think it uses some transcode
> switches, which in turn, of course, call mpeg2enc with the appropriate switches
Lots of long lines... Possible to set the margins to something
closer to 80 characters or so? ;)
Hmmm, I don't know what scaling algorithms it uses either - or if
they allow you to specify/tailor the scaling behaviour.
That's why I avoid the all-in-one programs. I'd rather figure out
what needs to be done and write the necessary shell script to tie
it all together.
> Right, dvd::rip does all this already. I see -r 2298 in the logfile with the -V
> (vbr) parameter.
That's just an estimate (often close but not 100% accurate) - might
need to be a little higher. Might need to be 2500 to account for
one peak in the middle - or you might need to increase the VBV size
with "-b" (default for VCD is 46 but with an XVCD that can have
higher peak rates you might want to try "-r 220" to mplex).
> Is the -N 1.0 not required with -K tmpgenc also?
See the commentary earlier ;) Basically yes, unless you have reason
to further adjust the matrices, leave out the -N.
Using '-K file=yourfile' you can create custom tables to use - I've
had good results (posted here I believe) from using the Intra
'hi-resolution' entries with the TMPGEnc nonIntra values.
> And then I walk into Best Buy (an electronics superstore here in the US),
> and see all these one-click copy-DVD/VCD/SVCD packages on the shelf which
> claim to make flawless copies of digital (or even analog!) material with ...
> Needless to say, all these are Windows-based packages. ...
Look who they're being marketed to ;) Flawless? Advertising hype.
Couple weeks ago I was "treated" to the experience of a DVD produced
by someone who used one of those type of packages. Not something
I want to do again any time soon...
> So what gives?
"Good enough for Joe Casual User". I don't think many of those
create an outofspec XVCD going for absolute maximum play time by
allowing *you* to choose the tradeoff point between quality and
playtime.
Apple's iMovie/iDVD for example just tosses lots of bits at a DVD
and well, yeah - with 7500+ kbits/sec just about anything will look
good ;)
> > If you're using the cvs version of mpeg2enc you can also try adding
> > "-E -10" to the options - for clean source (such as from a DVD)
>
> Ok, will try -E -10 -q 7
The other thing that can be tried, although with clean material the
effect will probably be minor, is "-R 0" or "-R 1" to turn off or
use only 1 B frame.
Interestingly enough I have finally found a software player (allthe
hardware players I've tried have no problem) that doesn't like
movies without B frames. Seems Apple's Quicktime player (with the
MPEG-2 module) is allergic to movies without at least 1 B frame between
the P frames. Haven't tried the DVD Player application to see if
it will handle a DVD with no B frames - should, but who knows?
Cheers,
Steven Schultz
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