On 26 Nov 2003, Florin Andrei wrote:
> > High motion videos might benefit from '-g' being decreased - in fact
> > you could set that to 1 (if you're using the cvs version of mpeg2enc
>
> Issues with set-top-boxes in that case?
None. Smaller GOP sizes just increase the filesize but allow the
encoder to handle scene changes better. Set -g to 1 for maximum
flexibility.
I have a fairly complete set of test results showing the effect
of '-g 1 -G N' where N was varied from 1 to 15. The effect of
longer GOP sizes starts dropping a lot at around 10 or so.
> > I use -4 2 -2 1. Dropping -4 from 2 to 1 increases the encoding
> > time by a lot (30 - 40%) for a nominal (couple percent at best)
>
> ...and no visible quality gain, right?
I suppose if you have golden eyeballs you might see (or imagine you
see) a difference ;)
> > -10 is a good non-aggressive/mild setting (i've seen good results
> > with -5 to -8).
>
> What's the default? (the equivalent if i don't use -E at all)
0. Meaning no effect - the single coefficient logic is not invoked
at all.
> > 9800 is too high. Some standalone players can not handle the maximum.
> > For portability you'll really want to back off to something like 8500.
>
> But most of the professional DVDs i've seen are at or around 9800 kb/s
Not really. Or rather how are you determining that? By taking
the .m2v streamsize in bytes and dividing by the playing time? If
you do that you'll find it's a rare DVD that goes over 7500. I've
a couple very high quality DVDs (they used a dual layer disc for a
140 minute concert) that averaged around 6000-6500 (but they did
include 3 audio tracks - PCM, AC3 5.1, and DTS).
It's necessary to leave room for peaks or spikes in the bitrate -
exceeding the legal limit even briefly will cause playback problems
Cheers,
Steven Schultz
-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
Does SourceForge.net help you be more productive? Does it
help you create better code? SHARE THE LOVE, and help us help
YOU! Click Here: http://sourceforge.net/donate/
_______________________________________________
Mjpeg-users mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/mjpeg-users
