Hi -
On Wed, 12 Nov 2003, John Ribera wrote:
> Did I just hear elimination of B frames:
Not exactly ;)
They are optional now though so you can choose if you want/need
them or not.
> 1) lowers bitrate, ie file size
In some cases - mostly with noisy sources. Good clean (D8, DV)
input will not benefit as much (might even grow a few percent).
> 2) improves output
It's supposed to improve output in the high motion scenes, true.
> 3) faster encoding (ok so i'm reaching)
Not at all. B frames are much more cpu intensive than I or P
frames to compute - not generating B frames brings a fairly
substantial boost in encoding speed.
> so, basically, unless you're editing, B frames are a 3 strike out, IMO.
Two strikes - the B frames have a place and perhaps just using 1
of them ("-R 1") would be a Good Thing in some cases.
There's no hard rules for "always use feature XXX" or "never use
feature YYYY". Encoding is very sensitive to the source of the
data as well as the other parameters being used - it could well
be that using the high resolution quantizing matrices with the
"-E -10" option will work better using 1 B frame than leaving out
the B frames completely.
Encoding the data multiple times to try out various combinations is
a time consuming but necessary job in some cases. Obviously for
casual viewing (and discarding of the movie after viewing) it's not
important to select the "best" parameters. When making DVDs for
archival or viewing by a wider audience then it can be worth the
time to do several trial encodings and select the best looking one.
Cheers,
Steven Schultz
-------------------------------------------------------
This SF.Net email sponsored by: ApacheCon 2003,
16-19 November in Las Vegas. Learn firsthand the latest
developments in Apache, PHP, Perl, XML, Java, MySQL,
WebDAV, and more! http://www.apachecon.com/
_______________________________________________
Mjpeg-users mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/mjpeg-users
