[MEncoder-users] capture: synchronization problems

[Kyle Schmitt]

--- RC <rcooley at spamcop.net> wrote:
> On Sat, 19 Mar 2005 20:52:55 +0100
> newsgrabber at poczta.onet.pl wrote:
> > I think mjpeg gives a pretty good material for
> further encoding into DVD or 
> > CVCD. Or do you know something better? 
> I don't know why you would use MJPEG.  Why not just
> capture with MPEG-2 with a rather high bitrate?

  The mpeg4 codecs of all descriptions have had a ton
of work put into optimizing them for speed.  Mpeg2
hasn't.  Mjpeg stores each frame separately so it
might not be computationally as intense, but it chokes
your disc bandwidth (so you get dropped frames and out
of sync and all sorts of nastiness).

  Go ahead and look at the fps your able to encode
vcodec=mpeg4 vs vcodec=mjpeg or vcodec=mpeg2video. 
Don't turn on 101 quality optimizations like vhq and
qpel and all that, just capture at plain
vcodec=mepg4:vbitrate=4096.

  On every box I've ever used for tv capture (Pentium
II 233, Pentium II 400, Athlon 700, Athlon 1800XP)
mpeg4/divx encoding provided the best and most
consistant framerates if I was capturing to a normal
drive.  When capturing to a striped raid array its a
different story, but even then I don't know if the
added visual acuity of mjpeg vs mpeg4 is worth it for
the pain of setting it up(or if there will even BE a
visible difference when capturing from broadcast tv)

--Kyle
  


		
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