[MPlayer-dev-eng] [patch] DVD NAV work continues...

Arpi arpi at thot.banki.hu
Mon Apr 1 03:21:41 CEST 2002


Hi,

> > Several possible reasons
> > - interlaced mpeg calls vo->draw twice (will be fixed soon)
> 
> That could definitely be it! Memory throughput is the #1 performance
> issue on my machine it seems. Do you know when this change was made,
> so I can compare before and after to confirm that this is the problem?

dunno, as i have no such mpeg files. usually ntsc dvds have.
btw the change must be when moving from dec_video to libmpcodecs.
if it happened earlier, it wasn't me.

> > - runtime cpudetect enabled by default
> > - vfm=5 somewhere?
> > - gcc upgrade?
> > - kernel upgrade?
> 
> Nope.

what about -nosound ? or -ao null ?

> > Try to find teh date when it gots slower!
> 
> Yep, that's what I plan to do....when I get around to it... :)

just use binary search... half the time range and choose the half
when it is broken at the one end and is ok at the other end...

> Anyway, in the meantime I just ripped the DVD to mpeg4 with the new
> 2pass libavcodec code. It worked really well for the most part, except
> it tried to make a 10 gig file when I specified the bitrate on the
> command line with the second pass. Removing this fixed it, but the
> resulting file was somewhat smaller than it should have been with the
> requested bitrate from pass1....still looked great though! I'm going
> to try to figure out what's up with this strangeness...

basic rule of 2pass: do not change encoding parameters between pass 1 and
pass 2!!! including vme, bitrate etc.

it worked fine for me, but the file at 2nd pass was a few % smaller than
the bitrate would allow. i think it's known 'bug' of the 2pass code,
maybe added by reason to workaround divx4's inaccurate rate control.

> In any case, it's been a long time since I really used libavcodec for
> serious encoding. The progress is VERY impressive, and 2pass makes it
> even better! Congrats to you and to all the people working on ffmpeg!
It's only work of Michael.


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu



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