[MPlayer-users] Re: Joseph's Fun of Ripping Laser Discs (Fun?)

[Joseph N. Hall]

Rich,

Ah, cool, thanks.

What is it about crop that is weird? I have noticed that trying
to combine crop and expand doesn't seem to work the way I expected.
I was trying to add a black border by cropping and then expanding,
and it basically seemed to have no effect.  Or is this another issue
with crop altogether?

Mencoder isn't particularly intuitive (not to bite the hand that
feeds me) but in the absence of information to the contrary, one
would think that postprocessing a cropped (smaller) image would
make more sense.  Does pp work only at the beginning of the filter
chain?  Uh, why?

About -mc: I don't recall where I read that. I was having trouble
with audio sync at one point when combined with detc.  There were
some things that were mysterious to me, like, I would transcode
a few minutes of video with mencoder (at that time, going from
huffyuv to lavc mpeg4) and at the end of encoding, mencoder would
report xxx.xx seconds of video and yyy.yy seconds of audio, where
yyy.yy was generally about .5 seconds > xxx.xx. But the A-V sync
wasn't off any anything like that much.  My current approach, using 
huffyuv out and doing my transcoding back to MPEG2 in avidemux,
is producing either drift-free A-V or very nearly so.  It's 
tight after 60 minutes at least.  Anyway, I don't recall where I
read about -mc but I do recall that users, in 2003 (I tend to
ignore mencoder postings from pre 2003 now), had reported that some
sync problems went away when -mc was set to a non-zero value.

I had no idea about any huffyuv thing in 0.9 at all, because
-vcodec=huffyuv -> core dump, until for some reason I had the
inspiration to try it with 422P.  Maybe it should be called 
"422P-no-core-dump." :-p

Thanks!

  -joseph

---

A few comments...

You're doing postprocessing after crop, which won't work. Instead put
pp=hb:128:80/vb/dr first in the filter chain.

About your comment: "The -mc option is reputed to improve (or perhaps
enable) audio sync correction with the detc filter." This may very
well be true, but I'm curious where you heard it.

About huffyuv: You can force mencoder to write (non-compliant) 4:2:0
huffyuv files by using the vstrict=-1 option to -lavcopts.

Rich

On Tue, 30 Sep 2003 21:08:00 -0700, Joseph N. Hall <joseph at 5sigma.com> wrote:
> The details of mencoder are still mostly mysteries to me.  Comments
> and recommendations on how to do these things in better ways would
> be much appreciated.  Or maybe just comments that tell me what the
> heck I am really doing.
> 
> http://www.5sigma.com/joseph/video/laser_fun.html
> 
>   -joseph
>