[MPlayer-advusers] [BUG] mencoder floating point exception with -of lavf

[Corey Hickey]

> this patch implements buffering, but I don't really like it (yet another
workaround
> rather than a real solution).
> Please, test and report if it works.

Thanks for the patch; I can't test it right now, but I will tomorrow.

> I don't understand why on earth mencoder should initialize the muxer
before
> having the single elementary streams configured :(

I've been working on a patch to make mencoder do the buffering independently
of the individual muxers. It's been a rough road so far, but I'm getting
close to having something that works and I've learned a lot on the way.

I'm working on just getting it to work with mplayer's avi muxer, but after
that I'll work on the mpeg and lavf muxers (ideally they'll just work, but
I'm more realistic than that).

Right now, with my patch, mencoder runs without complaint and mplayer plays
the file just fine. "cmp -l" reports about a dozen bytes different, though,
so I still have a few things to iron out.

> (even creating the container without knowing what will go into it is
conceptually
> wrong, IMHO).

Oddly enough, mplayer's avi muxer writes the header three times:
- first without knowing anything about the video
- second once it knows about the video stream
- third when it's completely done and it can write the number of video frames

My buffering layer can make the first header-writing unneccessary, but can't
help the third. I can't think of any way to avoid it.

> I hope someone will implement preinit_video(), but in the meantime I can
temporarily commit this patch.

What specifically would preinit_video() do? Would it be better than the
approach I'm taking? I've just been trying to figure it out as I go, and I
don't have any experience at all with what I'm trying to do.

I've attached a patch of my current progress.

Nico, thanks for fowarding your mail to me. What's wrong with
mplayer-advusers? I can't see a problem from here, but I'll CC you anyway.

-Corey
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: muxer-buffer-try2.diff
URL: <http://lists.mplayerhq.hu/pipermail/mplayer-advusers/attachments/20051108/8db3e5a7/attachment.asc>