[MPlayer-dev-eng] MPCF: Features and Goals

[D Richard Felker III]

On Fri, Feb 14, 2003 at 06:01:07PM +0000, Martin Collins wrote:
> On Fri, 14 Feb 2003 11:21:40 -0500
> D Richard Felker III <dalias at aerifal.cx> wrote:
> 
> > > Will mpcf files be readable before writing is complete?
> > 
> > Of course. Actually pretty much all formats are if the player
> > doesn't suck; most players just suck. MPlayer plays incomplete files
> > just fine.
> 
> Hmm. There was some discussion on mjpegtools about this recently as it
> was regarded as a common problem. Certainly, mplayer will not play the
> AVI output of lavrec correctly until lavrec is finished (and sometimes
> not even then). Maybe it's a lavrec problem. Still, if mpcf will
> do it that's great.

It probably stupidly omits writing essential headers until the file is
finished. Either that, or else mplayer's demuxer for it is broken.

> > I don't see any difference, but the second is the main goal. Or if
> > we want to be politically correct, its purpose is mainly for
> > "archival" of your movies. :))
> 
> OK, but surely for archival purposes you want all the DVD-style
> gimmicks that some people here have been decrying and criticizing
> Matroska for including?

No. That's useless junk. No one sane would reduce video bitrate to fit
some idiotic menu crap on the cd. (Well, maybe the idiot 'release
group' kids who put their watermarks and logos and intro screens on
movies would, but I have no interest in satisfying them.)

> > You're pretty much off-base, but I don't see how there's a
> > significant difference in requirements for the two.
> 
> Maybe one format can satisfy the demands of both uses, I don't know,
> it just seemed to me that the potential dichotomy had not been
> explicitly recognised in the discussions so far.

That's because it's irrelevant.

> > Anyway,
> > creation/manipulation doesn't really need a nice format; you're
> > going to be storing raw pcm audio and raw yuv frames anyway if you
> > want to be able to edit without losing quality...
> 
> Right, I use mjpeg rather than yuv. But there isn't AFAIK a simple
> format for such purposes that doesn't have at least one major

Umm, raw yuv stream (w*h*2 bytes per frame) and raw pcm audio file
(samplerate*4 bytes per second). No need for any headers or 'file
format', and seeking is trivial. MJPEG is bad -- it will lose lots of
quality. But if you really insist on using mjpeg or something, there's
no reason mpcf won't meet your needs entirely for editing.

> drawback. It would be a shame if mpcf ends up a half-way house that
> doesn't fully statisfy either camp.

It definitely won't. Why don't you actually READ something before
making such silly statements?

Rich