[MPlayer-users] Re: lavc-Options for *BEST* quality?

[D Richard Felker III]

On Fri, Feb 14, 2003 at 11:05:06AM +0100, Ketil Z. Malde wrote:
> >>> codec specific header packet
> >>>   64bit startcode
> >>>   codec specific data
> 
> >> What's this for? [snip]
> 
> > Huh? I don't understand your question at all.
> 
> I'm just curious what kind of data would be retained.

Many codecs -- mostly stupid windows crap, but also vorbis audio and
perhaps mjpeg in some cases -- need extra data to intialize the codec.
This data would be stored here. Think codebooks, huffman tables, extra
parameters similar to width/height/depth, etc.

> >>> per frame header packet
> 
> >> Do you by 'frame' mean what I think you mean?
> 
> > Depends on what you think he means.
> 
> One image in a movie, e.g. 1/25th of a seconds worth, or similar.
> Having a separate packet per frame sounds like a lot of overhead.

Not at all. The overhead is very minimal. Less than 0.5%, IIRC.

> > Have you failed to read any of the past discussion whatsoever? This
> > has already been covered many many times. The story goes like this.
> 
> Guilty, I suppose. I can't keep up with all the posts on
> mplayer-users, so I only read it sporadically.  And I haven't use file
> sharing, so I've naturally not encountered this problem.  Okay, so I
> should probably have stayed out of the discussion. :-)

Since this is a *development* issue, most of the discussion has been
on mplayer-dev-eng. If you're interested in following the design of
the container format, I suggest you read what's been said there.

Rich