[NUT-devel] a few things about nut.txt

Michael Niedermayer michaelni at gmx.at
Sun Nov 26 21:35:17 CET 2006


Hi

On Sun, Nov 26, 2006 at 01:57:54PM -0500, Rich Felker wrote:
[...]
> > > well! It also means seeking will be _incorrect_, in the sense that if
> > > you disable video and just enable audio and subs, seeks will go
> > > farther back than they need to in order to find the _useless_ blank
> > > subtitle.
> > 
> > which will cause a few milliseconds of useless computations after a seek
> 
> Depends on the behavior of the player, but hopefully yes.
> 
> More fundamentally, the principle of "correct seeking" is violated,
> and if we're going to violate that we might as well not have put so
> much effort into ensuring that it works to begin with. You never cared
> much about it but I did...

yes
btw, last time i checked 50% of the code in libnuts demuxer is for seeking
and its O(n) or more precissely it will in some not unreasonable scenarios
(watch middle to end of movie then watch begin) have to move O(n) data
around for every demuxed frame, in the cache used for seeking ...

so IMHO optimal seeking is pretty hard and considering the amount of code
needed for it i think its not worth it, but its of course nice if its
possible ...


[...]

> > it means IMHO the thing is too complex already or the
> > case which needs it is pretty obscure or the reasoning hasnt been 
> > documented, in which case disscussing the issue and documenting the reasoning
> > seems like a good idea ...
> 
> OK if someone can come up with a list of requirements/features/etc. in
> NUT that seem unjustified, I will write up detailed documentation on
> what they're needed for. Maybe I'll be wrong and it will be easy to
> understand once I've written this...

ok, the following is a list of things which i think might look unjustified
to at least some people (some people actually asked on nut devel about some
of these) ...

* the dts-pts ordering rule vs. strict dts ordering vs. one of the previous
  with a max latency in a stream header vs. unrestricted ordering
* EOR
* no info packet compression vs. deflate vs. a fixed table of strings vs.
  a table in the first info packet or main header
* codec_id/fourcc stuff
* single global header vs. several
* lack of timestamp discontinuities
* crcs on frame headers, other headers and length values but not frames

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In the past you could go to a library and read, borrow or copy any book
Today you'd get arrested for mere telling someone where the library is



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