[MPlayer-dev-eng] A few minor things about NUT

[Michael Niedermayer]

Hi

On Sat, Jan 28, 2006 at 02:04:40PM -0500, Rich Felker wrote:
> On Sat, Jan 28, 2006 at 05:50:21PM +0100, Michael Niedermayer wrote:
> > > > 1. (key)frame repeation
> > > > at least in some cases like info streams or subtitles the muxer might wish to
> > > > repeat frames
> > > > demuxers must know about repeated frames, and should know about repeated
> > > > keyframes
> > > > should we add a is_redundant flag to the flags in the frame code table? 
> > > > IMHO yes otherwise we wont know / be able to discard repeated keyframes during
> > > > remuxing
> > > 
> > > Sounds weird, if you see a frame with redundancy flag, how do you know if 
> > > you've seen it or not? you keep a cache of all pts's you've seen? redundant 
> > > frames can only repeat right after the frames they repeat? either way this 
> > > can be implemented without the flag...
> > 
> > ok, forget it 
> > pts difference == 0 <-> redundant
> 
> If we allow the old pts to be reused we need to make a special
> exception to muxing order and possibly complicate the seeking
> algorithm a lot (since it can't immediately tell that the frame is
> duplicate just from the pts, because it doesn't know the previous
> pts).
> 
> I would rather have a flag so that these frames can be totally ignored
> if desired, and then probably use new/current pts values for the
> repetitions.

ok, indeed, pts difference == 0 wont be possible, we need a flag ...


> 
> BTW I'd like to restrict this type of repetition to EOR-able streams,
> and restrict EOR to subtitle and info streams with decode_delay=0.
> Otherwise there's lots of unneeded complexity. If there's a legitimate
> need we could lift these restrictions in the future but I doubt there
> would be.

ok

[...]

-- 
Michael