[MPlayer-dev-eng] NUT (informal) proposal, based on discussions

[Oded Shimon]

On Wed, Jan 18, 2006 at 07:47:43PM +0100, Michael Niedermayer wrote:
> On Wed, Jan 18, 2006 at 07:41:40PM +0200, Oded Shimon wrote:
> > writing a syncpoint will still point to last_target. Or did I completely 
> > miss something. (Also don't forget, for your back_ptr method we need to 
> > buffer several keyframes, not just the last one.)
> 
> hmm, my idea was to use the last keyframes (no buffering) and use their
> max pts as timetsamp, this seems pretty easy but maybe iam missing some
> issues associated with it?

Oh, I missed that - you never pointed that out.

> it wont give you the optimal keyframe in a single seek but there is no
> way that could be possible with a single pts anyway you would always end
> up with a syncpoint per keyframe and O(n^2*log n) overhead if there are many
> streams

Yes we gave up single seek with syncpoints, we still want single seek with 
index and that's a whole other and very easy story.

Now that you change the idea so you just use max pts of last keyframes for 
syncpoint ts instead of the dts mess it was before, yes, implementation is 
MUCH easier, no buffering, however...

A1  A2  A3  A4  A5  ...
  I5  B3  B4  P6  ...

All syncpoints between I5 and A5 will have pts 5. When seeking to 4, 
you'll end up at A2, and will have to linear search all the way till A4. 
This linear search is bounded by O(max_b_frames+decode_delay), which is 
quite worse than O(max_distance). :/

- ods15