[Kdenlive-devel] more merges

[Rolf Dubitzky]

On Thursday 18 September 2003 11:28, jasonwood at blueyonder.co.uk wrote:
> Unless you have fixed some of the leaks since my last post, the level of
> memory leakage in Piave is too severe - it is not a steady trickle that
> would make the computer thrash after a couple of hours, it can use up all
> of the computers memory within minutes.
>
> I guess that holding back until the situation is not quite so bad would be
> a good idea :-)

;-) Ok, I actually havent spend any time on this, since I am usually satisfied 
with _any_ image these days ;-)

> I will try and run valgrind on piave as well, and see where it says the
> memory is leaking from. I am guessing that there are only one or two
> issues, and they just happen to be where large amounts of memory get
> allocated :-)

I'll look into it too. In case you actually look into piave, here some advice 
to guide you. There are three major areas where memory gets alocated:

- the render tree. 
   - destruction of the tree is probably in BAD BAD shape, but has oresumably 
     a small memory footprint. Still, it may become a problem with many 
     scenelists beeing sent. Fixing this is probably straight forward

- the property nodes (the XML gets translated into this private format)
   - ownership policy of the property nodes is still under change and thus 
     most likely broken, I guess that with many scenelists beeing sent, this
     might cause problems. Fixing this needs a decent ownership policy.
   
- the video/audio frame buffers.
   - This is handled by the BufferPool class wich handles reference counted 
     frame buffers. Determination of when to drop references is not automatic 
     and thus target to errors, e.g. the 'CopyAOp' binary video operation 
     should drop the reference of the video buffer in src_b, but it doesn't,
     which is a bug that can lead to huge memory leaks. However, if there are 
     no parallel video streams, this operation is not used.

This is probably my chance to really use valgrind for the first time ;-). Up 
to now I only used GreatCircle.

Cheers, Rolf

-- 
contacts: www.physi.uni-heidelberg.de/~dubitzky