[MEncoder-users] Adding harddup as an afterthought?

[Rich Felker]

On Thu, Sep 27, 2007 at 05:42:28AM +0000, Ilya Zakharevich wrote:
> > In principle you could drop-in zero-change frames, but the presence of
> > B frames would make it a lot more complicated.
> 
> Why?  I do not know the precise details of ASP, but why would the
> following not work:
> 
>   a) if the preceding frame is I or P, drop in a zero-change frame;

I think the motion vectors in P frames might be predicted from the
vectors of the previous frame, in which case this would break
subsequent frames. But I'm not familiar with the details so I may be
wrong about this.

>   b) if the preceding frame is B, duplicate it?
> 
> (Of course, it could overload the maximal count of B-frames supported
> by the player; but I do not think the probability of this mattering is
> high...)

This would probably work decently, albeit wasting some space.

If you want to try this all, you're welcome to. But it would require
writing some tools to parse, deconstruct, and reconstruct AVI files.

Rich