[FFmpeg-user] Documentation and feature request

[Michael Koch]

>>> While some of your suggestions will not be accepted (for example
>>> to document for some filters that they can be concatenated),
>> Why not? atempo does it.
> I suspect nearly all filters can be concatenated and given that the
> documentation is already hard to read, I don't think it should be
> mentioned filter-wise.

I think in this special case (contrast enhancement with eq filter) it 
makes sense, because it's the only possible workaround for strong 
contrast enhancement by a factor >2. And it's running fast!
The "geq" filter has the problem that it has no limiter.
The "curves" filter has the problem that it introduces nonlinearities 
because it uses smooth curves.
Well, theoretically it could be done with the haldclut filter. But 
that's slow.
If you know any other solution for strong (>2) contrast enhancement, 
please let me know.

Michael