#12 support analysis pass with no output

[Anonymous]

Some filter/encoder need more than one passes. The current release always generate a output file which is not needed in the first pass, this waste CPU time and disk space unnecessarily.

Some examples are the deshaker filter and 2 pass divx encoder.

VirtualDub has a function RunNullVideoPass() which could be called in the first pass instead of SaveAVI().

I have changed ??? and it seem to work fine. I just make the assumption that if the output is called 'null.avi' I will call RunNullVideoPass() instead of SaveAVI().

I have attached the code here. A better way will be to have a option to specify we are only doing first pass in the UI.

yujia.huang@xtra.co.nz

[Nobody/Anonymous]