stats file recycling

[check]

I do a reasonable amount of messing with parameters to see what does what with x264, and I was wondering if it was possible to reuse a stats file from a single first pass for a number of second passes. I'm guessing changing most of the options in x264 is ok, because 'turbo' generated stats files are done with totally different options to the second pass, but what about:
changing the bitrate. Obviously the difference would be minimal for changes of a few kilobits/sec, but what about from 1000kbits -> 250kbits?
changing AVS filters. If i added something that does the same operation to each frame (blur(0.3) or something) would that be ok?

Any opinions would be appreciated :)

[quake74]

I asked a related question a while ago but shark shot me down.
http://forum.doom9.org/showthread.php?p=832712#post832712

[unmei]

For the bitrate difference, if it is large enough a macroblock that was before for example as P may be more efficient to encode as B when the target compression/bitsize differs considerably. Also the nonlinear scale of quantizers probably causes further deviation from optimal allocation when your stats bitrate is very different from your 2nd-pass bitrate.

Wouldn't the AVS filter have to introduce a constant change in "compressability" over all frames in order to have minimal effect on the usefulness of the stats file? If so, that is probably close to impossible to achieve - even a noise reductor or blur will not vary compressability linearly on a perfectly flat surface (hopefully not at all instead ;).

In both cases I'd rather use one-pass encodes (QC or even CRF) to compare.

[check]

Thanks for the info unmei, I didn't think I could keep my script file from one AVS file to a totally different one, but I was hoping to be proved wrong >_>