[MPlayer-dev-eng] [PATCH] More accurate af_volume

[Zoltan Hidvegi]

The attached patch improves the accuracy of af_volume for 16-bit
signed integer samples.  The previous version also had a bug, that
reduced the gain by -0.03dB (the multiplier was 255/256 times the
requested value).

I've also added printing the maximum volume for the integer case to
match the float case.  Also, the float filter did not print the max
volume if you did not use -af-adv force=4.

And as far as I can tell, af_volume is really reentrant, so I've
removed the AF_FLAGS_NOT_REENTRANT flag.  Anyone knows whay that was
there originally?

Zoli