jpeg2000: Fix unintended sign extension in malloc arguments of prec

Fixes: CID1026772/3
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
jpeg2000dec: assert that curtileno is valid when used

Fixes CID1026755
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
tiff: fix memleak

Fixes CID1026764
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avfilter/af_astats: rename stat()

See CID1026741
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>