avfilter/vidstabtransform: update optzoom range values for recent vid.stab update.

Signed-off-by: Georg Martius <martius@mis.mpg.de>
avformat/mxfdec: check sample size more completely

Fixes division by zero
Fixes Ticket2992

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mlpdec: Fail if the input is too small

This fixes a infinite loop
Fixes Ticket2986

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