avcodec/vmdav: use av_freep() and reset unpack_buffer_size

Signed-off-by: Paul B Mahol <onemda@gmail.com>
avcodec/mimic: use av_freep() and reset swap_buf_size

Signed-off-by: Paul B Mahol <onemda@gmail.com>
tools/probetest: use named constant for the maximum number of formats

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
tools/probetest: also print the time the probe functions needed

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/mxfdec: optimize probing

about 71 times faster

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