avfilter: add signalstats filter

Signed-off-by: Mark Heath <silicontrip@gmail.com>
Signed-off-by: Dave Rice <dave@dericed.com>
Signed-off-by: Clément Bœsch <u@pkh.me>
avfilter/showcqt: fix misc style issues
avfilter/showcqt: move qsort_sparsecoeff closer to where it belongs
doc/filters: add forgotten " to zoompan example

Signed-off-by: Lou Logan <lou@lrcd.com>
avcodec/motion_est: Only clip MVs which are used

Fixes valgrind mpeg4 failures

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec: increase FF_INPUT_BUFFER_PADDING_SIZE to 32

Sometimes the input buffers get directly used as raw images and
SIMD optimized video/image filters can sometimes read more than 16 bytes
over the end.
a specific example is the AVX 24bpp to yuv code

This also fixes fate-vsynth3-rgb

Reviewed-by: Christophe Gisquet <christophe.gisquet@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>