Add APIchanges entry and bump libswscale micro version for making gray16 full-scale.
avcodec/mjpegdec: factorize parse_avid out

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpegdec: switch interlaced_polarity to 0 for PAL AVID

0 should have been the default, this change should make no difference
but this is needed for the following bugfix

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpeg: print info from parse_avid() if requested

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpegdec: parse avid data from extradata

Makes no difference for any file tested but is needed
for following bug-fix

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/mjpegdec: Switch default interlaced polarity for MJPG to 1

Fixes Ticket3229

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