proresenc_kostya: properly account for alpha

The packet buffer allocation considered as dct-coded, while it is
actually run-coded and thus requires a larger buffer.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/lcldec: initialize encoded correctly

Fixes out of array read
Fixes: yuv111_no_compr_crash.avi

Found-by: Piotr Bandurski <ami_stuff@o2.pl>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>