Log Message:
Changes 2.3.3:
avcodec/h264_mb: fix grayscale only decoding with weighted prediction
avformat/mpegts: Use differential score for analyze()
avcodec/mjpegdec: Support AV_PIX_FMT_YUV420P16 with upscale_h
proresenc_kostya: properly account for alpha
avformat/matroskadec: Check avpriv_new_chapter() for failure
proresenc_kostya: report buffer overflow
proresenc_kostya: remove unneeded parameters