n4.3.9
fate: add adpcm_ima_ssi encoding test
fate: update reference files after the recent dash manifest muxer changes
avformat/matroskaenc: Don't ignore tags of chapters written late
Merge commit '896fe15dbb7b78de495c4a7dd75e7faec66778da'
avcodec/snowenc: Fix visual weight calculation
Merge commit 'f919cc7df6ab844bc12f89fe7bef4fb915a47725'
tests: Rename vsynth2 to vsynth_lena