Changes in 4.2

• tpad filter
• AV1 decoding support through libdav1d
• dedot filter
• chromashift and rgbashift filters
• freezedetect filter
• truehd_core bitstream filter
• dhav demuxer
• PCM-DVD encoder
• GIF parser
• vividas demuxer
• hymt decoder
• anlmdn filter
• maskfun filter
• hcom demuxer and decoder
• ARBC decoder
• libaribb24 based ARIB STD-B24 caption support (profiles A and C)
• Support decoding of HEVC 4:4:4 content in nvdec and cuviddec
• removed libndi-newtek
• agm decoder
• KUX demuxer
• AV1 frame split bitstream filter
• lscr decoder
• lagfun filter
• asoftclip filter
• Support decoding of HEVC 4:4:4 content in vdpau
• colorhold filter
• xmedian filter
• asr filter
• showspatial multimedia filter
• VP4 video decoder
• IFV demuxer
• derain filter
• deesser filter
• mov muxer writes tracks with unspecified language instead of English by default
• add support for using clang to compile CUDA kernels