lavfi/hue: force table initialization for the first frame
lavfi/hue: use av_clip_uint8() instead of av_clip_uint8_c()

The generic version should be faster if optimized.
lavfi/hue: show first decimal value of saturation
avformat/pva: Make sure the first byte of pes_header_data has been initialized

Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f53c1d0e95c_2674_PVA_test-partial.pva
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avformat/pva: Make sure the header is large enough before reading the timestamp from it

Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f34b5dc6d58_2674_PVA_test-partial.pva
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>