The previous commit concluded the shrub body's 6-byte payload was
VIF-packed, on the strength of recurring patterns like 7ea5 and 1ab6. That
was pattern matching dressed up as a conclusion, and a control kills it.
Decoding every 32-bit word of every shrub body as a VifCode:
shrub bodies 24.9% unpack, 128 distinct cmds
uniform random 25.1% unpack, 128 distinct cmds
sound_bank (definitely not VIF) 19.0% unpack, 122 distinct cmds
gs_ram (mixed) 13.6% unpack, 128 distinct cmds
moby class 0 span (known VIF) 40.1% unpack, 105 distinct cmds
Shrub sits on the random baseline and exercises all 128 possible command
bytes, which is what unstructured data looks like.
Worth being precise about what this does and does not show. The test is
weak -- even the known-VIF region only reaches 40.1%, well short of a
clean signal -- so this does not prove shrub is not VIF. It proves the
claim was never established, which is the part that was wrong.
Spotting three recurring byte values and naming them a format is the same
mistake as the three stride guesses it was meant to replace, one level
down. A hypothesis needs a discriminating test before it goes in a commit
message, and I skipped that step because the finding was welcome.
What still stands is the part that rests on differential analysis rather
than recognition: 8-byte records, 6 varying and 2 constant, 144 varying
bytes per group regardless of count. The payload's encoding is unknown.
ReaperOfVeriod
52228c14ed