Claude
d3f77d1d96
Decoded the structural framing of the Blastware waveform body — the bytes between the 21-byte STRT record and the 26-byte file footer. The body is a sequence of tagged variable-length blocks, NOT raw int16 LE. Five tag types (10/20/00/30/40 NN) and their lengths are now confirmed against the 4-event May 2026 fixture bundle. Body splits cleanly into ~16 segments (for a 1280-sample event) separated by 40 02 segment headers carrying a monotonically incrementing uint32 LE counter at bytes [8:12]. What's done: - minimateplus/waveform_codec.py — block walker, segment splitter, segment header parser. decode_waveform_v2 is a stub returning None until the byte-to-sample mapping is solved; client.py is unchanged. - tests/test_waveform_codec.py — 31 tests covering block detection, lengths, contiguous-walk, segment splitting, segment-header parsing, and counter monotonicity. All pass. - tests/fixtures/decode-re-5-8-26/ — bundled fixtures (4 events, BW binary + Blastware ASCII export each). - docs/instantel_protocol_reference.md §7.6.1 — replaced retraction box with the verified structural decoding plus an explicit list of what's still open. What's still open: the per-byte mapping inside 10 NN / 20 NN blocks. 96 channel-permutation × nibble-order × sign-convention combinations were brute-force tested; none match BW's ASCII export to within ±1 ADC count. The codec is more elaborate than uniform 4-bit deltas — likely a hybrid variable-bit-width scheme with segment-anchor resync points. Next recommended step: capture an event with a known calibration tone to pin down magnitude scaling. Walker also bails out partway through event-b (open issue documented in both the module and the protocol reference).
76 lines
2.6 KiB
Python
76 lines
2.6 KiB
Python
"""
|
|
Walker v4: alternate [10 NN] data chunks and [00 NN] (or other) marker tags.
|
|
|
|
Hypothesis:
|
|
- [10 NN]: data block, length NN/2 + 2 bytes (2-byte tag + NN/2 bytes data)
|
|
- [00 NN]: 2-byte marker block (no data)
|
|
- [20/30/40 NN]: special blocks with type-dependent length
|
|
"""
|
|
import sys
|
|
sys.path.insert(0, ".")
|
|
from analysis.load_bundle import load_bundle
|
|
|
|
|
|
def walk(body, start):
|
|
i = start
|
|
blocks = []
|
|
while i + 1 < len(body):
|
|
t0 = body[i]
|
|
t1 = body[i + 1]
|
|
if t0 == 0x10 and t1 % 4 == 0 and 0 < t1 <= 0x80:
|
|
# data chunk: length NN/2 + 2
|
|
length = t1 // 2 + 2
|
|
blocks.append((i, "10", t1, bytes(body[i + 2 : i + length]), length))
|
|
i += length
|
|
elif t0 == 0x00 and t1 % 4 == 0:
|
|
# 2-byte marker
|
|
blocks.append((i, "00", t1, b"", 2))
|
|
i += 2
|
|
elif t0 == 0x20 and t1 % 4 == 0:
|
|
# type 2 — try length 2+t1/2 (similar to 10) OR fixed
|
|
length = t1 // 2 + 2
|
|
blocks.append((i, "20", t1, bytes(body[i + 2 : i + length]), length))
|
|
i += length
|
|
elif t0 == 0x30 and t1 % 4 == 0:
|
|
length = t1 // 2 + 2
|
|
blocks.append((i, "30", t1, bytes(body[i + 2 : i + length]), length))
|
|
i += length
|
|
elif t0 == 0x40 and t1 == 0x02:
|
|
# Special "footer transition" block — try fixed 22 bytes
|
|
length = 22
|
|
blocks.append((i, "40", t1, bytes(body[i + 2 : i + length]), length))
|
|
i += length
|
|
else:
|
|
# Unknown tag — stop
|
|
blocks.append((i, "??", t0, bytes(body[i:i+8]), 0))
|
|
break
|
|
return blocks, i
|
|
|
|
|
|
def main():
|
|
for name in ("event-c", "event-d", "event-a", "event-b"):
|
|
b = load_bundle(name)
|
|
body = b.body
|
|
# Auto-detect start
|
|
for s in range(15):
|
|
if body[s] == 0x10 and body[s+1] % 4 == 0 and 0 < body[s+1] <= 0x80:
|
|
start = s
|
|
break
|
|
else:
|
|
start = 7
|
|
blocks, end = walk(body, start)
|
|
# Categorize
|
|
from collections import Counter
|
|
types = Counter(b[1] for b in blocks)
|
|
print(f"\n=== {name} === body={len(body)} N={len(b.samples['Tran'])} start={start}")
|
|
print(f" total blocks: {len(blocks)}, walk ended at {end}/{len(body)}")
|
|
print(f" type counts: {dict(types)}")
|
|
# Print last 5 blocks
|
|
print(f" last 5 blocks: {[(bb[0], bb[1], bb[2]) for bb in blocks[-5:]]}")
|
|
if end < len(body):
|
|
print(f" bytes at end: {body[end:end+24].hex(' ')}")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|