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).
28 lines
825 B
Python
28 lines
825 B
Python
"""Dump body bytes around a specific offset."""
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import sys
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sys.path.insert(0, ".")
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from analysis.load_bundle import load_bundle
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def dump_around(name: str, center: int, radius: int = 96):
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b = load_bundle(name)
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body = b.body
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start = max(0, center - radius)
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end = min(len(body), center + radius)
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print(f"\n=== {name} body[{start}:{end}] (full body={len(body)}) ===")
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for i in range(start, end, 32):
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row = body[i:i+32]
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marker = " <-- center" if i <= center < i+32 else ""
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print(f" +{i:>5} {row.hex(' ')}{marker}")
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def main():
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# Look at the trailer transitions
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trailer_starts = {"event-a": 7047, "event-b": 6475, "event-c": 4043, "event-d": 3941}
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for name, off in trailer_starts.items():
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dump_around(name, off, 96)
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if __name__ == "__main__":
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main()
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