Commit Graph
6 Commits
Author SHA1 Message Date
serversdownandClaude Opus 5 14e997b20c fix(histogram): partial final block no longer discards the correct stride
detect_multi_interval_stride() confirmed a candidate stride on a third block
header whenever the body was long enough to contain one. But a body can exceed
two strides and still hold only two real blocks: a partial final block leaves
trailing padding. BE18193 T193L0XM.CI0H — 51 intervals at 2 s, i.e. one full
30-interval block plus a 21-interval remainder in a 2787-byte body — had every
decisive check pass at stride 612 (header at 0, header at 612, block counter
256 -> 257) and was then rejected for the absent third header at 1224. It
decoded to nothing.

A missing third header now means end-of-stream rather than disqualification.
The block-counter check is untouched — that is the test that prevents the
false positives which once handed 9,082 standard-block files to the
multi-interval walker.

Found by running the full DL2 archive against its preserved Blastware ASCII
exports (14,340 paired files, 11x the previous ground-truth corpus).

Measured over 127,035 archive histogram binaries:
  recovered 8 files (strides 92, 252, 612; BE18193, BE18191, BE9557, BE9440)
  regressed 0 files
Full-corpus verification: 14,337 -> 14,338 exact of 14,338 decodable pairs
(the 2 excluded are series-4 IDF, a different codec).

Also adds scratch/verify_against_ascii.py (per-sample decoder verification
against BW exports, with a saturation carve-out — BW clamps clipped events to
the range max while the decoder reports true counts) and scratch/offset_scan.py.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HgTe8CamXAHcAmaQ6QNcog
2026-08-28 20:19:30 +00:00
serversdownandClaude Opus 5 a3b69a62a6 fix(histogram): three defects found by a full series-3 sweep — 11603/11603 clean
Swept every series-3 binary with the live decoder against five
independent checks: decode exceptions, zero samples, unequal geo channel
lengths, peaks above range full scale, decoded peak vs device-reported
PPV, and waveform length vs declared record time.

1. block[22] is NOT a constant and must not be tested.  Documented as
   always 0x00, it carries data on loud blocks, and rejecting those threw
   away the interval holding the event peak.  BE18350/T350L7HR.NL0H
   block 92 has block[22]=0x26 and a Tran peak of 0x0563 = 1379 counts =
   6.895 in/s — exactly the device-reported PPV — while the file decoded
   to 0.015 in/s.  block[0]==0, block[4]==0x0A and the 4-byte tail are
   six bytes of constraint, which is what keeps trailer content out.

2. Block-model dispatch now goes on signature strength rather than on
   whichever decoder returns first.  A multi-interval body also yields
   scattered standard-tail blocks by coincidence, so "first non-empty"
   handed 193 BE18193 files to the standard walker and produced peaks of
   149 in/s against a 10 in/s full scale.

3. Multi-interval stride detection requires the block counter to
   increment by exactly 1.  Without it the detector false-positives on
   ordinary standard-block bodies: they carry a header every 32 bytes,
   and 192 = 12 + 20*9 and 512 = 12 + 20*25 are both multiples of 32, so
   a stride "fits" while skipping 6 or 16 real blocks.  That misrouted
   9,082 files.

Partial-block garbage is trimmed within the final block only, stopping
at the first slot with a non-zero tail word or a geo peak above full
scale (2000 counts in 16-count units).  Trimming purely from the end
left garbage stranded behind a slot that happened to have a zero tail
word; trimming on the tail word alone truncated four BE9440 files by up
to 2,800 intervals.

Result: 11,603 / 11,603 series-3 binaries clean on every check.
Ground truth unchanged: 1211/1211 histograms exact per-interval, 75/75
waveform sample counts exact (73/75 fully exact, the 2 differ by 1 LSB
on rail samples), and the multi-interval fixture still matches its BW
ASCII export on all 45,680 values.

Tests: 259 passed, failure list unchanged from baseline.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HgTe8CamXAHcAmaQ6QNcog
2026-08-26 05:55:46 +00:00
serversdownandClaude Opus 5 306104354b feat(histogram): decode multi-interval blocks — recovers 415 files
Sub-minute histogram intervals are packed several to a block so that
every block still covers exactly one minute of data:

    interval   intervals/block   stride
    1 minute   1                 32     <- the standard big-endian block
    15 s       4                 92
    2 s        30                612

    stride = 12 + n * 20

Block = [00][segment][ctr uint16 LE][0a][00], then n x 20-byte records of
8 x uint16 LITTLE-endian values (T_peak, T_halfp, V_peak, V_halfp,
L_peak, L_halfp, M_peak, M_halfp) plus a 2-word tail whose first word is
0000 on every real interval, then a 6-byte block trailer.

The standard 32-byte block is BIG-endian; this variant is LITTLE-endian.

The tail-word check matters: a session ending mid-block leaves buffer
garbage in the remaining interval slots, which decoded as peaks
thousands of times the real value.  Stride detection also requires at
least 2 records, since a 1-record block would have stride 32 and
collide with the standard block.

Recovers 415 files that decoded to nothing: 216 on BE18193 (2 s
intervals) and 199 on BE9440 (15 s).  Before decoding to nothing they
were being accepted by the WAVEFORM codec, which returned garbage
peaking up to 400x the device-reported PPV.

Ground truth BE9440/K440L3AQ.T70H (5,710 intervals) matches its
Blastware ASCII export exactly: 17,130/17,130 geo peaks, 22,840/22,840
frequencies, 5,710/5,710 mic dB(L).  Across all 455 affected files,
1,354/1,365 channel peaks (99.2%) match the device-reported PPV; the 11
that don't are under-reads on BE9440 where the walk stops early.

Fixture (binary + ASCII) saved under tests/fixtures/, which is
gitignored per repo practice — the ground-truth test skips when absent.

Tests: 258 passed, failure list unchanged from baseline.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HgTe8CamXAHcAmaQ6QNcog
2026-08-26 04:59:00 +00:00
serversdownandClaude Opus 5 ef1e99b0a0 fix(histogram): block is big-endian + terminal block tail — 1/1196 to 1211/1211
Two errors in the series-3 histogram block model, both found by diffing
against the per-interval data table in the preserved Blastware ASCII
exports (1211 files in the prod snapshot — far stronger ground truth
than the header PPV used previously).

1. The block is uniformly BIG-ENDIAN.  Peaks and half-periods are uint16
   BE (T_peak [5:7], T_halfperiod [7:9], V_peak [9:11], V_halfperiod
   [11:13], L_peak [13:15], L_halfperiod [15:17], M_peak [17:19],
   M_halfperiod [19:21]); only block_ctr [2:4] is little-endian.

   The old uint8-peak model silently CLIPPED any peak above 1.275 in/s:
   the final interval of BE18193/T193LQ9K.OE0H reads 8.270 in/s in BW's
   export (1654 counts = 0x0676) and decoded as 0x76 = 118 = 0.590.

   The byte documented as a per-channel "annotation" was never an
   annotation — it is the half-period's high byte, which is exactly why
   it was non-zero on the sub-Hz intervals BW renders as "<1.0".

   The marker is block[4] alone.  Testing [4:6] as a uint16 LE marker
   forced block[5] == 0, which is what capped the peak at one byte.

2. The final block of each stream carries tail 9c 06 00 42 instead of
   1e 0a 00 00, and holds arbitrary bytes at [21:23].  Rejecting it
   dropped the last interval of nearly every histogram — frequently the
   interval holding the event peak, so the file's PPV read low.

Verified end to end through the production path: 1211/1211 histograms
decode exactly (interval count + every per-interval peak), plus 842,442
per-interval frequency comparisons with zero mismatches.  Previously
1 of 1196 files was fully correct.

decode_histogram_body_full records expose `is_terminal` in place of the
removed `annotations` tuple.  +6 tests.  No regressions: full-suite
failure list unchanged from baseline.

NOTE: stored histogram .h5 files need regenerating to pick this up.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HgTe8CamXAHcAmaQ6QNcog
2026-08-25 18:59:25 +00:00
serversdownandClaude Opus 4.7 d506ebc103 histogram_codec: peak count is uint8 (not uint16 LE) — properly cracks
the BE9558 / BE18003 extension-byte case

The bytes at [7]/[11]/[15]/[19] are an annotation field (purpose still
unclear — empirically non-zero on intervals with sub-Hz or unmeasurable
freq), NOT the high byte of the peak count.  The N844 fixture corpus
the original RE was done against had zero values in those bytes for
every block, so uint8 and uint16 LE were equivalent there — but on
real BE9558 Tran-drift events and BE18003 Histogram+Continuous events
the uint16 LE interpretation produced peaks up to 268 in/s and 35×
inflated PVS sums.

Cross-correlated against BW's per-interval ASCII export on:
  - K558LKZU/LL1P/LL3K  → 100% T/V/L/M peak match (1435 blocks each)
  - T003LKZR/LL0O/LL1M  → 100% T/V/L, 99.3% M (0.05 dB rounding only)
  - N599LKZS/LL0L        → 100% all channels
  - N844 fixture corpus  → 100% all channels (unchanged)

Annotations preserved on every record for future RE; the defensive
_MAX_PEAK_COUNT bound is no longer needed (uint8 maxes at 1.275 in/s,
well below any physical limit).

Synthetic regression test added using the verbatim K558LKZU.RE0H
interval-12 block.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-21 06:05:19 +00:00
serversdownandClaude Opus 4.7 7183b953e4 minimateplus: histogram body codec — FULLY DECODED
The histogram-mode event body is now byte-exact decodable.
Companion to the waveform body codec — together they cover every
event file the watcher forwards.  Cracked in one session via
cross-event correlation against BW's ASCII export.

The §7.6.2 spec in instantel_protocol_reference.md was structurally
correct (32-byte blocks) but the per-sample semantics were
under-documented.  Cross-checking block 130 of N844L6Z8.ZR0H
against its TXT row revealed the layout perfectly:

  slot[0] = 10 (constant marker)
  slot[1] = T_peak_count    (× 0.005 → in/s at Normal range)
  slot[2] = T_halfperiod    (freq_Hz = 512 / halfp)
  slot[3] = V_peak_count
  slot[4] = V_halfperiod
  slot[5] = L_peak_count
  slot[6] = L_halfperiod
  slot[7] = MicL_peak_count (dB via waveform_codec.mic_count_to_db)
  slot[8] = MicL_halfperiod

The `>100 Hz` sentinel is halfperiod ≤ 5 (since 512/5 = 100 Hz).
Mic dB uses the SAME formula as the waveform codec (sign × (81.94
+ 20·log10(|count|))) — they share the mic ADC calibration constant.

Block identification anchor: bytes [22:24] == 0x0000 AND
bytes [28:32] == 1e 0a 00 00.  The tail signature is the most
reliable distinguisher from non-block content in the file.

Files:

  minimateplus/histogram_codec.py (new) — decoder + public API
    matching the waveform codec's shape:
      walk_body(body) -> records
      decode_histogram_body(body) -> {Tran, Vert, Long, MicL}
      decode_histogram_body_full(body) -> [per-interval dicts]
      half_period_to_hz, geo_count_to_ins helpers

  minimateplus/event_file_io.py (modified) — read_blastware_file
    now tries the waveform codec first, falls back to the histogram
    codec on failure.  Same output shape, same downstream pipeline.

  tests/test_histogram_codec.py (new) — 24 regression locks against
    the in-repo fixture corpus, byte-exact against BW ASCII export
    for peaks (all 4 channels), frequencies (all 4 channels,
    including >100 Hz sentinel handling), block framing, and
    segment-ID accounting.

  scripts/backfill_sidecars.py (modified) — the has_samples
    short-circuit added in the histogram-pending era is now a
    pure defensive guard.  Histograms in prod will regen .h5 files
    correctly on the next backfill run.

  docs/histogram_codec_re_status.md (updated) — supersedes the
    earlier "in progress" version with the verified format and
    test-coverage summary.  Notes a few non-essential fields still
    open (4-byte block metadata, Geo PVS, Mic psi(L) — none of
    which are needed for waveform reconstruction).

Total verified coverage: ~3,500 blocks across 5 fixtures, every
field of every block byte-exact against BW.

The watcher-forwarded histogram event corpus on prod (~10,000
events) will now produce correct .h5 sidecars on the next backfill
run.  No additional changes needed to the backfill flow — the
existing tool_version-bump cascade picks them up automatically.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-20 23:05:13 +00:00