series 4 codec work, inital decode success

2026-05-29 06:33:06 +00:00
parent 1bccc44b88
commit 9b71ead44b
20 changed files with 1578 additions and 76 deletions
@@ -0,0 +1,64 @@
+"""Look at what's at the divergence boundary."""
+from __future__ import annotations
+import sys
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(REPO))
+
+from minimateplus.waveform_codec import walk_body, find_data_start, parse_segment_header
+from analysis_idf.recon import TARGET, TXT, load_sidecar_samples
+
+
+def main():
+    buf = TARGET.read_bytes()
+    body = buf[0x0f1f:]
+    start = find_data_start(body)
+    print(f"data_start: {start}  (= file offset 0x{0x0f1f + start:04x})")
+
+    blocks = walk_body(body, start)
+    print(f"{len(blocks)} blocks total")
+    print()
+
+    # First 25 blocks
+    print("=== first 30 blocks ===")
+    for i, b in enumerate(blocks[:30]):
+        body_off = 0x0f1f + b.offset
+        if b.tag_hi == 0x40:
+            hdr = parse_segment_header(b)
+            print(f"  [{i:3d}] @0x{body_off:04x}  {b.kind}  (segment header)  counter={hdr['counter'] if hdr else '?'}  field2={hdr['field2'].hex() if hdr else '?'}  anchor={hdr['anchor_bytes'].hex() if hdr else '?'}  tail={hdr['tail'].hex() if hdr else '?'}")
+        else:
+            print(f"  [{i:3d}] @0x{body_off:04x}  {b.kind}  len={b.length}  data={b.data[:16].hex()}")
+    print()
+
+    # Cumulative sample counts per block to find which block contains sample 254
+    print("=== cumulative samples through blocks ===")
+    cur_ch = "Tran"
+    rotation = ["Vert", "Long", "MicL", "Tran"]
+    seg_count = 0
+    samples_in_curseg = 2  # preamble Tran[0], Tran[1]
+    for i, b in enumerate(blocks[:30]):
+        if b.tag_hi == 0x40:
+            seg_count += 1
+            prev_ch = cur_ch
+            cur_ch = rotation[(seg_count - 1) % 4]
+            print(f"  [{i:3d}] 40 02 -> end of {prev_ch} segment, start {cur_ch} (segment {seg_count})")
+            samples_in_curseg = 2  # anchors
+        elif (b.tag_hi & 0xF0) == 0x10:
+            nn = ((b.tag_hi & 0x0F) << 8) | b.tag_lo
+            samples_in_curseg += nn
+            print(f"  [{i:3d}] {b.kind} nibble: +{nn} samples, ch={cur_ch}, ch_total~{samples_in_curseg}")
+        elif (b.tag_hi & 0xF0) == 0x20:
+            nn = ((b.tag_hi & 0x0F) << 8) | b.tag_lo
+            samples_in_curseg += nn
+            print(f"  [{i:3d}] {b.kind} int8: +{nn} samples, ch={cur_ch}, ch_total~{samples_in_curseg}")
+        elif b.tag_hi == 0x00:
+            samples_in_curseg += b.tag_lo
+            print(f"  [{i:3d}] {b.kind} RLE: +{b.tag_lo}, ch={cur_ch}, ch_total~{samples_in_curseg}")
+        elif b.tag_hi == 0x30:
+            samples_in_curseg += b.tag_lo
+            print(f"  [{i:3d}] {b.kind} packed12: +{b.tag_lo} samples, ch={cur_ch}, ch_total~{samples_in_curseg}")
+
+
+if __name__ == "__main__":
+    main()