adeed manual processing using UVtools

diagnose/decode_rle_blocks.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""
+Decode the composite block and first layer block from a pm4n file,
+report pixel counts and first/last pixel values.
+Run: python3 decode_rle_blocks.py output/pm4n/Flow_Controller_Panel-Front.pm4n
+"""
+import struct, sys
+
+path = sys.argv[1]
+data = open(path, 'rb').read()
+fsize = len(data)
+print(f"File: {path}  ({fsize} bytes)\n")
+
+LAYE_HDR = 0x20
+STRIDE   = 0x20
+
+laye = data.find(b'LAYE')
+n_entries    = struct.unpack_from('<I', data, laye + 0x10)[0]
+composite_off = struct.unpack_from('<I', data, laye + 0x14)[0]
+block_size   = struct.unpack_from('<I', data, laye + 0x18)[0]
+
+print(f"LAYE n_entries={n_entries}  composite_off=0x{composite_off:06X}  block_size={block_size}")
+
+def decode_rle(data, offset, max_bytes):
+    """Decode RLE starting at offset, stop after max_bytes read. Returns pixel list."""
+    pixels = []
+    i = offset
+    end = min(offset + max_bytes, len(data))
+    while i + 1 < end:
+        b0 = data[i]; b1 = data[i+1]
+        nibble = (b0 >> 4) & 0xF
+        colour = 255 if nibble == 0xF else 0
+        run = ((b0 & 0x0F) << 8) | b1
+        run += 1
+        pixels.extend([colour] * run)
+        i += 2
+    return pixels, i - offset
+
+def summarize_block(name, offset, size):
+    print(f"\n{name} at 0x{offset:06X}, {size} bytes:")
+    if offset + size > fsize:
+        print(f"  *** PAST EOF (file ends at 0x{fsize:06X}) ***")
+        size = max(0, fsize - offset)
+    
+    # Show first 16 bytes raw
+    raw = data[offset:offset+16]
+    print(f"  First 16 bytes: {raw.hex()}")
+    
+    # Decode RLE
+    pixels, bytes_consumed = decode_rle(data, offset, size)
+    print(f"  Decoded: {len(pixels)} pixels from {bytes_consumed} bytes")
+    print(f"  Expected: {9024*5120} pixels ({9024}×{5120})")
+    
+    if pixels:
+        whites = sum(1 for p in pixels if p >= 128)
+        blacks = len(pixels) - whites
+        print(f"  White px: {whites} ({100*whites/len(pixels):.1f}%)")
+        print(f"  Black px: {blacks} ({100*blacks/len(pixels):.1f}%)")
+        
+        # Check if it decodes to correct pixel count
+        if len(pixels) == 9024 * 5120:
+            print(f"  ✓ Correct pixel count")
+        else:
+            print(f"  *** WRONG pixel count (off by {len(pixels) - 9024*5120})")
+        
+        # Show first few runs
+        print(f"  First pixels: {pixels[:20]}")
+
+# Composite block
+summarize_block("Composite block (block 0)", composite_off, block_size)
+
+# First entry block  
+e0_base = laye + LAYE_HDR
+e0_data_off = struct.unpack_from('<I', data, e0_base + 0x14)[0]
+e0_data_sz  = struct.unpack_from('<I', data, e0_base + 0x18)[0]
+summarize_block("Entry[0] block", e0_data_off, e0_data_sz)