use over 61 workers

compress_pngs.py

@@ -7,12 +7,21 @@ Compresses all PNG files in subdirectories with maximum parallelism.
 import os
 import sys
 import argparse
+import platform
 from pathlib import Path
 from concurrent.futures import ProcessPoolExecutor, as_completed
 from PIL import Image
 import multiprocessing
 import time
 
+# Try to unlock ProcessPoolExecutor on Windows to bypass 61-worker limit
+try:
+    import unlock_processpool
+    unlock_processpool.please()
+    UNLOCKED = True
+except ImportError:
+    UNLOCKED = False
+
 def compress_png(input_path, output_path, force_bitdepth=None):
     """Compress a single PNG file.
     
@@ -311,7 +320,17 @@ def main():
     print(f"Corrupted files will be moved to: {corrupted_dir}")
     
     # Use all available CPU cores
-    max_workers = multiprocessing.cpu_count()
+    cpu_count = multiprocessing.cpu_count()
+    if platform.system() == 'Windows' and not UNLOCKED:
+        # Windows ProcessPoolExecutor has a maximum of 61 workers (unless unlocked)
+        max_workers = min(cpu_count, 61)
+        if cpu_count > 61:
+            print(f"Detected {cpu_count} CPU threads, but Windows limits ProcessPoolExecutor to 61 workers.")
+            print("Install 'unlock-processpool-win' package to use all cores: pip install unlock-processpool-win")
+    else:
+        max_workers = cpu_count
+        if UNLOCKED:
+            print(f"Using unlock-processpool-win to bypass Windows 61-worker limit")
     print(f"Using {max_workers} worker processes for compression...")
     print("-" * 80)