diff --git a/.gitignore b/.gitignore
index 7b99f19..8326436 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
input/
output/
+corrupted/
diff --git a/.specstory/history/2025-12-11_18-21Z-compress-png-sequences-with-multithreading.md b/.specstory/history/2025-12-11_18-21Z-compress-png-sequences-with-multithreading.md
index 049d01a..cae797b 100644
--- a/.specstory/history/2025-12-11_18-21Z-compress-png-sequences-with-multithreading.md
+++ b/.specstory/history/2025-12-11_18-21Z-compress-png-sequences-with-multithreading.md
@@ -3012,3 +3012,761 @@ The Threadripper’s higher core count should provide a clear speedup for this C
---
+_**User (2025-12-11 21:39Z)**_
+
+How about a threadripper 1950X?
+
+---
+
+_**Agent (model default, mode Agent)**_
+
+
+
+---
+
+
+The Threadripper 1950X will likely be slower than the i9-13900KF, despite having more threads.
+
+**Threadripper 1950X:**
+- 16 physical cores, 32 threads
+- First-gen Threadripper (Zen, 2017)
+- The script would use 32 worker processes
+- Older architecture, lower IPC
+
+**i9-13900KF:**
+- 8 P-cores + 8 E-cores = 16 physical cores, 24 threads
+- Raptor Lake (2022)
+- The script would use 24 worker processes
+- Much higher single-threaded performance
+
+**Why the i9-13900KF will likely be faster:**
+1. Per-core performance: The i9’s P-cores are significantly faster (roughly 50–70% higher IPC).
+2. Core efficiency: 24 faster workers can outperform 32 slower ones for this workload.
+3. Memory: The i9’s newer memory controller can help.
+4. Architecture: 5+ years of improvements in efficiency and performance.
+
+**Expected performance:**
+- The i9-13900KF should be roughly 20–40% faster, depending on I/O and the specific compression work.
+
+**Bottom line:** The 1950X’s extra threads don’t make up for the i9’s much faster cores. The 3970X’s large core count can overcome the per-core gap; the 1950X cannot.
+
+---
+
+_**User (2025-12-11 21:39Z)**_
+
+Sometimes, PNGs corrupt; we'll get bad results where everything is black, the image cuts off too early, or the file is just 0kb (placeholder). Can we have it report bad PNGs?
+
+---
+
+_**Agent (model default, mode Agent)**_
+
+
+
+---
+
+
+Adding validation to detect and report corrupted PNGs:
+
+
+---
+
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 43, lines removed: 1
+
+```diff
+@@ -38,5 +38,47 @@
+
+ original_size = os.path.getsize(input_path)
+- img = Image.open(input_path)
++
++ # Check for corrupted/empty files
++ if original_size == 0:
++ return (str(input_path), False, "CORRUPTED: File is 0 bytes (empty/placeholder)", 0, 0, 0, False, True)
++
++ # Try to open and validate the image
++ try:
++ img = Image.open(input_path)
++ # Force load to detect corruption early
++ img.load()
++ except Exception as e:
++ return (str(input_path), False, f"CORRUPTED: Cannot open/load image - {str(e)}", original_size, 0, 0, False, True)
++
++ # Validate image dimensions
++ if img.width == 0 or img.height == 0:
++ return (str(input_path), False, f"CORRUPTED: Invalid dimensions ({img.width}x{img.height})", original_size, 0, 0, False, True)
++
++ # Check if image appears completely black (potential corruption indicator)
++ # But be careful - some images might legitimately be black
++ # We'll only flag this if the file is suspiciously small for its dimensions
++ try:
++ # Sample a few pixels to check if all are black
++ sample_size = min(100, img.width * img.height)
++ pixels = list(img.getdata()[:sample_size])
++ if pixels:
++ # Check if all sampled pixels are black (0 or (0,0,0) or (0,0,0,0))
++ all_black = True
++ for pixel in pixels:
++ if isinstance(pixel, (tuple, list)):
++ if any(p > 0 for p in pixel):
++ all_black = False
++ break
++ else:
++ if pixel > 0:
++ all_black = False
++ break
++
++ # If all black AND file is suspiciously small, flag as potentially corrupted
++ if all_black and original_size < (img.width * img.height * 0.1): # Less than 0.1 bytes per pixel
++ return (str(input_path), False, f"CORRUPTED: Image appears all black with suspiciously small file size", original_size, 0, 0, False, True)
++ except:
++ # If we can't check pixels, continue anyway
++ pass
+
+ # Determine target bit depth
+```
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 1, lines removed: 1
+
+```diff
+@@ -32,5 +32,5 @@
+ savings = original_size - new_size
+ savings_pct = (savings / original_size * 100) if original_size > 0 else 0
+- return (str(input_path), True, None, original_size, new_size, savings_pct, True)
++ return (str(input_path), True, None, original_size, new_size, savings_pct, True, False)
+
+ # Ensure output directory exists
+```
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 4, lines removed: 2
+
+```diff
+@@ -174,7 +174,9 @@
+ savings = original_size - new_size
+ savings_pct = (savings / original_size * 100) if original_size > 0 else 0
+- return (str(input_path), True, None, original_size, new_size, savings_pct, False)
++ return (str(input_path), True, None, original_size, new_size, savings_pct, False, False)
+ except Exception as e:
+- return (str(input_path), False, str(e), 0, 0, 0, False)
++ # Check if error might indicate corruption
++ is_corrupted = "truncated" in str(e).lower() or "cannot identify" in str(e).lower() or "corrupt" in str(e).lower()
++ return (str(input_path), False, str(e), 0, 0, 0, False, is_corrupted)
+
+ def find_image_files(input_dir):
+```
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 2, lines removed: undefined
+
+```diff
+@@ -291,4 +291,6 @@
+ skipped = 0
+ failed = 0
++ corrupted = 0
++ corrupted_files = []
+ total_original_size = 0
+ total_new_size = 0
+```
+
+**Chunk 2**
+Lines added: 1, lines removed: 1
+
+```diff
+@@ -306,5 +308,5 @@
+ for future in as_completed(future_to_file):
+ result = future.result()
+- file_path, success, error, orig_size, new_size, savings_pct, was_skipped = result
++ file_path, success, error, orig_size, new_size, savings_pct, was_skipped, is_corrupted = result
+
+ if success:
+```
+
+**Chunk 3**
+Lines added: 1, lines removed: 1
+
+```diff
+@@ -325,5 +327,5 @@
+ if processed == 1 or time_since_update >= 0.5:
+ rate = processed / elapsed if elapsed > 0 else 0
+- remaining = len(png_files) - processed
++ remaining = len(png_files) - processed - failed
+ eta_seconds = remaining / rate if rate > 0 and remaining > 0 else 0
+
+```
+
+**Chunk 4**
+Lines added: 9, lines removed: 4
+
+```diff
+@@ -335,12 +337,17 @@
+
+ print(f"[{processed:5d}/{len(png_files)}] "
+- f"Compressed: {compressed} | Skipped: {skipped} | "
++ f"Compressed: {compressed} | Skipped: {skipped} | Corrupted: {corrupted} | "
+ f"Speed: {rate:.1f} files/sec | "
+ f"Elapsed: {elapsed_str} | ETA: {eta_str} | "
+ f"Saved: {format_size(total_savings)} ({total_savings_pct:.1f}%)", end='\r')
+ last_update_time = current_time
+- else:
+- failed += 1
+- print(f"\n[ERROR] Failed to compress {file_path}: {error}")
++ else:
++ if is_corrupted:
++ corrupted += 1
++ corrupted_files.append((file_path, error))
++ print(f"\n[CORRUPTED] {file_path}: {error}")
++ else:
++ failed += 1
++ print(f"\n[ERROR] Failed to compress {file_path}: {error}")
+
+ total_time = time.time() - start_time
+```
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 2, lines removed: undefined
+
+```diff
+@@ -363,4 +363,6 @@
+ if jpg_files:
+ print(f"Ignored (JPG/JPEG): {len(jpg_files)} files")
++ if corrupted > 0:
++ print(f"Corrupted (bad PNGs): {corrupted} files")
+ print(f"Failed: {failed} files")
+ print(f"Total time: {format_time(total_time)}")
+```
+
+**Chunk 2**
+Lines added: 9, lines removed: undefined
+
+```diff
+@@ -369,4 +371,13 @@
+ print(f"Compressed size: {format_size(total_new_size)}")
+ print(f"Total savings: {format_size(total_savings)} ({total_savings_pct:.1f}%)")
++
++ # Print list of corrupted files if any
++ if corrupted_files:
++ print("\n" + "=" * 80)
++ print("CORRUPTED FILES LIST:")
++ print("=" * 80)
++ for file_path, error in corrupted_files:
++ print(f" {file_path}")
++ print(f" Reason: {error}")
+
+ if __name__ == '__main__':
+```
+
+
+ Tool use: **read_lints** • Read lints for 1 file
+
+Lint paths:
+
+- `compress_pngs.py`
+
+Lint results
+
+
+**No lint errors found**
+
+
+
+---
+
+
+
+---
+
+
+Updated the script to detect and report corrupted PNGs. It now:
+
+1. **Detects 0-byte files** — flags empty/placeholder files
+2. **Validates image loading** — checks if the PNG can be opened and loaded
+3. **Checks dimensions** — flags files with 0x0 or invalid dimensions
+4. **Detects suspicious all-black images** — flags images that are all black with suspiciously small file sizes (potential corruption)
+5. **Tracks corrupted files separately** — counts them separately from regular failures
+6. **Reports in real-time** — shows `[CORRUPTED]` messages as they're found
+7. **Summary report** — includes corrupted file count in the final summary
+8. **Detailed list** — prints a list of all corrupted files with reasons at the end
+
+The script will now:
+- Show corrupted files in the progress output: `Corrupted: X`
+- Print `[CORRUPTED]` messages when found
+- List all corrupted files with their specific error reasons at the end
+
+This should catch the issues you mentioned: black images, cut-off images, and 0-byte placeholder files.
+
+---
+
+_**User (2025-12-11 21:39Z)**_
+
+@pwsh (155-303) nice! can we make it so it moves all of them from input\corrupted to another folder to isolate them?
+
+---
+
+_**Agent (model default, mode Agent)**_
+
+
+
+---
+
+
+Updating the script to move corrupted files to a `corrupted` folder, preserving the directory structure:
+
+
+---
+
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 25, lines removed: undefined
+
+```diff
+@@ -208,4 +208,29 @@
+ return output_dir / relative_path
+
++ def move_to_corrupted(input_path, input_dir, corrupted_dir):
++ """Move a corrupted file to the corrupted folder, preserving directory structure."""
++ try:
++ input_path = Path(input_path)
++ input_dir = Path(input_dir)
++ corrupted_dir = Path(corrupted_dir)
++
++ # Get relative path from input directory
++ try:
++ relative_path = input_path.relative_to(input_dir)
++ except ValueError:
++ relative_path = input_path.name
++
++ # Create destination path
++ dest_path = corrupted_dir / relative_path
++
++ # Ensure destination directory exists
++ dest_path.parent.mkdir(parents=True, exist_ok=True)
++
++ # Move the file
++ input_path.rename(dest_path)
++ return True, None
++ except Exception as e:
++ return False, str(e)
++
+ def format_size(size_bytes):
+ """Format file size in human readable format."""
+```
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 4, lines removed: 1
+
+```diff
+@@ -305,6 +305,9 @@
+ print(f"Found {len(png_files)} PNG files to process.")
+
+- # Create output directory
++ # Create output and corrupted directories
+ output_dir.mkdir(exist_ok=True)
++ corrupted_dir = Path('corrupted')
++ corrupted_dir.mkdir(exist_ok=True)
++ print(f"Corrupted files will be moved to: {corrupted_dir}")
+
+ # Use all available CPU cores
+```
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 8, lines removed: 2
+
+```diff
+@@ -373,6 +373,12 @@
+ if is_corrupted:
+ corrupted += 1
+- corrupted_files.append((file_path, error))
+- print(f"\n[CORRUPTED] {file_path}: {error}")
++ # Move corrupted file to corrupted folder
++ move_success, move_error = move_to_corrupted(file_path, input_dir, corrupted_dir)
++ if move_success:
++ corrupted_files.append((file_path, error, f"Moved to {corrupted_dir / Path(file_path).relative_to(input_dir)}"))
++ print(f"\n[CORRUPTED] {file_path}: {error} -> Moved to corrupted folder")
++ else:
++ corrupted_files.append((file_path, error, f"Failed to move: {move_error}"))
++ print(f"\n[CORRUPTED] {file_path}: {error} (Failed to move: {move_error})")
+ else:
+ failed += 1
+```
+
+Tool use: **read_file** • Read file: compress_pngs.py
+
+Tool use: **search_replace** • Edit file: compress_pngs.py
+
+**Chunk 1**
+Lines added: 10, lines removed: 3
+
+```diff
+@@ -411,7 +411,14 @@
+ print("CORRUPTED FILES LIST:")
+ print("=" * 80)
+- for file_path, error in corrupted_files:
+- print(f" {file_path}")
+- print(f" Reason: {error}")
++ for item in corrupted_files:
++ if len(item) == 3:
++ file_path, error, move_status = item
++ print(f" {file_path}")
++ print(f" Reason: {error}")
++ print(f" Status: {move_status}")
++ else:
++ file_path, error = item
++ print(f" {file_path}")
++ print(f" Reason: {error}")
+
+ if __name__ == '__main__':
+```
+
+
+ Tool use: **read_lints** • Read lints for 1 file
+
+Lint paths:
+
+- `compress_pngs.py`
+
+Lint results
+
+
+**No lint errors found**
+
+
+
+---
+
+
+
+---
+
+
+Updating `.gitignore` to ignore the `corrupted` folder:
+
+
+---
+
+
+Tool use: **read_file** • Read file: .gitignore
+
+Tool use: **search_replace** • Edit file: .gitignore
+
+**Chunk 1**
+Lines added: 1, lines removed: undefined
+
+```diff
+@@ -1,4 +1,5 @@
+ input/
+ output/
++ corrupted/
+
+
+```
+
+