fix_bitmap_header.py

#!/usr/bin/env python3
"""
Script to fix bitmap headers after Audacity raw export.
Copies the first 255 bytes (0xFF) from the original bitmap to the raw file.
"""

import os
import sys
from pathlib import Path

def fix_bitmap_header(original_bitmap_dir="input-bitmap", raw_dir="output-raw", output_dir="output"):
    """
    Fix bitmap headers by copying the first 255 bytes from original to raw files.
    
    Args:
        original_bitmap_dir (str): Directory containing original bitmap files
        raw_dir (str): Directory containing raw exported files
        output_dir (str): Directory to save fixed bitmap files
    """
    
    # Create output directory if it doesn't exist
    Path(output_dir).mkdir(exist_ok=True)
    
    # Get paths
    original_path = Path(original_bitmap_dir)
    raw_path = Path(raw_dir)
    output_path = Path(output_dir)
    
    if not original_path.exists():
        print(f"Error: Original bitmap directory '{original_bitmap_dir}' does not exist.")
        return
    
    if not raw_path.exists():
        print(f"Error: Raw files directory '{raw_dir}' does not exist.")
        return
    
    # Find all raw files
    raw_files = list(raw_path.glob("*.raw"))
    
    if not raw_files:
        print(f"No .raw files found in '{raw_dir}' directory.")
        return
    
    print(f"Found {len(raw_files)} raw file(s) to fix:")
    
    # Process each raw file
    for i, raw_file in enumerate(raw_files, 1):
        try:
            print(f"[{i}/{len(raw_files)}] Processing {raw_file.name}...")
            
            # Find corresponding original bitmap file
            # Remove .raw extension and add .bmp
            original_filename = raw_file.stem + '.bmp'
            original_file = original_path / original_filename
            
            if not original_file.exists():
                print(f"  ✗ Original bitmap file '{original_filename}' not found in '{original_bitmap_dir}'")
                continue
            
            # Read the first 255 bytes from the original bitmap
            with open(original_file, 'rb') as f:
                header = f.read(255)  # 0xFF bytes
            
            # Read the raw file content
            with open(raw_file, 'rb') as f:
                raw_content = f.read()
            
            # Combine header with raw content
            fixed_content = header + raw_content
            
            # Create output filename
            output_filename = raw_file.stem + '.bmp'
            output_file = output_path / output_filename
            
            # Write the fixed bitmap
            with open(output_file, 'wb') as f:
                f.write(fixed_content)
            
            print(f"  ✓ Fixed bitmap saved as {output_filename}")
            print(f"    Original size: {len(raw_content)} bytes")
            print(f"    Fixed size: {len(fixed_content)} bytes")
            
        except Exception as e:
            print(f"  ✗ Error processing {raw_file.name}: {e}")
    
    print(f"\nHeader fixing complete! Fixed bitmap files saved to '{output_dir}' directory.")

if __name__ == "__main__":
    # Allow command line arguments for directories
    original_dir = sys.argv[1] if len(sys.argv) > 1 else "input-bitmap"
    raw_dir = sys.argv[2] if len(sys.argv) > 2 else "output-raw"
    output_dir = sys.argv[3] if len(sys.argv) > 3 else "output"
    
    fix_bitmap_header(original_dir, raw_dir, output_dir)