import subprocess
import sys
import os

def transcode_video(input_file, output_file, crop_param, hw_accel=False):
    """
    Transcodes the video and applies cropping.
    crop_param: string in the format "W:H:X:Y"
    hw_accel: boolean, if true we use hardware acceleration (NVENC as an example)
    """
    cmd = ['ffmpeg', '-y', '-i', input_file]
    
    # We apply the crop filter
    vf_param = f'crop={crop_param}'
    
    if hw_accel:
        # Example using NVIDIA NVENC. 
        # In a real Jellyfin environment, this would be constructed based on Jellyfin's profile.
        cmd.extend([
            '-c:v', 'h264_nvenc',
            '-preset', 'fast',
            '-vf', vf_param,
            '-c:a', 'copy' # Keep audio as is
        ])
    else:
        # Software encoding fallback
        cmd.extend([
            '-c:v', 'libx264',
            '-preset', 'fast',
            '-crf', '23',
            '-vf', vf_param,
            '-c:a', 'copy'
        ])
        
    cmd.append(output_file)
    
    print(f"Running transcoding command: {' '.join(cmd)}")
    
    # In a real scenario, this would stream to Jellyfin's output or write to the required segment files.
    process = subprocess.Popen(cmd)
    process.wait()
    
    if process.returncode == 0:
        print("Transcoding completed successfully.")
    else:
        print(f"Transcoding failed with code {process.returncode}")

if __name__ == '__main__':
    if len(sys.argv) < 4:
        print("Usage: python transcode_crop.py <input_file> <output_file> <crop_param>")
        sys.exit(1)
        
    input_file = sys.argv[1]
    output_file = sys.argv[2]
    crop_param = sys.argv[3]
    
    transcode_video(input_file, output_file, crop_param, hw_accel=False)