add timestamp to video using ffmpeg

ffmpeg.txt

ffmpeg -i "SB25 Timelapse.MP4" -filter_complex "[0:v]sendcmd=f=test.cmd,drawtext=fontfile='C\:/Users/benja/Downloads/droid-sans-mono/DroidSansMono.ttf':text='': fontcolor=white:fontsize=96:fontcolor=white:box=1:boxcolor=black@0.5:x=10:y=10" output.mp4

timestamps.py

from datetime import datetime, timedelta

def create_cmd_file(start_time, fps, interval_seconds, output_file, duration):
    frame = 0
    with open(output_file, 'w') as f:
        current_time = start_time
        total_frames = int(duration * fps)
        while frame <= total_frames:
            n = frame / fps
            next_n = (frame + 1) / fps
            time_str = current_time.strftime('%Y-%m-%d %H:%M:%S').replace(':', '\\:')
            cmd = f"{n:.6f}-{next_n:.6f} drawtext reinit 'text={time_str}';\n"
            f.write(cmd)
            current_time += timedelta(seconds=interval_seconds)
            frame += 1
            
    print("success")

if __name__ == "__main__":
    START_TIME = datetime(2025, 5, 30, 13, 1, 0)
    FPS = 29.97003
    INTERVAL_SECONDS = 15
    DURATION = (7 * 60) + 21 + 1
    OUTPUT_FILE = "sendcmd.cmd"
    
    create_cmd_file(START_TIME, FPS, INTERVAL_SECONDS, OUTPUT_FILE, DURATION)