hls_download.py

import subprocess
import os

def download_clips(stream_url, out_dir, start_time, end_time, resize=True):
    output_file = os.path.join(out_dir, f"train_{len(os.listdir(out_dir))}.mp4")
    
    ffmpeg_cmd = [
        'ffmpeg',
        '-f', 'hls',
        '-i', stream_url,
        '-ss', str(max(0, start_time - 2)),  # Ensure start time is not negative
        '-to', str(end_time + 2),
        '-r', '30',
        '-c:v', 'libx264',
        '-preset', 'ultrafast',  # Use fastest encoding preset
        '-crf', '23',  # Slightly lower CRF for better quality
        '-maxrate', '1M',  # Limit bitrate
        '-bufsize', '2M',
        '-vf', f"scale=-2:{360 if resize else 720}",
        '-c:a', 'aac',  # Re-encode audio for better compatibility
        '-b:a', '128k',
        '-max_muxing_queue_size', '1024',  # Increase muxing queue size
        '-y',  # Overwrite output file if it exists
        output_file
    ]

    print([f'{x} ' for x in ffmpeg_cmd])
    
    try:
        subprocess.run(ffmpeg_cmd, check=True, capture_output=True, text=True)
        return output_file
    except subprocess.CalledProcessError as e:
        print(f"Error occurred: {e}")
        print(f"FFmpeg output: {e.output}")
        return None