import os, ffmpeg def compress_video(video_full_path, output_file_name, target_size): # Reference: https://en.wikipedia.org/wiki/Bit_rate#Encoding_bit_rate min_audio_bitrate = 32000 max_audio_bitrate = 256000 probe = ffmpeg.probe(video_full_path) # Video duration, in s. duration = float(probe['format']['duration']) # Audio bitrate, in bps. audio_bitrate = float(next((s for s in probe['streams'] if s['codec_type'] == 'audio'), None)['bit_rate']) # Target total bitrate, in bps. target_total_bitrate = (target_size * 1024 * 8) / (1.073741824 * duration) # Target audio bitrate, in bps if 10 * audio_bitrate > target_total_bitrate: audio_bitrate = target_total_bitrate / 10 if audio_bitrate < min_audio_bitrate < target_total_bitrate: audio_bitrate = min_audio_bitrate elif audio_bitrate > max_audio_bitrate: audio_bitrate = max_audio_bitrate # Target video bitrate, in bps. video_bitrate = target_total_bitrate - audio_bitrate i = ffmpeg.input(video_full_path) ffmpeg.output(i, os.devnull, **{'c:v': 'libx264', 'b:v': video_bitrate, 'pass': 1, 'f': 'mp4'} ).overwrite_output().run() ffmpeg.output(i, output_file_name, **{'c:v': 'libx264', 'b:v': video_bitrate, 'pass': 2, 'c:a': 'aac', 'b:a': audio_bitrate} ).overwrite_output().run() # Compress input.mp4 to 50MB and save as output.mp4 compress_video(r"D:\Python\VideosReplacer\test.mp4", r"D:\Python\VideosReplacer\test_out.mp4", 8 * 1000)