An example Python code for compressing video file to target size.

compress_video.py

# Simplified version and explanation at: https://stackoverflow.com/a/64439347/12866353

import os
import ffmpeg

def compress_video(video_full_path, size_upper_bound, two_pass=True, filename_suffix='cps_'):
    """
    Compress video file to max-supported size.
    :param video_full_path: the video you want to compress.
    :param size_upper_bound: Max video size in KB.
    :param two_pass: Set to True to enable two-pass calculation.
    :param filename_suffix: Add a suffix for new video.
    :return: out_put_name or error
    """
    filename, extension = os.path.splitext(video_full_path)
    extension = '.mp4'
    output_file_name = filename + filename_suffix + extension

    # Adjust them to meet your minimum requirements (in bps), or maybe this function will refuse your video!
    total_bitrate_lower_bound = 11000
    min_audio_bitrate = 32000
    max_audio_bitrate = 256000
    min_video_bitrate = 100000

    try:
        # Bitrate reference: https://en.wikipedia.org/wiki/Bit_rate#Encoding_bit_rate
        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 = (size_upper_bound * 1024 * 8) / (1.073741824 * duration)
        if target_total_bitrate < total_bitrate_lower_bound:
            print('Bitrate is extremely low! Stop compress!')
            return False

        # Best min size, in kB.
        best_min_size = (min_audio_bitrate + min_video_bitrate) * (1.073741824 * duration) / (8 * 1024)
        if size_upper_bound < best_min_size:
            print('Quality not good! Recommended minimum size:', '{:,}'.format(int(best_min_size)), 'KB.')
            # return False

        # Target audio bitrate, in bps.
        audio_bitrate = audio_bitrate

        # 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
        if video_bitrate < 1000:
            print('Bitrate {} is extremely low! Stop compress.'.format(video_bitrate))
            return False

        i = ffmpeg.input(video_full_path)
        if two_pass:
            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()
        else:
            ffmpeg.output(i, output_file_name,
                          **{'c:v': 'libx264', 'b:v': video_bitrate, 'c:a': 'aac', 'b:a': audio_bitrate}
                          ).overwrite_output().run()

        if os.path.getsize(output_file_name) <= size_upper_bound * 1024:
            return output_file_name
        elif os.path.getsize(output_file_name) < os.path.getsize(video_full_path):  # Do it again
            return compress_video(output_file_name, size_upper_bound)
        else:
            return False
    except FileNotFoundError as e:
        print('You do not have ffmpeg installed!', e)
        print('You can install ffmpeg by reading https://github.com/kkroening/ffmpeg-python/issues/251')
        return False

if __name__ == '__main__':
    file_name = compress_video('input.mp4', 50 * 1000)
    print(file_name)

@ESWZY hi I used your code and it works perfectly for my project. I am new to python so I struggling on how to get the stdout to get the realtime status to a progressbar.can you help me out?

@ESWZY hi I used your code and it works perfectly for my project. I am new to python so I struggling on how to get the stdout to get the realtime status to a progressbar.can you help me out?

That's interesting! But I think it is difficult to get the stdout directly from the code above without modifications.

As an idea, the ffmpeg library in Python just calls the ffmpeg binary, you can use this library as an alternative (just rename this library as ffmpeg):

https://github.com/althonos/ffpb

https://github.com/althonos/ffpb/blob/da41f96433bfc1d48a3ba4523d647ea1dac6a44e/ffpb.py#L155C21-L155C27

Or, you can parse the output of this Python snippet by following answers:

https://stackoverflow.com/questions/747982/can-ffmpeg-show-a-progress-bar

Do you have any function to compress a video file in Django in production? Thanks

skvideo.io.FFmpegWriter con esta Clase es posible utiliar H264, una fiesta