This Python script compresses an MKV video file to an MP4 format while preserving embedded subtitles and audio tracks. It uses ffmpeg to perform the compression and saves the log information to a specified text file.

• Python 3.x
• ffmpeg installed on your system
• ffprobe installed on your system

brew install ffmpeg

Video Compression Script

1. Calculate Duration and Bitrate:

• The script first calculates the duration of the input video using ffprobe.
• It then determines the total bitrate needed to compress the video to the target size of 4GB.

2. ffmpeg Command:

• The script constructs an ffmpeg command to compress the video.
• It maps all streams from the input file, excludes the problematic stream #6, and sets the video codec to libx264.
• The video bitrate is set to 75% of the calculated total bitrate.
• Audio tracks are encoded using the aac codec at 128k bitrate.
• Subtitles are encoded using the mov_text codec.
• The -max_muxing_queue_size option is set to prevent muxing queue overflow.
• The -y option is used to overwrite the output file if it already exists.

3. Run the Command:

• The ffmpeg command is executed, and the log output is saved to the specified log file.

• The script saves detailed log information to the specified log file. This log can be reviewed to troubleshoot any issues that may arise during the compression process.

• Adjust the audio bitrate if higher audio quality is needed.