Adding Custom Commands to Your Shell Configuration

Adding custom functions to your shell configuration files like .bashrc or .zshrc can significantly streamline your workflow. Here’s a quick guide on how to add a custom command to convert screen recordings to YouTube-friendly formats using a script and the ffpb tool.

Step-by-Step Guide

1. Open Your Shell Configuration File:

• For Bash, open .bashrc:
  sh nano ~/.bashrc
• For Zsh, open .zshrc:
  sh nano ~/.zshrc

1. Add the Custom Function:
   Append the following function to the end of the file:

   # Converting Mac M1 screen recording to YouTube format
   youtube-converter() {
     if [[ $# -eq 0 ]] ; then
       echo 'Usage: youtube-converter input.mov output.mp4'
       return 1
     fi
     source /Users/user/code/ffpb-venv/bin/activate && ffpb -i "$1" -c:v libx264 -preset slow -crf 18 -c:a aac -ar 48000 -ac 2 -b:a 320k -profile:v high -level 4.0 -bf 2 -coder 1 -pix_fmt yuv420p -b:v 15M -threads 8 -cpu-used 0 -r 60 "$2"
   }

3. Save and Close the File:

• Press CTRL + X, then Y, and hit Enter to save the changes.

3. Reload the Configuration File:

• For Bash:
  sh source ~/.bashrc
• For Zsh:
  sh source ~/.zshrc

Using the youtube-converter Command

Once you have added the function to your shell configuration and reloaded it, you can easily convert your screen recordings. Here’s how:

1. Record Your Screen with QuickTime:

• Save the recording as input.mov.

1. Convert the Recording:

• Use the youtube-converter function to convert the .mov file to .mp4:
  sh youtube-converter input.mov output.mp4

How the Conversion Works

The youtube-converter function utilizes ffpb, a simple and fast FFmpeg front-end. It activates a Python virtual environment where ffpb is installed, and then executes the conversion command with the specified parameters.

Command Breakdown:

• -i "$1": Specifies the input file.
• -c:v libx264: Uses the H.264 codec for video.
• -preset slow: Sets the compression preset.
• -crf 18: Controls the quality of the output video.
• -c:a aac: Uses the AAC codec for audio.
• -ar 48000: Sets the audio sampling rate.
• -ac 2: Specifies two audio channels (stereo).
• -b:a 320k: Sets the audio bitrate.
• -profile:v high: Uses the high profile for H.264.
• -level 4.0: Sets the level to 4.0.
• -bf 2: Uses two B-frames.
• -coder 1: Enables CABAC entropy coding.
• -pix_fmt yuv420p: Sets the pixel format.
• -b:v 15M: Sets the video bitrate.
• -threads 8: Utilizes 8 CPU threads.
• -cpu-used 0: Optimizes CPU usage.
• -r 60: Sets the frame rate to 60 fps.

By following these steps, you can efficiently convert QuickTime screen recordings to a YouTube-compatible format directly from your terminal. This method is particularly useful for Mac M1 users looking for a streamlined workflow.