🎬 Video Postprocessing Script#

A simple Ubuntu/Linux shell script for merging a video file with a background music track.
It automatically trims/pads audio to match video length and applies a smooth fade-out at the end of both video and audio.

✨ Features#

  • 🎵 Merge video with background music (choose via --music or interactively).
  • ⏳ Automatically trims audio if longer than video, or pads silence if shorter.
  • 🌗 Fade-out effect for both video and audio (FADEOUT_TIME configurable).
  • ⚙️ Configurable encoding options (CRF, preset, codec, audio bitrate).
  • 💾 Output saved next to input video with _processed suffix.
  • 🖱️ Optional integration with Kubuntu Dolphin right-click menu.

📦 Installation#

  1. Clone or copy the script to your system, e.g.: bash mkdir -p ~/scripts cp postprocess_video.sh ~/scripts/ chmod +x ~/scripts/postprocess_video.sh

  2. Make sure you have ffmpeg and ffprobe installed:

bash sudo apt install ffmpeg

🚀 Usage#

Basic command#

./postprocess_video.sh <video_file> [--music <music_file>]

Parameters#

  • <video_file> → main video input.
  • --music <music_file> → optional audio track (if omitted, script will show a numbered list of files in MUSIC_FOLDER).

⚙️ Configuration#

Inside the script you can adjust defaults:

DEFAULT_CRF=27         # Quality (lower = better, 20–30 typical)
PRESET="slow"          # Encoding speed (faster = lower compression)
AUDIO_BITRATE="192k"   # Audio bitrate ("0" or "" to disable/copy)
SUFFIX_PROCESSED="_processed"
CODEC="libx264"        # Video codec
MUSIC_FOLDER="$HOME/Music"
FADEOUT_TIME=2.5       # Fade-out duration in seconds

💡 Examples#

1. Auto-select music interactively#

./postprocess_video.sh holiday.mp4

👉 Script lists all audio files in $HOME/Music and lets you pick one.

2. Provide music directly#

./postprocess_video.sh holiday.mp4 --music ~/Music/song.mp3

3. With Dolphin file explorer (Kubuntu)#

You can integrate the script into KDE Dolphin for right-click usage.

Create the service menu file:

# ~/.local/share/kservices5/ServiceMenus/postprocess_video.desktop
[Desktop Entry]
Type=Service
ServiceTypes=KonqPopupMenu/Plugin
MimeType=video/mp4;video/x-matroska;video/avi;video/x-msvideo;video/webm;
Actions=postprocessvideo;
X-KDE-Priority=TopLevel

[Desktop Action postprocessvideo]
Name=Post Process Video
Exec=konsole -e /home/username/scripts/postprocess_video.sh %F
Icon=video
Terminal=true

Now, update the menu:

kbuildsycoca5

Now you can right-click any video in Dolphin → Post Process Video.

🛠️ Requirements#

  • ffmpeg
  • ffprobe
  • Bash shell

✅ Output#

  • Resulting file is saved in the same directory as the input video.
  • Example: holiday.mp4 → holiday_processed.mp4

📜 License#

MIT License. Free to use and modify.