CatMerge – Easily Merge Media Files

🇩🇪 Deutsche Version

CatMerge is a shell script that lets you merge video/audio files right from your file manager.
Ideal for action cams or drones that split recordings into 4-GB segments.

The script tries to merge losslessly using ffmpeg -c copy.
If that isn’t possible (e.g. variable bitrate), it asks to re-encode.

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Requirements

• ffmpeg
• yad or zenity (for dialogs; script still prints to terminal if neither is available)

Ubuntu/Debian:

sudo apt update
sudo apt install -y ffmpeg yad  # or: zenity

Fedora:

sudo dnf install -y yad  # or: zenity
# ffmpeg via RPM Fusion
sudo dnf install -y   https://mirrors.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm
sudo dnf install -y ffmpeg

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Install the script (common step)

git clone https://github.com/Pappmann/CatMerge.git
cd CatMerge
mkdir -p ~/.local/bin
cp "Merge Media Files" ~/.local/bin/catmerge
chmod +x ~/.local/bin/catmerge

The script is universal: it accepts Nautilus environment variables or %F arguments from other file managers.

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Integrate with your file manager

Nautilus (GNOME Files)

mkdir -p ~/.local/share/nautilus/scripts
ln -sf ~/.local/bin/catmerge ~/.local/share/nautilus/scripts/"Merge Media Files"
nautilus -q

Nemo (Cinnamon)

mkdir -p ~/.local/share/nemo/scripts
ln -sf ~/.local/bin/catmerge ~/.local/share/nemo/scripts/"Merge Media Files"
nemo -q || true

Caja (MATE)

mkdir -p ~/.config/caja/scripts
ln -sf ~/.local/bin/catmerge ~/.config/caja/scripts/"Merge Media Files"
caja -q || true

Dolphin (KDE)

mkdir -p ~/.local/share/kio/servicemenus
cat > ~/.local/share/kio/servicemenus/catmerge.desktop << 'EOF'
[Desktop Entry]
Type=Service
X-KDE-ServiceTypes=KonqPopupMenu/Plugin
MimeType=video/*;audio/*;
Actions=CatMerge;
Icon=media-tape
X-KDE-Submenu=CatMerge

[Desktop Action CatMerge]
Name=Merge Media Files (CatMerge)
Icon=media-tape
Exec=/bin/bash -lc '~/.local/bin/catmerge %F'
EOF

PCManFM-Qt

mkdir -p ~/.local/share/file-manager/actions
cat > ~/.local/share/file-manager/actions/catmerge.desktop << 'EOF'
[Desktop Entry]
Type=Action
Name=Merge Media Files (CatMerge)
Icon=media-tape
Profiles=profile-zero;

[X-Action-Profile profile-zero]
MimeTypes=video/*;audio/*;
Exec=/bin/bash -lc '~/.local/bin/catmerge %F'
Name=Default profile
EOF

Thunar (Xfce)

Create a Custom Action via GUI:

• Name: Merge Media Files (CatMerge)
• Command: /bin/bash -lc '~/.local/bin/catmerge %F'
• Appearance Conditions: enable for Audio Files and Video Files.

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Usage

From your File Manager

1. Select the media segments (e.g., …_001.MP4, …_002.MP4, …).
2. Right-click → Scripts/Actions → Merge Media Files.
3. If required, confirm re-encoding.
4. Output is saved in the same folder (default name includes the source date).

From the Terminal

You can also run CatMerge directly on the command line:

# Merge files in natural sort order
catmerge file1.mp4 file2.mp4 file3.mp4

# Or use shell globs (sorted automatically)
catmerge *.MP4

# Works with audio too
catmerge track1.mp3 track2.mp3

Log output is written to /tmp/catmerge.log.

Optional timestamp sync

By default, the merged file inherits the modification timestamp of the first source file. You can toggle this behavior by editing the PRESERVE_SOURCE_TIMESTAMP switch near the top of the catmerge script (or the Merge Media Files source file) and setting it to true or false.

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License

CC0 – Public Domain