I often work with media files. These are some tools I really like in this domain:

• Exiftool Best metadata editor around. And it’s basically a single massive perl script…
• MediaInfo Metadata viewer specifically for AV Files. Comes with a GUI viewer but also works just from the command line.
• FFprobe part of the ffmpeg project. For getting information about streams in AV files
• ImageMagick For editing/convertig images.
• G’Mic Also for image processing. But more for creative stuff.
• GStreamer (gst-launch for running pipelines) AV Stream manipulation, Video Editing
• DNGLab For convertig RAW Images to DNG. Its the only one I found that works well with fujifilm RAF files (and its fast)
• SoX Swiss Army Knife of sound processing
• Gltfpack For reducing the size of gltf files (3d meshes)