FFmpeg
Also known as: ffprobe, ffmpeg command line
A free, open-source command-line toolkit that decodes, encodes, remuxes and inspects nearly every audio and video format in use today.
Updated
What it means
FFmpeg started in 2000 and grew into the engine under a large share of the video world. Many players, converters, editors and web services rely on its libraries to read and write media, often without saying so.
The project ships a few tools. ffmpeg converts and processes files, ffprobe reports what a file contains, and ffplay is a simple player. Together they handle almost any Container format and Video codec a camera produces.
For people with action-camera footage, it is the universal fix-it tool: when an app refuses a file, FFmpeg can usually tell you why and often change it into something that works.
How it works in practice
Start with ffprobe on a problem clip. It lists the codec, resolution, frame rate, rotation and duration, which is often enough to explain why an editor shows a black screen.
Remuxing with stream copy changes the container without touching the picture, for example MKV to MP4, and runs fast because nothing is re-encoded. Adding the faststart flag moves the Moov atom to the front for web playback.
Real Transcoding re-encodes the video, for example HEVC from a GoPro Hero 11 into H.264 for an older laptop. Choose quality settings deliberately, because each encode loses a little detail.
What to watch out for
Commands are unforgiving. A wrong flag can silently drop the audio track, the metadata or the rotation tag, and the output still plays, just not correctly.
Re-encoding by default is the most common mistake. Without stream copy, FFmpeg encodes the video again, which takes longer and lowers quality for no reason when only the container needed changing.
Downloads from random sites bundle old or modified builds. Get it from the official project page or a trusted package manager. Files from Google Drive link sharing or any web transfer should be checked with ffprobe before you delete the originals.
How RawClip handles it
RawClip reads the files your camera wrote, MP4, MOV, AVI, MKV or M4V in H.264 or HEVC, so there is no need to convert them with FFmpeg first. Remuxing only helps when a file arrives in a container outside that list. Clips from an Insta360 X5 or other .insv cameras are exported to MP4 in Insta360's own software instead.