Making simple, fast edits to video files before sharing them online can often involve multiple compression steps, potentially degrading quality. The typical way involves copying compressed video from your camera to your computer, making changes with a video editor, and then exporting the video, which compresses it again. When you share it, platforms might compress it further for streaming optimization. However, there's a method using a free tool called Avidemux that avoids unnecessary re-compression.
The advantage of the method Avidemux enables is that you can trim or merge your videos without compressing them again, preserving the original quality directly from the camera. This is particularly useful for cameras like GoPros, which often split a single long recording into multiple MP4 files. These files are usually named sequentially (e.g., the first two digits show the order, the remaining digits identify the recording).
About Avidemux
Avidemux is a free video editor designed for simple cutting, filtering, and encoding tasks. It supports many file types, including AVI, DVD compatible MPEG files, MP4, and ASF, using a variety of codecs. Tasks can be automated using projects, job queue, and powerful scripting capabilities.
Making Edits with Avidemux
To start, open Avidemux and then open the '01' MP4 file (or the first file in the sequence) for the recording you want to edit. Next, append each remaining MP4 file for that specific recording in the correct order. It's important to note that you can't merge just any arbitrary video files like this; they generally need to have been recorded on the same camera with the same settings to ensure compatibility.
Once your files are loaded and merged, you can trim what you don't need, ensuring you only share the parts you want people to see. A limitation with this lossless method is that you must trim at key frames. Avidemux provides specific buttons to jump between key frames, making navigation easier. You can select portions of your video to remove using the selection marker buttons ('A' and 'B'). After selecting a portion, you can delete it simply by pressing the Delete key on your keyboard.
Before you save your edited file, it is crucial to ensure both Video Output and Audio Output are set to Copy. This setting is what prevents Avidemux from re-encoding (compressing) your file, thereby preventing any loss in quality and making the saving process much faster than a full export. For compatibility, it's suggested to set your Output Format to MP4 Muxer. The default configuration options for the muxer should generally be fine.
Now you can save your video. The process might take a few minutes depending on the file size, but it is still significantly faster than encoding everything again. The result is a merged and trimmed video file ready for sharing online or on social media platforms. Since the video and audio streams are direct copies from your camera's original files, it represents the best possible quality without any external enhancements.
Key Features
Lossless Editing
Trim and merge video segments without re-encoding, preserving the original quality.
Direct Stream Copy
Utilizes "Copy" mode for video and audio streams to avoid compression and speed up saving.
Sequential File Appending
Easily join multi-part files from cameras like GoPro into a single file.
Keyframe Navigation
Provides tools to jump directly to keyframes, which are necessary cut points for lossless editing.
Format Support
Works with various input formats and allows saving in common containers like MP4.
Pros and Cons
Pros:
👍 Preserves original video and audio quality completely.
👍 Significantly faster saving times compared to full re-encoding.
👍 Simple interface for basic tasks like cutting and joining.
👍 Handles multi-part camera files effectively.
Cons:
👎 Cutting is restricted to keyframes only in "Copy" mode.
👎 Not suitable for complex editing involving effects, transitions, or precise frame-level cuts outside keyframes.
👎 Merging requires files to be compatible (same settings/camera).
Availability
Use
Ideal for quick trimming of unwanted footage (beginnings/ends), removing sections, and joining sequential clips from the same source without quality loss.
Download
Avidemux is available for Linux, BSD, Mac OS X, and Microsoft Windows under the GNU GPL license.
Cost
It is completely free and open-source software.
