How to Trim Videos Without Re-encoding Using Avidemux

Sometimes you need to trim a long video clip to get a much smaller section, whether you recorded a much longer video and only need a shorter segment, or need a short clip from an already existing video. The problem with trimming videos using traditional video editors is that they require you to re-encode your video, meaning that it takes a long time, especially on low-end computers, and results in a lowering of video quality. Due to these reasons, it can be useful to know how to trim videos without re-encoding, which essentially just takes the data for he frames you want along with its corresponding audio and copies it into a valid video file. Doing this means that it is super quick, only taking as long as it does to read the file from disk and write your new version.

In order to trim videos in Avidemux, first you need to open the video in Avidemux. This can be done either with using the 'File' menu, or by dragging and dropping the video file onto Avidemux. Then you need to select which part of the video you want. This can be achieved by dragging the selector to the part of the video you want to have as the start of your trimmed video. The use the red-coloured button with an 'A' on it. Then, drag the slider to what you want as the end of your video, and click on the button to the right of that 'A' button, which is labelled 'B'. At this point you have selected the part of your original video to use as your trimmed clip.

To export your clip, simply go 'File' then 'Save As'. This will export your video as an .mkv file, but if you want to change the export format, you can use the drop box directly under 'Output Format' on the left-hand side to change this.