Copy most frames, but re-encode only a few seconds?

[trevor]

I have a video 36 minutes long. There is a section I need to apply a minor edit to. The edit is only about 2 seconds of the video.

Is there a way to avoid re-encoding the entire 36 minutes, and copy the existing frames? It would be much, much faster to avoid re-encoding the entire video, for the sake of about 2 seconds.

I’m looking for something similar to doing ffmpeg -vcodec copy on all but the edited segment.

[daniel47]

You can use Shotcut for the split part, but you’ll have to use ffmpeg for the merge.

So split your original clip into 3, and use the Extract Sub-Clip option in the properties panel to make the 2 large lossless cuts. Export the edited 2 seconds only, then use ffmpeg -concat

[brian]

Extract Sub-clip

Shotcut can not “pass through” or copy codecs without re-encoding. The closest thing available to that is Properties > menu > Extract sub-clip, which uses the in and out points of a trimmed clip. [image] Extract sub-clip will find the key frame closest to the in/out points and copy the codecs into a new container without re-encoding. Any filters applied to the clip will not be applied to the sub-clip because that would require re-encoding. This feature has some limitations and may not always…

Shotcut can not do what you are asking for automatically. Using @daniel47’s hints, you might be able to accomplish it manually. But the manual effort would probably take longer than just re-encoding the whole clip.