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

[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.