DCP-o-matic

Sometimes I'd like to extend the video. Let's say 3 sec of black at the start and at the end. At the start it's simple: just trim the start time 3 sec later.
Has anyone a smart idea, how to add a few sec of black at the end of the video?
Actually I am using a black jpg, but it's tricky. You have to add the start trimming of the main video to the start time of the black jpg and the trimming of the main video is reset after importing the jpg.

You could also just add a 3s silent audio file. I would probably prefer a still, because a single still can be set to whatever length you want.

It's pretty straightforward: Add video, add black.jpg, adjust black play time, rightclick black.jpg->Repeat one time. Just use the up/down buttons to order all in a sequence.

For the black lead-in, you wouldn't even need a black image, just shift your content in timeline view or adjust Position to 3s, then shift lead-out image to the end (use snap).

The format/pixel dimension of the black is irrelevant. As a matter of fact, it could be just a single black pixel.

Thanks a lot.
That's kind of the way I did.

But i have still one problem: Let's say I imported a video and set the start to +3 sec to get black on the first seconds. Then i add a black still for the last 3 sec. But now the 3 sec trim of the video is set back to 0 by magic. So I set it to 3 sec again, switch to the still and set it to 3 sec duration. And again the trim of the video is set back to 0. That's confusing, and it gets more complicated when you import a ST file, too.
Perhaps it's my fault, I don't know. Using the timeline is a solution.

The shift of the video is caused by the 'Keep video and subtitles in sequence' function in the timelineview. It is enabled by default and will always rearrange new content so that no gaps occur. You may disable it, but the easier way to do it is to add a still, set it's playtime to the desired length, repeat it, and arrange with the earlier/later buttons to that both blacks wrap the content, as shown in my first screenshot above. Takes only a few seconds to do it.

Hard to say wether the automatic shift to zero of content is a bug or unexpected behaviour. But, there are always multiple ways to achieve the same result, so, use what works best for you.