Mixed Video Sources, Stuttering with One of Them

Hi, All. First, I’m not very technically minded when it comes to codecs, frame rates, etc, so please go easy on me.

So, I’ve just made a video of my last motorcycle ride using GoPro footage AND drone footage. I have exported it, and the GoPro footage is great, but the drone footage is a little stuttering. What info do you need from me to help you advise me? I thought I’d ask before posting a load of random stuff that I’m guessing at. Thanks.


Do they both have the same framerate, or are they different (e.g. 60fps, 25fps)?

Is either, or are both videos, variable frame-rate?

To find out, click on a clip and show Properties. Try to post screenshots of the properties pane,

What are the your video settings?

Hi, Elusien. Thanks for your reply. You are right (of course), the frame rates are different. I didn’t even think to check. So, I’m guessing I need to alter my whole project to the 29.97 fps rate of the drone? Also, what should I do about the differing resolutions? I’m thinking (in my inexperience) that the drone is fine scaled down to the same resolution of the GoPro, but you can’t do it the other way around? And, finally, can I cheat and add another issue I’m having? If it’s not the right protocol for the forum, I can start a new topic. Let me know. Anyway, I took some screenshots of the properties of both sources of video.

Edit: I just exported it trying the 29.970030 frame rate. Funnily enough, some of the drone footage is smoother, but most of it is still stuttering.

I uploaded it to YouTube so you can take a look at the stuttering.
First drone footage begins at [2:16]
Second drone footage begins at [12:25]

Your issue is similar to the one described here:

There are several suggestions in this thread, including converting one of the videos using frame-rate overide with the “blend” mode for motion interpolation. This is post #8 by @Austin.

You might like to try this to see how it fares and let us know.

Gosh, that sounds complicated, but I’ll go take a look. Thanks, Elusien, for your help in pointing me to the right direction. Much appreciated.

Most of the GoPro footage seems to occur while you riding the bike so of course the camera is jumping about a bit, while the drone is flying smoothly. So to me, keeping the framerate equal to that of the drone is a better option, since stuttering on the GoPro will mostly be lost in the camera shake. Although you have much more footage from the GoPro than the drone. So I’d be tempted to go with the drone’s frame-rate and convert the GoPro footage.

Also computer monitors usually have a refresh rate of 60fps, so watching a 29.970030fps video on such a monitor should be less “stuttery” than watching a 50fps video. So again this would would indicate that converting the GoPro footage to the same frame-rate as the drone is the way to go.

Watching your video brought back memories of a trip my wife Sue and i did to New Zealand in 2017. We hired a camper van and toured both islands over a 6 week period. Unfortunately we never made it to Gisborne (cut from Rotorua down to Napier instead). It was one of the best holidays we’d had, the scenery was fantastic and people so friendly. I kept a blog as we travelled, so family and friends could keep tabs on where we were, what we did and what we’d seen. It is here:

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Wow that’s a lot of unexpected stuttering.

One other solution you could have a look at, and it’s way faster than converting from 29.97 to 50 fps with frame blending/advanced is to speed up/slow down the drone footage to 25 fps (25/29.97=0.834 speed, so just a bit slower, usually gives a more cinematic look anyway) or 50 fps (50/29.97=1.668 so about 1.5x faster, depending on the shot this might ruin it).

The hard lesson here is it’s a lot of pain to mix framerates, and the best way forward is to remember to set all your cameras to the same value (or multiple: 30 works with 60, 25 with 50, 24 with 60, etc).

Edit: I noticed the video on youtube is 30fps, did you change the video mode in Shotcut (Settings → Video Mode) to 29.97 or just the fps in the export panel? Make sure both video mode and export fps is at 29.97.

That breaking down of your explanation was very helpful. Thank you. I will get onto it and let you know (a bit of medical drama happening here at the moment, so I’ve been super busy). I was surprised, however, that you mentioned the GoPro footage “jumping about a bit”. I think the GoPro footage is very stable, and the only jumping about is because it on my helmet, and I look around a little. Is that what you mean by “jumping about a bit”?

I’m so glad you enjoyed your holiday here! Yes, we are super friendly, but as I discovered after living in England for a short time, though we are super friendly and always happy to help, we aren’t nearly as open as the English in a friendship context. I mean, I love the friends we made in England. They really wanted to be involved in our lives. It was awesome. But here in NZ, I find we don’t make such an effort as the English do. We’ve also had a couple of people from overseas who we’ve made friends with here, and both of them said it was actually really difficult to make CLOSE friendships with Kiwis. In fact, one of them decided to go back to Brazil because he found it really difficult (he lived in a different city from us). As he talked about his experiences here, he acknowledge Kiwis are very friendly, but he couldn’t make any decent friendships. It wasn’t him, either. He is a really nice guy, very open and warm.

Thanks for the link. I’ll go take a look.

Hi, Daniel. Thank you for that. Yes, you are right. I did change the framerate in the export panel in Shotcut to 29.97. I didn’t know about video mode and export frame rate having to be the same (29.97). I will definitely do that. I’m going to do some tests with short clips (so it doesn’t take so long to export), and hopefully with your and Elusien’s advice, I’ll be able to make a successful export. Thanks, again.

Sorry, I didn’t express myself very well. What I meant was that the GoPro footage from the bike shows bushes, fences and trees close to the road wizzing past at a high rate of knots, so the eye is less likely to register stuttering on that footage, rather than the smooth tranquil footage taken from a distance by the drone.

Ahh, got it. Yes, that’s true. The stabilisation on that GoPro is amazing. I attached it to the back of my barrel-shaped pooch, and as he ran around, it was moving all over the place. But the footage came out smooth as batter. I’ve been really happy with it. Anyway, thanks, buddy…I appreciate all your input. :slight_smile:

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