Lag and Choppy Video in Finished Product - Newbie

Good Evening everyone,

I am new to this forum, new to filmography, and entirely new to FCPX. I use a DJi Mini 2 for Ariel videography, and I love the footage it captures. However, I seem to be running into problems that I don't fully understand and hoped someone here may know. 

The drone captures 4k at 30 fps. I film in this and I am careful to maintain a low shutter speed to avoid jumping/jittery footage. However, whenever I put the footage from my SD Card to my MacBook Pro 2020, the footage looks unstable and jittery. It looks like a panning shutter judder, but it isn't this as the footage plays smooth on both my iPad and my 4k television. It is the Mac that seems to be the issue. Tonight I tried to edit the footage and export it in FCPX. I played the final footage from my mini film back on my 4k TV and low and behold, it is jittery on there now too. TV still plays the original footage smooth, but the edited footage through my Mac now is unstable. Is this a common problem and if so, what suggestions would you have to resolve it? 

As I said, the original raw footage from my camera plays smooth on everything but my Mac, and then when I edit the file in FCPX, the smooth footage is no longer smooth on my other devices also. I am confused! Any help would be appreciated.

thanks so much,

Tim

What format/codec do you have the DJI recording in?

Thank you for getting back to me! The Mini 2 can only record in 

• MP4 (H.264/MPEG-4 AVC）

I seem to have clean, smooth footage on my television and other devices in its raw off the sd video format, but choppy footage only on my MBP. My smooth footage, however, becomes choppy on other devices, as soon as I run it through FCP and export it. 

Try optimizing your media in FCP. Check an application like MediaInfo for complete details of the file, especially it's frame rate and frame rate stability. Can you upload a short clip somewhere so we can download it?

Seems to me like a frame rate issue. Are you editing and then exporting? At what frame rate is the project/timeline? My guess is your timeline is at 23.98 but your footage is :30. FCPX will play the 30fps in a 24 timeline, but it can be choppy. There are 2 ways to fix it, 1. create a new project/timeline with the correct framerate, then select all from the previous timeline and past into the new. (Check for gaps, converting from one frame rate to another can sometimes open up gaps if you have mixed frame rates). 2. Select a clip, then under modify/retime change it to automatic speed, this will slow the clip down to 80% to match the timeline frame rate.

When you say optimize, are you referring to optical flow? If I slow the footage and use optical flow, this seems to help. But still odd that my raw footage on the Mac is laggy but fine else where. I feel like I am putting a band aid on a problem. 

Where is the best spot to upload the footage? I assume you would need it unedited and in the original file format to download it? Thanks!

No, optimize is different. Right-click on a clip or clips and select Transcode Media. When you chose Optimize you get large, high quality ProRes files. It might stabilize frame rate issues.

Yes, the original file if you can. Either Dropbox or WeTransfer and post the link here. 

Optimizing can help playback, but it wouldn't affect your output. I think you have a framerate issue between your timeline and the footage. For instance, if your project/timeline is at 24fps but you're using 30fps, changing the speed of your clip to automatic speed would slow your 30fps footage down to 80% in a 24fps timeline. The other option is to make sure you're footage and project FPS match.

I right clicked on the clip and transcode media was not there. I did find it in the menu bar at the top, but it is greyed out. 

I think what SMOJO said might be the issue. I filmed at 30FPS but the project is showing 24FPS. Perhaps that could be the reason for it. I tried to slow down to 80% and will see if that helps. Though, I still don't fully understand why the raw footage plays back slowly and jittery on my Mac but smoothly on other devices. Any suggestions on that?

www.dropbox.com/s/x41vt7ojelft2el/TEST.mov?dl=0

Attached is the drop box file. very quick 30 second clip, pan down to up. You will see jittery footage either side of the road on the pan up. Let me know if you need more to review! Thanks 

You transcode in the browser. Why are you working in 24? Do you have mixed media at different frame rate?

Mp4 is a great format for playback, but not for editing, that's why FCP has the option to create optimized media. Click on the clip in the browser, not the timeline to transcode. To change the speed it would be best to select the clip in the timeline, then under modify in the menu bar go to retime, then automatic speed.

The mini 2 shoots in 24 fps or 30 fps. I am actually working in 30 fps, but may have mistakenly set my project to 24fps. I will be more mindful of that on the next one I do. I have tried the automatic speed option and I am exporting a new file now to see if it helps with playback on my television/other devices. Nothing seems to help the lag on the Mac. As I said, it is on the original file also without editing or any FCP input. 

There's nothing wrong with the file. It's 29.97. A 30fps project will be fine.

Select everything in your project Cmd-A and use Cmd-X to cut it. Then go to project properties Cmd-J. Click the Modify button and change the frame rate to 30fps.

Paste the cut content back into the project. You have to do that because you can't change the timebase of the project while there's media in it.

The clip you uploaded plays fine in FCP in the browser and in a project at the right frame rate. Not sure you want to slow that shot down any further by using automatic speed in a 24fps project. 

Good Evening Folks,

I wanted to quickly follow-up on all of your great feedback. Below I have attached a link:

www.dropbox.com/s/g4fv34cgi1785sx/Jittery.MP4?dl=0

This is raw footage out of my Mini 2 drone at ISO 100, with SS 1/60. Filmed in 4K 30FPS. This is unedited and un touched footage. Does anyone else see the jitter in the footage? It's odd, there are no frames being dropped since I counted frame by frame, but for some reason when I watch this footage back., it seems to have this uncomfortable jitter to my eyes that makes me feel a little dizzy watching at times. Attached is a link for your viewing pleasure. Would you mind sharing with me if you see this jitter? And if you do, what is it I am doing wrong?

I tried playback on my MacBook Pro 2020 and my iPad, both have it, but the Mac being far worse. It looks pretty smooth on my 4k TV playing off a USB drive. I just want to make sure this isn't a fault with my drone, and it is either me blaming my tools.. or perhaps even my computer. (I tried converting CODEC on my computer to Pro Res and others, and this did not work either.) Expert advice is much appreciated

Have a great week everyone!

Thanks so much all!

It plays smooth as silk in the Finder quickview, QT player, FCP on both 2017 iMac Pro and 2015 rMBP 15".  In FCP 4K and 1080 projects at various frame rates.  I don't have any issues with this clip at all.

timmiles1989 wrote: ...This is raw footage out of my Mini 2 drone at ISO 100, with SS 1/60. Filmed in 4K 30FPS. This is unedited and un touched footage. Does anyone else see the jitter in the footage? It's odd, there are no frames being dropped since I counted frame by frame, but for some reason when I watch this footage back., it seems to have this uncomfortable jitter to my eyes that makes me feel a little dizzy watching at times...

It plays smoothly on my 2017 iMac Pro in Quicktime Player. I see no jitter, frame judder or lag. The material is UHD 4k/29.97p, 8-bit 4:2:0, H.264 (MPEG-4/AVC), 100 mbps, format profile = High@5.1, ref frames=1, GOP size=30.

There is some very fine-grained compression noise on a few detailed surfaces such as tree branches and gravel. That is normal for a highly-compressed Long GOP codec with that scene type using those encoding parameters. 

You can see those small artifacts right after the camera tilts downward. This is because the drone is only recording every 30th frame and the other frames are reconstructed using frame difference data. That is how compression works and why the file is about 1/8th the size of an all-intraframe codec.

thank you both for your detailed responses, it is much appreciated. Good to know the footage is smooth for you. Any idea what might be causing those jittery play back issues on my laptop? It is a 2020 MBP with 32gb RAM and an I7 processor. Could it be the graphics card causing issues? I have the Intel Iris Plus Graphics 1536 MB

thanks JoeMa! Is there a resolution to those artifacts? or is that just inherent with the drone camera? I bought some ND Filters for my drone which should be coming today. Noticed the jitter I am seeing is worse with panning. I will post another shot for you to see. this one was in auto and the SS is pretty high, which I expect contributes to the issue, but it is a brighter scene!

timmiles1989 wrote: thanks JoeMa! Is there a resolution to those artifacts? or is that just inherent with the drone camera? I bought some ND Filters for my drone which should be coming today. Noticed the jitter I am seeing is worse with panning.

The artifacts are unavoidable -- that is why people use the Inspire 2 with ProRes or other similar drones which have more robust codecs. However in many cases the compression artifacts are minor and not likely visible to most final viewers, especially after upload, re-encoding and streaming.

The jitter should not be happening. However you must distinguish between two different scenarios:

(1) Jitter or frame judder during playback of the original video file. Your machine should be plenty fast for that, assuming the file is copied to the internal SSD hard drive and not played from a micro-SD card or similar external storage (which can have unpredictable performance). However there are limits to panning speed based on the frame rate. A basic rule of thumb is max panning rate should not exceed seven seconds per screen width. This will vary based on frame rate and shutter speed, but the main point is don't pan rapidly. If you shoot 23.98 fps, panning speed is more constrained. If you shoot 59.94 fps you can pan faster but if the final viewer doesn't have 59.94 fps playback it can still be jerky.

(2) Jerky motion cadence if importing 29.97 fps or 59.94 fps material to a 23.98 fps timeline in FCP. The timeline frame rate should match the frame rate of the material, or at least be an even multiple such as 59.94 footage in a 29.97 fps timeline. If the frame rates are not an even multiple this requires "rate conforming" which in some cases can cause jerky motion. See below Gerald Undone video:

here is the other video promised:

RAW FOOTAGE:
www.dropbox.com/s/rzq658aluaq6e9i/DJI_0004.MP4?dl=0

What I see on my laptop screen (some jitter in there on the panning):

www.dropbox.com/s/j3r08cg4zp3qzew/IMG_0691.MOV?dl=0

I tried capturing what I saw on my laptop screen as best as possible, but it is hard and seems more prominent on some than the other. It feels like it has very sharp individual frames that create that quick tiny jolt from frame to frame. You see it a little on the texture of the fields on my laptop screen sample.

Thanks so much once again for your detailed responses! This might be a local issue with my laptop rather than the files, I am just trying to narrow it down!