Export video trembles - Reverse clip

Hello to all.

To begin with I am not an advance user in Davinci at all, so I am almost sure that I am doing something wrong. And I want to mention that I haven't any training to video editing, only by reading forums and watching videos/tutorials.

My issue is the result of the export. My exporting video trembles! And that happens only with the parts I used videos.

Below I shared with you a small sample of my exporting. As you can see the exported video trembles a lot, while the source doesn't! And I can not understand why. The editing, that I did, were to cut, reverse and speed up.

I made some test and I found out that the problem appears when I reverse the clip..

The source video (mp4 format, H.264 codec) was captured by DJI Mavic Air 2 drone with 4K video quality and 60fps. My timeline, video monitoring and export formats are the same: 3840x2160 UHD at 60fps. I export the video at mp4 format and the default codec H.264.

https://drive.google.com/file/d/11hidO59vWh1E89nTU6TCWJBQF-C378Bi/view?usp=sharing

At my signature, you will have all information about my desktop machine. Any help to understand a) why this is happened and b) how to solve it, would be more than helpfull!!

Thank you in advance!

After several tests, with the same video clip and with others of the same resolution, I came to this result: for some, unknown to me, reason, the reversal of a clip in 3840x2160 resolution with 60fps creates the problem of trembling exported video.

If I reduce the resolution to 1080p and 24fps, the exported video is without any tremble. But this resolution is not what I need for my projects. I strictly need to export in 4K resolution.

Any suggestion? Am I doing something wrong? I am the only one faced this problem? This is a bug?

Might be too much for your GPU.

Might be too much for your GPU.

Thanks for your answer.
My GPU can support up to 8K resolution. The image below is from the site of the manufacturer and this is the link: https://www.amd.com/en/products/graphics/amd-radeon-rx-5700-xt.

If things work in HD, but not in 4K it's pointing in that direction.

Try to switch off "Frame Reordering". If that doesn't help, try a "Render in Place" for the reversed clips.

Might be too much for your GPU.

Thanks for your answer.
My GPU can support up to 8K resolution. The image below is from the site of the manufacturer and this is the link: https://www.amd.com/en/products/graphics/amd-radeon-rx-5700-xt.

I've read about similar issues with using H.264 clips because of the way they're compressed/stored. Things like odd frames showing up, etc.

Could you try optimizing the clip to a DNxHD (or similar) codec? I think your issue will go away.

If things work in HD, but not in 4K it's pointing in that direction.

Try to switch off "Frame Reordering". If that doesn't help, try a "Render in Place" for the reversed clips.

I tried both ways but none of them didn't work out..

Could you try optimizing the clip to a DNxHD (or similar) codec? I think your issue will go away.

I tried that also, and I had less trembling.

I tested to reverse the clip in a previous version of Davinci (16.2.7010) and the result was just perfect! My optimizing data was the default DNxHDX and the export settings was 3840x2160 UHD at 60fps, mp4 format and codec H.264.

Is there any possibility to be a bug to Davinci 17.1 version? May I ask you to test yourself if reverse clip in high resolution works fine for you? Thank you both in advance!

Might be too much for your GPU.

Thanks for your answer.
My GPU can support up to 8K resolution. The image below is from the site of the manufacturer and this is the link: https://www.amd.com/en/products/graphics/amd-radeon-rx-5700-xt.

what your GPU can handle in a game and what it can handle in Davinci Resolve is quite different. Is the GPU in the correct slot giving it max bus speed?
hardrives? are source files on the same drive as where you are exporting to - if so then that may cause problems as well as the drive has large amounts being read and written at the same time which causes bottlenecks.

a couple of things to try - the reversed clip, render that in place (DR17 new feature) then once that is done render the whole video
also try slowing the render speed - if it works fine at 50% try 75% and see how it goes.

I tested to reverse the clip in a previous version of Davinci (16.2.7010) and the result was just perfect! My optimizing data was the default DNxHDX and the export settings was 3840x2160 UHD at 60fps, mp4 format and codec H.264.

The point of the DNxHDX was to avoid H.264 or H.265 entirely. Please try again without using H.264 or H.265 as the codec.

Is there any possibility to be a bug to Davinci 17.1 version? May I ask you to test yourself if reverse clip in high resolution works fine for you? Thank you both in advance!

That's possible, but trying something like NOT using H.264 or H.265 can help narrow it down. If it goes away when you avoid that codec that's a valuable clue to BMD. It also would give you a workaround so you could keep going while BMD fixes the bug (which would probably take a couple of weeks at the soonest).

Unfortunately, I don't have any high-res footage to test. (But I do know that I've read about H.264 problems with non-linear frame access over the years with products other than Resolve. Especially GPU decoding.)

Note that someone else has pretty much the same problem as you on pretty much the same original footage: viewtopic.php?f=21&t=137222

what your GPU can handle in a game and what it can handle in Davinci Resolve is quite different. Is the GPU in the correct slot giving it max bus speed?
hardrives? are source files on the same drive as where you are exporting to - if so then that may cause problems as well as the drive has large amounts being read and written at the same time which causes bottlenecks.

a couple of things to try - the reversed clip, render that in place (DR17 new feature) then once that is done render the whole video
also try slowing the render speed - if it works fine at 50% try 75% and see how it goes.

I know that there is different customization, this is the reason that I have read a lot to be able to customize my gpu for video editing only. I slowed down a lot the render speed but it didn't work out for me.

That's possible, but trying something like NOT using H.264 or H.265 can help narrow it down. If it goes away when you avoid that codec that's a valuable clue to BMD. It also would give you a workaround so you could keep going while BMD fixes the bug (which would probably take a couple of weeks at the soonest).

Unfortunately, I don't have any high-res footage to test. (But I do know that I've read about H.264 problems with non-linear frame access over the years with products other than Resolve. Especially GPU decoding.)

Note that someone else has pretty much the same problem as you on pretty much the same original footage: viewtopic.php?f=21&t=137222

Wfolta you has so right!!! This problem happens when I export my clip in coden H.264. I have tried to export it to mpeg and work fine, but it doesn't work for DNxHR.

Thank you all for your time and your answers!