GoPro footage ruined when I render at 30fps

[MDH438]

When the Beast from the East hit last week we headed out on the sledges and I shot at 2.7k 60fps.  There are a few jumps in there that I wanted to playback as slo-mo so set up the project at 1080p 30fps.  The output is horrible very grainy and very distorted apart from the slowmotion parts where the footage is crisp like the original.  I've tried again with a project at 60fps and it looks fine but the slowmotion stuff doesn't look so good. 

Is this normal that this happens when you reduce the framerate from what was shot originally compared to the final export? And any online resources which would give me a better understanding of framerates and when to choose which framerate for both filming and final export of the edited product?

Thanks

Matt

[Steve Grisetti]

It depends on the specs of your video and how closely they match your project settings and what method you used to slow it down. Also, are you judging the quality by raw timeline playback, rendered timeline playback or 1920x1080 MP4 output?

Simply putting 60p footage into a 30p project won't give you half-speed video. Putting 60p video into a 30p project will result in video that has been conformed to 30p.

If your original video is 1920x1080p60, start a new Premiere Elements project. On the New Project panel, click Settings and select the preset for AVCHD 1080p60. Then, back on the New Project panel, check the option to force these settings.

Add your video to this file and use Time Remapping to slow it to half speed (or whatever, making sure to select the Blend Frames option on the Time Remapping panel). Then go to Export & Share/Devices/Computer and output your movie as a 1920x1080 mp4.

And, for best playback, use the free download VLC Media Player rather than your computer's default player to play your finished piece.

[MDH438]

So to be clear my original footage is 2704x1520 at 60fps.  I  want my final editied work to be 1920x1080 at 30fps.

My understanding was that using 2.7k footage and editing it down to 1080p mean that you had a "bigger" image that I could crop in post processing withoit the image being "stretched" to fill the screen.  I also thought that I could shoot at 60fps and render it to 30fps and when I did use the time remapping for slow motion it would be better quality.

The quality issue is apparant when i take the 60fps footage and render it at 30fps it becomes very grainy.  I know that rendering the footage at 30fps won't half the speed of the footage.  I'm comparing renderered timeline footage to the original footage viewed on my laptop.   I got 95% through what i was editing last night and was watching it back in full screen when I noticed the quality issue so I didn't export it.  I will do a test export tonight.

Are you able to explain how Premiere Elements changes it from 60fps to 30fps?  Is it by dropping out every other frame or by merging the frames?  Or can I decide how it does it?

Thanks

Matt

[Ann Bens]

You could also try setting up a 60p timeline and interpreting the slomo footage to 30p.

[Steve Grisetti]

Yes. When you put 60p footage into a 30p project, it is dropping and blending frames.

Also, if you put a 2704x1520 video into a 1920x1080 project, the program is dropping pixels.

I'm not sure Premiere Elements is going to work well at all with that non-standard video frame size. It can work with 4k and it can work with 1920x1080, but yours is somewhere between.

Nonetheless, I look forward to hearing your results when you use the workflow I described.

[MDH438 · Accepted solution]

I got round to finishing off the edit last night and exported it.  When its finally exported the footage looks great.  I apologise for creating a storm in a teacup! 

[Bill Sprague]

MDH438  wrote

When its finally exported the footage looks great. 

If you can, would you please post some details.  Questions about GoPro 2.7K footage come up often enough that it would be helpful to provide answers. 

What were the project settings?  Did you autoset them by sliding a clip to the time line?  Or, did you force set them when opening a new project? 

For the slow motion part, did you try using either the Time Stretch or Time Remapping tools?

One last request... If you have some short 2.7K clips that you are willing to share, would you put them on DropBox so I can see how they work?

Thanks in advance. 

Bill

[MDH438]

Hi Bill,

I set the project up as 1080p 30fps rather than draging a clip to the timeline.  I used the time remapping tool to make the slomotion section.  I halved the speed of the footage and my understanding is that this uses every frame rather than repeating the frames. I'll pop a clip of the original footage versus the rendered output on dropbox later on.

thanks

matt

[Bill Sprague]

Thank you Matt.  The next time someone asks a GoPro 2.7k question and I am reading it, I will suggest your 1080p30 solution. 

Bill