What are best practices for editing GoPro 4K footage together with Sony XAVC 4K footage together in a FCP X Timeline?

I understand the demands and implications of working in 4K fully, and I will be using an external Thunderbolt RAID drive for all media.

I do want to combine 2 different formats in the FCP X timeline, but they are not the same. One is Sony XAXC-S, the other GoPro, which is MP4.

I'd like to convert them both to a ProRes 4K format, but GoPro specifically states that one should leave optimized media unchecked when importing their footage into FCP X In order to be able to go back and make changes to the original GoPro footage, such as angle of view, within their GoPro Studio proprietary media converter.

Having said that, this GoPro issue is really throwing a wrench into things as theit support does not want to answer any questions related to 3rd party NLEs. Here is what I asked them, but have not gotten a response other than, "case closed:"

"When exporting to the GoPro CineForm codec using 3rd party applications, there is an encoding limit of 1920 x 1080 resolution with the free version of GoPro Studio. This means that if you wish to encode at resolutions higher than 1920 x 1080 using 3rd party applications, you will need to use GoPro Studio Premium or GoPro Studio Professional (available at cineform.com)."

So, now I'm trying to find an answer to the following question:

Can original camera card media that was shot in 4K on Hero 4 Black be imported into another NLE and be transcoded to a 4K format, or does one need to use the legacy GoPro Studio Professional software to first convert the footage before ingesting into another NLE in order to obtain 4K quality?

I know that Adobe CC supports ingest of original GoPro camera card footage for direct editing of the MP4 files in Premiere Pro, but I don't want to switch out of FCP X. My question is whether or not I'm going to lose quality if I import and optimize the original GoPro MP4 files into ProRes? I ask this because the difference in size between a 32GB GoPro SDXC media card and that same card transcoded to their highest quality Cineform codec is tenfold, 328GB.

Thanks for the quick reply, Russ. I have indeed done the same tests on my own. One reason why GoPro recommends unchecking "optimize media" is so that you can go back and forth between FCP X and their GoPro Studio to make further adjustments to the footage, such as removing the fisheye view, something that can't be easily done in FCP X (unless there's a plug-in I'm unaware of), which is something one might not know if they want to remove or not initially.

However, since the MP4 file befomes exponentially larger when converted to the Cineform codec in GoPro Studio Pro (a legacy product that won't be supported after 12/2015), it seems to me that conversion process must be doing something to the file that could be lost if the original MP4 is simply optimized to ProRes in FCP X, and I don't want to sacrifice quality for speed or ease-of-use. Rather, I want to obtain the highest 4K image quality possible from the footage that was shot, but still be able to edit it alongside Sony XAVC-S. Had I known in advance that this would become an issue in post, I would have used a Sony Action Cam, which shoots XAVC-S, instead of a GoPro Hero 4 Black, but initial tests showed better quality imagery coming out of the GoPro.

Yes, to clarify in case anyone else wants to chime in:

To convert, or not to convert (to Cineform codec using GoPro Studio Pro), that is the question.

Would there be any sacrifice of quality between the following workflows invloving GoPro Hero 4 Black 4K footage edited in FCP X?

1. First convert GoPro 4K 24p MP4 files to Cineform codec (High, or F1, or F2 setting?), and then ingest into FCP X with "optimize media" unchecked (as GoPro recommends, but ending up with massive file sizes).
2. First convert GoPro 4K 24p MP4 files to Cineform codec (High, or F1, or F2 setting?), and then ingest into FCP X with "optimize media" set to ProRes ( resulting in smaller, more easily editable files, but still requiring conversion to massive Cineform files).
3. First convert GoPro 4K 24p MP4 using MPEG Streamclip (to... codec?), and then ingest directly into FCP X.
4. Import GoPro 4K 24p MP4 files directly into FCP X with "optimize media" set to ProRes (and forget any other initial conversion entirely).

My goal is to obtain the highest possible 4K image quality, but still be able to edit the footage on an FCP X Timeline alongside Sony XAVC-S S-Log-3 4K 24p files shot on a Sony a7sll. I am willing to edit using proxy media, but I still need to figure out how to get the best quality from the GoPro 4K footage.

Hi Tom, normally I would think the same thing, that the video would not improve by converting. However, according to the GoPro Studio User Manual for Mac Operating Systems (I've bolded text for emphasis):

Thanks, Tom. I'll post here if I ever get a definitive response from GoPro on all of this.

I still have to figure out a workflow, and was hoping that someone who has done 4K work with GoPro in the mix might help to define what that should entail. Adobe has an entire page dedicated to a GoPro workflow, but it doesn't translate to FCP X, nor does it address the 4K issue. Given that so many Hollywood films are throwing GoPro 4K cameras into the mix (such as Mad Max: Fury Road according to American Cinematographer), I would think it would be easy to find information about best practices for editing GoPro footage along with other file formats, but that's not the case.

I received a response from a Senior Tech at GoPro who said the following:

Firstly rest assured GoPro does have a vested interest in providing continued support for 4k editing in GoPro Studio. As you are aware 4k is more widely available to consumers hence our free GoPro Studio supports exportation in 4k in either H.264 or GoPro Cineform format.

Please find the workflow details below for editing and exporting 4k footage in Final Cut.

1. Start a new Project choosing the following settings:
   • 4k - 3840 x 2160 - 24p
   • Audio and Render Properties - Use default.
2. Import and edit all video and audio
3. Share Project
4. Export File or Master File
5. Select Video Codec
   • Apple ProRes 4444 (ProRes is a lossy video compression) - Larger File Size
   • H.264 (Substantially smaller bit rates) - Smaller File Size.
6. Select 'NEXT'
7. Choose 'Save To' location
8. Export File.

There is no need to import into another NLE and then transcode. The .MP4 file that the camera records in is supported by Final Cut. As you will see the workflow id actually identical to any other resolution. The only possible issue will be the size of the Render and Exported files. You may wish to export using Compressor to reduce the file sizes.