FCPX & Sony RX100V 4K?

[Ray Sherman]

Thanks for replying…….. Would you suggest transcoding to .MOV? Thanks again, Ray

[Joe Marler]

[Ray Sherman] “Would you suggest transcoding to .MOV? Thanks again, Ray….”

As I previously said, you simply need to import your camera’s XAVC-S (a form of H.264). That is your camera’s native codec, and is the best available quality for your camera at 4k. You do not need to transcode to optimized media for quality reasons. If you need to transcode to proxy for performance reasons, that is OK. You do not need to externally transcode to .MOV (maybe you mean ProRes). .MOV is a Quicktime container format that may contain either H.264 or ProRes.

You can optionally re-wrap (not transcode) the XAVC-S before import using EditReady, but IMO this isn’t needed. You can import XAVC-S content with “leave files in place” if you copy the video files out of the media folder before import. Using EditReady does preserve all original metadata prior to in-place import, but so far I haven’t seen problems with not using it (on XAVC-S). AVCHD is very different however — the bare files should never be imported to FCPX using “leave files in place”. In that case using EditReady should be mandatory: https://www.divergentmedia.com/editready

Transcoding to optimized ProRes media will increase your media size by about 6x, greatly increase the I/O burden, and will not help quality any. You cannot create resolution or color data from nothing. It will help editing performance but so will proxy and without the size penalty and I/O load.

Since FCPX always edits H264 using a ProRes buffer, editing H264 media does not handicap color correction, compositing, gradients or most anything else.
Transcoding to ProRes does not reduce the need for a powerful GPU. E.g, compute-intensive effects such as Neat Video are just as slow whether the material is ProRes or H264. It is true that some editing software which does not use Quick Sync can struggle with 4k H264 or even FCPX can on a Xeon-based Mac Pro since Xeon CPUs (with few exceptions) don’t have Quick Sync. However transcoding to proxy will greatly increase performance.

Proxy does not support alpha channel (ie transparency) data so in that specific case using optimized ProRes might be necessary. Optimized media might be needed if editing mixed H264 1080p and 4k material. FCPX has a global proxy mode so all content is viewed either as proxy or optimized/original. Proxy of 4k is 1/2 the linear resolution (1/4 the total pixel resolution), or 1080p. In that case there’s plenty of resolution for editing decisions. However proxy of 1080p is only 960 x 540, which can be a little low for some editing decisions. This might necessitate transcoding to optimized media to obtain good performance on 4k yet retain original resolution on 1080p for editing decisions.

You can edit the 8-bit 4:2:0 4k H264 material in a 1080p timeline and export it as 10-bit 4:4:4 1080p. That is not creating bit depth and improved chroma sampling from nothing, but *trading* resolution for it. If you don’t crop it and export to ProRes it will supposedly become true 1080p 10-bit 4:4:4 on output, although I haven’t put this under a microscope to test it. See white paper by Barry Green “The Benefits of Shooting in 4k”: ftp://ftp.panasonic.com/provideo/agdvx200pj/4kbenefits_techbrief.pdf

[Claude Lyneis]

That is really helpful in understanding dealing with 4k and the Sony formats. I am close to buying a Canon XF-400 and will be faced with similar decisions since it also can do 4k and some form of XAVC.

[Ray Sherman]

Wow….. Thanks Joe for the awesome information! As a newbie, I can’t thank you enough! I’m going to save this in my notes to reflect back on as needed. Thanks again and for taking the time in explaining the best methods, I sincerely appreciate it. Ray