I don't understand Share-->Master options

[Darin Boville]

I have a Sony AX-100 shooting in 4k. What is want to do is shoot clips, import them into Final Cut, trim the footage, then maybe add a title or do minor color correction, and then output the file.

For the output file I want the highest quality possible without adding extra storage space requirements that don't add any image quality value to the footage. I may want to work on the clip at some point in the future so I don't want to lose any real data. But I have a lot of clips to store so storage space is a consideration.

Here's what I see:

A 10-minute clip, imported into FCX and viewed in the finder is 4.1 GB.

If I take a single minute of that clip and output it using share-->master, here are the options I see:

444xQ at 46.1 GB
444 30.8
422 HQ 20.6
422 13.8
422 LT 9.64
422 Prox 4.35
H264 1.6
8 bit uncompressed 91.92

I don't understand what I'm doing, obviously. I would expect am output file, without data loss, to be about the same size as the original file. Given the one-minure excerpt here that would be on the order of 0.4 GB.

What option is the right one for my needs?

--Darin

[Nate Haustein]

The H264 would probably be a good choice for a final deliverable file. FCPX won't render into XAVC-S, so you need to use the presets in FCPX or create your own presets in Compressor.

The H264 file is 20,000 kbps I believe and should look very good for internet/computer/home use.

[Wacharapong Chiowanich]

On the Mac platform you have to either export to one of the ProRes formats to preserve the original quality of the imported file or sacrifice some (usually little) of the original quality by exporting to H.264 (Better Quality option) because FCPX cannot export to XAVC-S which is the recording format of the Sony AX100.

IMO, exporting to ProRes LT would be the best compromise if you plan to rely solely on the exported/edited files for future use and have no original files kept in your archive. ProRes 422 could be a better option if your storage space allows but anything higher than this I think is pretty useless in terms of quality preservation due to the limited data recorded by the XAVC-S format.

[Darin Boville]

Does that mean that I might be better off using a program that does offer XAVC-S as an export option?

I'm surprised about how large these files sizes are getting. The one minute XAVC-S (maybe 0.4 GB) blows up to 13.8 GB with 422--and even at this I think you are suggesting that there is some trivial loss of quality. With these sorts of numbers the tiny original files could easily be stored along with the huge FCX export without additional harm. But if I have, say, fifty of these videos then I'm looking at several hard drives of storage--for video that originally didn't fill the memory chip in the camera!

Have I made an error in my numbers? It's a little hard to get my head around.

The videos, by the way, are intended for display on a 4k screen in a museum/gallery setting.

--Darin

[William Hohauser]

Welcome to the world of 4K. Your camera is filming in a highly compressed format with several frames referenced to a key frame while FCPX is exporting into a modestly compressed format, ProRes, where each frame is compressed individually. ProRes is a professional standard for finished projects. For storage you will have to explore your options, I would keep the original files and your FCPX project with the adjustments for future outputs. No need to keep a ProRes version unless you consider it a finished work.

[Darin Boville]

Originally Posted by William Hohauser

Welcome to the world of 4K. Your camera is filming in a highly compressed format with several frames referenced to a key frame while FCPX is exporting into a modestly compressed format, ProRes, where each frame is compressed individually.

Oh! Now it's all starting to make sense. So basically the ProRe codec are like bunch of JPEGs all in a row rather than a more advanced algorithm that only records the changes from one frame to the next. So the real bottleneck here is still raw processing power? And the codec are all geared toward playback (which plays) rather than a storage format (which would need to be decoded first)? Ahhhh......

Originally Posted by William Hohauser

For storage you will have to explore your options, I would keep the original files and your FCPX project with the adjustments for future outputs. No need to keep a ProRes version unless you consider it a finished work.

It never occurred to me that that would work--seems obvious in hindsight, like all good ideas. :) Is there an automated way to do this or do I just do this by dragging source clips from the finder and somehow saving the project adjustment files with them?

Thank you William, very helpful.

--Darin

[Darin Boville]

Just to update my initial post, I decided to actually export files from that one-minute test video to see what the real-world file sizes would be at various settings vs trusting the estimate.

The first thing I noticed was that the estimates this time were very different--consistently one-third of what I posted in the original post.

Here are the actual file sizes of the one-minute clip (again, the original source was a ten minute video at 4.1 GB):

ProRes 422: 5 GB
ProRes 422 LT: 3.34 GB
ProRes 422 Proxy: 1.49 GB
H264: 517 MB
Uncompressed 8-bit: 32.7 GB

--Darin

[William Hohauser]

Originally Posted by Darin Boville

Oh! Now it's all starting to make sense. So basically the ProRe codec are like bunch of JPEGs all in a row rather than a more advanced algorithm that only records the changes from one frame to the next. So the real bottleneck here is still raw processing power? And the codec are all geared toward playback (which plays) rather than a storage format (which would need to be decoded first)? Ahhhh......



It never occurred to me that that would work--seems obvious in hindsight, like all good ideas. :) Is there an automated way to do this or do I just do this by dragging source clips from the finder and somehow saving the project adjustment files with them?

Thank you William, very helpful.

--Darin

This is something you have to decide. I shoot long interviews with 2 cameras that make roughly 14 minute long files that FCPX doesn't recognize as contiguous recording. For these I use a great program called Edit-Ready to stitch the camera files together so I can do easy multi cam edits. I put these files in a folder and create a FCPX library in that folder. WhenI shoot with my GH3 cameras I can import directly into a FCPX library. Either way I have just one folder or file to transfer with everything in it.

[Mark Ahrens]

I would think your starting point would be what device is going to play the video in the gallery/museum and output the best quality that the device supports.

[Darin Boville]

Originally Posted by Mark Ahrens

I would think your starting point would be what device is going to play the video in the gallery/museum and output the best quality that the device supports.

What I'm hoping to get to--still pondering and experimenting--is a master file from which I can then make derivative conversions to suite the playback device. I don't want to leave the "master" as the source file inside FCX (with adjustments) since I'm worried that in years down the road there will be some incompatibility or other.

I thought I would just export them as 422 but was shocked at how much the file size grew. So now I have a storage problem. My ideal would be a highly compressed format, but as lossless as possible. It would not need to be suitable for fast editing. I would be happy to wait for it to re-encode into some other format should I wish to modify it in some way.

--Darin

[William Hohauser]

Choosing h264 instead of ProRes when you master is a possible route. The files are very good although I personally would rather recompress from ProRes.

[Mark Ahrens]

Late reply but . . . as far as i know, ProResLT is your only option to reduce size without going to the double compression inherent in a H264 master.
That said . . . any other compression cycles would be going to what? 720p or smaller?
Go for it, it will look fine.
If it's a master work that you want to preserve, then, you shouldn't even be worried about space; get a 5TB backup drive for $150.