FCPX and C100 footage...AVC MOVs vs MTS

J

Josh Bass

Veteran
so I recently started a personal project shot on several cameras including the C100.

We shot on several different days, same cards.

The first day, when I copied off a card to the disk, I took the whole "private" AVCHD package.

Every day after that, I dug into the package and copied the new MTS files from the stream folder.

Looks like FCPX doesn't like that.

Even though (I think) these are the same type of file (did not transcode, this is all native footage), it plays/scrubs the MOV files that were imported from the Private folder fine, does not like the MTS stuff at all (beach ball, hitches, long pauses during playback or when messing with browser). This is consistent with another project that plays smoothly, where all the files have .mov extensions but the Codec is AVC, so says Mediainfo.

I didn't even know this was a thing to worry about, so now that it is, what to do other than reimport everything from Private and start over, basically recreate the edit? Doesn't seem to like optimized media either, trying transcoding everything to proxy (not done yet). Again, personal project so nothing really at stake.
 
Very common mistake I've seen for about 10 years now...people separating the 'video' files from the metadata/folders. Definitely need to copy everything in its structure.

Proxy should playback fine once it's done...I imagine playback may be having a rough time now if you're trying to take a look as the process is still going. Need to of course flip the switch and be in the proxy mode as FCPX won't see/use them if you're still in the regular/optimized mode.
 
I knew about that when talking about P2, it was a huge no-no, didn't know it was a big deal with .mts files. Oh well, lesson learned, I guess. I think old FCP would probably auto-transcode to prores upon import, and this is the first FCPX project where I've imported C100 footage. With EX1 footage (the other camera I often work with) I never thought twice about it and just used XDCAM transfer to make movs before I start projects.
 
Next time, if you don't feel like importing into the software, just copy and paste all of the folders from the card(s) into another folder named "Card 1" or "Card 2", etc.

You can then later import those folders as FCPX will read them as cards.
 
Yeah, that’s what I’ve always done with the BPAV folders with XDCAM footage. I guess I’m not as used to it with the C100 using SD cards. Just stupidity on my part basically.
 
Josh Bass said:
...took the whole "private" AVCHD package.

Every day after that, I dug into the package and copied the new MTS files from the stream folder.

Looks like FCPX doesn't like that...
Click to expand...

FCPX can handle AVCHD fine, but NOT if you copy MTS files out of the bundle then import with "leave files in place". That will cause serious I/O performance problems, apparently due to FCPX dynamically re-wrapping each MTS file upon each reference.

Your best options are:

1 - Import from AVCHD bundle which means FCPX does not allow "leave files in place" and will re-wrap the files and copy to the library
2 - Re-wrap externally using EditReady, then import to FCPX using "leave files in place". This is super fast: https://www.divergentmedia.com/editready
 
Yes thanks. I ended up taking the time to reimport native from the “private” package to rewrap them as movs and re-lay those edits. Lesson learned, I guess. better now but sometimes it still hangs for a second or two (no beach ball but video doesnt pkay smoothly until after a couple plays through same piece of footage). I dont know if thats system limitations or the avchd (would it like prores better the way fcp7 did?). I also have stacks of connected clips in many areas cause I’m using them as auditions (turn one on, all others off). I know about the audition function but this seems more flexible. This project also mixes c100, gopro and 5Dm3 footage so maybe that has something to do with it. Lastly, even though there shouldnt be anything in the timeline I left the MTS clips i dragged in the library because I’d gone through and used markers to make notes on those before I restarted and seems like you cant copy and paste mulitiple markers from one clip to another, so theyre in there as kind of a reference for where certain key moments are in the footage.
 
Josh Bass said:
...ended up taking the time to reimport native from the “private” package to rewrap them as movs and re-lay those edits....sometimes it still hangs for a second or two (no beach ball but video doesnt pkay smoothly until after a couple plays through same piece of footage). I dont know if thats system limitations or the avchd ... I also have stacks of connected clips in many areas cause I’m using them as auditions ...This project also mixes c100, gopro and 5Dm3 footage so maybe that has something to do with it. Lastly, even though there shouldnt be anything in the timeline I left the MTS clips i dragged in the library because I’d gone through and used markers to make notes on those before I restarted and seems like you cant copy and paste mulitiple markers from one clip to another...
Click to expand...

What year and model of Mac hardware are you on? Normally any 2012 or later iMac 27 has no problem handling H264 1080p material (which AVCHD is). Starting in 2012 the iMac used the Ivy Bridge CPU which has Quick Sync that FCPX uses for hardware-accelerated H264 encode and decode. If it's a 2013 or earlier Mac Pro, Xeon doesn't have Quick Sync so that can be a problem for 4k H264. The iMac Pro uses Xeon but FCPX uses AMD's similar UVD/VCE hardware acceleration, producing about the same improvement.

If you have mixed 1080p and 4k material, 4k (without proxies) can be difficult on any hardware, even an iMac Pro. However this varies by codec -- there are many flavors of H264 codecs. 4k material from GoPros and XAVC-S from Sony's Alpha series are more sluggish to handle than 4k from a Panasonic GH4, GH5 or DVX200 -- even though they are all UHD 4k 8 bit 4:2:0 at about 100 mbps.

If you have *any* leftover MTS files in the library -- even if not used -- that can cause performance problems, at least when scrolling the Event Browser. I don't remember if it causes timeline problems but in general bare MTS clips imported with "leave files in place" can potentially poison performance even if only a few such clips are in a large library. This is often not well understood in the FCPX community which is unfortunate.

To my knowledge this problem is limited to AVCHD -- it doesn't happen when copying and importing bare files from other tree-oriented formats such as XAVC-S.

I think if you transcoded the MTS to optimized media it would probably eliminate that as a possible problem source. Of course that's 6x the size of the camera native files.

By far the best procedure with AVCHD is externally re-wrap it using EditReady. It is super-fast, automatically folds in the metadata to the re-wrapped file and allows FCPX to rapidly import using "leave files in place" with no side effects: https://www.divergentmedia.com/editready

Re your existing markers on the unused MTS clips, if transcoding to optimized media doesn't solve the perf. issue, maybe you could copy those to another library then delete them from the main library. That would preserve the markers and notes.
 
Didnt read that whole thing (will go back and take a look later) but no 4k material in project but yes you got it I left the MTS files in there with their markers for reference so may that’s it. It’s a 2017 Imac maxxes out execept for RAM (of which i have 16GB).
 
The 2017 iMac is really fast on H264 because the Kaby Lake CPU has updated Quick Sync logic and FCPX uses that on both decode and encode sides. 1080p material should never be sluggish or laggy unless there are compute-intensive effects like stabilization, video noise reduction, etc.

If there is some doubt whether the effects are causing it you can make a duplicate snapshot of the timeline (aka project) then select all clips in the timeline and use the command Edit>Remove Effects to strip all effects. Then evaluate performance on that copy of the timeline which has no effects.
 
Certainly not on every shot. I havent done much at all to the footage except some basic transform (scale up, flopping screen direction) so far. Sounds like its having the MTS files in the library. Im close enough to done that I’ll just leave em there and be sure not to do this again.

So editready is somehow better than importing from the card/folder with the “private” folder/avchd file in it? That procedure rewraps to .mov.

So is optimized media not simply prores 422? At least for this particular camera/media?
 
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Josh Bass said:
....So editready is somehow better than importing from the card/folder with the “private” folder/avchd file in it? That procedure rewraps to .mov...So is optimized media not simply prores 422? At least for this particular camera/media?
Click to expand...

Importing AVCHD from the card/folder mandates copying the media either (a) within the library, or (b) to an on-disk location specified by "Modify Settings" in the library inspector. EditReady allows importing re-wrapped media files using "leave files in place".

If you import AVCHD from the card/folder structure, the media is re-wrapped and should cause no performance problems. I personally prefer using "leave files in place" for all media, and using EditReady on AVCHD allows a uniform on-disk media layout.

Re optimized media, yes that is ProRes 422. If you create optimized media for the MTS files that were improperly imported, I think it will solve the performance problem. However, optimized media is 6x the size of H264 (the AVCHD codec), so it takes space and time to transcode. After the edit if you if you ever forget that was used as a workaround and the optimized media is deleted prior to archiving, then the problem would come back, maybe years later when nobody remembers how to fix it.

I think you could also create proxies but those are 1/2 the linear resolution and 1/4 the pixel resolution, so for 1080p AVCHD that's 960x540, maybe a bit low for some editing decisions.

This problem is unique to how FCPX uses AVCHD MTS files that are copied out of the folder tree. It does not happen for Sony XAVC-S files imported the same way. It is apparently caused by FCPX dynamically re-wrapping each "in place" MTS file upon each reference. Examination of the I/O histogram using the dtrace terminal command bitesize.d when FCPX was scrolling through a library with AVCHD .MTS files shows excessive small I/Os: https://joema.smugmug.com/Computers/FCPX-Event-Browser-Perf-Data/n-M7bG7L/i-bCH2XFX/A
 
That last bit is a little over my head but copy on the rest. In the future I will either copy “private” to a drive and import/leave files in place or import to library from card. Probably keep native either way. I mean timeline is already prores so it’s transcoding anyway. Although perhaps there’s a difference between color grading/correcting on the optimized vs native media, so hmmmmm.....
 
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