ProRes Multiclip Editing in FCP

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Shizznid

Active member
So I've been editing with Final Cut for years, and I've been using the Multiclip Editing feature to cut multi-cam SD footage with great success.

Last week, I started editing my first multi-cam footage from 2 HMC150's. The footage was transcoded using Log & Transfer, into the Apple ProRes format.

However, I couldn't seem to play back the footage in the multiclip editor without dropping frames, stuttering, etc. Single streams of video playback without any fuss.

I'm guessing my system isn't up to spec to handle this much data simultaneously. I'm using a Mac Pro 2 x 2.8 GHz Quad-Core Intel Xeon machine, with 10 GB of RAM. Or maybe it's my scratch drive (where the footage lives) - which is a 7200 rpm Firewire 400 external drive.

Anyone else have experience with this? Thanks in advance!
 
on a 2.5 year old 8 core (Clovertown) with 12 gigs of ram and 512 graphics i was able to play back 11 clips of SD in "Multiclip" mode. it was huffin and puffin at that point on a single 7200 rpm drive. scrubbing through the timeline was very rough. this was the MAX and it wasnt pretty.

now i will bring it up to date...
current machine is 8 core 2.93ghz Nehalem/16gb ram/4870 graphics. apps only on stock startup disk. data on a Seagate 1.5TB 7200rpm drive (INTERNAL). (no raid). Leopard / FCP7.

here are a few tests using various framerates and quantities of video streams...

3----streams of 1920x1080p 24fps XDCAM EX. very smooth during execution with full framerate, no real stress on the computer, CPU average 160% usage, scrubbing playback afterwards is very smooth..

6---steams of 1920x1080p 24fps XDCAM EX. very smooth during exectuion, dont feel any stress on the computer while executing, CPU average 285%, scrubbing playback is a little stuttery but not a biggie. playback is smooth with full framerate.

8---streams of 1280x720p 60fps XDCAM EX. very smooth during exectution with NO sense of stress, CPU average 425%, scrubbing playback is a bit rough like the 6 stream above, playback is smooth with full framerate.

11---streams of 1280x720p 60fpx XDCAM EX. a bit stuttery during execution with some sense of stress, CPU average 416-465% (CPU jumped around more than all the others), scrubbing afterwards is almost painful being rough and jumpy, playback is mildy "stroby" & fluttery. for critical things that need a keen sense of timing...this would not work for me since its to stuttered. for a simple down and dirty cuts only for preliminary viewing...i could tolerate this if i had to.

i am shocked that it did this good. i havent noticed much of an improvement from general usage from my new 8 core over my older Clovertown 8 core from 2.5 years ago. up till this point i hadnt tested the multiclip. my kid has my older 8 core. i will try to get in there and test these exact same sessions on that machine and see if it will keep up with my current setup.

being that i could only get 11 streams of SD on my older 8 core i am shocked that i am getting almost the same on the new 8 core. in fact i think that 11 streams of HD is currently running slightly better than the 11 streams of SD a few years ago. maybe the hardrive is making the difference???

i always have 7200rpm drives with seek time between 8.5-8.9msec.

i would love to hear some test results from others as well.

to the OP. could you be a little bit more specific as to how many streams you are able to get before it gets funky? are these 1080p? framerates? what are your settings for playback in the timeline as far as *RT*. mine are *unlimited, high & full framerate*. i did start to get the orange colored indicator line above the clip ***only*** after the 3 clip stream.

all the detail you can give would be helpful.

{{EDIT}} my 1.5TB data drive is also my scratch drive.

david
www.davidprobst.com
 
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David P - thanks for the response. WOW - based on what you've experienced, I shouldn't have any problem! Hmmm...

I was only trying to run 2 streams. A master shot, and a b-roll angle. Both are synced and continuous. Both streams are 1080 - 24p.

I tried changing the RT settings to lower quality, and it didn't help at all.

I'm also running the apps only on the startup disk. External drive is a Western Digital 1TB "MyBook" (I have 4 of these drives, and I've never had a problem with them.) My graphics card is "stock" (as delivered with my Mac Pro) - ATI Radeon HD 2600

Like you, I've been able to run nearly a dozen SD streams without a hitch.

Any other details I can provide to help diagnose this problem?
 
Sounds to me like you're hitting the bandwidth limit of FireWire 400. ProRes requires about 20Mb/sec per stream, so two streams maxes out FW400 even without allowing for any overhead. You'd expect to be able to play a single stream reasonably well, but no more than that. Some of my old FW400 drives top out at about 18Mb/sec (dodgy chipsets, I think), and I wouldn't dream of putting ProRes on them except for archival purposes.

With FireWire 800 drives, three stream of ProRes is possible, but you get used to the 'dropped frame' error dialogue. With a single, average SATA drive (either internal in a 8x2.8 Mac Pro or in an eSATA enclosure) I can cut three streams of ProRes comfortably, with only very occasional issues.

In Final Cut, the setting that makes the biggest difference for ProRes playback, I believe, is setting RT playback quality to 'medium.' This makes a significant difference on my MacBook Pro. But it won't help if you can't physically move the data around.

My advice would be to buy a new terabyte SATA drive and pop it in one of your Mac Pro's internal bays. Should be good for 100Mb/sec or so. Alternatively, run one of the streams from the boot drive, which should reduce the load on your FW400 bus.
 
hi Shizznid,

i think a problem with my test is that i ran the SD multiclip from an older 8 core and the HD multiclip from the newest 8 core. not an apple to apples comparison.

my son uses my older 8 core. i will try to test some multiclip scenarios on his computer as well. he uses an internal 1TB drive to edit on he does have a firewire 400 external that is his backup plus uses it to import. he has some ProRez variant files on that drive (whatever log and transfer converts to from the HMC150). i would like to see how his firewire 400 handles these files compared to his internal 1 TB.

i do agree with JonathanS that using a SATA internal would be better than firewire 400. i dont usually work in prorez much so i cant say how different it would be to the XDCAM EX. i did do a little testing when i got FCP7 using prorez LT and Proxy to see if i go better performance than the XDCAM EX files. i couldnt feel any notable difference but i have to admit that my tests were very loosey goosey.

one more thing...when i did the multiclip testing i only used *one* audio stream in all of the tests.

thanks
david
www.davidprobst.com
 
Thanks for all the help, guys. I agree - I think the FireWire 400 scratch drive is the achilles heel. I've been working with SD footage for so long, I didn't really think about it.

Gotta love the 4 plug-n-play hard drive bays in the Mac Pro. I'm off to Fry's for a couple SATA drives today. Thanks!
 
my above post show tests for Multiclip on a new 8 core 2.93ghz (read above for more comparitive specifics).

NEW ***ProRez422*** TEST ON 2.5 year old (Clovertown) Mac Pro 8 core 3.0ghz / 12gigs ram / 512mb 1900xt graphics / Leopard / FCP7---RT setting /Unlimited RT-High-Full. when i did the multiclip testing i only used *one* audio stream in all of the tests.



FIRST TESTS for Multiclip performance...using an OWC Neptune firewire 400 external hardrive. this disk contained the video data and was the scratch disk as well.

2---streams of 1280x720p 60fps ProRez 422. very smooth during execution. felt no real stress on the computer, average CPU usage 274%. playback was smooth with full framerate, scrubbing afterward was mildly rough...no real problem.

3---streams of 1280x720p 60fps ProRez 422. ****BAD****! could not execute an edit. a few times it still showed the edit cuts only after stopping the timeline. EXTREMELY WHACKED! whats even more odd is that observing the CPU usage while trying to do a multiclip pass...the CPU usage actually stopped working near completely. could jump from around 300% to...40%...like it just didnt recognize that i was trying to do an edit. so yes to the OP...firewire 400 with more than 2 HD prorez streams does not work.



SECOND TESTS for Multiclip performance. i now switched to an internal 1TB SATA drive. the 720p 60fps ProRez 422 were on this internal drive and it was the *SCRATCH* drive as well.

2---streams of 1280x720p 60fps ProRez 422. smooth execution and playback with smooth scrubbing after the fact and no stress on the computer. CPU average usage 275%.

3---streams of 1280x720p 60fps ProRez 422. smooth execution and playback and felt no stress on the computer. near perfect scrubbing after. CPU average usage 397%.

4---streams of 1280x720p 60fps ProRez 422. smooth execution and playback. felt no stress on the computer but scrubbing after was a little rough but still tolerable. CPU average usage 512%.

5---streams of 1280x720p 60fps ProRez 422. smooth execution and playback. felt no stress on the computer but scrubbing after was getting pretty rough. CPU average usage 565%.

6---streams of 1280x720p 60fps ProRez 422. ***NOPE***. sort of like the "3 streams" on the firewire 400 external. very erratic and non usable.


other info...the internal SATA drive was only 1/3rd full. the firewire 400 was 2/3rds full.

i guess the only thing left to do is to try the ProRez422 on my new 8 core using exteral firewire and internal SATA (since the above tests were with XDCAM EX 720p 60fps & XDCAM EX 1080p 24fps). maybe this would illustrate the difference between the two *different* 8 cores?

for the OP. this is no brainer that the internal SATA is the only way to have success with Multiclip editing. it is a little interesting though that you couldnt even get **2** HD streams to play. my guess is that the WD mybook does not have as fast of a "seek" time as my OWC Neptune?

{{EDIT}} i just remember that the OP was doing 1080p. maybe thats why you didnt even get 2 HD streams to play and i did since i was only doing and XDCAM EX 720p 60fps. (?)

good luck to you,
david
www.davidprobst.com
 
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