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Choppy Multiclip

Hi!

I'm having trouble with a multiclip in Final Cut 7. I have four angles in my multiclip and Final Cut can't seem to play the multiclip without the following happening:

After a few seconds it gets choppy and ultimately freezes. The audio continues though. When I hit pause, the freeze frame changes to the "current" freeze frame, as if the clip had rolled as normal.

I have changed the RT-settings to an absolute minimum (Playback video quality: Low. Playback Frame Rate: Quarter), but that doesn't help at all. Same thing if I click "Sync off", just to watch the current angle in Canvas - doesn't help.

The thing is, I made a multiclip containing only three of the four angles, and that clip works as a charm. It's like four streams is to much for the hardware to handle, but considering the workstation I'm working on that should not be a problem. Or should it?

Anyone had the same problem? And is there a solution, other than to wait for Final Cut X and hope for the best?

/Magnus

Here are the specs:

Software

Final Cut Pro 7

Hardware

Mac Pro

MacPro5,1

6-Core Intel Xeon

3,33 GHz

L2-cache: 256 K

L3-cache: 12 MB

Memory: 12 GB

Graphics

ATI Radeon HD 5870

VRAM: 1024 MB

Material

1280x720

Apple Prores 422 (HQ)

50 fps

Data Rate: 21,6MB/sec

Storage

Sonnet Fusion DX800 RAID

Posted on May 24, 2011 3:09 AM

Best reply

BenB

Level 6

12,103 points

Posted on May 24, 2011 3:54 AM

ProRes HQ? Really? What camera is your footage from? HQ is a CPU hog and can easily bog down in Multiclips. Unless this is footage from a RED or other high end camera, you don't have any reason to use ProRes HQ. DSLR & AVCHD footage should use LT, HDV should use 422.

View in context

33 replies

May 25, 2011 6:31 AM in response to MagnusLekberg

You need to be factoring the combined data rate of all four clips, since they're all streaming off your drive at the same time to create the multiclip.

I don't think your video card would cause this.

Do you have thumbnails and waveforms turned on or off in your timeline?

You mentioned that a multiclip created from 3 of your angles played fine. Have you tried creating that 3 angle multiclip with different combinations of your 4 angles? Perhaps one clip is simply corrupted and is choking your multiclip.

Your system should handle this. Confusing.

May 25, 2011 6:59 AM in response to thrillcat editorial

Also, make sure you do not have Video Scopes Playback selected in your timeline. If you must see the scopes during playback, leave Video Scopes Playback selected and select Limited Lines (fastest).

The idea is to reduce the load as much as possible.

Again, investigate the possibility that your Fusion DX800 has a drive that has gone paws up. If you're not sure how to do this, call Sonnet Tech Support.

May 25, 2011 7:15 AM in response to MagnusLekberg

The problem still sounds like a disk throughput problem...

Remember, your RAID may be able to do that data rate from a single file, but with multiclip, you're reading from 4 separate files. That can involve considerable latency as the drive heads may have to be jumping all over the platters.

Patrick

May 25, 2011 7:23 AM in response to Patrick Sheffield

Jeez, Patrick, why the negative vibes? 😉

BenB

Level 6

12,103 points

May 25, 2011 8:13 AM in response to thrillcat editorial

I'd chop that Multiclip up into smaller sections. An hour long Multiclip could be too much.

May 25, 2011 8:28 AM in response to BenB

He mentioned that he has tried an approx 60 second 4 angle multiclip with the same issues. I've done 90 minute 6-7 angle ProRes multiclips without a problem.

Magnus, how big is your project file?

May 25, 2011 8:36 AM in response to Patrick Sheffield

Especially if the RAID 5 set is degraded due to a drive that's gone down. The OP still hasn't clarified if he's checked that.

Studio X

Level 7

27,229 points

May 25, 2011 2:59 PM in response to Brian Conner

Brian Conner wrote:

Especially if the RAID 5 set is degraded due to a drive that's gone down. The OP still hasn't clarified if he's checked that.

I concur. I'd bet the external raid device is not playing up to spec.

May 25, 2011 5:13 PM in response to Studio X

AJA Disk test should confirm his throughput...

Patrick

May 25, 2011 6:13 PM in response to Patrick Sheffield

Upthread, the OP says Aya Stem Test benches the DX800 at 650 MB/sec. But that array should be giving him something in the 800 MB/sec range. Sunds like 1 drive is down, which could create throughput problems beyond the raw data rate.

May 25, 2011 6:34 PM in response to Brian Conner

Stem should be System (Aja System Test)

May 25, 2011 6:54 PM in response to Patrick Sheffield

I agree with the thoughts about it being disc throughput related.

If it worked with ProRes LT, but not with ProRes or ProRes HQ that seems to suggest that ProRes LT's lower bitrate is solving the multiclip problem.

Perhaps you multiclip with LT, then reconnect to HQ?

May 25, 2011 6:59 PM in response to soundman1024

I suggested that upthread, but I think the OP has left the building.

cineblue

Level 1

19 points

May 25, 2011 10:44 PM in response to thrillcat editorial

I've done 90 minute 6-7 angle ProRes multiclips without a problem.

I'm curious, what quality were the ProRes? HQ? Were they 720 50p or superior? What was the data rate of those clips? What was your setup?

It would be interesting for everyone to know. Because the OP's situation and question is pertaining to his particular setup and material, but in the interest of everyone reading, it would be interesting to know if it's possible to edit a hour long 4 camera show filmed in HD and converted to ProRes HQ on a MacPro like the OPs

MacPro 5,1, 3,3 GHz 6-Core Xeon with 12 GB of RAM

Perhaps the OP has left the discussion because he found that using LT and Proxy he could edit the piece as I suggested upthread and for that he gave me the 5 points that I have since shoved up my bum. 🙂

May 26, 2011 3:02 AM in response to cineblue

Oh, I'm not going Elvis on you quite yet. I live in Sweden, though, and the time difference between Sweden and North America (where I think some of you may live) is around 6-9 hours. So when you post replies I sleep, and vice versa.

The RAID is working fine, which I'm sure everybody is glad to hear. It has 8 hard drives, of which 7 is working furiously. Number 8 is a hot spare, which would explain the somewhat slower output data rate.

I've decided to do multiclips of Apple ProRes 422 (LT) files, and then reconnect to the HQ, as many of you have suggested. But I'm also going to test multiclips in FCP X, maybe this will be my pilot project with the new software.

As for the technical problem, I'm still not convinced the ATI Radeon HD 5870 is up to par with the high data rate delivered by the RAID. If it's memory bandwidth is 153.6GB/sec, and memory bandwidth is comparable to the data rate possible, this would explain quite a lot. But of course, I could be wrong about this. A reinstall of the whole thing down to every component might just help.

/Magnus

Choppy Multiclip