Solving Dropped Frame Errors

[ This article was first published in the May, 2007, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe. ]

There are three questions I get asked all the time:

• How do I trash preferences?
• How do I deal with images?
• How do I deal with dropped frames?

The first two are already covered in articles in my library (Click the question to read related article.) However, this last one I haven’t really addressed. So, here is a quick checklist you can use to solve a dropped frame problem.

In general, dropped frame issues are caused by a hard disk that is too slow to keep up with the video format you are using.

Here’s an article that provides an overview of hard disk speeds compared to video data rates.

NOTE: By the way, if terms like RAID 0 or RAID 1 confuse you, read this short explanation of how RAIDS are defined.

System Setup Issues

1. Make sure your hardware is supported by Final Cut – check Apple’s web site.
2. Make sure you are not using a hard disk connected using USB.
3. Make sure your drive spins at least 7200 RPM, many inexpensive drives are slower.
4. Don’t capture media to your internal boot drive.
5. If you are using FireWire drives, make sure your total cable length is less than 15 feet total among all devices.
6. Make sure all your data drives are formatted for the Macintosh (Utilities > Disk Utility > Erase tab — if the format popup menus says anything EXCEPT Mac OS Extended or Mac OS Extended Journaled you may have problems.)
7. If you are using a third-party hard drive or RAID, make sure you have the latest drivers.
8. Disconnect all external devices. Reattach one at a time to see when the problem recurs.
9. Adding a second FireWire bus, via PCI card, can also solve data bottlenecks.

Operational Fixes

1. Make sure your Easy Setup settings correctly match the video format you are capturing.
2. If problem occurs during playback of an RT sequence, render the sequence.
3. If problem occurs during a rendered sequence, delete render files for that clip (Control+B) and re-render.
4. Make sure you have at least 20% free space on the hard disks you are using for capture.
5. Save your work, quit, and restart Final Cut Pro.
6. Save your work, quit, and shut down your computer. Wait 30 seconds, then restart.
7. If the room temperature is too hot, let things cool down.
8. Make sure AC power is not fluctuating wildly.
9. Do a Safe Boot on your boot disk. (Click here to learn how.)
10. Repair permissions on your boot disk. (Click here to learn how.)
11. Run Utilities > Disk Utility and repair the disk containing your scratch disks.
12. If you own Disk Warrior X, rebuild the disk directories on the disk containing your scratch disks.
13. Using System Preferences > Accounts, create a new user. Log into that new user. Restart Final Cut and see if that fixes your problem; if so, you have corrupted operating system preferences.
14. If all the prior steps don’t work, then trash your FCP Preferences.

UPDATE

Herb Issacs writes:

Why do you say not to use an internal disk to capture? Isn’t the internal bus faster than firewire input?

This was amplified by comments from Trent Anderson:

I frequently get dropped frames, and the error message at the bottom in red says, RT Extreme has determined that your hard drive is too slow, please increase the speed of the hard drive. Well, it is 7200 RPM, and I don’t see how I can get a faster one.

 

I notice that you said to not save to an INTERNAL hard drive. It would seem to me that having those things set to an External hard drive, via Firewire, would be even slower than going to an internal hd.???

And from Ben Balser:

Reading the newsletter, and in avoiding dropped frames you say, “2. Don’t use an internal drive to capture media.” Why not? It’s the most efficient and best method to capture without dropped frames. I don’t understand why you mention this. There must be something I’m not aware of.

Larry replies: Herb, Trent and Ben – thanks for pointing this out. I stated this poorly. What I meant is not to capture to your internal boot disk because it doesn’t have the ability to service the operating system, all running applications and still feed media reliably over time. It isn’t an issue of bus speed, it’s an issue of contention, rotation speed, and priorities. Complicating matters is that most laptops spin their hard disks slowly to save battery life.

An internal, second drive is perfectly acceptable.

UPDATE – Dec. 2007

I’ve recently learned that the Canon XL-1, and perhaps other Canon cameras, must not be directly connected to a FireWire drive. The chip set the camera uses does not communicate properly with the drive, causing dropped frame errors. This is a Canon problem, not a hard disk problem.

The only known solution is to add a PCI-based FireWire card to provide a second FireWire bus (if you have a tower) or to capture to the internal drive of the computer (if you have an iMac or laptop), then copy the files after capture to your media drive. It is never a good idea to edit video files stored on your boot drive.

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