What Are Dropped Frames?
Dropped frames are frames that are unintentionally skipped during playback or output, either because the hard disk cannot keep up with the video data rate or because the computer processor cannot perform all of the applied effects in time. Some real-time playback modes allow dropped frames, while others require rendering to avoid dropped frames.
Dropped frames during editing are usually tolerable. However, during capture and output, dropped frames are almost always unacceptable. Dropped frames during playback are almost always caused by a hardware setup issue. When properly configured, Final Cut Pro should not drop frames.
Reporting Dropped Frames During Playback
There are two similar "Warning -- Dropped Frames" messages that might appear:
- The first message can appear if dropped frames are detected for any reason during playback
- The second is like the first, but with the explicit notification that the disk I/O speed is the reason for the dropped frames.
The suggestion to try increasing the speed of your disks involves using a hard disk solution capable of greater throughput; it's generally not possible to actually increase the spin speed of a given hard disk.
Dropped frames during playback may indicate that your hard disk or RAID is too slow or your video footage uses a codec that is too processor-intensive for your computer to handle. If you plan to output your sequence to tape, you will need to resolve this issue at some point. However, for editing purposes, you can disable the message that appears when dropped frames occur.
To disable the dropped frames message:
- Choose Final Cut Pro > User Preferences.
- In the General tab, deselect the "Report dropped frames during playback" checkbox.
Note: A separate option, "Abort ETT/PTV on dropped frames," controls whether Final Cut Pro cancels playback if frames are dropped during Print to Video and Edit to Tape operations. In most cases, you should keep this checkbox selected.
Improving Real-Time Performance
If the processing demands of all applied effects exceed the capabilities of your computer, you have several options to improve real-time performance:
- Reduce the playback video quality and frame rate in the RT pop-up menu in the Timeline or in the Playback Control tab of the System Settings window.
- Play your sequence using the Unlimited RT mode instead of the Safe RT mode.
- Choose Play Base Layer Only from the RT pop-up menu.
- Render any clips whose render status bars indicate they can't be played in real time before you play them back.
- Turn off external video monitoring.
Refer to the Final Cut Pro User Manual for detailed information on the options listed above.
Check your hard drives
It's critical for Final Cut Pro to have sufficient and continuous access to the files on disk that it's using.
Final Cut Pro may report dropped frames if your hard disk is not capable of the throughput required by the video format or number of streams you are using.
Final Cut Pro may also report dropped frames if your hard disk is extremely fragmented or damaged, or if your RAID or network-based storage contains a bad hard disk or is not configured correctly.
For more information about hard disk and storage considerations for Final Cut Pro, refer to the related Knowledge Base document, "Final Cut Pro: Choosing a Hard Disk"
Memory configuration in Mac Pro computers
To achieve optimal performance when running Final Cut Studio applications, memory DIMM pairs should be installed evenly on both risers. For details, refer to the related Knowledge Base document, "Final Cut Studio: For best performance on Mac Pro, install memory in risers symmetrically "
HD Video may require more RAM
Certain workflows involving HD Video may require additional system resources. Additional RAM may be necessary in order to avoid dropping frames when editing with High Definition video. For more information, see this document.
PCIe Card Slot Configuration
When using Final Cut Studio in a configuration that uses more than one PCI Express (PCIe) card, it's important to check that the expansion slots are configured to best utilize the bandwidth required by those cards. For more information, refer to the related Knowledge Base document, "Final Cut Studio: How to optimize PCI Express card performance"
Refer to manufacturer's support information for your video interface card, and confirm that you have the latest applicable software, drivers and recommended configuration:
Some video interface cards have the ability to automatically change the field cadence pattern (known as "pulldown"), performing an on-the-fly conversion from 24 fps to 29.97 fps. In some cases, this process may result in dropped frames being reported.
To determine if pulldown is the reason that dropped frames are reported, you can test by playing the video in the Timeline at its native frame rate:
Turn off external video in Final Cut Pro to avoid playback through the capture card.
- Choose View > External Video > Off.
- Next, choose View > Video Playback Video > None.
Update to the latest release of QuickTime
Get the latest QuickTime version with the most recent update. Choose Software Update from the Apple menu to install the latest update, or get it from the QuickTime Download page.
Disable "Mirror on Desktop"
Try deselecting "Mirror on desktop during Playback" in the A/V Devices tab in the Audio/Video Settings window. If your computer is running close to its capacity, this setting may prevent dropped frames.
Too many sequences open
A potential cause of dropped frames during output is having too many sequences open simultaneously in the Timeline. Especially with complex sequences with numerous edits, having more than one sequence open at the same time can affect playback performance. To resolve this, close all sequences except the one you want to output to video.
Lots and lots of little clips
Another cause of dropped frames is playing sequences with numerous short edits. Projects with a large number of short edits (for example, a video made up of several hundred ten-frame clips) can sometimes overwhelm a hard disk's ability to jump from one clip to another. In this case there are a couple of things you can try:
- Write out one single file. When rendering out using the Export QuickTime Movie command, disable the Recompress All Frames feature to save unnecessary rendering time.
- Another solution, particularly in the case of long sequences, is to split a single long sequence into multiple short sequences, outputting them to tape one at a time.
Using Final Cut Pro with Xserve RAID
If your Final Cut Pro workstations are connected to Xserve RAIDs, ensure that each Xserve RAID has been configured with the setting described in this document.
Using Final Cut Pro with Xsan
Xsan configuration may impact Final Cut Pro performance. To ensure optimal Xsan performance and stability, see this document.
Switching to Final Cut Pro from Soundtrack Pro
When you switch from Soundtrack Pro to Final Cut Pro, there may be a short period when Soundtrack Pro is storing data from RAM to the hard disk. If you try to play your project in Final Cut Pro while the data is storing, you may see dropped frame warning messages . The specific length of time of the data storage may vary depending on the sizes of the Soundtrack Pro and Final Cut Pro projects and the amount of physical RAM on the computer.
See the following documents for more information:
"Final Cut Pro: Choosing a Hard Disk"
"Final Cut Pro: Troubleshooting Basics"
"Final Cut Studio: How to optimize PCI Express card performance"
"Final Cut Studio: For best performance on Mac Pro, install memory in risers symmetrically"
User Manual: Final Cut Pro 6 User Manual (PDF).