Problems Playing Back Your Media

     

Sometimes improper settings can cause problems with playing back your picture and sound files in Final Cut Pro. The following sections explain the most common solutions to these sorts of problems.

You Can't View External Video or Hear Audio Playback

Make sure you have set your system to view externally. This setting is at the bottom of the View menu. Set it to be All Frames or Single Frames. All frames will play all the video as you play from Final Cut Pro. Single frames display the current frame you are parked on in the active monitor and allow you to hear audio from your computer's speakers during playback.

Check the settings in the A/V Devices tab of the Audio/Video Settings. They have to be set to the proper outputs during playback for you to see external video and hear audio from your selected device.

Remember that real-time playback of your DV material is more taxing on your computer when you view external video. It only previews effects supported by your computer. Rendering all your effects makes this much easier on slower G4s. G5 computers have an easier time with this feature. They also play back many more effects in real time.

The Media Has Become Offline

If you move media files on your computer from the location where Final Cut Pro last saw them, they are reported as "Media files Offline," and those pesky red lines run through the clips in the Browser. Don't panic; reconnect them. Highlight any and all clips whose media suddenly "disappears" from the Browser, Ctrl-click them, and select Reconnect Media from the context menu that appears. You did just that when you installed the media files used in this book. Final Cut Pro assumes that the media files referenced by the clips in the Browser are where you left them last. So it's easy to reconnect them if you move them.

New to Final Cut Pro 4, FCP warns you if scratch disks are missing during its startup, so you have a way to mount it or restart your computer (in the case of SCSI arrays).

Be aware that if you have media files on external drives , they must be mounted on your desktop for your project file in order for you to find them. If you need information about where your media files were "last seen," Ctrl-click a column header in the Browser (other than the Name column) and select Source to open this column in the Browser. The location where your media files were last located is shown in this column. Look there to see if you've deleted or moved them, or if you need to connect an external disk drive to bring them back online. This is especially useful if you have changed the names of master clips or used subclips that don't reference the master clips they came from. This column also lists the name of the media file these sorts of clips referenced originally. You can turn off the Matched Name Only option in the Reconnect Media window to manually attach unmatched media filenames to clips in your project file. This is very handy indeed.

Audio Sync Problems During Playback

Most of the time, audio sync problems are caused when you record audio on your camera at 12 bits per sample, and you have captured the material into FCP at 48kHz, 16-bit (or vice versa). If you record audio at the 12-bit setting with your camera, capture it with an audio capture preset setting of 32kHz, 16-bit. If you have recorded audio at 16-bit, capture it at 48kHz, 16-bit. It's not recommended that you record at an 8-bit setting. You can check the bit depth recorded (12- or 16-bit) from the viewfinder in your camera via its menu display, or from the playback deck's menu display. Some decks have lights on them to let you know what bit depth they are playing back.

Sometimes dropping frames during capture can cause audio to go out of sync with your video. See the next section to troubleshoot this specific problem.

If your audio is out of sync with the computer's display of video playback when you view video externally and monitor audio externally, your audio will be in sync with the external video monitor.

Turning off file sharing is also recommended. Having other computers access your FCP station can cause problems while you are running Final Cut Pro.

Dropping Frames During Playback

If your clip is not being displayed at Fit to Window or smaller, and you are cutting off some of its edges because you are zoomed in on the Viewer or Canvas window, you can experience audio playback out of sync. Check to make sure that nothing is touching either window. They should not overlap each other.

Make sure that you are running the proper version of QuickTime for your particular version of Final Cut Pro. Also check to make sure that you are running the proper OS for the version of Final Cut Pro you are using. Final Cut Pro does not run under Classic. Check Apple's website for the proper set of software to be running with your version of Final Cut Pro. The correct version of QuickTime is supplied on your Final Cut Pro installation disk. Depending on when you bought Final Cut Pro, there probably will be updates to it, to QuickTime, and to the current OS you are running. You will want to investigate these. Apple routinely updates professional applications, and there will no doubt be an update or two you should run on a new installation. Run Software Update from your System Preferences and see what turns up. Check with the sites listed in Appendix E for any information you can find, or post a question to the Creative Cow or in the Discussion groups about any updates and your specific computer setup.

I highly recommend reading Philip Hodgetts' article on the subject of installing Final Cut Pro 4. It's in the Articles section of the Creative Cow at http://www.creativecow.net/.

Reducing the number of real-time audio tracks being monitored or mixing them down can also improve audio playback problems. Also, it's easier on your computer if all your audio files are the same kHz, because it doesn't have to convert different audio files with different kHz recordings. This becomes more critical the more tracks of audio you ask your computer to play back. If your computer is slower, you need to use one of two techniques to relieve its CPU from doing more work than it has to: You can use Item Level renders and the Audio Mixdown command.

When you select Item Level Audio rendering by selecting Sequence, Renders, any audio clips are resampled to match the sample rate of the sequence they are contained in. Also, audio clips that you've added filters to are rendered. FCP saves them as item-level render cache files. Audio-level mixing can still be done in real time, and mixing performance improves , because audio resampling and audio effects no longer rely on real-time mixing and playback for you to hear them. This reduces computer overhead and improves performance playback.

You can use the Mixdown Audio option (found under Sequence, Render Only) to render all the audio in a sequence (or a set of sequences if multiple sequences are highlighted in the Browser) to a single group of render cache files, one for each audio output assigned to the selected sequence. This can improve playback performance by eliminating the need for Final Cut Pro to do any real-time mixing or audio effects playback.

In either case (using the Item Level or Audio Mixdown command), these renders are rendered at the highest quality, regardless of the setting chosen in the Audio Playback Quality pop-up menu in the General tab of the User Preferences. Using them also improves viewing video externally and lowers the instances of dropped frames during playback.

You will experience better performance in general with this problem if you are capturing to a disk drive that is separate from your startup disk. Ultra SCSI 160 systems (such as those from Huge Systems) and Apple's X RAID Fibre Channel drives are the fastest . You cannot get drives that are too fast to play back your media. ATA 7200rpm drives are certainly fast enough for DV, but they are not fast enough for higher-quality video by themselves . Using faster disk drives or disk drive arrays improves playback performance in any resolution. Even adding a new, faster computer display card improves playback of real-time effects. Open GL is used to enhance real-time playback in your computer, so the faster your video display card, the better the performance you'll see.

Your computer's monitor should always be set to a 75Hz or greater refresh rate.

Don't fill up your scratch disks. You might be able to improve playback by defragmenting them, but filling them up is not recommended. Keep at least 50 to 100MB free.

Don't keep too many sequences open at the same time. If you are having problems, close all but the sequence you are working with. If you have a lot of sequences open, Final Cut Pro uses more RAM resources. Keep much RAM available for use in playing back the sequence you are currently working on to improve playback reliability. This varies from one computer to the next, depending on how much RAM is installed.

Try turning off mirroring on the desktop during playback if you are having troubles with consistent playback through your FireWire output. In general, don't ask your computer to do anything tougher than it has to do to perform the task. Especially take a look at your RT Extreme settings. Higher-quality settings are simply more taxing on your computer. Setting them lower can make a huge difference in playback reliability.

Sometimes when you're having problems with dropping frames during playback, you can export the sequence as a self-contained Final Cut Pro movie, and this new file will play back without problems. Try this especially with complicated, many-rendered, multiple-edit sequences. Again, you are asking your disk drive to simply do less work, because it has to play back only one media file, not many. This problem is also minimized by using faster SCSI drives, because less drive latency is associated with them (they have larger buffers). This issue is exacerbated with ATA drives playing back DV files. If you add drives with larger buffers, such as IBM's 180GXP series hard drives and others, you'll have a drive that will play back DV media more reliably. When adding ATA drives, look for those with 8MB buffers. Avoid those with only 2MB buffers.

Don't run virus-checking utilities and the like while running Final Cut Pro. You'll experience a lot of problems running virus checking, especially when capturing video. Running these checks is always best done when you aren't running any NLE. Virus checkers are the number one cause of failed captures, it seems. Remarkably few viruses spread to Mac users anyway.

In general, the fewer applications you run at the same time, the better. However, you can run more applications at the same time if you install more RAM in your computer. You cannot install too much RAM. This is probably the single most important upgrade you should consider when you want a faster machine but you aren't ready to buy a new one. It will serve Final Cut Pro as well as every other application you run .



Jerry Hofmann on Final Cut Pro 4
Jerry Hofmann on Final Cut Pro 4
ISBN: 735712816
EAN: N/A
Year: 2005
Pages: 189

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