Final Cut Pro Audio Filter Guide Part 1

In my conversations with other editors it became clear that for a lot of them (myself included), audio was a major area of weakness. They could handle editing, color correction, graphics, etc, but only knew a few ways of improving bad audio. This inspired me to create this guide to show people exactly what Final Cut Pro offers out of the box.

Filters in FCP are split into two categories - Apple Audio Units (AU) which ship with the operating system and are available to any application, and FCP-specific ones. Today I'll be giving details on the Audio Units with the FCP-specific ones coming in Part 2.

AUBandpass

The bandpass filter allows a certain range of frequencies to pass through and rejects any frequencies that are outside of that range. So if you have a person talking with rumbling traffic and high-pitched TV static in the background, you could use the bandpass filter to isolate the center frequencies of the person's voice.

AUDynamicsProcessor

This filter allows you to adjust the dynamic range of the audio (the difference between the loudest and softest sounds). Compression lowers the volume when it exceeds a certain threshold (making loud sounds quieter and therefore decreasing dynamic range). Expansion lowers the volume when it is lower than the threshold (thus making quiet sounds quieter and therefore increasing dynamic range).

Using a compressor and expander at the same time allows you to avoid overly-loud peaks while still maintaining dynamic range. The compressor will reduce the louder portions of the audio in proportion to their distance from the threshold (i.e. louder sounds will be reduced by a much larger amount), helping to even out amplitude variations. The expander will then take the quieter sounds and reduce their volume (again, proportionally), thus evening out the amplitude variation of the quieter sounds and increasing the dynamic range.

Imagine some music where you have loud crashing drums, a relatively quiet triangle and a trumpet somewhere in between. The drums are far too loud so you apply a compressor to bring them down. The drums are now a lot quieter but you've noticed that the subtlety of the triangle has been lost - it is now far too prominent. So you apply an expander to lower the volume of the triangle to an acceptable level. The AUDynamicsProcessor allows you to do this with one filter instead of two, which is a much more efficient use of system resources.

Attack time refers to the amount of time it takes for the compressor to implement a change in volume and release time is the time taken to reduce the compressor back to its original level afterwards.

There's a bit of debate over what "headroom" actually means as it's not a standard term. To the best of my knowledge, it refers to the number of dB the signal is permitted to exceed the threshold of the compressor/limiter.

The Dynamics Processor is a great way of compressing and/or expanding your audio to make sure that it fits within the audible range of your listening equipment.

AUDelay

This repeats parts of your audio. Dry/wet mix controls whether or not the repeated sounds overlap each other. 100% dry means no overlapping and 100% wet means full overlapping. Delay time is the delay before the repeat starts. Feedback controls the number of repetitions. Lowpass cutoff frequency stops certain low sounds from passing through the filter.

This filter is normally used for atmospheric effects. For more environmentally realistic results (at the cost of performance), I recommend the Reverberation filter that comes with Final Cut Pro.

AUDistortion (Leopard only)

This is a very comprehensive distortion filter offering a lot of control. I can't give much advice on the various parameters as I don't actually know what they mean and there's no documentation available. I would suggest adjusting by ear (it is probably worthwhile lowering the render quality while adjusting, and then raising it again once you're happy with the results).

AUFilter

I use this one a lot. It allows you to take 5 bands (5 ranges of frequencies) and adjust the gain up or down for each one. If a person's voice is muffled, increasing the gain on the higher frequencies can often improve this. I also sometimes use it to add bass to make a person's voice sound richer.

The bandwidth slider allows you to adjust the size of each frequency range, with the frequency sliders referring to the center of the range.

AUGraphicEQ

(image truncated for space reasons)

This is similar to the AUFilter above but the size of the frequency ranges cannot be adjusted and you can have up to 31 bands instead of just 5. This site provides a guide to common frequency ranges.

I've used this a couple of times to boost bass in a person's voice but I generally prefer AUFilter for this. It's good for removing or reducing a specific frequency range.

AUHighShelfFilter

This cuts off frequencies above the cutoff frequency, allowing lower sounds to pass through. The gain slider controls the amount that the frequencies passing through will be boosted.

Good for reducing high-frequency noise.

AUHipass

This reduces lower frequencies and allows higher ones to pass through. Resonance controls the intensification of the higher frequencies that pass through.

Good for removing low rumbling sounds such as traffic or for reducing very deep voices (I have had to do this at times).

AULowpass

Reduces (attenuates) higher frequencies and lets lower ones through, controlled by the cutoff frequency. Resonance controls the intensification of the frequencies that pass through.

Good for removing high-pitched noise.

AULowShelfFilter

Reduces frequencies lower than the cutoff frequency and lets higher ones pass through. This is similar to the AUHighPass filter above but this offers the ability to adjust the gain instead of resonance.

Good for removing low hums.

AUMultibandCompressor

This allows you to compress multiple bands (frequency ranges) individually for more control than a traditional compressor.

Pre-gain boosts the signal before it is processed which is useful if the signal is too low to be processed adequately by the compressor, and post-gain reduces the gain back to a normal level afterwards.

Crossovers 1, 2 and 3 define the point at which the previous band ends and the next one begins. Threshold refers to the amplitude level at which the compressor kicks in. Headroom, as stated above, probably gives you extra leeway above the threshold. Eq allows you to boost or lower each band.

Possible uses for the Multi Band Compressor include lowering the dynamic range of bass sounds without interfering with higher frequency sounds. This is different from the High Shelf Filter which indiscriminately cuts all bass below a certain frequency.

AUNetSend

AUNetSend is one of the most interesting filters in that it's not actually a filter. It does absolutely nothing to affect the way your audio sounds but what it does do is allow you to send audio across a network.

You need to have an application that implements audio generators. Audio editing applications such as Logic implement these. Alternatively, there is a tool called AU Lab in /Developer/Applications/Audio if you have the developer tools installed. Soundtrack Pro does not support this. Add an AUNetReceive generator to the track in your audio application, add an AUNetSend filter to your FCP audio clip and hit play in FCP. You should see "AUNetSend" pop up in the AUNetReceive configuration dialog. Select it and your track should be receiving the audio from Final Cut Pro. Note that it only appears while the timeline is playing in FCP.

In my testing, the Status parameter appeared to do absolutely nothing.

AUParametricEQ

This allows you to boost or lower the amplitude of a signal within a certain range. This is useful if for example you have a high-pitched buzzing noise in the background and you only want to eliminate that particular frequency and keep your higher sounds intact.

AUPeakLimiter

The Peak Limiter differs from a compressor in that a compressor reduces the volume of an entire track when a frequency reaches a certain level whereas the Peak Limiter reduces just that frequency. This is particularly useful if there is background noise on the track that would produce a noticeable fluctuation if the entire track were to receive a volume adjustment.

Attack and release time, as mentioned above, control the amount of time it takes for the filter to implement a change in amplitude, with longer times allowing a smoother transition. Pre-gain allows you to boost the volume before it reaches the filter in order to change the number of frequencies being affected. The limiting amount allows you to limit the amount that the filter will reduce the amplitude.

AUPitch

Adjusts the pitch of your audio, obviously. There are a LOT of controls though, and I have to admit that I don't have a clue what a Glb Trigger Thresh or a Loud Aggr K is. Effect blend blends the pitch-shifted audio with the original and is sometimes necessary to make voices sound natural. It is worth mentioning that I've gotten perfectly acceptable results by adjusting the first two parameters and not bothering with any of the others. I'd imagine that most people wouldn't have to adjust more than these.

I tried a Google search on some of these parameters but they only turned up forum threads where people were asking what on Earth they meant and no-one was able to solve their problem. If anyone does know, I'd be interested to hear from them.

This can be useful for making a male actor's voice more masculine (yes, I have had to do this!).

AURogerBeep (Leopard only)

This emulates the "roger beep" sound when someone lets go of the button on a walkie talkie. It will automatically play the sound when the audio level drops below a certain threshold for a certain amount of time (as if the person stopped speaking).

In gate threshold and in gate time refer to the time that the threshold amplitude must be maintained before the sound kicks in. Out gate threshold and out gate time refer to the amount of time that the threshold must be maintained before it ends the roger beep (adjust this if there is background noise). Roger level is the volume of the roger beep, and I think sensitivity and roger type are self-explanatory.

This is an effects filter with quite a narrow purpose so it's not something that gets used very often.

AUSampleDelay

Similar to AUDelay except that the delay time is set as a number of audio samples instead of a number of seconds.

Important:

Two of the above filters are Leopard only. If you use those filters and then transfer your project to a Tiger machine, you will receive an error message and will be unable to use those filters within the project.

Part 2 covers the filters built into FCP.

Pro Applications Update 2008-03

Don't know how I missed this. On Thursday, Apple released Pro Applications Update 2008-03 that patches both Compressor and Qmaster to 3.0.4.

Only one fix is included in the release notes but it's a big one:



I'm sure you know the drill by now - don't update in the middle of a project, only update if it's entirely necessary and make sure everything is backed up before you do.

This update is concerning to me for two reasons. Firstly, it requires OS X 10.5.5, completely locking Tiger users out. Presumably 2008-04 will require 2008-03 so will all patches require 10.5.5 from now on? Was 2008-02 the last Tiger-compatible patch for Final Cut Studio? There has been no official word from Apple on this.

Secondly, when you go to the download page it only lists 2008-03 as an option, with 2008-02 nowhere to be seen. How are you supposed to download Final Cut Pro 6.0.4? There's always Software Update but that's not really practical if you have a lot of machines. Apple seriously needs to rethink the way it offer patches to FCS users.

Mac OS X 10.5.5 released

Earlier this week Apple released Mac OS X 10.5.5. There are a lot of fixes but I will just list the ones potentially useful to Pro App users.

* Addresses stability issues with video playback, processor core idling, and remote disc sharing for MacBook Air
* Includes extensive graphics enhancements [not sure what this means really]
* Improves Time Machine reliability with Time Capsule.
* Addresses performance issues that may affect initial and in-progress Time Machine backups.
* Fixes an issue in which an incorrect alert message could appear stating that a Time Machine backup volume does not have enough free space.
* Time Machine can now back up items in ~/Library/Application Support.

Usual disclaimer applies - don't update in the middle of a project, don't update unless it's absolutely essential and always have a backup or clone of your system handy in case things go awry.

The iPhone Development Story

Mike Ash has an interesting and witty article about the hurdles he went through when submitting his application to the iTunes App Store.

He sums up at the end:


We are currently at the Step 3: Wait for your account to be verified stage. We have been at this stage for weeks now with no communication from Apple or any company appointed by Apple. And that is why none of our web apps have counterparts in the store as of yet. I fully agree with Mike that the iPhone development and submission processes are not up to the high standards we have come to expect from Apple and I hope this is a temporary phase.

[via TUAW]

Troubleshooting - FCS Remover does not remove files

I've received a few emails about this recently. Some people have been firing up FCS Remover, running it and restarting their machines - only to find that all their Final Cut Studio files are still there.

This is most likely a permissions problem. You must have the necessary write permissions for all files that FCS Remover will try to remove. If FCS Remover is unable to delete a file from your system, it will post a message listing the offending file in the Console. Go to /Applications/Utilities/Console to view these messages.

I am working on version 2.0 of FCS Remover which will give more information about any errors encountered, as well as allowing you to select individual items to remove. Keep an eye on this blog or our appcast feed.

P.S. I've also had a lot of mail asking me to convert our iPhone web apps to App Store applications. Digital Rebellion submitted an application to be a developer a while ago and we still haven't heard back yet. I will keep you posted as things progress.

QuickTime 7.5.5 released

Apple today released QuickTime 7.5.5 to coincide with iTunes 8, FrontRow and various other patches released today. The update is required for the latest iTunes update and also fixes vulnerabilities from maliciously-crafted movies and images. If you just use your machine for editing, this patch is not necessary. If you are likely to be using iTunes 8 or doing a lot of web surfing on your FCP machine (it's ideally best to avoid using your FCP machine for other purposes) I would advise waiting around for at least a week for any issues to surface.

As always, only update if it is absolutely necessary, NEVER update in the middle of a project unless there is a serious problem preventing you from completing the project, and always clone your disk before updating so that you have an exact copy of your original configuration to revert back to.

QuickTime 7.5.5 for Leopard
QuickTime 7.5.5 for Tiger

Apple releases ProRes codecs for non-FCP machines

A couple of days ago, Apple released Apple ProRes QuickTime Decoder 1.0 for Mac and Apple ProRes QuickTime Decoder 1.0 for Windows. This allows Windows users and Mac users without Final Cut Pro 6 installed on their machines to view ProRes-encoded files. This is great because in my experience, there are very few options when it comes to sending high-quality files to Windows machines and it should aid adoption of the ProRes format.

It should be noted, however, that you still need Final Cut Pro 6 in order to write ProRes files.

P.S. Sorry for the lack of updates but I haven't had internet access in about a month, which sucks big time.

After Effects CS4 to drop PowerPC support

There's a post on the Keyframes blog (the official Adobe blog of the AE product manager, Michael Coleman) stating that due to limited time and resources, they have decided to drop PowerPC support in After Effects CS4 in favor of adding new features for Intel users.



So After Effects CS3 is the last Universal Binary version so if you still have a PPC Mac, you'll have to buy it before the new one goes on sale (which is a bit tricky because a release date hasn't been announced). It should be noted that this only applies to After Effects and not Photoshop or the other apps but it's obvious that they will all go that way eventually.

I don't see this as a major issue as the number of Intel users is currently very large and will get even larger by the time CS4 is released. It's a shame for people with old PPC machines still kicking around (me) though, and it's reducing the resale value of the older machines. Universal Binaries were such a great idea but to companies who also develop for Windows and have very large codebases, it unfortunately makes more sense to make Intel-only versions.

Preference Manager 1.0.5 released

Yes, it's been a while but here is a minor update to Preference Manager with a couple of new features:

* File locking - You can now lock preference files so that you (or Final Cut Pro or some rogue application on your system) can't modify them. This can help to prevent them becoming corrupted. You can still change user preferences but the settings will be reverted to the locked ones when you restart Final Cut Pro. This is useful if you know someone else is going to be using your machine and you don't want your settings messed about with.

* Restoring trashed prefs - If you trash your preferences and then change your mind, never fear - Preference Manager can now restore those preferences for as long as they remain in the Trash (if you click Empty Trash, they are gone). Just go to File > Restore Trashed Preferences.

You can download the new version here or use the updating facility within the software.

For those that don't know, Preference Manager is an application that allows you to trash, lock, backup and restore preference files for Final Cut Studio. Preference files contain user settings and other information but over time they can become corrupted, causing problems such as being unable to launch the application. Preference Manager can trash these (meaning the application will recreate them but you will lose your settings) or restore from a previously-working backup. It is completely free.

We are trying to make the best application we can so we appreciate any feedback you can give us. Also check out our resources section for more tools.

Bug Report
Feature Request

Speed editing

There is a great article currently up on the COW about ways to speed up your Final Cut Pro editing. This inspired me to add a few of my own. Of course, they're specific to the kind of work I'm doing (currently TV) and the way I work but other people might find them useful.

Playing things back at a faster rate
I think the purists will hate this one. For TV shows, I often get pre-cut footage from the studio (from the on-set mixer) and it's my job to cut out the parts where they screwed up. I normally get a wide cam as well, as something to cut between for safety. I've found that I can cut it very quickly if I play it at a faster-than-normal rate and use keyboard shortcuts.

If you press L once, it will play at a faster rate (1.5x?) BUT, crucially, you can still understand every word that is said. Go to Tools > Keyboard Layouts > Multiclip and you can use the Cmd-Numpad 1 and Cmd-Numpad 2 (and so forth) buttons for cutting between cameras. Then I press Ctrl + V when someone screws up so that a cut point is generated, which I later come back and delete. So I can get a rough cut done in less than the time it would take to watch it normally. This works very well for the kind of shows I'm currently working on, but this method obviously won't work for every situation such as drama and music videos.

Use Multiclips whenever you can
If you have two cameras shooting in sync, there is no reason to not use Multiclips. I'm a big fan of them because you sync them once and once only. Then the hard work is over and when the Producer demands that you change a shot to the other angle, you can do it in a matter of seconds.

Use keyboard shortcuts instead of tools where possible
Keyboard shortcuts for certain functions can save time. But what really saves a lot of time is using a keyboard shortcut to replace a tool. Here are a few of them -

• Ctrl-V - Razor blade (cuts at the playhead)
• R, then V, then < or > - R selects the Roll tool, V selects the nearest cut point and < or > rolls the clip backwards or forwards.
• RR, then V, then < or > - RR selects the Ripple tool, V selects the nearest cut point and < or > ripples the clip backwards or forwards.
• S, then < or > - S selects the Slip tool and < or > slips the selected clip backwards or forwards.
• SS, then < or > - SS selects the Slide tool and < or > slips the selected clip backwards or forwards.
• [ and ] - Press V to select the nearest edit point and press [ or ] to trim it left or right.
• Type a number anywhere on the timeline (e.g. 5 or -10) - Moves the selected clips the specified number of frames

Keep your timeline rendered as much as possible
If you go on a break or something, press Alt + R to render your timeline. That way, the majority of the timeline should stay rendered, with only the parts you change requiring a re-render. When your client asks you for a preview copy, you can very quickly render out a reference movie, plug it into Compressor and then continue with your work. The next time you do it, it will be even quicker. And when (if) you come to put it on tape, it will speed up the rendering process there too.

Use Motion projects instead of rendered movies
If you use Motion for effects, it is far quicker to insert the actual project into your timeline than it is to render out a movie clip. And if you want to make a change just Alt + Tab to Motion, make your change, save, Alt + Tab back to FCP and there it is. No exporting necessary. This method depends on you having a decent graphics card.

Use Master Templates where possible
Taking it one step further, if, say you have a standard animated namestrap format for a show. You could take it into Motion, change the name then save it as a new copy but this takes time and you end up with hundreds of files. Instead, create the template version and then in Motion go to File > Save as Template. Create a new folder and name your new template. Now go back to Final Cut Pro and in the Generators pop-up or the Effects window, click on Master Templates and select your new template. Go to the Controls tab and you can enter any text you like. Much quicker.


One final note - there is a fine line between a fast editor and a sloppy one. There is very much an art and a science to editing and I believe that you can speed up the science but rushing the art will make it suffer. Producers like to give me a lot of footage. I like this a lot because it gives me more to work with but for some reason, the more footage they give me, the faster they expect the end product. The more footage I have, the more decisions I can potentially make and so it takes longer to decide on the "right way" to cut it (there is no right way but you know what I mean). This can't really be sped up.

I'll probably think of some more later so keep your eyes peeled. And if you've got any speed tips of your own, I'd love to hear them.

Update: Thought of another one. When I'm cutting montages, I like to go through the footage finding short clips I like and putting them up the other end of the timeline so that they are easily within reach. I used to mark the ins and outs, manually drag the clip to the timeline, then click on the Viewer to select it again. You can do this much quicker with keyboard shortcuts. Mark the ins and outs (I and O) then press F9 to insert edit the clip or F10 to overwrite edit it (note: Tiger and Leopard have F9 and F10 bound to Expose by default). Then press Cmd-1 to re-select the Viewer. I can go through footage very quickly with this method.