Frequently Asked Questions
About Film & TV Post-Production
What is Audio Post-Production?
Audio Post-Production is the process
of creating the soundtrack for a visual program of some kind. Ever since
silent movies began to talk, filmmakers have been looking to control and
improve the quality of the sound of their creation. As soon as creators
realized there was a way to control and enhance the sound of their pictures,
Audio Post was born, and has been a fact of life ever since. In Television,
audio was originally "live", like the visual program it was part of. As
TV evolved, and the art form grew to include "videotaped" and "filmed"
programming, the need for Audio Post increased. Nowadays, it would be difficult
to find any feature film or television show that hasn't been through audio
is involved in Audio Post ?
Audio Post usually consists of several processes.
Each different project may need some, or all of these processes in order
to be complete. The processes are:
does all that mean in English ?
It's really pretty simple, once you
know the breakdown::
Editing - In order for the production audio recorded on the set or
on location to be properly mixed, a Dialogue Editor needs to properly
prepare it. This means locating the proper take from the recorded
production audio, checking sync (so it actually works with the picture
properly), and eliminate extraneous noise so the Mixer has clean dialogue
to use during the Mix.
ADR [Automated Dialogue
Replacement] - In cases where the production audio is too noisy, or
otherwise unusable (bad line reading, airplane fly-by, etc.) the Dialogue
Editor will "cue" the line for ADR. This means replacing that
line or lines of dialogue using the Automated process of Dialogue
Replacement. This process takes place on the ADR Stage, a specialized
recording studio where the actor can record lines in sync with the picture.
Once a replacement line of dialogue has been
recorded, the Dialogue or ADR Editor will check the sync carefully, editing
the take if necessary to precisely match it to the picture, and prepare
it for the Mixing Stage. This process is also known as "looping".
Sound Effects Editing
and Design - Ever wonder how they made the sound of Darth Vader's helmet
breath, or the Empire's Tie Fighters, or that great train wreck sequence
from "The Fugitive"? - Sound Effects Editors and Sound Designers
are how. The process of adding sound effects (backgrounds like:
air, rivers, birds, traffic, and hard effects like: gunshots, door
slams, body falls, etc.) has been the domain of sound effects editors for
years. Although originally edited using 35mm magnetic film, recent years
have seen the development of many different Digital Sound Editing systems.
More and more projects are using digital technology because of the efficiency
and quality it can bring to sound effects. Sound Designers use digital
and analogue technology to create sound effects that have never been heard
before, or to artistically create specific "mood" sounds to complement
the director's vision of the visuals.
Foley - Taking
its name from Jack Foley, the Hollywood sound effects person generally
regarded as the "father" of these effects, Foley effects are sounds that
are created by recording human movement in sync with the picture. Different
from the environmental backgrounds and hard effects that comprise edited
sound effects, Foley effects are sounds like footsteps, prop movement,
cloth rustling, etc. The players involved in this process are the Foley
Mixer, who records the sounds, and the Foley Walkers who create
those sounds. After the Foley Effects are recorded, the Foley Editor
will make any slight timing adjustments necessary to ensure that they are
exactly in sync with the final picture.
- Music for film/TV falls into three general categories: Score, Source
and Songs. The Composer is the individual hired with the responsibility
to prepare the dramatic underscore. Source music is that music we hear
coming from an on screen or off screen device of some kind; some examples
are radio source music, phonograph records, TV show themes, when seen on
a TV set in the shot, and many other similar variations. Source music may
be original, or licensed from a number of libraries that specialize in
the creation of "generic" music. Songs may occupy either function, depending
on the dramatic intent of the director. Using "Pulp Fiction" as an example,
Director Quentin Tarantino hired a Music Supervisor (Karyn Rachtman,
FYI) to "score" the picture using period music of the 1970's almost exclusively.
Most contemporary films use a combination of score and source music.
- The Music Editor assists the Composer in the preparation of the
dramatic underscore. Frequently working also with the Music Supervisor
the Music Editor will take timings for the Composer, (usually during a
spotting session )in order to notate the specific locations in the
film where underscore or source music will punctuate the narrative. Once
the underscore is recorded, and the source music gathered, the Music Editor
will usually be the person who edits or supervises the final synchronization
of all music elements prior to the mix.
Mixing (also called
Dubbing) - The Mixers have the responsibility of balancing
the various elements, i.e., - the Dialogue (and ADR), Music, Sound Effects,
and Foley Effects, in the final mix. The Dialogue Mixer, (also called
the Lead Mixer or Gaffing Mixer) commands the mixing stage; his partners
in the mix are the Effects Mixer and the Music Mixer. On
large features, it is not uncommon to have an additional mixer handling
just the Foley effects. On huge pictures with tight deadlines, it is possible
that several teams of mixers are working simultaneously on numerous stages
in order to complete the mix by the release date.
Where does post-production begin
If you haven't shot your film yet, it begins
before you shoot - by selecting the finest production dialogue mixer you
can afford. The little bit extra paid to a great production mixer can save
you tenfold later in post-production.
What does the
production sound mixer do ?
The production mix team are the individuals
charged with recording your live dialogue, in sync with the camera team.
The Production Sound Mixer is your most important ally at this stage in
the movie's production. Although you will be anxious to complete as many
setups as possible during each shooting day, a little extra time guven
to the sound mixer to allow him to capture scene ambience (called room
tone) will pay off hamdsome dividends later during our dialogue editing.
The production mixer will have with him a boom operator, who handles the
boom mics, and usually a cable person, who will be in charge of wrangling
the audio cables needed to mike the set appropriately. Usually they will
record on a Nagra recorder, but digital recordings on Portable Time code
DAT machines are becoming more common.
We are shooting
our film on location...what now ?
Generally, each day after the completion of
the shoot, the production audio rolls will be sent to an audio post house
for transfer to "dailies" form. If the film is being edited filmstyle,
using 35mm mag audio and film dupes (as opposed to electronically, using
an Avid or Lightworks edit system), the production select takes will be
transferred to 35mm mag film. This sprocket-based medium will allow the
film editor or assistant to sync that day's select film takes with the
audio track that corresponds to it.
If the production is being edited electronically,
using a computer-based edit system, the options are a bit different. Frequently,
a video post house will be engaged during shooting to telecine the selected
and printed film takes. In addition, they will transfer the production
audio from Nagra or DAT and generally synchronize the dailies onto some
form of videotape, for later digitizing into the Avid or Lightworks editing
system. Syncing dailies at the video house eliminated the need for the
assistant film editor to do it, and allows the assistant to load the editing
system instead. An important task to accomplish during the digitizing is
for the assistant to correctly log in the dailies time code that is recorded
on the Nagra or DAT location tracks. This will allow the EDL (edit decision
list) that is created later on to accurately reflect the original time
code that was shot with that scene, and allows the audio post house to
electronically automate the re-loading of the production dailies, should
they need to be replaced.
And this goes on all during
Yes. Dailies transfers will continue until
there are no more dailies coming in, and shooting has wrapped. During this
time the editor may also need reprints of previously transferred takes,
or prints of previously unprinted takes. They are processed in the same
We are done shooting...now
Now the real fun begins. The editor
has been syncing dailies all during shooting, choosing which scenes should
begin to form the final cut. During the next several weeks, the process
of editing will continue as the decisions are narrowed down to final choices.
It is at this time that the final form of the film begins to take shape.
Although the film editor may have been assembling the "editor's cut" during
the shooting period, the first formal edit period is generally referred
to as the director's cut, and it is when the first full assembly of the
film is refined.
Do I need
Audio Post during editing?
Well, yes. During the editing you may
still need reprints of selected takes or outtakes. The audio post facility
will duplicate these for you. But the real job is starting to come into
view: the locked cut.
What is the locked
In short, the final version of the finished
film. Although it may receive a small edit here or there in the next few
weeks, the film is essentially "locked" into this form.
happens once the cut is locked ?
Audio Post begins now in earnest. Once
the cut has been locked, the film can be spotted for the placement of sound
effects and music. The Supervising Sound Editor, the Director and possibly
the Film Editor and Composer will gather at one or more spotting sessions
to determine the film's audio post needs. "Spotting for music" is the process
of viewing the locked cut and deciding where the music score will be, and
where the source music will be needed. "Spotting for sound" is the process
if and where any dialogue problems may exist,
so that ADR can be cued to be recorded
where sound effects are needed and what kind
what Foley effects will be needed in the film,
If Sound design (the creation of special sound
effects), will also be needed.
What actually happens
The real job of audio post has now begun.
In the next weeks or months, the sound editors will locate and synchronize
all of the sound effects needed in the film. If necessary, they will create
Field Recordings of new sound effects needed for the film. The Foley
supervisor will cue all of the Foley effects that will be needed; they
will be recorded by the Foley Mixer and the Foley Walkers; the ADR
supervisor will cue all of the Automated Dialogue Replacement
lines that need to be recorded during the ADR sessions, and the Music
Editor will begin providing for the needs of the Composer and/or music
supervisor. The Dialogue editor(s) will begin preparing the
production audio for final mixing, and the ADR editors can commence editing
in the ADR lines, once they have been recorded.
What happens after spotting
Typically, the next few weeks or months
are occupied with sound editing of all types. The Director will be checking
on the various aspects of the sound job as time progresses, to be sure
that his vision is being realized. Usually, there is provision for one
or more "effects reviews" where the effects are listen to and approved.
The same goes for Foley, Dialogue, ADR, Sound Design and Music. When everything
is completed and approved, the next step is Mixing (also called 'dubbing'
What happens during
the mix ?
During the mix, the edited production
dialogue and ADR, sound effects, Foley and Musical elements that will comprise
the soundtrack are assembled in their edited form, and balanced by a number
of mixers to become the final soundtrack. In New York, single-mixer sessions
are more commonplace than in Hollywood, where two-mixer and three-mixer
teams are the norm.
The mixers traditionally divide the chores
between themselves: the Lead Mixer usually handles dialogue and ADR, and
may also handle music in a two-man team. In that case, the Effects mixer
will handle sound effects and Foley. In three-man teams, they usually split
Dialogue, Effects and Music; sometimes the music mixer handles Foley, sometimes
the effects mixer covers it.
To keep the mix from becoming overwhelming,
each mixer is actually creating a small set of individual sub-mixes, called
STEMS. These mix stems (dialogue, effects, Foley, music, adds, extras,
etc) are easier to manipulate and update during the mix.
is done, what then ?
After the mix is completed and approved, films
generally require a last step called Printmastering, that combines the
various stems into a final composite soundtrack. When this is completed,
an optical or digital sound track can be created for a feature film release
It is also usual at this time to run an
'M & E' (which stands for Music and Effects) track. This
is essentially the film's soundtrack with the English language dialogue
removed. This allows foreign language versions of the project to be dubbed
easily, while preserving the original music, sound effects and Foley. During
the M & E, effects or Foley that are married to the production dialogue
tracks are removed along with the dialogue. To "fully-fill" an M &
E for a quality foreign release, those effects and Foley must be replaced.
Television movies usually do not require
print masters, unless they have been created using SURROUND SOUND techniques.
In most cases, the final stems are combined during a process called LAYBACK,
at which time the soundtrack is united with a final edited master videotape
for ultimate delivery.
What about optical
Optical soundtracks (we mentioned them
earlier). Almost all of the release formats, including the digital ones
have provision for some kind of optical soundtrack, even if only as a backup.
The optical soundtrack refers to the two-channel soundtrack that is carried
on the optical track of the film release print.
How do I get an optical
Once your surround sound format has
been selected (see the paragraph below for more), you need to order an
optical soundtrack negative for the film. In the case of LCRS mixes,
a traditional two-channe; Printmaster track is created, and this is sent
to an optical sound house for the creation of the optical negative. The
optical sound house will record the soundtrack onto 35mm film using a special
camera, and some will also develop their own soundtrack masters. Once the
optical negative is shot and developed, it can be incorporated into your
answer printing process, and a composite answer print containing your complete
soundtrack can be printed or "shot" at your film lab. This usually happens
during the first or second trial answer print phase.
What about: THX
- Dolby - Ultra*Stereo - DTS - SDDS?
This is a BIG question. This one point alone
causes much confusion amongst filmmakers. Please take a moment and read
this paragraph carefully. If you need more information after that,
please contact either Gnome Productions or Magnolia Studios and we will
help you out.
First, about THX.
THX [tm] is not something that you
DO to your soundtrack, it is just a set of sound reproduction or mixing
conditions that optimize the sound of your film's soundtrack in exhibition.
Simply put, the THX standards that many dubbing stages and movie theaters
adhere to are a way of being certain that "what you mix is what
you get", so to speak. You may choose to mix in a stage that is
THX certified, and you may not. If you do, your soundtrack should sound
reasonably the same in THX theaters all around the world. It is this standardization
that THX brings to the filmmaking community.
You may want to visit the
THX Web Site for further information. They can be found at http://www.thx.com/thx/thxmain.html.
To make sense out of the rest of the names,
we need to know about Film (and Television) Surround Sound
Film sound tracks (and some television ones)
go beyond just Left-Right Stereo; there is a Center Channel for the dialogue,
and at least one "Surround Sound" channel. The Surround channel is used
to project the sound out into the theater, to "surround" the audience.
This is to enhance the illusion of being "in the picture". This four-channel
format is called LCRS (for the Left, Center, Right and Surround
channels that the soundtrack contains). Although the technical means behind
this process is beyond the scope of this discussion, suffice it to say
that it works well enough to have become a standard format for release
prints for many years.
You've probably already figured out that you
cannot reproduce a four-channel soundtrack from a medium that only plays
back two tracks. You are very right. In order to reproduce the LCRS
soundtrack from a traditional film optical soundtrack (more on opticals
later) you need a way to encode the channels....the Matrix
The Surround Sound Matrix Encoder (or,
how to put FOUR into the space where TWO should go!)
The solution is to use an encoding device
that can fold the four channels of audio down into the two channels available
on the film's optical soundtrack. When the audio tracks have been processed
this way, they are labeled Lt/Rt [Left Total/Right Total] in order
to distinguish them from ordinary Left/Right Stereo soundtracks. The Surround
Sound Matrix Encoder is a necessary piece of hardware that the audio post
house must have available during your film's mix, in order to create the
The Licensing of Surround Sound formats
Now we're really getting into the heart of
the matter. Dolby Labs, Ultra-Stereo Labs, DTS (Digital Theater Systems)
and Sony [SDDS] all have technologies available for the encoding of film
surround soundtracks into film release prints. Although these processes
vary somewhat as to their method, they essentially accomplish similar things.
Additionally, some of these vendors offer Digital Encoding formats (Dolby
Digital, DTS and SDDS currently, and Ultra-Stereo soon to come).
The Differences in Surround Sound formats
In the most basic form, Theatrical Surround
Sound consists of LCRS: Left, Center, Right, and mono
Surround. A soundtrack can be encoded into this format by using
a Dolby or Ultra-Stereo encoding matrix during the film's Printmastering
session. DTS also has a process called DTS Stereo that can create a typical
LCRS film soundtrack (check with DTS directly for more on their specific
Surround Sound formats beyond L-C-R-S:
Some of the surround sound encoding processes
can create different, more complex soundtrack formats; Dolby SR/D and DTS,
for example, can create six-track soundtracks for release, and Sony's SDDS
is an eight-track format. In the case of six tracks, you get Left,
Center, Right, Left Surround, Right
Surround and a Sub-woofer channel (for enhanced low-frequency
response). The split surrounds (as they are called) make it possible to
move sounds around in the surround speakers, or to use stereo background
sounds for even more impressive film soundtracks (Jurassic Park comes to
mind, here). And if you heard Jurassic Park in a good THX theater with
a DTS Digital soundtrack, you know what the sub-woofers are there for!
That T-Rex really gave the sub woofers a run for their money, as well as
Jeff Goldblum...Six-track sound reproduction has been with us for a while,
since 70mm film releases have had the ability to deliver a six-track soundtrack
that was magnetically encoded on the release print. This, unfortunately,
was very expensive to produce, and problematic to control quality.
Sony's SDDS (Sony Dynamic Digital Sound)
uses an eight-track delivery configuration that adds two speakers in between
the Left/Center and Center/Right positions in the front speaker wall. Known
variously as InterLeft, InterRight or LeftCenter and
RightCenter, these channels allow for additional separation of music,
effects and dialogue in the front speaker wall, while preserving the split
The Differences in Digital Sound delivery
The three digital systems (Dolby, DTS and
SDDS) use proprietary methods to deliver the digital audio to the theater;
two of these methods (Dolby, SDDS) encode the digital soundtrack onto the
release print. DTS uses a different method, that of encoding a "timing
stripe" onto the release print, and synchronizing a digital audio playback
from an accompanying CD-ROM that carries the encoded soundtrack. In either
case, the digital audio is reproduced in the theater with the same fidelity
it was recorded at during the encoding process. This system neatly bypasses
the traditional limitations of optical soundtracks: noise, bandwidth limitations,
and headroom (transient peak) limits. Soundtracks sound cleaner, clearer
and louder as a result. Please don't take this as a condemnation of optical
soundtracks. A well-mixed movie can (and they still do) sound great with
a well-produced optical soundtrack.
To summarize this difficult topic:
THX specifies a set of standards that
affect how sound is recorded and reproduced in a movie theater.
You get the benefits of the THX standard
whenever you mix in a THX-certified mixing stage.
There is NO additional fee required.
You may display the THX logo in your film's
credits if you sign a simple one-page form.
Dolby Surround is a 4-channel optical
surround format; this format is encoded in the optical soundtrack
You must license this format from Dolby
Labs; There IS a license fee for this service
Ultra-Stereo is a 4-channel optical
surround format; this format is encoded in the optical soundtrack
You must license this format from Ultra-Stereo
Labs; There IS a license fee for this service
DTS is a 6-channel digitally-encoded
surround format; this format is encoded on an external CD-ROM, but the
timing and other information in encoded on the film release print;
You must license this format from Digital
Theater Systems (DTS); There IS a license fee for this service
Dolby Digital is a 6-channel digitally-encoded
surround format; it is encoded on the film release print;
You must license this format from Dolby
Labs; There IS a license fee for this service
SDDS is an 8-channel digitally-encoded
surround format; it is encoded on the film release print;
You must license this format from Sony
Corporation - SDDS division; There IS a license fee for this service
I have got a video project
- What's this DVD, AC-3?
relax - take a breath and we'll walk you through
this...It's actually pretty simple;
Surround sound program on video materials
are now released in a number of analog AND digital forms...
Straight Left-Right Stereo program is still
utilized a lot for Television, and Industrial formats...
VHS Home video releases can be encoded in
Dolby Surround (L,C,R,S), just like feature films;
Laserdisc releases have also been using digitally
encoded L,C,R,S surround formats, just like VHS
All of these formats can easily be handled
or prepared by a knowledgeable sound house. Please contact us if you have
specific questions that you would like answered...no obligation, of course...
NEW DIGITAL VIDEO RELEASE FORMATS have allowed
for new DIGITAL SOUND FORMATS
AC-3 - is a digitally-encoded surround
sound format that is capable of reproducing six tracks of sound
Ac-3 actually refers to Dolby's Audio
Compression 3 format used to compress the data
DVD releases are also utilizing AC-3
digital sound format as well as traditional Surround Sound
My mix sounded great
on the mixing stage - but my print isn't in sync!
Well, we didn't say this would be EASY, just
that we could help take some of the mystery out of it for you...You should
IMMEDIATELY contact your post sound house and tell them what you've experienced.
The Sound Supervisor on your show should be willing to take some time and
help you sort this out. In the meantime, here's a few things that you can
Some likely possibilities:
(1) If the Final Mix Printmaster has
been transferred or copied, be sure the copy was done correctly. We
have had experiences where a perfectly fine Printmaster was thrown out
of sync because a copy was made first, and the optical shot from the copy;
(2) If the soundtrack DRIFTS from
being in sync to gradually being
more and more OUT of sync during the reel, suspect this possibility: If
the Printmaster is on Multitrack tape, the SMPTE code on the tape could
cause the optical soundtrack to drift in speed; If you mixed to VIDEO TAPE,
a slight difference between 29.97 frame code and 30.00 frame code could
throw you out of sync by many frames over 1000 film feet. If the soundtrack
was shot on Mag, a mistake in running the film chain at video speed could
cause the Mag to be "offspeed", just like the Multrack tape example above;
(3) If the Mag Printmaster was
in sync when you reviewed the final mix, check to be sure the film
lab didn't accidentally "misprint" the soundtrack by moving the optical
negative a perf or two, or a frame or two when they married it to the picture.
This can easily happen IF THE HEAD POP or TAIL POP is not EXACTLY CORRECT
on your final Printmaster.
(4) If you printmastered in 2000-foot
film reels, and FOR ANY REASON these reels were then separated and rejoined
later, this poses a prime opportunity for sync to slip. If the beginning
of a 2000 foot reel is in sync, and the last 1000 feet is suddenly (and
consistently) out of sync until the end of the reel, suspect this phenomenon
(5) If one or two shots suddenly
are out of sync but were IN sync when you mixed, ask yourself this:
did you mix from an Avid or Lightworks (or other electronic edit system)
output? If so, it's possible the film negative was not cut to the exact
same shot length as the electronic output; Have you verified the length
of all optical effects? If you have inserted optical effects, they
may not have been counted exactly right, and you may have gained (or lost)
a perf or frame or two in the effect; either way, your soundtrack will
lose sync right then and there, and STAY out of sync for the rest of the
reel (unless another optical effect error magically puts it back in sync
(6) Finally, when all else fails,
it is remotely possible that the optical negative might be offspeed. A
quick call to the optical sound house will help them verify this for you.
My foreign distributor
says I need an "Emenee" to make a sale ?
Actually, it's an "M and E" or "M&E".
This element comprises the "MUSIC and EFFECTS" elements of
your original soundtrack, with ALL of the English language dialogue and
Walla removed to allow for foreign language dubbing. In most contemporary
post sound packages, an "M&E" is allowed for in the original bid. This
process requires preparation during the original sound editing, as well
as some additional Foley coverage that might NOT be needed for a straight
domestic release. If you NEED an M&E, be sure that you tell your post
sound house that UP FRONT. It WILL add some dollars to your post bid, but
you WILL want it, if you are to have any possibility of a foreign release
or sale at all. Preparing this element NOW will buy you plenty of "peace
of mind" later on. The M&E can be on Mag, on DA-88, on DAT, or on almost
any format that can be synchronized. It DOES NOT need to be converted to
an Optical soundtrack form at this time...only later, when a new foreign
Printmaster is created after the foreign language has been added to it.
Do I need to know
about the academy rolloff ?
Well, although it is a holdover from
film sound's infancy, we need to be aware of it, since it does have some
relevance in certain circumstances. The academy rolloff is a specific frequency
response curve that is used in dubbing stages to simulate the effect that
the old-time optical soundtrack would have on the frequency of the final
soundtrack. With advances in technology in today's film industry, its use
is diminishing, although it has been used on mono theatrical trailers to
How do I
get more info about Surround Sound Licensing?
It would be best to
consult the various vendors themselves...
THX can be reached at http://www.thx.com/thx/thxmain.html,
or in San Rafael, CA through 415-662-1800
Dolby Labs can be reached
at http://www.dolby.com, or
locally in L.A. at 213-845-1880
Digital Theater Systems can
be reached at http://www.dtstech.com,
or locally in L.A. at 818-706-3525
Sony Corporation maintains
a web page at http://www.sony.com
Ultra-Stereo Labs can be
reached directly by telephone at: 818-609-7405
|Bruce Nazarian, M.P.S.
(Motion Picture Sound Editors)
Gnome Digital Post