Applications For Content Creation - PRG MBOX User Manual

Mbox's compatibility with different audio file formats has been greatly enhanced with the release of Mbox v4. In Mbox
v4, sidecar audio files can use any of several container types (AIFF, AAC, WAV, M4A, and MP3) and the formatting of
the audio (sample rate, endian-ness, etc.) does not matter. With the release of Mbox v4.2, sidecar audio files (with the
exception of the MP3 container) can have up to 24 channels.
Audio playback using sidecar file can be sped up or slowed down, and the sidecar audio files will loop and obey in and
out frame values. It is still important to make sure that the audio file is exactly the same length as the movie though.
The best way to do this is to keep the audio and video components of movies together until the very last minute (all
throughout the editing process). Once the editing process is complete, then separate the two files into movie file
and sidecar audio file. Try to avoid any manipulations of either file (especially the movie file) once the two have been
separated.
Mbox v4 can also play the audio directly from a QuickTime movie that has embedded audio tracks. Because Mbox now
uses AVFoundation technology rather than QuickTime 7 technology, playback performance when playing embedded
audio is much better than with Mbox v3.x.
However, there is one important restriction on what kind of embedded audio Mbox v4 can play. Whereas Mbox v3 used
uncompressed LPCM encoding, embedded audio in Mbox v4 must now use the AAC audio codec, otherwise the audio
will not play properly. Beyond that, the other audio properties are not critical. Beiginning in Mbox v4.2, movies with
embedded audio can have up to 24 channels. However, it appears that many content creation applications (e.g. the
Adobe CC suite) do not allow movies to have multi-channel AAC audio. Therefore, sidecar audio is currently a better
choice for multi-channel audio output.
Recommendations for embedded audio encoding:
+ Sample rate = 48KHz
+ Bitrate = 320kbps
+ Number of channels = 1 or 2 (mono or stereo), up to 24 channels (multi-channel)
The audio volume control channel on the Global Master fixture can be used to modify the volume of all audio file
playback. Alternately, the Layer Volume parameter can be used to control audio volume on a per-layer basis. Refer to
"Audio Output Volume Control"

Applications for Content Creation

There are many applications that can be used to create or edit content for Mbox, varying from the high end (Adobe
After Effects , Apple Final Cut
®
guidelines to be observed:
+ Never create a movie with compressed headers or prepare a movie for internet streaming.
+ Do not use QuickTime 7 Pro to modify both the framerate of a movie and trim the movie at the same time, as this
will modify the headers of the QuickTime file to the point where Mbox cannot play it. However, QuickTime 7 Pro can
be used to convert a movie from one codec to another or to trim an existing movie. It is recommended that more
complex tasks (changing the framerate) be performed using some other application, so that the movie's source
elements are re-rendered into a new file. This is especially critical if the movie has audio tracks.
+ Mbox can playback H.264 content using either the QuickTime (.mov) or H.264 (.mp4) container formats.
+ Avoid including extraneous tracks (e.g. timecode) in QuickTime movies if at all possible.
+ Mbox only renders onscreen with 8-bit color, so there is no advantage to creating content with a higher color depth.
+ To create and play content using some codecs (e.g. ProRes, Hap), the appropriate codec must be installed on the
computer that makes the content, and the Mbox computer that plays the content.
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on page 101 for details.
) to the low end (QuickTime
®
7 Pro). Each has different strengths, but there are some
®