User manual

Recording and Acquisition : Recording
Page 59
MJPEG codec. A 100 value corresponds to an average 1/3 compression ratio, and a 50 one to an average 1/20
compression ratio.
Audio
File Format The field shows the current File Format. The drop-down list offers a choice of formats
from the following depending on the wrapper chosen. If both Video and Audio are of the
same type, e.g. AVI or QuickTime they are merged inside a single Media File : The drop-
down list offers a choice of formats from the following depending on the wrapper cho-
sen:
None
AVI (*avi)
MPEG (*mpg)
MPEG (*mpeg)
MPEG (*mpa)
PMF (*pmf)
WAV (*wav)
BWF (*bwf)
AIF (*aif)
SD2 (*.sd2)
QUICKTIME (*.mov)
Number of Channels Indicates the number of physical outputs fed by Audio layers in the Composition.
Word Length Field shows the Word Length selected currently. The drop-down list offers a choice of:
16 bits Fix
24 bits Fix
32 Bits Float
Compression Field shows the Compression scheme selected currently. The drop-down list offers a
choice of schemes depending on the selected Audio File Format. QuickTime offers vari-
ous solutions for compressing audio data.
Note: The AVI and QuickTime MPEG2 Media Handlers support multiple audio channels in a sin-
gle file. When recording more than 2 channels in an AVI2 or QuickTime file, each channel is
treated as a separate mono channel. I.e. if you have 4 channels in VCube, they will appear as 4
mono channels in an AVI file. The Windows Media Player from Microsoft and the QuickTime
player from Apple will playback a 4 channel audio file into a stereo mix of the 4 mono channels.
Using Video files with embedded audio decreases playback performance. For Compositions with
complex compositing, two or more separate Media Files (one for video, one or more for audio)
are preferable.