Operation Manual

Digital Inputs
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Audio tab
Use the following table to configure the audio digital input settings for an MPEG4 encoder.
Note: The choices in the drop-down list may vary.
Figure 187. Audio tab
To configure audio settings:
1.
In the Source field, select an audio source from the drop-down list.
IMPORTANT! The audio input must match the connectors on the back of the Niagara
system and your audio source.
2.
Select the Overlay Closed Caption check box to enable overlay closed captions. Field 1 CC 1
is the default setting.
3.
Click the Audio Format.
4.
Click the Audio Type. The drop-down list box provides two choices:
 Main – The same as Low Complexity, but adds backward prediction.
 Low Complexity – The simplest and most widely used AAC audio format type.
 HE-AAC VI – Uses spectral band replication (SBR) to enhance the compression efficiency
in the frequency domain.
 HE-AAC V2 – Enhances the compression efficiency of stereo signals.
Note: Depending on the player on which the resulting stream will be rendered, either
choice will use a specific set of tools to encode the audio stream. Make your choice
based on the requirement of the playback software or device. The most widely
supported format is the Low Complexity profile.
5.
The default Audio Encoder is AAC (Advanced Audio Coding) – a standardized, lossy
compression and encoding scheme for digital audio. AAC achieves better audio quality
than MP3. AAC and MP3 are MPEG standards.
6.
Click the Bitrate from the drop-down list.
7.
Drag the slider to adjust the Left Volume and Right Volume.