VBrick Systems 7000 manual Audio Template Settings, Aac-He

	Video/Audio Configuration
Automatic Volume	The volume is continually monitored and automatically adjusted to
Control	normalize audio levels as follows. Default = Standard.
	• Standard – Default. Use for general content which may already be
	companded (compressed and expanded).
	• Light – Peak limiting. Best dynamic range.
	• Moderate – Peak limiting with expansion. Reduced dynamic range.
	• Aggressive – strong normalization, low dynamic range, most
	noticeable.
	• User-Defined – Advanced users only. User Defined values employ
	two thresholds (high level limit and low level boost) which define
	db threshold levels to which volume changes are applied. The low
	level boost threshold defines the threshold whereby lower signals
	lower will be amplified by gain. The gain is applied gradually until
	the audio level is higher than the configured threshold. The high
	level limit threshold defines the threshold whereby signals higher
	than this value will be attenuated until the audio level is reduced to
	a lower value than the threshold.
	Minimum Level – the minimum (boosted) audio level you wish to
	achieve after reaching the threshold.
Noise Gate	Used to suppress unwanted audio noises that are continuous and
	predictable (for example air conditioning equipment or traffic sounds).
	A a noise gate allows a signal to pass through only when it is above a
	certain threshold. If the signal falls below the threshold no signal is
	allowed to pass.
	Note: The noise gate is particularly useful in AVC (automatic volume
	control) configurations to keep ambient, low-level noise from
	propagating with gain (i.e. being amplified).
Noise Gate Level	Displayed only if Noise Gate is enabled. Range: -34 to -82 dB.

Audio Template Settings

The lower area of the Audio page has a set of parameters that can be controlled by pre- configured templates. Use the Load Template button to populate the Audio Template Settings with pre-configured audio values. The audio templates vary depending on the selected Audio Source (Stereo, Mono, or Dual). Med Fidelity is the default template. All audio encoder parameters defaults will match these values.

Table 6. Audio Template Settings

Name	Stereo as Mono?	AAC-HE	Sample Freq	Bit Rate †
				Stereo/Dual	Mono
Best Fidelity	Off		48k	256k	84k
High Fidelity	Off		48k	160k	84k
High Fidelity – AAC-HE	Off	Enable	48k	64k	32k
Med Fidelity ††	Off		32k	72k	40k
Med Fidelity - AAC-HE	Off	Enable	32k	40k	24k

VBrick H.264 Appliance Admin Guide 41