Configuration: Encoder > Destination 1 & 2 - VBrick 6000 series Admin Manual

Audio Template Settings
The following audio settings can be changed by choosing a Template setting in the
Configuration: Encoder > Template section of IWS. For more about templates, see Table 1
on page 24. The following settings are affected by a Template setting.
Audio Channels
L+R Bit Rate
(bits/sec)
Sample Frequency
Audio Speech
Mode
Configuration: Encoder > Destination 1 & 2
Using Unicast
With one encoder, it is possible to send unicast video and audio to two separate locations
using the Configuration: Encoder > Destination 1 and/or Destination 2 parameters. The
VBrick MPEG-4 Appliance Admin Guide
The audio output mode can be configured to 1 of 3 possible settings:
• Stereo – Stereo directs the input left channel to the left channel in
the audio stream and the input right channel to the right channel in
the audio stream. In this mode, the encoder expects that the two
channels are not totally discrete and have audio components that
are common to both the left and right channels. In Stereo mode,
the encoder can compress the audio more efficiently and achieve
higher performance with lower bitrates. Always select Stereo for
DVD/VCR reproduction.
• Mono (left to stereo) – Mono directs the left input channel to both
the left and right channel.
• Dual – Each channel is compressed independently. Two totally
separated channels are compressed and decompressed. Dual is
ideal for voice applications where the microphone input from two
channels is separated to avoid crosstalk.
• Mono (left only) – This option allows only the left input channel to
be carried in the stream. Output is to the left channel only.
The value can be set in 2 K increments from 8K to 320K (8000 to
320000 in increments of 2000). The default value is 256,000 bps. This
is the audio encoding bit rate of the audio stream. If the Encoder
Audio Output is set to stereo or mono, the value can be set from
16000 to 320000. The sampling rate is based on the per channel bit
rate:
• Up to 12000, the sampling rate is set to 8kHz.
• 12000 to 30000, the sampling rate is set to 16kHz.
• 30000 to 40000, the sampling rates is set to 24kHz.
• Greater than 42000, the sampling rate is set to 48kHz.
Example. A stereo output bit rate of 48000 uses a sampling rate of
16kHz (the per channel bit rate is 24000). A mono output bit rate
48000 uses a sampling rate of 48k; only one channel is being
transmitted.
Frequency at which the audio is sampled at the encoder. Settings
include 8, 16, 24, 44.1 and 48 KHz. The default is 48 KHz.
Applications that are low-bit rate (8 to 12kbps) voice only will benefit
from speech mode enabled. This will help reduce any reverb effects.
In all other applications (such as music or voice bit-rates greater than
12kbps) this mode should be disabled.
MPEG-4 Configuration
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