Extron electronics VN-Matrix 250 Series, Руководство пользователя

Страница: 72 / 140

Figure 43. Audio Bandwidth Tab
Audio output selection (Audio Control panel)
Select the appropriate check boxes to output the received audio stream to the
HDMI
port,
the
Analog
output port, or both. The HDMI output level cannot be controlled and is equal to
the level seen on the encoder device.
The analog audio output level is controlled using
Analog Output Level
. The output level
is correct if the input level on the encoder has been correctly configured for optimum signal
level.
Return audio configuration (Audio Control panel)
The return audio input must be separately enabled and the level must be manually
configured to achieve an undistorted signal with the optimum signal to noise ratio. The
input level is selected using the
Analog Input Level
setting and is set to a value just larger
than the maximum input value. If this level is unknown, the
Analog Input Measurement
continuously shows the current input level. If the input measurement shows over-range the
input level should be increased until the over-range condition clears. If the measurement
is more than 2 dB below the set input value, the input value should be reduced to be 1dB
greater. These measurements must be carried out when the content of input signal is at a
maximum volume and the stream must be connected to a suitable encoder. If the audio is
not being streamed, the measurement shows disabled.
Reverse audio data is always sampled using 16 bits stereo at 48000 Hz. It is then
compressed to the "decimate 2" level resulting in a reverse bandwidth of 784 kbps. It uses
a "best effort" delivery making no effort to obscure dropped packets and not managing the
delay between decoder and encoder.
Decoder audio stream statistics
The audio stream Statistics operate in the same ways as the video statistics (see Decoder
video stream statistics on the previous page).
Decoder audio buffer
The decoder audio buffer operates in the same ways as the video buffer (see Decoder
video buffer on page 62).
NOTE: The frame delay setting reflects the value that is set in the video buffer and
cannot be adjusted.
VNM 250 • VNM 250 GUI Overview 64