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audio outputs are either active or forced to silent depending on the settings for Enable and
Mute as described below.
Decoder Configuration Topics:
Latency and Quality Tuning
VBrick 7000 Series and 9000 Series encoders offer a wide range of high quality and low
latency steaming capabilities to VBrick 9000 Series decoders. This section describes how to
choose the right combination of systems and configure them to meet your streaming needs.
VBrick 9000 Series encoders and decoders have default settings that (when used together)
will provide low latency of approximately 300 ms and high quality video and audio over a
good network. By default the 9000 Series encoder Video Template settings use the
Baseline
Profile and CAVLC
Entropy Coding
for compatibility with a broad range of standard PC and
mobile video players. However, when using the 9000 encoder with a 9000 decoder, you will
achieve better quality by using
High
Profile and CABAC
Entropy Coding
. Even for ultra-low
latency applications as described below,
High
Profile and CABAC Video Template settings are
always recommended on the 9000 Series encoder when streaming to a 9000 Series decoder.
9000 Series encoders can stream to 9000 Series decoders with ultra-low latency of 100 ms or
less when properly configured and when connected through a very good network. Configure
the
Rate Control Setting
in the Encoder's Video Template settings to level 1 for Lowest
Latency and then evaluate the decoder's playback quality and statistics using the lowest
Jitter
Queue Time
settings that provide acceptable performance. When
Jitter Queue Time
is set to 0,
the end-to-end latency is approximately 100 ms. Adding milliseconds to your configured
Jitter Queue Time
will allow the decoder to manage jitter better and will correspondingly add
approximately the same number of milliseconds to the end-to-end latency.
Audio sampling and compression at the encoder introduces unavoidable jitter that will cause
some audio frames to be dropped when the decoder
Jitter Queue Time
is set very low. The
decoder is designed to minimize the quality degradation from dropped frames so, after
listening to the decoder output, you might consider a few light audio clicks or faint static to
be an acceptable trade-off to achieve ultra-low latency, or you can increase the
Jitter Queue
Time
slightly to avoid audio frame drops. Disabling audio in the encoder's Stream
configuration will obviously avoid the issue of audio jitter and also improves the decoder's
Field
Description
Enable Audio Output Enable|disable audio output.
Mute
Suppress audio output.
Attenuation
Used to lower the level of the decoder’s analog audio output. Does
not affect digital audio on HDMI or SDI. Range is -127–0. Default
= 0.
Содержание 9000 Series
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