HDCP Mode
— The HDCP mode control (see
on the previous page) sets the
encryption negotiation method between the decoder and an HDCP compliant display.
•
Auto:
HDCP negotiation occurs each time a new stream is decoded. Encryption is
set automatically, dependent on the decoded stream. Encryption is enabled if the
decoded stream is protected and disabled if not.
•
On:
Encryption is forced on (enabled) at all times regardless of the decoded stream
type. Forcing encryption results in a cleaner switching transition between encrypted
and non-encrypted content.
Genlock
— Enables the synchronization of the output to a reference waveform. The
VND 250 uses TTL level signaling which is not compatible with normal genlock sources.
•
Enable:
Setting this option enables the decoder output to lock to an incoming
genlock signal generated by another VND 250 device.
•
Disable:
The decoder output is locked to its own internal timing reference. Any
incoming genlock signal is ignored.
Framelock Ref:
This drop-down control is used with the genlock control described
above. It defines which VND 250 device is used as the frame reference in a genlock
group. When such a group is formed, a network-based protocol permits the chosen
VND 250 to coordinate frame timing so that all decoders are showing frames captured
at the same time.
Channel Delay(s)
— The channel delay is unique to each channel of video, audio, data
or whiteboard data and is set in seconds. In normal operation on a LAN, Channel Delay
is set to 0.0.
Total Delay(s)
— The delay time between the data being input to the encoder and
output on the decoder is controlled by setting the Channel Delay(s) and the Frame
Delay. The Total Delay(s) time shown in this read-only field is the sum of the two values.
Where synchronization between channels is required, either between video and audio
on one device or between video channels on multiple devices, the default values
(Channel Delay: 0.0, Frame Delay: 6) results in an end to end delay of 100ms on a
60 fps signal. On a WAN, the Channel Delay parameter can be used to add an amount
corresponding to the one-way network delay (half of the round trip time [RTT]).
The hardware has a minimum delay requirement of 2.5 frames in progressive mode
and 3.5 fields in interlace mode. Setting a Total Delay less than these values results in
uneven playback and pipeline underflow alarms. There is one exception to this rule.
Setting the Total Delay to 0.0 (zero) places the system in a special minimum-latency
mode.
Excessively long delays cause data to build up in a software buffer within the decoder.
When the build up is more than 10 video frames, frames of data are discarded which
can result in on-screen artifacts.
Frame Delay
— The frame delay can only be modified on the video channel and
is converted from frames to seconds depending on the video mode the decoder is
currently receiving. In normal operation on a LAN, Frame Delay is set to 6 frames.
VNM EC 200 • Device Configuration and Control
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Summary of Contents for VNM EC 200
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