Alcorn Mcbride Digital Binloop HD, User Manual

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Alcorn McBride Binloop User’s Manual Page 66
A Word About Trigger Latency:
The Binloop uses two different types of Play commands. The first one,
called “Unsynchronized Play” is used mostly for “point-source” or other
audio/video applications where synchronization between channels is not
important.
The other type of Play command is called “Synchronous Play”. This
command needs to be used in those situations where absolute frame
synchronization is required across channels. This is the type of play
command issued by the
Play action. There are important differences
between how the Binloop reacts to these two commands.
Unsynchronized Play Latency
When this type of play command is sent to a reproducer, it starts playing
the file as soon as it possibly can. The latency is determined only by the
amount of time it takes the reproducer to process the play command,
load the clip from the compact flash card, and begin decoding and
playing the file. This latency is very short, but it is not predictable. For
that reason, this command is not recommended for use when the goal is
to synchronize playback between multiple reproducer cards. The
unsynchronized play command is normally used for applications that
require multiple channels of video that are unrelated to one another (like
individual kiosks, etc.).
Synchronized Play Latency
The exact amount of latency
time will depend on the
SMPTE frame rate being used.
When using Play commands
from the Timecode trigger list,
it is highly recommended that
the SMPTE clock is locked to
V-Sync. This ensures that the
timecode framerate and the
video framerate of the
reproducers is synchronous.
A Synchronized Play is the same as an Unsynchronized Play with
one key difference. Rather than playing the video as quickly as
possible, the reproducer will wait a consistent amount of time after the
play command was received before playback starts. This ensures
that every reproducer that received this command starts playing at the
same time.
The latency between when the play command occurs and when the
file actually starts playing is exactly
2 seconds for a Synchronized
Play . This delay provides the reproducer with more than adequate
time to process the command and load the video from the compact
flash card so that it’s ready to start playing when the consistent wait
period is over.
Use the Synchronized Play command for playing groups of Reproducers,
which must start playback in perfect synchronization (i.e. multi-channel
music tracks or video wall presentations).