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Output LTC timecode
When it is necessary to trigger remote device functions at precise moments durring an asset’s playback, most high-end lighting consoles as well other production equipment need to receive an LTC timecode signal tied to the media's current running time. They use it as the clock needed to coordinate the execution of individual script cues.
Legion can output this signal easily without needing the media file to contain a separate embedded timecode track. Instead, Legion has its own built-in generator and like the AVP Timecode packet network stream, the generator is always transmitting a signal. Both streams update their actual time packets based on the current position time stamp of which ever video or audio file is currently playing out to program. This update occurs in sync with the files frame rate.
Linear (or Longitudinal) Timecode (LTC) is an encoding of SMPTE timecode data in an audio signal. So, for us to transmit it we will need an additional audio output device available to the computer. Due to LTC’s very high frequency modulation, it is recommended that you only use your computers embedded speaker out or an installed sound card. The stream may become unstable if you use any USB to audio type converters due to their potentially slower response time. It would be better served if you use the USB device as your primary audio output instead.
Setup:
To enable go to the “Settings” menu and select “Global Properties” and check both “Enable AVP Timecode Packets”.
Next you need to select the audio output device you want to use then check “Enable LTC Output”. As soon as the setting are made the output signal will begin.
WARNING:It is important to prevent attaching to an output that is going to any speakers. The sound of an LTC stream can be very annoying.
Anytime, the enable checkbox or audio device are changed, the function will automatically reset.
The signal will remain running constantly even when no media is playing. It will remain on until either you disable it, or the app is closed.
During moments when nothing is playing the timecode readout will simply be zero. The important part is the receiving device never losses a signal. This prevents the need for any sort of old-school pre-rolling of media in order to establish a sync lock at the receiving end, potentially before the first cue is to be taken.
As with most other functions in Legion, once the change is made, they are saved. So, the LTC signal will automatically resume anytime the app is restarted.
