This chapter explains the Channel settings of the just:in Engine Preferences and how to enable a Channel for Capture, once it has been configured.

What is a Channel?

A Channel is a virtual representation of your Video Capture Device. Depending on the number of Capture Devices you have, you may configure one or multiple Channels.

Channels Tab

1. Channel List: each Channel represents one input of a Video Capture Device. Selecting a Channel in this list allows you to configure it. See (3) to learn what the checkbox means.
2. Channel Settings
   • Name: the desired Channel name, which will also be displayed in the just:in user interface.
   • Device Serial Number: shows the device serial number.
   • Video Mode: select the Video mode. The mode has to match the Video Signal which is attached to the selected Channel. If it does not match, a warning will be shown as described in the chapter Warning Messages (just:in v2.5).
   • Video/Audio Input: select the Video/Audio input if your Video device supports more than one input.
   • Audio Bitrate: select the Audio bitrate (native 24-bit for AJA, selectable 16- or 24-bit for Blackmagic).
   • VTR Control: select the serial RS-422 connection you want to use to control your VTR.
   • VTR Preroll in Seconds: set the desired VTR preroll value in seconds (1-10). Default value is 5.
   • Chunk Length: defines the maximum length of the recorded Video. The maximun Chunk Length is 12 hours, the default is 2 hours.
     • Recording does not reach the entered Chunk Length: clips will be automatically truncated to the expected recorded length.
     • Recording exceeds the entered Chunk Length: a new Recording (generating a new clip) will automatically be started.
   • Start Timecode: enabling this option overrides the local time or incoming timecode and makes every new clip start with the defined timecode value. 
   • Cache Options:
     • Don't Cache (default): files are directly written to disk, no caching is done.
     • Cache: tells the storage controller to cache data in order to flush it to disk later to improve write performance. If you experience low write performance, enable caching.
   • Video Output Buffer (QuickTime only): number of A/V frames to flush to the storage system at once. If you want to flush once a second, just enter the Video framerate.
   • Output Buffer Segments (QuickTime only): number of Buffer Segments. The Number of Buffer Segments multiplied by the Video Output Buffer (= storage flush size) is the total buffer size. We recommend not to exceed a total buffer size of 250 frames, otherwise the system may run out of RAM.
   • Preview Options: you can manually override the resolution and framerate of the Video Previews of the just:in user interface. This may be helpful to increase performance when displaying many Channels in the just:in user interface. Explained in detail below.
   • Action on Timecode break:
     • Ignore: Channel ignores timecode breaks.
     • Create new file: Channel creates a new file upon a timecode break.
   • Engine Port: port to access the Channel from just:in over an IP connection. Default port for the first Channel is 50000, 50001 for the second Channel and so on. You can leave this setting if the chosen ports are not in use on this machine.
     
   • Communication Interface: select the network interface which should be used to establish a connection to the just:in user interface. Usually this will be the same interface which has been used as the Preview Network Communication Interface (as described in the chapter Basic Engine Configuration).
3. Activating/Deactivating Channels: clicking on a checkbox activates the Channel for Capturing. At least the Video Mode and the Audio Bitrate must be defined before the Channel can be activated. Uncheck a Channel to configure it. Do not forget to activate the Channel afterwards, otherwise it will not be accessible by the just:in user interface.