This chapter describes the Channel Settings for a just:in mac channel and how to enable a Channel for Recording, once it has been configured.
To perform any changes, you have to unlock the Just Control Configuration panel on the bottom left first.
What is a Channel?
A Channel is a virtual representation of a Video Device or an NDI®5 Source within the network. Depending on the number of inputs, you can configure one or multiple Channels.
Channel Settings (AJA/Blackmagic Design)
Depending on your chosen Video device(s) the Channel Settings can look slightly different.
Settings
You can find a description of each Channel setting below:
The Device Serial Number will only be visible for AJA Video Devices. This Serial Number ensures the alignment of Video Devices with the connected Devices. There have been instances where the connected Devices do not consistently return in the same sequence following a system reboot, particularly with Thunderbolt-based systems.
Kindly take note that AJA utilises a 9-digit Serial Number for the IoX3 and Io4K Plus. However, just:in mac exclusively exhibits the initial 8 digits. The IoX3's Serial Number begins with "7," while that of the Io4K Plus begins with "5."
Device: Select the Video Device (AJA/Blackmagic Design) for this Channel.
Input Mode: Select the Input Mode for this Channel. Available options, depending on the Device are:
SDI (Blackmagic DeckLink)
SDI (AJA)
SDI (AJA 12G)
HDMI (AJA)
Input: Choose the Input of the Device for this Channel here (for Blackmagic Design Channels, only option “Input #1” is available).
Audio Input: Choose between different Audio Input (AJA/Blackmagic Design) and Audio Input Channel (AJA only) options. Audio Input options are:
Auto (same as video, normally SDI)
SDI (By choosing this option, the audio input channel option can be adjusted as well)
Analog
AES/EBU
Audio Input option “SDI”: When using this option, it is possible to distribute the incoming audio of SDI Input1 to all other Channels. Please note that the incoming video streams have to be synced correctly before. We recommend using Frame Stores for such a recording workflows. Moreover, please note that this is an AJA-only feature.
Additionally, there is a special use case, when using the AJA Corvid 88 video device. In this case, you have to use Input 1 & 5 to distribute the incoming audio to all other channels, as this is unfortunately a peculiarity of the AJA video device.
Video Mode: select the Video mode and ensure that it matches the incoming Video Signal, which is attached to the selected Channel. If it does not match, a warning will be shown (“No Signal”).
Please beware that “PSF” video mores are limited to HD modes and AJA devices.
AJA Frame Buffer: This setting overwrites the default Frame Buffer value of an AJA Channel. This setting is required for UHD recording workflows, where Channel Frame Buffer can be set to a higher value, to avoid any Dropped Frames while recording.
Enable RP-188 (SDI Embedded) Timecode (AJA only): This option enables the “SDI Embedded” Timecode Source option for an AJA Input Channel. By default, this option is enabled.
If you experience Frame Drop Errors, disable this option and try it again.
Enable End-To-End SDI If Available: This option does work for some specific AJA devices, such as the KONA 1 or the KONA LHe Plus, where the incoming signal will be passed to the output port, once the Just In Engine application is running.
File Overwrite Strategy:
Append Counter (Default): When using this option, the just:in mac engine will add “_2” to the actual file name in order to avoid overwriting an already existing file.
Replace: By choosing this option, the just:in mac engine will overwrite a file with the same name at the target location.
Chunk Length: defines the maximum length of the recorded Video. The maximum Chunk Length is 12 hours, the default option is 2 hours (02:00:00:00).
If the Recording does not reach the entered Chunk Length, the recorded 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.
Port: port to access the Channel from just:in mac over an IP connection. The default port for the first Channel is 50000, 50001 for the second Channel, and so on. You can keep this setting if the chosen ports are not in use on this machine.
MXF Write Buffer (Bytes in binary): This setting can be used to tune MXF writing for specific storage requirements, but should only be changed with care as it may lead to unexpected results including write errors. Recommended value: Block size of storage.
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.
Restart On No Signal if Not Recording: If this option is enabled, the Channel will automatically restart after a signal loss (only in Idle Mode). Options are:
Close container, write to new: Recording to the current file will be stopped and as soon as there is a valid signal again the recording will start into a new file.
Close container and stop: Recording will be stopped when Channel detects a signal loss.
Cache Options:
Don't Cache: files are directly written to disk, no caching is done.
Cache (Default): tells the internal macOS Ethernet controller to cache data to flush it to the network stack later to improve write performance.
Action on Timecode break:
Ignore: Channel ignores timecode breaks.
Create new file: Channel creates a new file upon a timecode break.
Preview
You can manually override the resolution, frame rate, and quality of the Video Previews within Just Control. This may be helpful to increase performance when displaying many Channels in Just Control. Please refer to the Channel Preview Options below for more information.
Resolution: two resolution options are available:
High: 640×360px
Low: 480×270px
Frame rate: the preview frame rate can be changed between “0” (i.e. native frame rate) and “30” (if the channel frame rate is higher than “30”, then the preview will be limited to 30 fps).
Quality: the “Preview Quality” setting can be changed between “10%” and “100%” (the default value is “50%”).
Enable a Channel for Recording
After configuring a Channel, you have to enable it by clicking on the checkbox next to the Channel name. The Channel can now be used by Just Control. When quitting and relaunching the Just In Engine application, previously activated Channels will still be active, so there is no need to open the Just Control Configuration Panel and activate the Channels again.
To change the Settings of a Channel, you will have to uncheck the corresponding checkbox first. Please note that the Channel will then go offline and will not be reachable by Just Control. Additionally, you cannot disable a Channel, if this Channel is currently in recording mode.
Once a Channel is enabled, it will be available in the “Connections” tab within the Inspector.
Change a Channel Name
The name of a Channel can only be changed when the Channel is disabled. First, make sure that the Channel is not enabled, and then click on the Channel Name (next to the Channel checkbox), adjust the name, and press the “Enter” key to confirm.
