2.8 Multi Channel Playout on a single Mac(v.2026.x)

Version 2026.x enables Multi-Out Playout with the ability to run up to four Just Out applications on a single Mac. Please note that the number of simultaneous engines is scalable and depends on your specific channel configurations to ensure optimal performance.

Important Information

The number of channels that can run on a single Mac is determined by the following parameters:

• CPU / GPU

• Amount of RAM available

• Playout format: SD, HD or UHD

• SDI or streaming

• GFX only or movie playout as well

• Movie Codec (e.g., ProRes vs H.264)

• Switch-to-Live yes/no

Please take the following points into account when configuring a machine for Multi Out Playout:

• Multi Out playout is supported using Apple silicon-based Mac mini (M1/M2/M4), Mac Studio (Max or Ultra) or Mac Pro 2023 (Mac14,8).

• We recommend the allocation of 4GB of RAM per Just Out application.

• Only the Blackmagic Design video devices that have been qualified by ToolsOnAir should be used (see Chapter 2.3 Supported Video Devices (v.2026.x).

• Multi-out functionality supports the use of multiple video devices, including integration with ONE AJA hardware device.

• Multi Out using a single video device from AJA is currently NOT supported.

• Multi Out using a single video device requires a multi device video hardware from BlackMagic Design.

• Available SDI ports are shown based on SDK detection. For a complete list of ports on your Blackmagic Design hardware, please check the Blackmagic Design Desktop Video Setup utility.

• All available ports are displayed and remain selectable, even if they have already been assigned to an Input or Output in another channel. Please note that a single physical port cannot be used by multiple engines simultaneously; attempting to assign the same port to multiple channels will result in a hardware conflict, causing subsequent engines to fail during initialization.

• Fill+Key functionality is limited to hardware capable of supporting dual-channel output. For users with Blackmagic Design Duo or Quad 2 hardware, ensure that the respective Fill and Key outputs are configured as a 'linked' pair within the Blackmagic Design Desktop Video Setup application.

• Although it is possible to run Just Out and Just Control on the same machine, we strongly recommend running Just Control on a separate machine.

• Real-time graphics are fully supported; however, complex templates and third-party HTML graphics must be thoroughly tested before live deployment to prevent performance issues.

• Please contact ToolsOnAir Helpdesk in case you have questions regarding the setup or a problem during installation:

Blackmagic Design Desktop Video Setup related settings

Using a single DeckLink video device for several engine outputs, the following settings have to be defined in the Configuration window of Just Control, and adjusted using the Blackmagic Design Desktop Video Setup application.

DeckLink Duo 2:

DeckLink Quad 2:

DeckLink 8K Pro:

Performance Benchmarks: Channel Capacity per Mac

The following data provides a baseline for estimating channel capacity per workstation. However, please note that these figures are estimates; a comprehensive, multi-day stress test is mandatory for every unique hardware configuration prior to live deployment.

Internal testing indicates that an M1 Mac with 8 GB of RAM can successfully support four HD channels, provided the system utilizes SDI I/O and ProRes or H.264 compressed video files. Conversely, our testing demonstrates that the same four-channel workload cannot be sustained on an M4 Mac with 16 GB of RAM when utilizing streaming I/O instead of SDI.

Initial Multi Channel Playout Installation

Please follow the chapter 7. Software Installation - Initial and Update (v.2026.x) for more information how to install several channels running several Just Out applications, on a single Mac.

Updating from a single channel to a multichannel setup

Please follow the steps described below to add more channels to a single channel installation.

1. Stop all ToolsOnAir applications on the Mac running the Just Connect application.

2. Navigate to “Library/Application Support/ToolsOnAir/Just Connect” and create a backup, by copying the channel file to the Desktop. Once the copy is complete, delete the original channel file from the “Just Connect” folder to ensure the directory is empty.

3. To install multiple channels, please refer to the Just Play Pro v.2026.x Getting Started or Just Live Pro v.2026.x Getting Started chapters.

4. Once the installation is complete, you can view all installed channels in the Just Connect folder.

5. Delete only the channel without an additional number.

6. Copy the original channel from the Desktop into the Just Connect folder.

7. Restart all ToolsOnAir Playout applications and finish the configuration of the new channels using the Configuration Panel.

Please contact the  → ToolsOnAir Online Helpdesk System for more information and in case you are unsure, how to update to more channels from a single channel setup.