Error while trying to connect and send message to switcher

[adamtow]

I'm having a problem trying to get the controller connected properly so I can send messages:

if let controller = try? Controller(ipAddress: "10.0.1.50") {
	print("Before sending message")
	controller.send(message: ChangeTransitionPosition(to: 5000))
}

This error occurs right after calling print in the EventLoopGroup extension of NIO.

NIO-ELT-1-#0 (10): Fatal error: BUG DETECTED: syncShutdownGracefully() must not be called when on an EventLoop.
Calling syncShutdownGracefully() on any EventLoop can lead to deadlocks.
Current eventLoop: SelectableEventLoop { selector = Selector { descriptor = 3 }, thread = NIOThread(name = NIO-ELT-1-#0) }

Do you have a sample app that uses the Swift-Atem package to send one or two commands to a switcher?

[Dev1an]

Here is an example of sending messages to the ATEM: /Sources/PreviewSwitcher/main.swift
You can run that by cloning this repository, and typing swift run PreviewSwitcher in the command line.

[Dev1an]

Note that the Preview Switcher example I referred to, uses a newer version of this library that isn't released yet.
I actually made quite some changes since the last release that are yet to be documented. You can take advantage of these changes by using the latest commit on the master branch and by looking at the example code that you can already find in the /Sources folder.

Let me know if you still have problems using this latest version, or if you have any questions on how to use it.

[adamtow]

Thanks for this. I got the controller to be instantiated and can see the PreviewBus updating in my console when I press the buttons on the switcher.

Now, I want to be able to send a message, such as turning the DSK1 to On, but I don't see any commands that send the "CDsL" message. Is that because it isn't implemented in your app, or is there a way to send arbitrary messages to the switcher?

Looking at the Config.Topology message, I don't see any listing for the upstreamKeyers. Is this also something that isn't yet implemented?

Finally, do you have plans to support listing out and running macros?

[Dev1an]

The preview switcher also has an example of how to send messages:

Swift-Atem/Sources/PreviewSwitcher/main.swift

Line 43 in b1ab46e

controller.send(message: Do.ChangePreviewBus(to: source))

Changing the downstream keyers isn’t implemented yet. But yes, you can send your own arbitrary messages if you know how they are structured. Just look at the ChangePreviewBus example:

Swift-Atem/Sources/Atem/Messages/Actions.swift

Lines 32 to 54 in b1ab46e

	public struct ChangePreviewBus: SerializableMessage {
	public static let title = Message.Title(string: "CPvI")
	public let mixEffect: UInt8
	public let previewBus: VideoSource
	public init(with bytes: ArraySlice<UInt8>) throws {
	mixEffect = bytes[relative: 0]
	let sourceNumber = UInt16(from: bytes[relative: 2..<4])
	self.previewBus = try VideoSource.decode(from: sourceNumber)
	}
	public init(to newPreviewBus: VideoSource, mixEffect: UInt8 = 0) {
	self.mixEffect = mixEffect
	previewBus = newPreviewBus
	}
	public var dataBytes: [UInt8] {
	return [mixEffect, 0] + previewBus.rawValue.bytes
	}
	public var debugDescription: String {return "Change preview bus to \(previewBus)"}
	}

Change the title from ‘CPvI’ to ‘CDsL’ and change the properties, initializer and the ‘dataBytes’.
‘dataBytes’ is the raw message that will be sent to the atem when you execute ‘ controller.send(message: yourMessage)’

[Dev1an]

The number of upstreamkeyers is not listed in the Topology command but it is instead listed in the Config.MixEffect command:

Swift-Atem/Sources/Atem/Messages/Configuration.swift

Line 190 in b1ab46e

public let numberOfKeyers: UInt8

.

There is another library out there (LibAtem) that is quite complete where you can look into the implementation to figure out most of the blackmagic protocol:
https://github.com/LibAtem/LibAtem/blob/27e1f7e3b6236eb1929f42b6b3cabd0575ee8652/LibAtem/Commands/DeviceProfile/MixEffectBlockConfigCommand.cs

They also implemented the macro commands: https://github.com/LibAtem/LibAtem/tree/master/LibAtem/Commands/Macro

[adamtow]

Thanks again. I've made some progress getting the USK and DSK commands working. I'll be submitting a pull request later.

[adamtow]

I submitted the following pull request which implements a bunch of features that I needed. Thank you for creating this library. It's been very helpful! #10