feat: Audio Channels

Author: Balte de Wit

src/defaults.ts

@@ -1,6 +1,7 @@
 import { VideoState, Enums } from 'atem-connection'
 import * as USK from 'atem-connection/dist/state/video/upstreamKeyers'
 import * as DSK from 'atem-connection/dist/state/video/downstreamKeyers'
+import { AudioChannel } from 'atem-connection/dist/state/audio'
 
 export namespace Defaults {
 	export namespace Video {
@@ -260,4 +261,14 @@ export namespace Defaults {
 			borderLightSourceAltitude: 0
 		}
 	}
+
+	export namespace Audio {
+		export const Channel: AudioChannel = {
+			sourceType: 0,
+			portType: 1,
+			mixOption: 0,
+			gain: 0,
+			balance: 0
+		}
+	}
 }

src/resolvers/__tests__/audio.spec.ts

@@ -0,0 +1,59 @@
+import { State as StateObject } from '../../'
+import * as audio from '../audio'
+import { AudioChannel } from 'atem-connection/dist/state/audio'
+import { AudioMixerInputCommand } from 'atem-connection/dist/commands'
+
+function literal<T> (o: T) { return o }
+
+const STATE1 = new StateObject()
+STATE1.audio.channels = [
+	literal<AudioChannel>({
+		sourceType: 0,
+		portType: 1,
+		mixOption: 0,
+		gain: 0,
+		balance: 0
+	}),
+	literal<AudioChannel>({
+		sourceType: 0,
+		portType: 1,
+		mixOption: 0,
+		gain: 0,
+		balance: 0
+	})
+]
+const STATE2 = new StateObject()
+STATE2.audio.channels = JSON.parse(JSON.stringify(STATE1.audio.channels))
+
+test('Unit: audio: same state gives no commands', function () {
+	// same state gives no commands:
+	const commands = audio.resolveAudioState(STATE1 as unknown as StateObject, STATE1 as unknown as StateObject)
+	expect(commands.length).toEqual(0)
+})
+
+test('Unit: audio: channel command', function () {
+	STATE2.audio.channels[0].gain = -192
+
+	const commands = audio.resolveAudioState(STATE1 as unknown as StateObject, STATE2 as unknown as StateObject) as Array<AudioMixerInputCommand>
+	expect(commands.length).toEqual(1)
+	expect(commands[0].rawName).toEqual('AMIP')
+	expect(commands[0].index).toEqual(0)
+	expect(commands[0].properties).toMatchObject({ gain: -192 })
+	expect(commands[0].flag).toEqual(2) // 010
+
+	STATE2.audio.channels[0].gain = 0
+})
+
+test('Unit: audio: new channel', function () {
+	const c = STATE1.audio.channels[1]
+	delete STATE1.audio.channels[1]
+
+	const commands = audio.resolveAudioState(STATE1 as unknown as StateObject, STATE2 as unknown as StateObject) as Array<AudioMixerInputCommand>
+	expect(commands.length).toEqual(1)
+	expect(commands[0].rawName).toEqual('AMIP')
+	expect(commands[0].index).toEqual(1)
+	expect(commands[0].properties).toMatchObject({ ...STATE2.audio.channels[1] })
+	expect(commands[0].flag).toEqual(7) // 111
+
+	STATE1.audio.channels[1] = c
+})

src/resolvers/audio.ts

@@ -0,0 +1,32 @@
+import { Commands as AtemCommands, Commands } from 'atem-connection'
+import { State as StateObject } from '../'
+import { AudioChannel } from 'atem-connection/dist/state/audio'
+import { compareProps } from '../util'
+
+export function resolveAudioState (oldState: StateObject, newState: StateObject): Array<Commands.AbstractCommand> {
+	let commands: Array<AtemCommands.AbstractCommand> = []
+	if (!newState.audio || !newState.audio.channels) return commands
+
+	for (const index in newState.audio.channels) {
+		const oldChannel = oldState.audio.channels[index]
+		const newChannel = newState.audio.channels[index]
+		let props: Partial<AudioChannel> = {}
+
+		if (!newChannel) continue
+
+		if (!oldChannel) {
+			props = newChannel
+		} else {
+			props = compareProps(oldChannel, newChannel, ['gain', 'mixOption', 'balance'])
+		}
+
+		if (Object.keys(props).length > 0) {
+			const command = new Commands.AudioMixerInputCommand()
+			command.index = Number(index)
+			command.updateProps(props)
+			commands.push(command)
+		}
+	}
+
+	return commands
+}

src/resolvers/index.ts

@@ -5,6 +5,7 @@ import { State as StateObject } from '../'
 import { resolveMixEffectsState } from './mixEffect'
 import { resolveDownstreamKeyerState } from './downstreamKeyer'
 import { resolveSupersourceBoxState, resolveSuperSourcePropertiesState } from './supersource'
+import { resolveAudioState } from './audio'
 
 export function videoState (oldState: StateObject, newState: StateObject): Array<AtemCommands.AbstractCommand> {
 	let commands: Array<AtemCommands.AbstractCommand> = []
@@ -13,6 +14,7 @@ export function videoState (oldState: StateObject, newState: StateObject): Array
 	commands = commands.concat(resolveDownstreamKeyerState(oldState, newState))
 	commands = commands.concat(resolveSupersourceBoxState(oldState, newState))
 	commands = commands.concat(resolveSuperSourcePropertiesState(oldState, newState))
+	commands = commands.concat(resolveAudioState(oldState, newState))
 
 	// resolve auxilliaries:
 	for (const index in newState.video.auxilliaries) {

src/util.ts

@@ -0,0 +1,11 @@
+export function compareProps<T> (oldProps: T, newProps: T, props: Array<keyof T>) {
+	const changedProps: Partial<T> = {}
+
+	for (let key of props) {
+		if ((newProps)[key] !== (oldProps)[key]) {
+			(changedProps)[key] = (newProps)[key]
+		}
+	}
+
+	return changedProps
+}