native macos backend, reduce latency

src/types/capture.ts

@@ -13,6 +13,9 @@ export interface CaptureSourceDescriptor {
   id: string
   label: string
   kind: CaptureMode
+  isDefault?: boolean
+  sampleRate?: number
+  channelCount?: number
 }
 
 export interface CaptureBackendSupportEntry {

src/types/nativeCapture.ts

@@ -0,0 +1,47 @@
+export interface NativeMacOSCaptureSupport {
+  available: boolean
+  reason: string | null
+}
+
+export interface NativeMacOSCaptureSource {
+  id: string
+  label: string
+  kind: 'system'
+  isDefault: boolean
+  sampleRate: number
+  channelCount: number
+}
+
+export interface NativeMacOSCaptureStartResult {
+  sampleRate: number
+  channelCount: number
+  deviceId: string
+  deviceLabel: string
+}
+
+export interface NativeMacOSCapturedChunk {
+  left: Float32Array
+  right: Float32Array
+  channelCount: number
+  capturedAtMilliseconds: number
+  sequence: number
+}
+
+export interface NativeMacOSCaptureDrainResult {
+  chunks: NativeMacOSCapturedChunk[]
+  overwriteCount: number
+  queueDepth: number
+}
+
+export interface NativeMacOSCaptureAPI {
+  getSupport: () => NativeMacOSCaptureSupport
+  listOutputDevices: () => NativeMacOSCaptureSource[]
+  start: (deviceId?: string) => NativeMacOSCaptureStartResult
+  stop: () => void
+  drain: (maxChunks?: number) => NativeMacOSCaptureDrainResult
+  nowMilliseconds: () => number
+}
+
+export interface NativeCaptureAPI {
+  macosCapture: NativeMacOSCaptureAPI
+}