AudioTee Swift CLI repo

2025-06-11 15:33:40 +01:00
commit 4a8bc657e3
26 changed files with 1559 additions and 0 deletions
@@ -0,0 +1,145 @@
+import AudioToolbox
+import CoreAudio
+import Foundation
+
+public class AudioRecorder {
+  private var deviceID: AudioObjectID
+  private var ioProcID: AudioDeviceIOProcID?
+  private var sourceFormat: AudioStreamBasicDescription?
+  private var finalFormat: AudioStreamBasicDescription?
+  private var audioBuffer: AudioBuffer?
+  private var outputHandler: AudioOutputHandler
+  private var converter: AudioFormatConverter?
+  private var chunkDuration: Double
+
+  init(
+    deviceID: AudioObjectID, outputHandler: AudioOutputHandler, convertToSampleRate: Double? = nil,
+    chunkDuration: Double = 0.2
+  ) {
+    self.deviceID = deviceID
+    self.outputHandler = outputHandler
+    self.chunkDuration = chunkDuration
+
+    // Get source format and set up conversion if requested
+    let sourceFormat = AudioFormatManager.getDeviceFormat(deviceID: deviceID)
+    self.sourceFormat = sourceFormat
+
+    if let targetSampleRate = convertToSampleRate {
+      // Validate sample rate
+      guard AudioFormatConverter.isValidSampleRate(targetSampleRate) else {
+        Logger.error("Invalid sample rate", context: ["sample_rate": String(targetSampleRate)])
+        self.converter = nil
+        self.finalFormat = sourceFormat
+        return
+      }
+
+      do {
+        let converter = try AudioFormatConverter.toSampleRate(targetSampleRate, from: sourceFormat)
+        self.converter = converter
+        self.finalFormat = converter.targetFormatDescription
+        Logger.info(
+          "Audio conversion enabled", context: ["target_sample_rate": String(targetSampleRate)])
+      } catch {
+        Logger.error(
+          "Failed to create audio converter, using original format",
+          context: ["error": String(describing: error)])
+        self.converter = nil
+        self.finalFormat = sourceFormat
+      }
+    } else {
+      self.converter = nil
+      self.finalFormat = sourceFormat
+    }
+  }
+
+  func startRecording() {
+    Logger.debug("Starting audio recording")
+
+    guard let sourceFormat = sourceFormat, let finalFormat = finalFormat else {
+      fatalError("Audio formats not initialized")
+    }
+
+    // Set up the audio buffer using source format and configurable chunk duration
+    self.audioBuffer = AudioBuffer(format: sourceFormat, chunkDuration: chunkDuration)
+
+    // Log format info and send metadata for FINAL format
+    AudioFormatManager.logFormatInfo(finalFormat)
+    let metadata = AudioFormatManager.createMetadata(for: finalFormat)
+    outputHandler.handleMetadata(metadata)
+    outputHandler.handleStreamStart()
+
+    // Set up and start the IO proc
+    setupAndStartIOProc()
+
+    Logger.info("Audio device started successfully")
+  }
+
+  // FIXME: note to self, what about installTap? Would require audio engine and a node?
+  private func setupAndStartIOProc() {
+    Logger.debug("Creating IO proc")
+    var status = AudioDeviceCreateIOProcID(
+      deviceID,
+      {
+        (inDevice, inNow, inInputData, inInputTime, outOutputData, inOutputTime, inClientData)
+          -> OSStatus in
+        let recorder = Unmanaged<AudioRecorder>.fromOpaque(inClientData!).takeUnretainedValue()
+        return recorder.processAudio(inInputData)
+      },
+      Unmanaged.passUnretained(self).toOpaque(),
+      &ioProcID
+    )
+
+    guard status == noErr else {
+      fatalError("Failed to create IO proc: \(status)")
+    }
+
+    Logger.debug("Starting audio device")
+    status = AudioDeviceStart(deviceID, ioProcID)
+
+    if status != noErr {
+      cleanupIOProc()
+      fatalError("Failed to start audio device: \(status). Device ID: \(deviceID)")
+    }
+  }
+
+  private func processAudio(_ inputData: UnsafePointer<AudioBufferList>) -> OSStatus {
+    let bufferList = inputData.pointee
+    let firstBuffer = bufferList.mBuffers
+
+    guard firstBuffer.mData != nil && firstBuffer.mDataByteSize > 0 else {
+      "Warning: Received empty audio buffer".print(to: .standardError)
+      return noErr
+    }
+
+    // Append raw audio data to buffer
+    let audioData = Data(bytes: firstBuffer.mData!, count: Int(firstBuffer.mDataByteSize))
+    audioBuffer?.append(audioData)
+
+    // Process and send complete chunks, applying conversion if needed
+    audioBuffer?.processChunks().forEach { packet in
+      let processedPacket = converter?.transform(packet) ?? packet
+      outputHandler.handleAudioPacket(processedPacket)
+    }
+
+    return noErr
+  }
+
+  func stopRecording() {
+    // Send any remaining buffered audio, applying conversion if needed
+    if let finalPacket = audioBuffer?.flushRemaining() {
+      let processedPacket = converter?.transform(finalPacket) ?? finalPacket
+      outputHandler.handleAudioPacket(processedPacket)
+    }
+
+    outputHandler.handleStreamStop()
+    cleanupIOProc()
+  }
+
+  private func cleanupIOProc() {
+    if let ioProcID = ioProcID {
+      AudioDeviceStop(deviceID, ioProcID)
+      AudioDeviceDestroyIOProcID(deviceID, ioProcID)
+      self.ioProcID = nil
+    }
+  }
+}