Atoll/DynamicIsland/audio/AudioTap.swift
2026-04-13 18:52:56 +08:00

355 lines
13 KiB
Swift

/*
* Atoll (DynamicIsland)
* Original work Copyright (C) 2026 ZephyrCodesStuff (https://github.com/ZephyrCodesStuff/rtaudio)
* Modified work Copyright (C) 2026 Atoll Contributors
*
* CoreAudio tap for capturing real-time audio from music applications.
* Uses macOS 14.2+ Process Tap API for efficient audio capture.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
import AppKit
import AudioToolbox
import CoreAudio
import simd
import os.log
private let audioTapLog = OSLog(subsystem: "com.atoll.dynamicisland", category: "AudioTap")
// Debug: track callback invocations
private var callbackCount: Int = 0
// CoreAudio fires this on a high-priority background real-time thread.
let audioIOProc: AudioDeviceIOProc = {
inDevice, inNow, inInputData, inInputTime, outOutputData, inOutputTime, clientData in
guard let clientData = clientData else { return noErr }
let scanner = Unmanaged<AudioTap>.fromOpaque(clientData).takeUnretainedValue()
if scanner.isPaused { return noErr }
let mutableInputData = UnsafeMutablePointer(mutating: inInputData)
let bufferList = UnsafeMutableAudioBufferListPointer(mutableInputData)
if let firstBuffer = bufferList.first, let data = firstBuffer.mData {
// CoreAudio gives us byte size, divide by 4 (Float size) to get array length
let floatCount = Int32(firstBuffer.mDataByteSize) / Int32(MemoryLayout<Float>.size)
let floatData = data.assumingMemoryBound(to: Float.self)
// Pass the mono array directly to C++
scanner.bridge.processBuffer(floatData, count: floatCount)
// Debug: log periodically with audio level info
callbackCount += 1
if callbackCount % 1000 == 0 {
// Calculate max absolute value in buffer to check if audio is present
var maxVal: Float = 0.0
for i in 0..<Int(floatCount) {
let absVal = abs(floatData[i])
if absVal > maxVal { maxVal = absVal }
}
os_log(.debug, log: audioTapLog, "🔊 Audio callback fired %d times, buffer size: %d, max amplitude: %f", callbackCount, floatCount, maxVal)
// Also log the current band values from the bridge
let mags = scanner.bridge.getSmoothedMagnitudes()
os_log(.debug, log: audioTapLog, "🎚️ Bridge magnitudes: [%f, %f, %f, %f]", mags.x, mags.y, mags.z, mags.w)
}
}
return noErr
}
private func getAudioObjectID(for pid: pid_t) -> AudioObjectID? {
var audioObjectID: AudioObjectID = kAudioObjectUnknown
var pidValue = pid
var address = AudioObjectPropertyAddress(
mSelector: kAudioHardwarePropertyTranslatePIDToProcessObject,
mScope: kAudioObjectPropertyScopeGlobal,
mElement: kAudioObjectPropertyElementMain
)
var size = UInt32(MemoryLayout<AudioObjectID>.size)
let qualifierSize = UInt32(MemoryLayout<pid_t>.size)
// We query the global system object (kAudioObjectSystemObject)
// We pass the PID as the "qualifier", and it returns the AudioObjectID
let status = AudioObjectGetPropertyData(
AudioObjectID(kAudioObjectSystemObject),
&address,
qualifierSize,
&pidValue,
&size,
&audioObjectID
)
if status == noErr && audioObjectID != kAudioObjectUnknown {
return audioObjectID
}
return nil
}
/// Singleton class for real-time audio capture from music apps
class AudioTap: NSObject {
static let shared = AudioTap()
let bridge = AudioBridge()
var isPaused: Bool = false
private var displayMagnitudes = simd_float4(0, 0, 0, 0)
// CoreAudio stuff
private var tapID: AudioObjectID = kAudioObjectUnknown
private var aggregateDeviceID: AudioObjectID = kAudioObjectUnknown
private var ioProcID: AudioDeviceIOProcID? = nil
private var captureIsRunning = false
// Serial queue to prevent race conditions
private let audioQueue = DispatchQueue(label: "com.atoll.audiotap", qos: .userInitiated)
// Debounce restart requests
private var pendingRestartWorkItem: DispatchWorkItem?
private let targetBundleIDs = [
"com.apple.Music",
"com.spotify.client",
"com.amazon.music",
"com.apple.Safari",
"com.tidal.desktop",
"tv.plex.plexamp",
"com.roon.Roon",
"com.audirvana.Audirvana-Studio",
"com.vox.vox",
"com.coppertino.Vox",
]
private override init() {
super.init()
}
// Helper function to smooth out the magnitudes for prettifying purposes
func getSmoothedMagnitudes() -> simd_float4 {
// Zero bridging overhead. Just passing 16 bytes of memory.
let targetLevels = bridge.getSmoothedMagnitudes()
let smoothingFactor: Float = 0.4
// Vector math! This does all 4 calculations simultaneously.
let difference = targetLevels - displayMagnitudes
displayMagnitudes += difference * smoothingFactor
return displayMagnitudes
}
func startCapture() async {
await withCheckedContinuation { continuation in
audioQueue.async { [weak self] in
self?.startCaptureSync()
continuation.resume()
}
}
}
private func startCaptureSync() {
guard !captureIsRunning else {
print("⚠️ [AudioTap] Capture already running, skipping start")
return
}
let runningApps = NSWorkspace.shared.runningApplications
var targetPIDs: [AudioDeviceID] = []
for app in runningApps {
if let bundleID = app.bundleIdentifier, targetBundleIDs.contains(bundleID) {
if let deviceID = getAudioObjectID(for: app.processIdentifier) {
targetPIDs.append(deviceID)
print("🎯 [AudioTap] Found \(app.localizedName ?? "App") with PID: \(app.processIdentifier), AudioObjectID: \(deviceID)")
}
}
}
if targetPIDs.isEmpty {
print("⚠️ [AudioTap] None of our target apps are running right now.")
return
}
let description = CATapDescription()
description.processes = targetPIDs
description.isMixdown = true
description.isMono = true
print("📋 [AudioTap] Creating tap for \(targetPIDs.count) processes: \(targetPIDs)")
tapID = AudioObjectID(kAudioObjectUnknown)
var status = AudioHardwareCreateProcessTap(description, &tapID)
guard status == noErr else {
print("🛑 [AudioTap] Tap Error: \(status) (\(fourCharCodeToString(status)))")
return
}
print("✅ [AudioTap] Created process tap with ID: \(tapID)")
// Get the tap's unique hardware UID
var tapUID: CFString = "" as CFString
var propertySize = UInt32(MemoryLayout<CFString>.stride)
var propertyAddress = AudioObjectPropertyAddress(
mSelector: kAudioTapPropertyUID,
mScope: kAudioObjectPropertyScopeGlobal,
mElement: kAudioObjectPropertyElementMain
)
status = withUnsafeMutablePointer(to: &tapUID) { uidPtr in
AudioObjectGetPropertyData(tapID, &propertyAddress, 0, nil, &propertySize, uidPtr)
}
guard status == noErr else {
print("🛑 [AudioTap] UID Error: \(status) (\(fourCharCodeToString(status)))")
cleanupPartialSetup()
return
}
print("✅ [AudioTap] Got tap UID: \(tapUID)")
// Create the Aggregate Device (a "virtual microphone" that we can route the tap into)
let tapList = [[kAudioSubTapUIDKey: tapUID]]
let aggregateDict: [String: Any] = [
kAudioAggregateDeviceNameKey: "Atoll_Virtual_Tap",
kAudioAggregateDeviceUIDKey: UUID().uuidString,
kAudioAggregateDeviceIsPrivateKey: true, // Hides it from the user's sound settings
kAudioAggregateDeviceTapListKey: tapList,
]
aggregateDeviceID = AudioObjectID(kAudioObjectUnknown)
status = AudioHardwareCreateAggregateDevice(
aggregateDict as CFDictionary, &aggregateDeviceID)
guard status == noErr else {
print("🛑 [AudioTap] Aggregate Error: \(status) (\(fourCharCodeToString(status)))")
cleanupPartialSetup()
return
}
print("✅ [AudioTap] Created aggregate device with ID: \(aggregateDeviceID)")
// Bind the Callback to the device
let selfPointer = Unmanaged.passUnretained(self).toOpaque()
status = AudioDeviceCreateIOProcID(aggregateDeviceID, audioIOProc, selfPointer, &ioProcID)
guard status == noErr, let validIOProcID = ioProcID else {
print("🛑 [AudioTap] IOProc Error: \(status) (\(fourCharCodeToString(status)))")
cleanupPartialSetup()
return
}
print("✅ [AudioTap] Created IO proc")
// Start listening
status = AudioDeviceStart(aggregateDeviceID, validIOProcID)
guard status == noErr else {
print("🛑 [AudioTap] Start Error: \(status) (\(fourCharCodeToString(status)))")
cleanupPartialSetup()
return
}
captureIsRunning = true
callbackCount = 0
print("🟢 [AudioTap] CoreAudio CATap flowing through Aggregate Device!")
}
private func cleanupPartialSetup() {
if let validIOProcID = ioProcID, aggregateDeviceID != kAudioObjectUnknown {
AudioDeviceDestroyIOProcID(aggregateDeviceID, validIOProcID)
}
if aggregateDeviceID != kAudioObjectUnknown {
AudioHardwareDestroyAggregateDevice(aggregateDeviceID)
}
if tapID != kAudioObjectUnknown {
AudioHardwareDestroyProcessTap(tapID)
}
tapID = kAudioObjectUnknown
aggregateDeviceID = kAudioObjectUnknown
ioProcID = nil
}
func restartCapture() {
// Cancel any pending restart
pendingRestartWorkItem?.cancel()
// Debounce: wait 500ms before actually restarting
let workItem = DispatchWorkItem { [weak self] in
self?.audioQueue.async {
print("🔄 [AudioTap] Restarting capture...")
self?.stopCaptureSync()
// Small delay to let CoreAudio fully release resources
Thread.sleep(forTimeInterval: 0.1)
self?.startCaptureSync()
}
}
pendingRestartWorkItem = workItem
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5, execute: workItem)
}
func stopCapture() {
audioQueue.sync { [weak self] in
self?.stopCaptureSync()
}
}
private func stopCaptureSync() {
guard captureIsRunning else { return }
// Stop listening
if let validIOProcID = ioProcID, aggregateDeviceID != kAudioObjectUnknown {
AudioDeviceStop(aggregateDeviceID, validIOProcID)
AudioDeviceDestroyIOProcID(aggregateDeviceID, validIOProcID)
}
// Destroy resources
if aggregateDeviceID != kAudioObjectUnknown {
AudioHardwareDestroyAggregateDevice(aggregateDeviceID)
}
if tapID != kAudioObjectUnknown {
AudioHardwareDestroyProcessTap(tapID)
}
tapID = kAudioObjectUnknown
aggregateDeviceID = kAudioObjectUnknown
ioProcID = nil
captureIsRunning = false
// Reset display magnitudes
displayMagnitudes = simd_float4(0, 0, 0, 0)
print("🔴 [AudioTap] CoreAudio CATap capture stopped")
}
var isCapturing: Bool {
captureIsRunning
}
deinit {
stopCaptureSync()
}
}
// Helper to convert OSStatus to readable string
private func fourCharCodeToString(_ code: OSStatus) -> String {
let bytes = [
UInt8((code >> 24) & 0xFF),
UInt8((code >> 16) & 0xFF),
UInt8((code >> 8) & 0xFF),
UInt8(code & 0xFF)
]
if bytes.allSatisfy({ $0 >= 32 && $0 < 127 }) {
return String(bytes: bytes, encoding: .ascii) ?? "????"
}
return String(code)
}