Hi,
I try to record audio on the iPhone with the AVAudioRecorder and Xcode 26.0.1.
Maybe the problem is that I can not record audio with the simulator. But there's a menu for audio.
In the plist I added 'Privacy - Microphone Usage Description' and I ask for permission before recording.
if await AVAudioApplication.requestRecordPermission() {
print("permission granted")
recordPermission = true
} else {
print("permission denied")
}
Permission is granted.
let settings: [String : Any] = [
AVFormatIDKey: kAudioFormatMPEG4AAC,
AVSampleRateKey: 12000,
AVNumberOfChannelsKey: 1,
AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
]
recorder = try AVAudioRecorder(url: filename, settings: settings)
let prepared = recorder.prepareToRecord()
print("prepared started: \(prepared)")
let started = recorder.record()
print("recording started: \(started)")
started is always false and I tried many settings.
Error messages
AddInstanceForFactory: No factory registered for id <CFUUID 0x600000211480> F8BB1C28-BAE8-11D6-9C31-00039315CD46
AudioConverter.cpp:1052 Failed to create a new in process converter -> from 0 ch, 12000 Hz, .... (0x00000000) 0 bits/channel, 0 bytes/packet, 0 frames/packet, 0 bytes/frame to 1 ch, 12000 Hz, aac (0x00000000) 0 bits/channel, 0 bytes/packet, 1024 frames/packet, 0 bytes/frame, with status -50
AudioQueueObject.cpp:1892 BuildConverter: AudioConverterNew returned -50
from: 0 ch, 12000 Hz, .... (0x00000000) 0 bits/channel, 0 bytes/packet, 0 frames/packet, 0 bytes/frame
to: 1 ch, 12000 Hz, aac (0x00000000) 0 bits/channel, 0 bytes/packet, 1024 frames/packet, 0 bytes/frame
prepared started: true
AudioQueueObject.cpp:7581 ConvertInput: aq@0x10381be00: AudioConverterFillComplexBuffer returned -50, packetCount 5
recording started: false
All examples I find are the same, but apparently there must be something different.
Audio
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Hello everyone,
I've written an audio unit plugin that needs to be aware of any upstream latency caused by heavy plugins before it on the channel. Is there any way to query this? I know that Logic applies PDC at the channel's output (summing point), but I need to know what the accumulated latency is at the point the audio enters my plugin. Thanks!
Topic:
Media Technologies
SubTopic:
Audio
Is there any way for me to use an AutoMix api in my IOS apps, I would play tracks using the Apple Music api and use AutoMix to attempt to merge tracks.
Is this feature/api available to developers.
I develop a application with an uvc camera, this camera is a webcam, I use the AVFoundation library ,but when I run the code "[self.mCaptureSession startRunning]" ,I can not get the buffer, I already set the delegate, any answer will help.
Hello,
I need to know what is a unique identifier of a MIDI device (source/destination). Important note: I want to get the same ID when a device is reconnected (unplugged and then plugged again).
The main candidate is kMIDIPropertyUniqueID property. But I don't know if it meets the requirement above or not. Additional question: is it always available for any endpoint?
Also there is kMIDIPropertyDeviceID property. What about it?
And one more option is just MIDIEndpointRef returned by MIDIGetSource or MIDIGetDestination.
So what is the proper way to get ID which persists between device reconnections?
In Instruments, I'm seeing "Zero Time Stamp" events in the "Audio Server" lane.
What does that mean?
Good day, ladies and gents.
I have an application that reads audio from the microphone. I'd like it to also be able to read from the Mac's audio output stream. (A bonus would be if it could detect when the Mac is playing music.)
I'd eventually be able to figure it out reading docs, but if someone can give a hint, I'd be very grateful, and would owe you the libation of your choice.
Here's the code used to set up the AudioUnit:
-(NSString*) configureAU
{
AudioComponent component = NULL;
AudioComponentDescription description;
OSStatus err = noErr;
UInt32 param;
AURenderCallbackStruct callback;
if( audioUnit ) { AudioComponentInstanceDispose( audioUnit ); audioUnit = NULL; } // was CloseComponent
// Open the AudioOutputUnit
description.componentType = kAudioUnitType_Output;
description.componentSubType = kAudioUnitSubType_HALOutput;
description.componentManufacturer = kAudioUnitManufacturer_Apple;
description.componentFlags = 0;
description.componentFlagsMask = 0;
if( component = AudioComponentFindNext( NULL, &description ) )
{
err = AudioComponentInstanceNew( component, &audioUnit );
if( err != noErr ) { audioUnit = NULL; return [ NSString stringWithFormat: @"Couldn't open AudioUnit component (ID=%d)", err] ; }
}
// Configure the AudioOutputUnit:
// You must enable the Audio Unit (AUHAL) for input and output for the same device.
// When using AudioUnitSetProperty the 4th parameter in the method refers to an AudioUnitElement.
// When using an AudioOutputUnit for input the element will be '1' and the output element will be '0'.
param = 1; // Enable input on the AUHAL
err = AudioUnitSetProperty( audioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, 1, ¶m, sizeof(UInt32) ); chkerr("Couldn't set first EnableIO prop (enable inpjt) (ID=%d)");
param = 0; // Disable output on the AUHAL
err = AudioUnitSetProperty( audioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Output, 0, ¶m, sizeof(UInt32) ); chkerr("Couldn't set second EnableIO property on the audio unit (disable ootpjt) (ID=%d)");
param = sizeof(AudioDeviceID); // Select the default input device
AudioObjectPropertyAddress OutputAddr = { kAudioHardwarePropertyDefaultInputDevice, kAudioObjectPropertyScopeGlobal, kAudioObjectPropertyElementMaster };
err = AudioObjectGetPropertyData( kAudioObjectSystemObject, &OutputAddr, 0, NULL, ¶m, &inputDeviceID );
chkerr("Couldn't get default input device (ID=%d)");
// Set the current device to the default input unit
err = AudioUnitSetProperty( audioUnit, kAudioOutputUnitProperty_CurrentDevice, kAudioUnitScope_Global, 0, &inputDeviceID, sizeof(AudioDeviceID) );
chkerr("Failed to hook up input device to our AudioUnit (ID=%d)");
callback.inputProc = AudioInputProc; // Setup render callback, to be called when the AUHAL has input data
callback.inputProcRefCon = self;
err = AudioUnitSetProperty( audioUnit, kAudioOutputUnitProperty_SetInputCallback, kAudioUnitScope_Global, 0, &callback, sizeof(AURenderCallbackStruct) );
chkerr("Could not install render callback on our AudioUnit (ID=%d)");
param = sizeof(AudioStreamBasicDescription); // get hardware device format
err = AudioUnitGetProperty( audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 1, &deviceFormat, ¶m );
chkerr("Could not install render callback on our AudioUnit (ID=%d)");
audioChannels = MAX( deviceFormat.mChannelsPerFrame, 2 ); // Twiddle the format to our liking
actualOutputFormat.mChannelsPerFrame = audioChannels;
actualOutputFormat.mSampleRate = deviceFormat.mSampleRate;
actualOutputFormat.mFormatID = kAudioFormatLinearPCM;
actualOutputFormat.mFormatFlags = kAudioFormatFlagIsFloat | kAudioFormatFlagIsPacked | kAudioFormatFlagIsNonInterleaved;
if( actualOutputFormat.mFormatID == kAudioFormatLinearPCM && audioChannels == 1 )
actualOutputFormat.mFormatFlags &= ~kLinearPCMFormatFlagIsNonInterleaved;
#if __BIG_ENDIAN__
actualOutputFormat.mFormatFlags |= kAudioFormatFlagIsBigEndian;
#endif
actualOutputFormat.mBitsPerChannel = sizeof(Float32) * 8;
actualOutputFormat.mBytesPerFrame = actualOutputFormat.mBitsPerChannel / 8;
actualOutputFormat.mFramesPerPacket = 1;
actualOutputFormat.mBytesPerPacket = actualOutputFormat.mBytesPerFrame;
// Set the AudioOutputUnit output data format
err = AudioUnitSetProperty( audioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 1, &actualOutputFormat, sizeof(AudioStreamBasicDescription));
chkerr("Could not change the stream format of the output device (ID=%d)");
param = sizeof(UInt32); // Get the number of frames in the IO buffer(s)
err = AudioUnitGetProperty( audioUnit, kAudioDevicePropertyBufferFrameSize, kAudioUnitScope_Global, 0, &audioSamples, ¶m );
chkerr("Could not determine audio sample size (ID=%d)");
err = AudioUnitInitialize( audioUnit ); // Initialize the AU
chkerr("Could not initialize the AudioUnit (ID=%d)");
// Allocate our audio buffers
audioBuffer = [self allocateAudioBufferListWithNumChannels: actualOutputFormat.mChannelsPerFrame size: audioSamples * actualOutputFormat.mBytesPerFrame];
if( audioBuffer == NULL ) { [ self cleanUp ]; return [NSString stringWithFormat: @"Could not allocate buffers for recording (ID=%d)", err]; }
return nil;
}
(...again, it would be nice to know if audio output is active and thereby choose the clean output stream over the noisy mic, but that would be a different chunk of code, and my main question may just be a quick edit to this chunk.)
Thanks for your attention! ==Dave
[p.s. if i get more than one useful answer, can i "Accept" more than one, to spread the credit around?]
{pps: of course, the code lines up prettier in a monospaced font!}
My app utilizes background audio to play music files. I have the audio background mode enabled and I initialize the AVAudioSession in playback mode with the mixWithOthers option. And it usually works great while the app is backgrounded. I listen for audio interruptions as well as route changes and I am able to handle them appropriately and I can usually resume my background audio no problem.
I discovered an issue while connected to CarPlay though. Roughly 50% of the time when I disconnect from a phone call while connected to CarPlay I get the following error after calling the play() method of my AVAudioPlayer instance:
"ATAudioSessionClientImpl.mm:281 activation failed. status = 561015905"
If I instead try to start a new audio session I get a similar error:
Error Domain=NSOSStatusErrorDomain Code=561015905 "Session activation failed" UserInfo={NSLocalizedDescription=Session activation failed}
Like I said, this isn't reproducible 100% of the time and is so far only seen while connected to CarPlay. I don't think Im forgetting so additional capability or plist setting, but if anyone has any clues it would be greatly appreciated. Otherwise this is likely just a bug that I need to report to Apple.
One very important note, and reason I believe it's just a bug, is that while I was testing I found that other music apps like Spotify will also fail to resume their audio at the same time my app fails.
Another important detail is that when it works successfully I receive the audio session interruption ended notification, and when it doesn't work I only receive a route configuration change or route override notification. From there I am able to still successfully granted background time to execute code, but my call to resume audio fails with the above mentioned error codes.
Hi, I'm trying to plan out development of an app and am wondering if it is possible to have user generated content automatically populate into a custom shazamkit catalogue and be able to query this catalogue non-locally?
Storing all the submissions locally would obviously not scale.
My code that streams buffers into AVAudioPlayerNode is stuttering when the buffer is finished and before the next one is played.
while engine.isRunning {
let framesToCopy = min(buffer.frameLength - framePosition, Self.BufferSize)
let srcRaw = UnsafeRawPointer(srcPtr)
let playbackBuffer = AVAudioPCMBuffer(pcmFormat: buffer.format, frameCapacity: Self.BufferSize)!
let playbackPtr = playbackBuffer.floatChannelData![0]
let destRaw = UnsafeMutableRawPointer(mutating: playbackPtr)
memcpy(destRaw, srcRaw, Int(framesToCopy) * MemoryLayout<Float>.stride)
srcPtr = srcPtr.advanced(by: Int(framesToCopy))
playbackBuffer.frameLength = framesToCopy
await player.scheduleBuffer(playbackBuffer,
at: nil,
options: [],
completionCallbackType: .dataRendered)
}
I've tried to schedule multiple buffers at once using a combination of both the synchronous and async versions of scheduleBuffer because I thought the delay might be but it still stutters and the data copied into the playbackBuffer matches the source buffer. I've tried all combinations of options and completionCallbackType but no luck.
I've tried increasing the buffer size but that just spaces out the stutters because the buffer is larger.
What am I missing about this API?
Hi everyone,
I’m trying to use AVAssetResourceLoaderDelegate to handle a live radio stream (e.g. Icecast/HTTP stream). My goal is to have access to the last 30 seconds of audio data during playback, so I can analyze it for specific audio patterns in near-real-time.
I’ve implemented a custom resource loader that works fine for podcasts and static files, where the file size and content length are known. However, for infinite live streams, my current implementation stops receiving new loading requests after the first one is served. As a result, the playback either stalls or fails to continue.
Has anyone successfully used AVAssetResourceLoaderDelegate with a continuous radio stream? Or maybe you can suggest betterapproach for buffering and analyzing live audio?
Any tips, examples, or advice would be appreciated. Thanks!
Let's consider the following code.
I've created an actor that loads a list of .mp3 files from a Bundle and then makes it available for audio reproduction.
Unfortunately, I'm experiencing a memory leak.
At the play method.
player.play()
From Instruments I get
_malloc_type_malloc_outlined libsystem_malloc.dylib
start_wqthread libsystem_pthread.dylib
private actor AudioActor {
enum Failure: Error {
case soundsNotLoaded([AudioPlayerClient.Sound: Error])
}
enum Player {
case music(AVAudioPlayer)
}
var players: [Sound: Player] = [:]
let bundles: [Bundle]
init(bundles: UncheckedSendable<[Bundle]>) {
self.bundles = bundles.wrappedValue
}
func load(sounds: [Sound]) throws {
try AVAudioSession.sharedInstance().setActive(true, options: [])
var errors: [Sound: Error] = [:]
for sound in sounds {
guard let url = bundle.url(forResource: sound.name, withExtension: "mp3")
else { continue }
do {
self.players[sound] = try .music(AVAudioPlayer(contentsOf: url))
} catch {
errors[sound] = error
}
}
guard errors.isEmpty
else { throw Failure.soundsNotLoaded(errors) }
}
func play(sound: Sound, loops: Int?) throws {
guard let player = self.players[sound]
else { return }
switch player {
case let .music(player):
player.numberOfLoops = loops ?? -1
player.play()
}
}
func stop(sound: Sound) throws {
guard let player = self.players[sound]
else { throw Failure.soundsNotLoaded([:]) }
switch player {
case let .music(player):
player.stop()
}
}
}
On Apple TV 4K 3rd generation, with tvOS 26 beta 2, when two HomePod 2 are paired to the device, music and movie sources with Dolby Atmos can only be listened to in stereo. dolby atmos not supported
Topic:
Media Technologies
SubTopic:
Audio
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Topic:
Media Technologies
SubTopic:
Audio
Since MacOS 26 Apple Music has inconsitent drops to the Quality of some Tracks indiscrimantly. I don't know if others Expereinced it. It doesn't happen on the Speakers or connected via Bluetooth, but the AUX I/O has it quite often. It is more noticable on Headphones with 48kHz and higher Frequency Bandwidth.
Here is the FB18062589
I'm working on adding Spatial Audio support to a game on the Mac. I'm looking at the SpatialAudioRenderer sample but having some issues.
It's unclear to me when a device is compatible with Spatial Audio and when I should attempt to render Spatial Audio. There is no property that I can find on the Mac that advertises Spatial Audio compatibility on a device.
The sample crashes when the output device is a USB device. This includes the Apple Studio Display.
The Apple Studio Display is supposed to be capable of rendering Spatial Audio. The device doesn't work with the sample - do I still need to render down the 7.1.4 source on this device? The sample always renders down to Stereo, but the Apple Studio Display is not a Stereo device.
I'm a bit confused by the sample and when/how I should configure the mixing unit.
Topic:
Media Technologies
SubTopic:
Audio
I'm streaming mp3 audio data using URLSession/AudioFileStream/AVAudioConverter and getting occasional silent buffers and glitches (little bleeps and whoops as opposed to clicks). The issues are present in an offline test, so this isn't an issue of underruns.
Doing some buffering on the input coming from the URLSession (URLSessionDataTask) reduces the glitches/silent buffers to rather infrequent, but they do still happen occasionally.
var bufferedData = Data()
func parseBytes(data: Data) {
bufferedData.append(data)
// XXX: this buffering reduces glitching
// to rather infrequent. But why?
if bufferedData.count > 32768 {
bufferedData.withUnsafeBytes { (bytes: UnsafeRawBufferPointer) in
guard let baseAddress = bytes.baseAddress else { return }
let result = AudioFileStreamParseBytes(audioStream!,
UInt32(bufferedData.count),
baseAddress,
[])
if result != noErr {
print("❌ error parsing stream: \(result)")
}
}
bufferedData = Data()
}
}
No errors are returned by AudioFileStream or AVAudioConverter.
func handlePackets(data: Data,
packetDescriptions: [AudioStreamPacketDescription]) {
guard let audioConverter else {
return
}
var maxPacketSize: UInt32 = 0
for packetDescription in packetDescriptions {
maxPacketSize = max(maxPacketSize, packetDescription.mDataByteSize)
if packetDescription.mDataByteSize == 0 {
print("EMPTY PACKET")
}
if Int(packetDescription.mStartOffset) + Int(packetDescription.mDataByteSize) > data.count {
print("❌ Invalid packet: offset \(packetDescription.mStartOffset) + size \(packetDescription.mDataByteSize) > data.count \(data.count)")
}
}
let bufferIn = AVAudioCompressedBuffer(format: inFormat!, packetCapacity: AVAudioPacketCount(packetDescriptions.count), maximumPacketSize: Int(maxPacketSize))
bufferIn.byteLength = UInt32(data.count)
for i in 0 ..< Int(packetDescriptions.count) {
bufferIn.packetDescriptions![i] = packetDescriptions[i]
}
bufferIn.packetCount = AVAudioPacketCount(packetDescriptions.count)
_ = data.withUnsafeBytes { ptr in
memcpy(bufferIn.data, ptr.baseAddress, data.count)
}
if verbose {
print("handlePackets: \(data.count) bytes")
}
// Setup input provider closure
var inputProvided = false
let inputBlock: AVAudioConverterInputBlock = { packetCount, statusPtr in
if !inputProvided {
inputProvided = true
statusPtr.pointee = .haveData
return bufferIn
} else {
statusPtr.pointee = .noDataNow
return nil
}
}
// Loop until converter runs dry or is done
while true {
let bufferOut = AVAudioPCMBuffer(pcmFormat: outFormat, frameCapacity: 4096)!
bufferOut.frameLength = 0
var error: NSError?
let status = audioConverter.convert(to: bufferOut, error: &error, withInputFrom: inputBlock)
switch status {
case .haveData:
if verbose {
print("✅ convert returned haveData: \(bufferOut.frameLength) frames")
}
if bufferOut.frameLength > 0 {
if bufferOut.isSilent {
print("(haveData) SILENT BUFFER at frame \(totalFrames), pending: \(pendingFrames), inputPackets=\(bufferIn.packetCount), outputFrames=\(bufferOut.frameLength)")
}
outBuffers.append(bufferOut)
totalFrames += Int(bufferOut.frameLength)
}
case .inputRanDry:
if verbose {
print("🔁 convert returned inputRanDry: \(bufferOut.frameLength) frames")
}
if bufferOut.frameLength > 0 {
if bufferOut.isSilent {
print("(inputRanDry) SILENT BUFFER at frame \(totalFrames), pending: \(pendingFrames), inputPackets=\(bufferIn.packetCount), outputFrames=\(bufferOut.frameLength)")
}
outBuffers.append(bufferOut)
totalFrames += Int(bufferOut.frameLength)
}
return // wait for next handlePackets
case .endOfStream:
if verbose {
print("✅ convert returned endOfStream")
}
return
case .error:
if verbose {
print("❌ convert returned error")
}
if let error = error {
print("error converting: \(error.localizedDescription)")
}
return
@unknown default:
fatalError()
}
}
}
It sounds simple but searching for the name "Favorite Songs" is a non-starter because it's called different names in different countries, even if I specify "&l=en_us" on the query.
So is there another property, relationship or combination thereof which I can use to tell me when I've found the right playlist?
Properties I've looked at so far:
canEdit: will always be false so narrows things down a little
inFavorites: not helpful as it depends on whether the user has favourite the favourites playlist, so not relevant
hasCatalog: seems always true so again may narrow things down a bit
isPublic: doesn't help
Adding the catalog relationship doesn't seem to show anything immediately useful either.
Can anyone help?
Ideally I'd like to see this as a "kind" or "type" as it has different properties to other playlists, but frankly I'll take anything at this point.
I have an AUv3 plugin which uses an FFT - which requires n samples before it can produce any output - so, depending on the relation between the host's buffer size and the FFT window size, it may receive a several buffers of samples, producing no output, and then dumping out what it has once a sufficient number of samples have been received.
This means that output is produced in fits and starts, in batches that match the FFT size (modulo oversampling) - e.g. if being fed buffers of 256 samples with an fft size of 1024, the output buffer sizes will be 0 for the first 3 buffers, and upon the fourth, the first 256 processed samples are returned and the remaining 768 cached; the next three buffers will return the remaining cached samples while processing and buffering subsequent ones, and so forth.
The internal mechanics of that I have solved, caching output if the current output buffer is too small, and so forth - so it all works as advertised, and the plugin reports its latency correctly. And when run as an app in demo-mode, playback works as expected.
In the plugin's render block, it captures the number of frames written, and if it is less than the number of frames passed in, adjusts the mDataByteSize of the output buffers to match the actual quantity of data being returned:
unsigned int framesWritten = (unsigned int) processHelper->processWithEvents(inAudioBufferList, outAudioBufferList, timestamp, frameCount, realtimeEventListHead);
if (framesWritten < frameCount) {
for (UInt32 i = 0; i < outAudioBufferList->mNumberBuffers; ++i) {
outAudioBufferList->mBuffers[i].mDataByteSize = framesWritten * 4; // assume 4 byte floats
}
}
However, there are a couple of serious issues:
auval -v fails it with - Render Test at 64 frames, sample rate: 22050 Hz ERROR: Output Buffer Size does not match requested
When connected to Logic Pro, it appears that mDataByteSize is ignored, and the entire allocated buffer is read - audio has sections of silence snipped into it which corresponds the number of empty buffers being returned
If I set Logic's buffer size to 1024 and use a 1024 sample FFT window, the plugin works correctly - but of course a plugin cannot dictate buffer size, and `1024 is too small a window size to be useful for anything but filtering very high frequencies
This seems like it has to be a solvable problem, and most likely the issue is in how my code reports the number of usable samples in the returned buffer.
So, what is the correct way for a plugin to report that it has no samples to return, but will, uh, real soon now?
I know I could convert this plugin to be one that does offline rendering of the entire input, but this is real-time processing, just with a fixed amount of latency, so that should not be necessary.
I'm working on a v2 Audio Unit that has some complicated internal state (audio, midi, other settings).
When the internal state changes, I want to inform the host (f.i. Logic Pro) that my plugin state has changed, and that the main window should show the 'project changed' status through the window close button.
This was easy to achieve for the VST version of the plugin, but I can't figure out a way to do it for the Audio Unit.
I've tried:
Notifying change of the kAudioUnitProperty_ClassInfo property that stores the plugin state:
unit->PropertyChanged(kAudioUnitProperty_ClassInfo, kAudioUnitScope_Global, 0);
Setting the kAudioUnitProperty_ClassInfo property value each time the plugin state changes.
Adding a new parameter called 'dirtystate' and toggling it and notifying the change each time the plugin state changes.
But nothing really make Logic take notice. This should be an easy task, but I can't put my finger on it.
How do I flag may AUv2 as needing its status saved (i.e. the host project needs saving)?