Fix audio clock drift and adaptive jitter buffering
.NET port / test (macos-latest) (push) Canceled after 0s
.NET port / test (ubuntu-24.04) (push) Canceled after 0s
.NET port / test (windows-latest) (push) Canceled after 0s
.NET port / apple-client (push) Canceled after 0s

This commit is contained in:
2026-09-20 16:26:03 +02:00
parent 3ee0df11a9
commit dd811a0bb8
23 changed files with 401 additions and 61 deletions
+2 -1
View File
@@ -20,7 +20,8 @@ The supported source-of-truth layout is:
## Release gates
- Run real multi-person calls on Windows, macOS, and physical iOS hardware.
- Run real multi-person calls on Windows, macOS, and physical iOS hardware, including adaptive
20/40/60 ms buffering, duration-aware DRED/FEC, and mismatched input/output endpoints.
- Complete NVDA and VoiceOver navigation/announcement passes.
- Exercise iOS background/lock, interruption, Bluetooth, route-change, ReplayKit, and iOS 27
ScreenCaptureKit paths on devices.
@@ -139,7 +139,7 @@ internal sealed class MacAudioBackend : IAudioDeviceBackend
private sealed class Playback : IAudioPlayback
{
private readonly PcmRing pcm = new(32_768);
private readonly AdaptivePcmBuffer pcm = new(2);
private readonly short[] renderScratch = new short[8_192];
private readonly AVAudioEngine engine = new();
private readonly AVAudioFormat format;
@@ -187,6 +187,7 @@ internal sealed class MacAudioBackend : IAudioDeviceBackend
}
public void Write(ReadOnlySpan<short> stereoPcm) => pcm.TryWrite(stereoPcm);
public int BufferMilliseconds { get => pcm.BufferMilliseconds; set => pcm.BufferMilliseconds = value; }
private unsafe int Render(IntPtr isSilence, IntPtr _, uint frameCount, IntPtr outputData)
{
@@ -199,8 +200,6 @@ internal sealed class MacAudioBackend : IAudioDeviceBackend
int frames = checked((int)frameCount);
int requested = checked(frames * 2);
if (bufferCount != 2 || requested > renderScratch.Length) return Fail("Core Audio returned an invalid planar stereo playback buffer.");
Span<short> discard = stackalloc short[1_920];
while (pcm.Count > 11_520) pcm.Read(discard[..Math.Min(discard.Length, pcm.Count - 11_520)]);
Span<short> source = renderScratch.AsSpan(0, requested);
int read = pcm.Read(source);
source[read..].Clear();
@@ -19,6 +19,7 @@ internal sealed class MacSettings
internal bool AuxiliaryEnabled { get; set; }
internal string? AuxiliaryDeviceId { get; set; }
internal float AuxiliaryGain { get; set; } = 1f;
internal int AudioBufferMilliseconds { get; set; } = 40;
internal bool EventSounds { get; set; } = true;
internal bool SpokenEvents { get; set; }
internal float EventVolume { get; set; } = 1f;
@@ -28,9 +29,9 @@ internal sealed class MacSettings
internal void Load()
{
NSString[] keys = [(NSString)"voice.inputMode", (NSString)"voice.vadThreshold", (NSString)"voice.inputGain", (NSString)"voice.outputGain",
(NSString)"voice.pttKeyCode", (NSString)"voice.auxGain", (NSString)"feedback.sounds", (NSString)"feedback.volume"];
(NSString)"voice.pttKeyCode", (NSString)"voice.auxGain", (NSString)"voice.audioBufferMs", (NSString)"feedback.sounds", (NSString)"feedback.volume"];
NSObject[] defaults = [NSNumber.FromInt32((int)AudioInputMode.VoiceActivation), NSNumber.FromFloat(0.05f),
NSNumber.FromFloat(1f), NSNumber.FromFloat(0.8f), NSNumber.FromInt32(0x60), NSNumber.FromFloat(1f),
NSNumber.FromFloat(1f), NSNumber.FromFloat(0.8f), NSNumber.FromInt32(0x60), NSNumber.FromFloat(1f), NSNumber.FromInt32(40),
NSNumber.FromBoolean(true), NSNumber.FromFloat(1f)];
values.RegisterDefaults(new NSDictionary<NSString, NSObject>(keys, defaults));
InputMode = Enum.IsDefined(typeof(AudioInputMode), (int)values.IntForKey("voice.inputMode"))
@@ -46,6 +47,7 @@ internal sealed class MacSettings
AuxiliaryEnabled = values.BoolForKey("voice.auxEnabled");
AuxiliaryDeviceId = EmptyToNull(values.StringForKey("voice.auxDeviceUID"));
AuxiliaryGain = Math.Clamp(values.FloatForKey("voice.auxGain"), 0f, 4f);
int audioBuffer = checked((int)values.IntForKey("voice.audioBufferMs")); AudioBufferMilliseconds = audioBuffer is 20 or 40 or 60 ? audioBuffer : 40;
EventSounds = values.BoolForKey("feedback.sounds");
SpokenEvents = values.BoolForKey("feedback.speech");
EventVolume = Math.Clamp(values.FloatForKey("feedback.volume"), 0f, 1f);
@@ -59,7 +61,7 @@ internal sealed class MacSettings
values.SetFloat(InputGain, "voice.inputGain"); values.SetFloat(OutputGain, "voice.outputGain");
values.SetBool(InputNoiseReduction, "voice.inputNoiseReduction"); values.SetBool(StereoMicrophone, "voice.stereoMic");
values.SetInt(PushToTalkKeyCode, "voice.pttKeyCode"); Set("voice.inputDevice", InputDeviceId); Set("voice.outputDevice", OutputDeviceId);
values.SetBool(AuxiliaryEnabled, "voice.auxEnabled"); Set("voice.auxDeviceUID", AuxiliaryDeviceId); values.SetFloat(AuxiliaryGain, "voice.auxGain");
values.SetBool(AuxiliaryEnabled, "voice.auxEnabled"); Set("voice.auxDeviceUID", AuxiliaryDeviceId); values.SetFloat(AuxiliaryGain, "voice.auxGain"); values.SetInt(AudioBufferMilliseconds, "voice.audioBufferMs");
values.SetBool(EventSounds, "feedback.sounds"); values.SetBool(SpokenEvents, "feedback.speech"); values.SetFloat(EventVolume, "feedback.volume");
values.SetBool(SelfTalkSounds, "feedback.selfTalk"); values.SetBool(PushToTalkSound, "feedback.ptt"); values.Synchronize();
}
@@ -210,6 +210,8 @@ internal sealed class MainWindowController : NSWindowController
if (settings.InputMode != AudioInputMode.PushToTalk) { client.Audio.PushToTalk = false; pushToTalkEngaged = false; }
client.Audio.InputGain = settings.InputGain; client.Audio.OutputGain = settings.OutputGain;
client.Audio.InputNoiseReduction = settings.InputNoiseReduction;
client.Audio.DeviceBufferMilliseconds = settings.AudioBufferMilliseconds;
if (playback is not null) playback.BufferMilliseconds = settings.AudioBufferMilliseconds;
if (auxiliaryStreamId != 0) client.Audio.SetLocalGain(auxiliaryStreamId, settings.AuxiliaryGain);
}
@@ -367,6 +369,7 @@ internal sealed class MainWindowController : NSWindowController
activeOutputDevice = settings.OutputDeviceId ?? SelectedDevice(outputDevice);
activeStereo = settings.StereoMicrophone;
playback = audioBackend.OpenPlayback(activeOutputDevice);
playback.BufferMilliseconds = settings.AudioBufferMilliseconds;
client.Audio.MixedPcm += PlayMixedPcm;
StreamInfo stream = await client.StartStreamAsync(StreamKind.StreamMic, "Microphone", settings.StereoMicrophone ? 2 : 1);
microphoneStreamId = stream.StreamId;
@@ -26,15 +26,18 @@ internal sealed class SettingsWindowController : NSWindowController
private readonly NSButton pttSound = NSButton.CreateCheckbox("Push-to-talk cue", () => { });
private readonly NSButton pttKey = new(new CGRect(220, 12, 200, 32)) { Title = "Change PTT key…" };
private readonly NSSlider eventVolume = new(new CGRect(160, 505, 260, 24)) { MinValue = 0, MaxValue = 100 };
private readonly NSPopUpButton audioBuffer = new(new CGRect(160, 545, 260, 28), false);
internal SettingsWindowController(MainWindowController owner, MacSettings settings, MacAudioBackend audio) : base(
new NSWindow(new CGRect(0, 0, 460, 620), NSWindowStyle.Titled | NSWindowStyle.Closable,
new NSWindow(new CGRect(0, 0, 460, 660), NSWindowStyle.Titled | NSWindowStyle.Closable,
NSBackingStore.Buffered, false))
{
this.owner = owner; this.settings = settings; this.audio = audio;
Window!.Title = "VoiceCat Settings"; Window.Center();
NSView view = Window.ContentView!;
mode.AddItems(["Voice activation", "Push to talk", "Always on"]);
audioBuffer.AddItems(["Low latency (20 ms)", "Balanced (40 ms)", "Stable (60 ms)"]);
Add(view, "Audio buffering", audioBuffer, 555);
Add(view, "Sound volume", eventVolume, 515);
Add(view, "Input mode", mode, 465); Add(view, "VAD sensitivity", vad, 425); Add(view, "Microphone volume", inputGain, 385);
noiseReduction.Frame = new CGRect(160, 340, 260, 24); stereo.Frame = new CGRect(160, 315, 260, 24);
@@ -46,7 +49,7 @@ internal sealed class SettingsWindowController : NSWindowController
selfTalk.Frame = new CGRect(265, 45, 180, 24); pttSound.Frame = new CGRect(25, 18, 180, 24);
view.AddSubview(sounds); view.AddSubview(speech); view.AddSubview(selfTalk); view.AddSubview(pttSound); view.AddSubview(pttKey);
foreach (NSControl control in new NSControl[] { mode, vad, inputGain, noiseReduction, stereo, input, output,
outputGain, auxiliary, auxiliaryDevice, auxiliaryGain, sounds, speech, selfTalk, pttSound, eventVolume }) control.Activated += Changed;
outputGain, auxiliary, auxiliaryDevice, auxiliaryGain, sounds, speech, selfTalk, pttSound, eventVolume, audioBuffer }) control.Activated += Changed;
pttKey.Activated += CapturePushToTalkKey;
Populate(input, true, settings.InputDeviceId); Populate(output, false, settings.OutputDeviceId); Populate(auxiliaryDevice, true, settings.AuxiliaryDeviceId);
LoadValues(); SetAccessibility();
@@ -76,6 +79,7 @@ internal sealed class SettingsWindowController : NSWindowController
eventVolume.DoubleValue = settings.EventVolume * 100;
selfTalk.State = State(settings.SelfTalkSounds); pttSound.State = State(settings.PushToTalkSound);
pttKey.Title = $"PTT key code: {settings.PushToTalkKeyCode}";
audioBuffer.SelectItem(settings.AudioBufferMilliseconds switch { 20 => 0, 60 => 2, _ => 1 });
UpdateEnabled();
}
@@ -102,6 +106,7 @@ internal sealed class SettingsWindowController : NSWindowController
settings.AuxiliaryGain = (float)auxiliaryGain.DoubleValue / 100; settings.EventSounds = On(sounds);
settings.EventVolume = (float)eventVolume.DoubleValue / 100; settings.SpokenEvents = On(speech);
settings.SelfTalkSounds = On(selfTalk); settings.PushToTalkSound = On(pttSound);
settings.AudioBufferMilliseconds = audioBuffer.IndexOfSelectedItem switch { 0 => 20, 2 => 60, _ => 40 };
settings.Save(); UpdateEnabled(); await owner.ApplySettingsAsync();
}
@@ -113,6 +118,7 @@ internal sealed class SettingsWindowController : NSWindowController
((INSAccessibility)output).AccessibilityLabel = "Output device"; ((INSAccessibility)outputGain).AccessibilityLabel = "Output volume";
((INSAccessibility)auxiliaryDevice).AccessibilityLabel = "Auxiliary input device"; ((INSAccessibility)auxiliaryGain).AccessibilityLabel = "Auxiliary input volume";
((INSAccessibility)eventVolume).AccessibilityLabel = "Event sound volume";
((INSAccessibility)audioBuffer).AccessibilityLabel = "Audio buffering";
}
private static bool On(NSButton button) => button.State == NSCellStateValue.On;
private static NSCellStateValue State(bool value) => value ? NSCellStateValue.On : NSCellStateValue.Off;
@@ -266,6 +266,8 @@ internal sealed class AppModel
owner.Audio.InputMode = settings.InputMode; owner.Audio.VadThreshold = settings.VadThreshold;
owner.Audio.InputGain = settings.InputGain; owner.Audio.OutputGain = settings.OutputGain;
owner.Audio.InputNoiseReduction = settings.InputNoiseReduction;
owner.Audio.DeviceBufferMilliseconds = settings.AudioBufferMilliseconds;
IosAudioEngine.Shared.BufferMilliseconds = settings.AudioBufferMilliseconds;
}
private void PollAudio()
@@ -8,7 +8,7 @@ namespace VoiceCat.iOS;
internal sealed class IosAudioEngine
{
internal static IosAudioEngine Shared { get; } = new();
private readonly PcmRing playbackRing = new(131_072);
private readonly AdaptivePcmBuffer playbackRing = new(2, capacityFrames: 65_536);
private readonly short[] renderScratch = new short[16_384];
private AVAudioEngine? engine;
private AVAudioSourceNode? source;
@@ -28,6 +28,7 @@ internal sealed class IosAudioEngine
private bool inputProvided;
private bool tapInstalled;
internal bool IsConnected { get; private set; }
internal int BufferMilliseconds { get => playbackRing.BufferMilliseconds; set => playbackRing.BufferMilliseconds = value; }
private IosAudioEngine() { microphoneWorker = PumpMicrophoneAsync(microphoneStop.Token); }
@@ -17,13 +17,14 @@ internal sealed class IosSettings
internal float EventVolume { get; set; } = 1f;
internal bool SelfTalkSounds { get; set; }
internal bool PushToTalkSound { get; set; }
internal int AudioBufferMilliseconds { get; set; } = 40;
internal void Load()
{
NSString[] keys = [(NSString)"voice.inputMode", (NSString)"voice.vadThreshold", (NSString)"voice.inputGain",
(NSString)"voice.outputGain", (NSString)"feedback.sounds", (NSString)"feedback.volume"];
(NSString)"voice.outputGain", (NSString)"voice.audioBufferMs", (NSString)"feedback.sounds", (NSString)"feedback.volume"];
NSObject[] defaults = [NSNumber.FromInt32((int)AudioInputMode.VoiceActivation), NSNumber.FromFloat(0.025f),
NSNumber.FromFloat(1f), NSNumber.FromFloat(1f), NSNumber.FromBoolean(true), NSNumber.FromFloat(1f)];
NSNumber.FromFloat(1f), NSNumber.FromFloat(1f), NSNumber.FromInt32(40), NSNumber.FromBoolean(true), NSNumber.FromFloat(1f)];
values.RegisterDefaults(new NSDictionary<NSString, NSObject>(keys, defaults));
int inputMode = checked((int)values.IntForKey("voice.inputMode"));
InputMode = Enum.IsDefined(typeof(AudioInputMode), inputMode) ? (AudioInputMode)inputMode : AudioInputMode.VoiceActivation;
@@ -31,6 +32,7 @@ internal sealed class IosSettings
InputGain = Math.Clamp(values.FloatForKey("voice.inputGain"), 0f, 4f);
OutputGain = Math.Clamp(values.FloatForKey("voice.outputGain"), 0f, 1f);
InputNoiseReduction = values.BoolForKey("voice.inputNoiseReduction");
int audioBuffer = checked((int)values.IntForKey("voice.audioBufferMs")); AudioBufferMilliseconds = audioBuffer is 20 or 40 or 60 ? audioBuffer : 40;
EventSounds = values.BoolForKey("feedback.sounds");
SpokenEvents = values.BoolForKey("feedback.speech");
EventVolume = Math.Clamp(values.FloatForKey("feedback.volume"), 0f, 1f);
@@ -42,6 +44,7 @@ internal sealed class IosSettings
{
values.SetInt((int)InputMode, "voice.inputMode"); values.SetFloat(VadThreshold, "voice.vadThreshold");
values.SetFloat(InputGain, "voice.inputGain"); values.SetFloat(OutputGain, "voice.outputGain");
values.SetInt(AudioBufferMilliseconds, "voice.audioBufferMs");
values.SetBool(InputNoiseReduction, "voice.inputNoiseReduction"); values.SetBool(EventSounds, "feedback.sounds");
values.SetBool(SpokenEvents, "feedback.speech"); values.SetFloat(EventVolume, "feedback.volume");
values.SetBool(SelfTalkSounds, "feedback.selfTalk"); values.SetBool(PushToTalkSound, "feedback.ptt"); values.Synchronize();
@@ -14,23 +14,23 @@ internal sealed class SettingsController : UITableViewController
public override void ViewDidLoad() { base.ViewDidLoad(); TableView.RegisterClassForCellReuse(typeof(UITableViewCell), "setting"); }
private void Reload() => TableView.ReloadData();
public override nint NumberOfSections(UITableView tableView) => 5;
public override nint RowsInSection(UITableView tableView, nint section) => section switch { 0 => 4, 1 => 4, 2 => 5, 3 => model.Client?.Permissions is { } p && (p.IsAdmin || p.CanAdminAccounts) ? 1 : 0, _ => 2 };
public override nint RowsInSection(UITableView tableView, nint section) => section switch { 0 => 5, 1 => 4, 2 => 5, 3 => model.Client?.Permissions is { } p && (p.IsAdmin || p.CanAdminAccounts) ? 1 : 0, _ => 2 };
public override string? TitleForHeader(UITableView tableView, nint section) => section switch { 0 => "Audio", 1 => "Voice", 2 => "Notifications", 3 => "Administration", _ => "Server" };
public override UITableViewCell GetCell(UITableView tableView, NSIndexPath path)
{
UITableViewCell cell = tableView.DequeueReusableCell("setting", path); cell.AccessoryView = null; cell.Accessory = UITableViewCellAccessory.None;
string title = path.Section switch
{
0 => path.Row switch { 0 => "Audio preset", 1 => "Speaker output", 2 => "Advanced audio", _ => model.ScreenSharing ? "Stop sharing screen audio" : "Share screen audio" },
0 => path.Row switch { 0 => "Audio preset", 1 => "Speaker output", 2 => "Advanced audio", 3 => "Audio buffering", _ => model.ScreenSharing ? "Stop sharing screen audio" : "Share screen audio" },
1 => path.Row switch { 0 => "Input mode", 1 => $"VAD threshold: {model.Settings.VadThreshold:0.000}", 2 => $"Microphone volume: {model.Settings.InputGain:P0}", _ => "Microphone noise reduction" },
2 => path.Row switch { 0 => "Event sounds", 1 => $"Sound volume: {model.Settings.EventVolume:P0}", 2 => "Speak events", 3 => "Own voice activity sounds", _ => "Push-to-talk cue" },
3 => "Manage accounts", _ => path.Row == 0 ? "Disconnect" : "VoiceCat 0.0.1"
};
var content = cell.DefaultContentConfiguration; content.Text = title; content.SecondaryText = path.Section == 0 && path.Row == 0 ? IosAudioRouter.Shared.Preset.ToString() : path.Section == 1 && path.Row == 0 ? model.Settings.InputMode.ToString() : path.Section == 0 && path.Row == 3 && model.ScreenSharing ? "Sharing" : null; cell.ContentConfiguration = content; cell.AccessibilityLabel = title;
var content = cell.DefaultContentConfiguration; content.Text = title; content.SecondaryText = path.Section == 0 && path.Row == 0 ? IosAudioRouter.Shared.Preset.ToString() : path.Section == 1 && path.Row == 0 ? model.Settings.InputMode.ToString() : path.Section == 0 && path.Row == 3 ? $"{model.Settings.AudioBufferMilliseconds} ms" : path.Section == 0 && path.Row == 4 && model.ScreenSharing ? "Sharing" : null; cell.ContentConfiguration = content; cell.AccessibilityLabel = title + (content.SecondaryText is null ? "" : ", " + content.SecondaryText);
if (path.Section == 0 && path.Row == 1) cell.AccessoryView = Toggle(IosAudioRouter.Shared.ForceSpeaker, "Speaker output", (_, _) => IosAudioRouter.Shared.SetForceSpeaker(((UISwitch)cell.AccessoryView!).On));
else if (path.Section == 1 && path.Row == 3) cell.AccessoryView = Toggle(model.Settings.InputNoiseReduction, title, (_, _) => { model.Settings.InputNoiseReduction = ((UISwitch)cell.AccessoryView!).On; model.ApplyVoiceSettings(); });
else if (path.Section == 2 && path.Row is 0 or 2 or 3 or 4) { bool value = path.Row switch { 0 => model.Settings.EventSounds, 2 => model.Settings.SpokenEvents, 3 => model.Settings.SelfTalkSounds, _ => model.Settings.PushToTalkSound }; int row = path.Row; cell.AccessoryView = Toggle(value, title, (_, _) => { bool on = ((UISwitch)cell.AccessoryView!).On; if (row == 0) model.Settings.EventSounds = on; else if (row == 2) model.Settings.SpokenEvents = on; else if (row == 3) model.Settings.SelfTalkSounds = on; else model.Settings.PushToTalkSound = on; model.Save(); }); }
else if (path.Section == 0 && path.Row == 2 || path.Section == 3) cell.Accessory = UITableViewCellAccessory.DisclosureIndicator;
else if (path.Section == 0 && path.Row is 2 or 3 || path.Section == 3) cell.Accessory = UITableViewCellAccessory.DisclosureIndicator;
return cell;
}
public override async void RowSelected(UITableView tableView, NSIndexPath path)
@@ -39,7 +39,8 @@ internal sealed class SettingsController : UITableViewController
{
if (path.Section == 0 && path.Row == 0) Choice("Audio preset", Enum.GetValues<IosAudioPreset>().Select(value => value.ToString()).ToArray(), index => IosAudioRouter.Shared.SelectPreset(Enum.GetValues<IosAudioPreset>()[index]));
else if (path.Section == 0 && path.Row == 2) NavigationController?.PushViewController(new AdvancedAudioController(), true);
else if (path.Section == 0 && path.Row == 3) ShowScreenSharing();
else if (path.Section == 0 && path.Row == 3) Choice("Audio buffering", ["Low latency (20 ms)", "Balanced (40 ms)", "Stable (60 ms)"], index => { model.Settings.AudioBufferMilliseconds = index switch { 0 => 20, 2 => 60, _ => 40 }; model.ApplyVoiceSettings(); });
else if (path.Section == 0 && path.Row == 4) ShowScreenSharing();
else if (path.Section == 1 && path.Row == 0) Choice("Input mode", ["Voice activation", "Push to talk", "Always on"], index => { model.Settings.InputMode = (AudioInputMode)index; model.ApplyVoiceSettings(); });
else if (path.Section == 1 && path.Row == 1) Slider("Voice activation threshold", 0.001f, 0.1f, model.Settings.VadThreshold, value => { model.Settings.VadThreshold = value; model.ApplyVoiceSettings(); });
else if (path.Section == 1 && path.Row == 2) Slider("Microphone volume", 0, 4, model.Settings.InputGain, value => { model.Settings.InputGain = value; model.ApplyVoiceSettings(); });
@@ -34,7 +34,7 @@ public sealed class WasapiAudioBackend : IAudioDeviceBackend
private sealed class Playback : IAudioPlayback
{
private readonly string? deviceId;
private readonly PcmRing pcm = new(32768);
private readonly AdaptivePcmBuffer pcm = new(2);
private readonly ManualResetEventSlim initialized = new(false);
private readonly Thread thread;
private volatile bool running = true;
@@ -47,6 +47,7 @@ public sealed class WasapiAudioBackend : IAudioDeviceBackend
thread.Start();
if (!initialized.Wait(5000) || !ready) { Dispose(); throw new InvalidOperationException("WASAPI playback could not start."); }
}
public int BufferMilliseconds { get => pcm.BufferMilliseconds; set => pcm.BufferMilliseconds = value; }
public void Write(ReadOnlySpan<short> stereoPcm) => pcm.TryWrite(stereoPcm);
private unsafe void Work()
{
@@ -68,7 +69,6 @@ public sealed class WasapiAudioBackend : IAudioDeviceBackend
render = (IAudioRenderClient)output;
if (client.Start() < 0) return;
ready = true; initialized.Set();
Span<short> discard = stackalloc short[1920];
while (running)
{
bufferReady.WaitOne(20); // Scheduling wait is outside the buffer-fill cycle.
@@ -77,8 +77,6 @@ public sealed class WasapiAudioBackend : IAudioDeviceBackend
if (frames == 0) continue;
if (render.GetBuffer(frames, out nint buffer) < 0) break;
var destination = new Span<short>((void*)buffer, checked((int)frames * 2));
// Keep queued playback bounded to ~120 ms, then fill underflow with silence.
while (pcm.Count > 11520) pcm.Read(discard);
int count = pcm.Read(destination); destination[count..].Clear();
if (render.ReleaseBuffer(frames, 0) < 0) break;
}
@@ -34,6 +34,7 @@ public sealed class AudioSettingsForm : Form
private readonly bool _origAuxEnabled;
private readonly string? _origAuxDeviceId;
private readonly int _origAuxGain;
private readonly int _origAudioBufferMilliseconds;
private readonly ComboBox _cboDevice;
private readonly Button _btnRefresh;
@@ -54,6 +55,7 @@ public sealed class AudioSettingsForm : Form
private readonly Button _btnAuxRefresh;
private readonly Label _lblAuxGain;
private readonly TrackBar _trkAuxGain;
private readonly ComboBox _cboBuffer;
private Keys _pttKey;
@@ -80,6 +82,7 @@ public sealed class AudioSettingsForm : Form
_origAuxEnabled = settings.AuxEnabled;
_origAuxDeviceId = settings.AuxDeviceId;
_origAuxGain = settings.AuxGain;
_origAudioBufferMilliseconds = settings.AudioBufferMilliseconds;
Text = "Audio settings";
FormBorderStyle = FormBorderStyle.FixedDialog;
@@ -87,7 +90,7 @@ public sealed class AudioSettingsForm : Form
MinimizeBox = false;
StartPosition = FormStartPosition.CenterParent;
AutoScaleMode = AutoScaleMode.Font;
ClientSize = new Size(420, 639);
ClientSize = new Size(420, 690);
// ── Device row ────────────────────────────────────────────────────────
var lblDevice = new Label
@@ -319,19 +322,34 @@ public sealed class AudioSettingsForm : Form
"Volume of the aux input stream. 100 is unity gain; range 0400 percent.";
_trkAuxGain.Scroll += TrkAuxGain_Scroll;
var lblBuffer = new Label { Text = "Audio &buffering:", Location = new Point(12, 590), AutoSize = true };
_cboBuffer = new ComboBox
{
Location = new Point(130, 586), Width = 190, DropDownStyle = ComboBoxStyle.DropDownList,
AccessibleName = "Audio buffering",
AccessibleDescription = "Local capture and playback buffering. Lower values reduce latency; higher values tolerate more scheduling jitter."
};
_cboBuffer.Items.AddRange(["Low latency (20 ms)", "Balanced (40 ms)", "Stable (60 ms)"]);
_cboBuffer.SelectedIndex = settings.AudioBufferMilliseconds switch { 20 => 0, 60 => 2, _ => 1 };
_cboBuffer.SelectedIndexChanged += (_, _) =>
{
_settings.AudioBufferMilliseconds = _cboBuffer.SelectedIndex switch { 0 => 20, 2 => 60, _ => 40 };
_client.SetAudioBufferMilliseconds(_settings.AudioBufferMilliseconds);
};
// ── OK / Cancel ───────────────────────────────────────────────────────
var btnOk = new Button
{
Text = "&OK",
DialogResult = DialogResult.OK,
Location = new Point(228, 600),
Location = new Point(228, 642),
Size = new Size(80, 27),
};
var btnCancel = new Button
{
Text = "&Cancel",
DialogResult = DialogResult.Cancel,
Location = new Point(316, 600),
Location = new Point(316, 642),
Size = new Size(80, 27),
};
@@ -350,6 +368,7 @@ public sealed class AudioSettingsForm : Form
_radioPtt, _lblPttKey, _btnChangePtt, _chkSystemWidePtt, _radioAlwaysOn,
lblGain, _trkGain, _chkNoiseReduction, _chkStereoMic,
_chkAux, _lblAuxDevice, _cboAuxDevice, _btnAuxRefresh, _lblAuxGain, _trkAuxGain,
lblBuffer, _cboBuffer,
btnOk, btnCancel,
]);
@@ -534,6 +553,8 @@ public sealed class AudioSettingsForm : Form
_settings.StereoMic = _origStereoMic;
_settings.PttKey = (int)_origPttKey;
_settings.SystemWidePtt = _origSystemWidePtt;
_settings.AudioBufferMilliseconds = _origAudioBufferMilliseconds;
_client.SetAudioBufferMilliseconds(_origAudioBufferMilliseconds);
if (_micStreamId != 0)
{
@@ -109,8 +109,11 @@ public partial class MainForm : Form
BootstrapFromServer();
}
private void ApplyPersistedVoiceSettings() =>
private void ApplyPersistedVoiceSettings()
{
_pttKey = (Keys)_voiceSettings.PttKey;
_client.SetAudioBufferMilliseconds(_voiceSettings.AudioBufferMilliseconds);
}
// ── Startup ──────────────────────────────────────────────────────────────
@@ -59,6 +59,9 @@ public sealed class VoiceSettings
/// to the captured PCM before feeding (the core's input gain is mic-only and global).</summary>
public int AuxGain { get; set; } = 100;
/// <summary>Local capture/playback safety buffer in milliseconds: 20, 40, or 60.</summary>
public int AudioBufferMilliseconds { get; set; } = 40;
private static readonly JsonSerializerOptions JsonOptions = new() { WriteIndented = true };
private static string AppDataDir => Path.Combine(
@@ -72,7 +75,9 @@ public sealed class VoiceSettings
{
if (!File.Exists(FilePath)) return new VoiceSettings();
string json = File.ReadAllText(FilePath);
return JsonSerializer.Deserialize<VoiceSettings>(json) ?? new VoiceSettings();
VoiceSettings result = JsonSerializer.Deserialize<VoiceSettings>(json) ?? new VoiceSettings();
if (result.AudioBufferMilliseconds is not (20 or 40 or 60)) result.AudioBufferMilliseconds = 40;
return result;
}
catch
{
@@ -55,6 +55,16 @@ public sealed partial class VoiceCatClient
public VcResult SetOutputVolume(float gain) { if (!float.IsFinite(gain) || gain is < 0 or > 4) return VcResult.InvalidArg; core.Audio.OutputGain = gain; return VcResult.Ok; }
public VcResult SetInputGain(float gain) { if (!float.IsFinite(gain) || gain is < 0 or > 4) return VcResult.InvalidArg; core.Audio.InputGain = gain; return VcResult.Ok; }
public VcResult SetInputNoiseReduction(bool enabled) { core.Audio.InputNoiseReduction = enabled; return VcResult.Ok; }
public VcResult SetAudioBufferMilliseconds(int milliseconds)
{
try
{
core.Audio.DeviceBufferMilliseconds = milliseconds;
if (Volatile.Read(ref playback) is { } output) output.BufferMilliseconds = milliseconds;
return VcResult.Ok;
}
catch (ArgumentOutOfRangeException) { return VcResult.InvalidArg; }
}
public VcResult SetRemoteStream(uint userId, uint streamId, float gain, bool muted, bool nr)
{ try { core.Audio.SetRemotePlayback(userId, streamId, gain, muted, nr); return VcResult.Ok; } catch { return VcResult.InvalidArg; } }
public (VcResult Result, RemoteStreamState? State) GetRemoteStream(uint userId, uint streamId)
@@ -159,7 +159,11 @@ public sealed partial class VoiceCatClient : IDisposable
{
try
{
if (backend is not null && playback is null) playback = backend.OpenPlayback();
if (backend is not null && playback is null)
{
playback = backend.OpenPlayback();
playback.BufferMilliseconds = core.Audio.DeviceBufferMilliseconds;
}
var result = core.SubscribeVoiceAsync().GetAwaiter().GetResult();
if (!result.Ok) { Interlocked.Exchange(ref playback, null)?.Dispose(); }
return result.Ok ? VcResult.Ok : VcResult.Audio;
+4 -2
View File
@@ -177,8 +177,10 @@ Noise reduction does not gate speech.
`TimeProvider` timestamps; tests inject a clock. Threshold changes are atomic; all
processing state otherwise has one owner. Codec/DSP processing methods allocate no
managed memory after initialization, verified across 1,000 combined cycles. They run
on a managed worker, never the native real-time device callback. Native device rings,
jitter, mixer, and audio scheduling remain later work.
on a managed worker, never the native real-time device callback. Managed capture/playback
rings compensate independent clock drift around a configurable 20/40/60 ms target. Receive
jitter is duration-aware, reserves one codec frame for DRED/FEC look-ahead, and decodes each
channel packet at its actual duration before the fixed 20 ms mixer stage.
## Initial managed server
+19 -7
View File
@@ -117,6 +117,9 @@ Guidance baked into defaults / docs:
(accumulating two 960-frames for a 40 ms channel, splitting each into two 480-frames for a
10 ms channel, etc.). This keeps the hardware/`vc_stream_feed_pcm` contract a single 48 kHz
clock regardless of the channel's window — see `vc_client::on_capture_frame`.
The device/mixer quantum is not the Opus packet duration: managed send streams reframe it
into the channel's 5/10/20/40/60 ms packets, and receive streams decode at that duration
before slicing decoded PCM back into 20 ms mixer blocks.
- **Mode/bitrate:** speech channels → `MONO`, `VOIP`, 2432 kbps, DTX on, FEC on.
Music/screen-audio channels → `STEREO`, `AUDIO`, 96128 kbps, DTX off, FEC optional.
- **`application`:** `VOIP` for talk, `AUDIO` for music/screen-share, `LOWDELAY` for
@@ -152,26 +155,30 @@ straight through to PLC.
## 5. Jitter buffer
Each receiver keeps an **adaptive jitter buffer per ssrc** with **bounded-depth playout**
(`core/src/audio/audio_engine.cpp``JitterBuffer` + `AudioEngine::on_playback`).
(`dotnet/src/VoiceCat.Audio/ReceiveStream.cs`).
- Frames are inserted by `timestamp`; playback reads in order at the device callback rate.
- **The playout clock is always bounded against the stream's *leading edge* (newest buffered
frame), never re-synced to the oldest.** The clock free-runs at the playback hardware rate,
frame), never re-synced to the oldest.** The managed playout clock is isolated from hardware
drift by the adaptive PCM ring,
while the sender omits VAD/PTT/DTX silence from its timestamps, so the two diverge across gaps
and late joins. Two corrections keep latency bounded:
- **(Re)seed to the leading edge** on first frame, on a talkspurt `marker`, or when the clock
has run past the newest frame (starved after silence). No artificial prebuffer — latency
starts as low as possible; buffered frames still play oldest-first.
has run past the newest frame (starved after silence). Playout retains the adaptive target;
when DRED/FEC is enabled that includes one codec frame of recovery look-ahead.
- **Frame-skip catch-up:** when the backlog grows past `target + hysteresis` (clock drift,
bursty arrival, reordering), fast-forward the clock to leave `target` buffered and drop the
now-stale frames. This is the downward force that prevents latency from ratcheting upward.
- `target` is the adaptive jitter estimate (EWMA of inter-arrival gap vs. the per-frame gap),
floored; silence gaps and reordered stragglers are rejected as outliers so they don't inflate
it. The late-drop window tracks `target` (floored/capped at 500 ms).
- `target` is an EWMA of arrival-gap variation measured in 48 kHz sample time. DRED or FEC
reserves one complete channel Opus frame of look-ahead, variation can raise the target to
120 ms, and packet history is bounded to 500 ms. Limits are durations rather than packet
counts, so 5 ms and 60 ms channels receive the same policy.
- Late frames past the playout point are dropped; gaps are filled by DRED (if the next frame
arrived) or PLC.
- The `marker` flag (start of talkspurt) — set by the sender on the first frame after a
transmission gap — lets the buffer reseed cleanly after silence/DTX without accumulating drift.
- One late device callback does not end a talkspurt. Capture resets only after 200 ms of
continuous starvation, avoiding a marker/rebuffer cascade from an isolated scheduling miss.
- Diagnostics per stream: `packets_lost`, `duplicates`, `underruns`, `target_depth_ms`.
```
@@ -180,6 +187,11 @@ Each receiver keeps an **adaptive jitter buffer per ssrc** with **bounded-depth
jitter estimate feeds depth
```
Capture and playback use an allocation-free adaptive PCM ring between the managed 20 ms clock
and the hardware clock. Linear-interpolation correction, limited to ±0.5%, holds the ring near
its target instead of periodically dropping a block or rendering silence as device clocks drift.
The local **Audio buffering** preset is 20, 40 (default), or 60 ms and is persisted per client.
## 6. UDP keepalive & NAT
- A `KEEPALIVE` (type 2) frame flows both directions on the media channel every ~5 s to
@@ -0,0 +1,97 @@
namespace VoiceCat.Audio;
// SPSC PCM handoff with a small occupancy-controlled sample-rate correction. Producers and
// consumers remain non-waiting; the correction keeps independent hardware and managed clocks
// from periodically reaching the hard underflow/overflow edges of a conventional ring.
public sealed class AdaptivePcmBuffer
{
private const int SampleRate = 48_000;
private const double MaximumCorrection = 0.005;
private readonly short[] samples;
private readonly int channels, frameMask;
private int readFrame, writtenFrame, producer, targetFrames;
private double phase;
private bool primed;
public AdaptivePcmBuffer(int channels, int bufferMilliseconds = 40, int capacityFrames = 16_384)
{
if (channels is not (1 or 2)) throw new ArgumentOutOfRangeException(nameof(channels));
if (capacityFrames < 2 || (capacityFrames & (capacityFrames - 1)) != 0) throw new ArgumentOutOfRangeException(nameof(capacityFrames));
this.channels = channels; samples = new short[checked(capacityFrames * channels)]; frameMask = capacityFrames - 1;
BufferMilliseconds = bufferMilliseconds;
}
public int Channels => channels;
public int CountFrames => unchecked(Volatile.Read(ref writtenFrame) - Volatile.Read(ref readFrame));
public int BufferMilliseconds
{
get => Volatile.Read(ref targetFrames) * 1000 / SampleRate;
set
{
if (value is not (20 or 40 or 60)) throw new ArgumentOutOfRangeException(nameof(value));
Volatile.Write(ref targetFrames, value * SampleRate / 1000);
}
}
public bool TryWrite(ReadOnlySpan<short> source)
{
if (source.Length == 0 || source.Length % channels != 0 || Interlocked.CompareExchange(ref producer, 1, 0) != 0) return false;
try
{
int frames = source.Length / channels, index = writtenFrame;
if (frames > frameMask + 1 - unchecked(index - Volatile.Read(ref readFrame))) return false;
for (int frame = 0; frame < frames; frame++)
{
int target = ((index + frame) & frameMask) * channels;
for (int channel = 0; channel < channels; channel++) samples[target + channel] = source[frame * channels + channel];
}
Volatile.Write(ref writtenFrame, unchecked(index + frames)); return true;
}
finally { Volatile.Write(ref producer, 0); }
}
// Returns interleaved samples written. A zero return means the caller should treat the
// already-cleared destination as silence. Once primed, short scheduling stalls re-prime
// instead of repeatedly clicking at the ring edge.
public int Read(Span<short> destination)
{
if (destination.Length % channels != 0) throw new ArgumentException("PCM must contain complete interleaved frames.", nameof(destination));
int requestedFrames = destination.Length / channels;
if (requestedFrames == 0) return 0;
int available = CountFrames, target = Volatile.Read(ref targetFrames);
if (!primed)
{
if (available < target) { destination.Clear(); return 0; }
primed = true; phase = 0;
}
if (available <= 0) { primed = false; phase = 0; destination.Clear(); return 0; }
double correction = Math.Clamp((available - target) / (SampleRate * 2.0), -MaximumCorrection, MaximumCorrection);
double step = 1.0 + correction;
int produced = 0, read = readFrame;
for (int frame = 0; frame < requestedFrames; frame++)
{
int baseOffset = (read & frameMask) * channels;
int nextOffset = ((read + 1) & frameMask) * channels;
int remaining = unchecked(Volatile.Read(ref writtenFrame) - read);
if (remaining <= 0) break;
double fraction = phase;
for (int channel = 0; channel < channels; channel++)
{
int first = samples[baseOffset + channel];
int second = remaining > 1 ? samples[nextOffset + channel] : first;
destination[produced++] = (short)Math.Clamp((int)Math.Round(first + (second - first) * fraction), short.MinValue, short.MaxValue);
}
phase += step;
int advance = (int)phase;
if (advance > remaining) advance = remaining;
read = unchecked(read + advance); phase -= advance;
}
Volatile.Write(ref readFrame, read);
if (produced < destination.Length)
{
destination[produced..].Clear(); primed = false; phase = 0;
}
return produced;
}
}
@@ -3,7 +3,11 @@ namespace VoiceCat.Audio;
public sealed record AudioDeviceInfo(string Id, string Name, bool IsDefault);
public delegate void CapturePcmHandler(ReadOnlySpan<short> pcm, int channels);
public interface IAudioCapture : IDisposable { }
public interface IAudioPlayback : IDisposable { void Write(ReadOnlySpan<short> stereoPcm); }
public interface IAudioPlayback : IDisposable
{
int BufferMilliseconds { get; set; }
void Write(ReadOnlySpan<short> stereoPcm);
}
public interface IAudioDeviceBackend
{
IReadOnlyList<AudioDeviceInfo> Enumerate(bool input);
+13 -2
View File
@@ -23,6 +23,17 @@ public sealed class AudioEngine : IDisposable
public volatile float InputGain = 1, OutputGain = 1, VadThreshold = 0.02f;
public volatile bool InputNoiseReduction, MicMuted, Deafened, PushToTalk;
public volatile AudioInputMode InputMode = AudioInputMode.VoiceActivation;
private int deviceBufferMilliseconds = 40;
public int DeviceBufferMilliseconds
{
get => Volatile.Read(ref deviceBufferMilliseconds);
set
{
if (value is not (20 or 40 or 60)) throw new ArgumentOutOfRangeException(nameof(value));
Volatile.Write(ref deviceBufferMilliseconds, value);
foreach (LocalStream stream in Volatile.Read(ref routes).Local) stream.BufferMilliseconds = value;
}
}
public Exception? Failure { get; private set; }
public AudioEngine(EncodedVoiceSender sender, bool startWorker = true)
@@ -42,7 +53,7 @@ public sealed class AudioEngine : IDisposable
lock (gate)
{
ObjectDisposedException.ThrowIf(disposed != 0, this);
var stream = new LocalStream(info, captureChannels);
var stream = new LocalStream(info, captureChannels, DeviceBufferMilliseconds);
Routes previous = routes;
var locals = previous.Local.Where(s => s.Info.StreamId != info.StreamId).Append(stream).ToArray();
Publish(locals, previous.Remote);
@@ -58,7 +69,7 @@ public sealed class AudioEngine : IDisposable
lock (gate)
{
var current = routes.Local.FirstOrDefault(s => s.Info.StreamId == streamId) ?? throw new ArgumentException("Stream not found.");
if (current.CaptureChannels != channels) Publish(routes.Local.Select(s => s == current ? new LocalStream(s.Info, channels) : s).ToArray(), routes.Remote);
if (current.CaptureChannels != channels) Publish(routes.Local.Select(s => s == current ? new LocalStream(s.Info, channels, DeviceBufferMilliseconds) : s).ToArray(), routes.Remote);
}
}
+13 -5
View File
@@ -15,7 +15,7 @@ internal sealed class LocalStream : IDisposable
{
internal readonly StreamInfo Info;
internal readonly int CaptureChannels;
internal readonly PcmRing Input = new(16384);
internal readonly AdaptivePcmBuffer Input;
internal volatile float Level;
internal volatile bool Talking;
internal volatile float Gain = 1;
@@ -27,6 +27,7 @@ internal sealed class LocalStream : IDisposable
private readonly short[] converted = new short[16384];
private int feeding;
private int buffered;
private int starvedSamples;
private uint timestamp;
private bool wasTransmitting, marker;
@@ -45,9 +46,12 @@ internal sealed class LocalStream : IDisposable
finally { Volatile.Write(ref feeding, 0); }
}
internal LocalStream(StreamInfo stream, int captureChannels)
internal int BufferMilliseconds { get => Input.BufferMilliseconds; set => Input.BufferMilliseconds = value; }
internal LocalStream(StreamInfo stream, int captureChannels, int bufferMilliseconds = 40)
{
Info = stream.Clone(); CaptureChannels = captureChannels;
Input = new(captureChannels, bufferMilliseconds);
encoder = new(new()
{
Channels = stream.Audio.Mode == ChannelMode.ModeStereo ? 2 : 1,
@@ -64,10 +68,14 @@ internal sealed class LocalStream : IDisposable
internal void Process(AudioEngine engine, EncodedVoiceSender sender)
{
var input = capture.AsSpan(0, 960 * CaptureChannels);
if (Input.Count < input.Length) { Level = 0; Talking = false; buffered = 0; wasTransmitting = false; return; }
while (Input.Count > input.Length * 6) Input.Read(input);
if (Input.Read(input) != input.Length)
{
Level = 0; Talking = false; starvedSamples += 960;
if (starvedSamples >= 9600) { buffered = 0; wasTransmitting = false; }
return;
}
starvedSamples = 0;
if (buffered == 0) timestamp = engine.SampleClock;
Input.Read(input);
bool mic = Info.Kind == StreamKind.StreamMic;
if (mic && engine.InputNoiseReduction)
{
+78 -17
View File
@@ -20,28 +20,36 @@ internal sealed class ReceiveStream : IDisposable
private readonly byte[][] packets = Enumerable.Range(0, 64).Select(_ => new byte[1275]).ToArray();
private readonly VoiceFrameHeader[] headers = new VoiceFrameHeader[64];
private readonly int[] lengths = new int[64];
private readonly long[] arrivals = new long[64];
private int read, written;
private readonly byte[][] jitter = Enumerable.Range(0, 6).Select(_ => new byte[1275]).ToArray();
private readonly uint[] timestamps = new uint[6];
private readonly int[] sizes = new int[6];
private readonly byte[][] jitter;
private readonly uint[] timestamps;
private readonly int[] sizes;
private int count, available, offset, missing, waiting;
private uint expected;
private bool started, hasTimestamp;
private bool hasMarker;
private uint lastMarker;
private readonly int channels, frameSamples, maximumDepth;
private long lastArrival;
private uint lastArrivalTimestamp;
private double jitterSamples;
private readonly TimeProvider clock;
internal int Depth => count;
internal int TargetDepthSamples => TargetSamples();
internal int ConcealedFrames { get; private set; }
internal int DredFrames { get; private set; }
internal int FecFrames { get; private set; }
internal ReceiveStream(uint userId, StreamInfo info)
internal ReceiveStream(uint userId, StreamInfo info, TimeProvider? clock = null)
{
if (info.Audio.FrameMs is not (5 or 10 or 20 or 40 or 60) || !Enum.IsDefined(info.Audio.Mode)) throw new ArgumentException("Unsupported remote audio configuration.", nameof(info));
UserId = userId; Info = info.Clone();
UserId = userId; Info = info.Clone(); this.clock = clock ?? TimeProvider.System;
channels = info.Audio.Mode == ChannelMode.ModeStereo ? 2 : 1;
frameSamples = checked((int)info.Audio.FrameMs * 48);
maximumDepth = Math.Clamp(120 / (int)info.Audio.FrameMs, 2, 6);
maximumDepth = Math.Clamp(500 / (int)info.Audio.FrameMs + 2, 8, 104);
jitter = Enumerable.Range(0, maximumDepth).Select(_ => new byte[1275]).ToArray();
timestamps = new uint[maximumDepth]; sizes = new int[maximumDepth];
decoder = new(48000, channels);
try { left = new(); } catch { decoder.Dispose(); throw; }
try { right = new(); } catch { left.Dispose(); decoder.Dispose(); throw; }
@@ -53,7 +61,7 @@ internal sealed class ReceiveStream : IDisposable
{
int index = written;
if (payload.Length is < 1 or > 1275 || unchecked(index - Volatile.Read(ref read)) >= 64) return false;
int slot = index & 63; payload.CopyTo(packets[slot]); headers[slot] = header; lengths[slot] = payload.Length;
int slot = index & 63; payload.CopyTo(packets[slot]); headers[slot] = header; lengths[slot] = payload.Length; arrivals[slot] = clock.GetTimestamp();
Volatile.Write(ref written, unchecked(index + 1)); return true;
}
@@ -67,8 +75,8 @@ internal sealed class ReceiveStream : IDisposable
if ((headers[source].Flags & VoiceFrameFlags.Marker) != 0 && (!hasMarker || unchecked((int)(timestamp - lastMarker)) > 0))
{
hasMarker = true; lastMarker = timestamp;
sizes.AsSpan().Clear(); count = available = offset = missing = waiting = 0;
expected = timestamp; started = false; delta = 0;
DropBefore(timestamp); available = offset = missing = waiting = 0;
expected = timestamp; started = false; delta = 0; lastArrival = 0; jitterSamples = 0;
}
bool duplicate = false;
for (int i = 0; i < sizes.Length; i++) if (sizes[i] != 0 && timestamps[i] == timestamp) duplicate = true;
@@ -79,14 +87,61 @@ internal sealed class ReceiveStream : IDisposable
int oldest = Oldest(); sizes[oldest] = 0; count--;
}
int target = Array.IndexOf(sizes, 0);
timestamps[target] = timestamp; sizes[target] = lengths[source]; packets[source].AsSpan(0, lengths[source]).CopyTo(jitter[target]); count++;
int oldestRemaining = Oldest();
if (count >= maximumDepth && unchecked((int)(timestamps[oldestRemaining] - expected)) > 0) expected = timestamps[oldestRemaining];
timestamps[target] = timestamp; sizes[target] = lengths[source];
packets[source].AsSpan(0, lengths[source]).CopyTo(jitter[target]); count++;
ObserveArrival(timestamp, arrivals[source]);
}
Volatile.Write(ref read, unchecked(read + 1));
}
}
private void ObserveArrival(uint timestamp, long arrival)
{
if (lastArrival != 0)
{
int timestampDelta = unchecked((int)(timestamp - lastArrivalTimestamp));
if (timestampDelta <= 0) return;
if (timestampDelta > 0 && timestampDelta <= frameSamples * 10)
{
double arrivalDelta = clock.GetElapsedTime(lastArrival, arrival).TotalSeconds * 48_000;
double deviation = Math.Abs(arrivalDelta - timestampDelta);
jitterSamples += (deviation - jitterSamples) / 16.0;
}
}
lastArrival = arrival; lastArrivalTimestamp = timestamp;
}
private int TargetSamples()
{
int recovery = Info.Audio.Dred || Info.Audio.Fec ? frameSamples : 0;
int variation = checked((int)Math.Ceiling(4 * jitterSamples / frameSamples)) * frameSamples;
return Math.Min(5760, recovery + variation);
}
private int Newest()
{
int newest = -1;
for (int i = 0; i < sizes.Length; i++) if (sizes[i] != 0 && (newest < 0 || unchecked((int)(timestamps[i] - timestamps[newest])) > 0)) newest = i;
return newest;
}
private void DropBefore(uint timestamp)
{
for (int i = 0; i < sizes.Length; i++)
if (sizes[i] != 0 && unchecked((int)(timestamps[i] - timestamp)) < 0) { sizes[i] = 0; count--; }
}
private void CatchUp()
{
if (!started || available != 0 || count == 0) return;
int newest = Newest(); int target = TargetSamples();
int lead = unchecked((int)(timestamps[newest] - expected));
if (lead <= target + frameSamples) return;
int keepBehind = target / frameSamples * frameSamples;
expected = unchecked(timestamps[newest] - (uint)keepBehind);
DropBefore(expected); missing = 0;
}
private int Oldest()
{
int oldest = -1;
@@ -108,11 +163,12 @@ internal sealed class ReceiveStream : IDisposable
else
{
int next = Oldest(); missing++;
if (next >= 0 && unchecked((int)(timestamps[next] - expected)) == frameSamples)
int recoveryOffset = next < 0 ? 0 : unchecked((int)(timestamps[next] - expected));
if (next >= 0 && recoveryOffset > 0 && recoveryOffset % frameSamples == 0)
{
var packet = jitter[next].AsSpan(0, sizes[next]);
if (dred?.TryRecover(decoder, packet, pcm, frameSamples) == true) { decoded = true; DredFrames++; }
else if (Info.Audio.Fec && decoder.TryDecode(packet, pcm, frameSamples, out int recovered, true) && recovered == frameSamples) { decoded = true; FecFrames++; }
if (dred?.TryRecover(decoder, packet, pcm, frameSamples, recoveryOffset) == true) { decoded = true; DredFrames++; }
else if (recoveryOffset == frameSamples && Info.Audio.Fec && decoder.TryDecode(packet, pcm, frameSamples, out int recovered, true) && recovered == frameSamples) { decoded = true; FecFrames++; }
}
}
int maximumConcealment = Math.Max(1, 200 / (int)Info.Audio.FrameMs);
@@ -127,11 +183,16 @@ internal sealed class ReceiveStream : IDisposable
internal void Mix(Span<int> output, bool deafened, PcmStreamHandler? sink)
{
Drain();
CatchUp();
if (!started)
{
waiting++;
if (!hasTimestamp || count < Math.Min(3, maximumDepth) && waiting < 3) return;
expected = timestamps[Oldest()]; started = true;
if (!hasTimestamp || count == 0) return;
int oldest = Oldest(), newest = Newest();
if (unchecked((int)(timestamps[newest] - timestamps[oldest])) < TargetSamples()) return;
int keepBehind = TargetSamples() / frameSamples * frameSamples;
expected = unchecked(timestamps[newest] - (uint)keepBehind);
DropBefore(expected); started = true; waiting = 0;
}
int copied = 0;
while (copied < 960)
@@ -7,6 +7,84 @@ namespace VoiceCat.Tests;
public class AudioEngineTests
{
[Theory]
[InlineData(-1000)]
[InlineData(1000)]
public void AdaptivePcmBufferAbsorbsIndependentClockDrift(int partsPerMillion)
{
var buffer = new AdaptivePcmBuffer(1, 40); short[] input = new short[962], output = new short[960];
input.AsSpan().Fill(1234); Assert.True(buffer.TryWrite(input.AsSpan(0, 960)));
Assert.True(buffer.TryWrite(input.AsSpan(0, 960)));
double produced = 0;
for (int cycle = 0; cycle < 10_000; cycle++)
{
produced += 960 * (1 + partsPerMillion / 1_000_000.0);
int frames = (int)produced; produced -= frames;
Assert.True(buffer.TryWrite(input.AsSpan(0, frames)));
Assert.Equal(output.Length, buffer.Read(output));
}
Assert.InRange(buffer.CountFrames, 480, 3840);
long before = GC.GetAllocatedBytesForCurrentThread();
for (int i = 0; i < 100; i++) { buffer.TryWrite(input.AsSpan(0, 960)); buffer.Read(output); }
Assert.Equal(0, GC.GetAllocatedBytesForCurrentThread() - before);
}
[Fact]
public void OneCaptureMissDoesNotRestartTalkspurtButSustainedStarvationDoes()
{
var sent = new List<(uint Timestamp, VoiceFrameFlags Flags)>();
using var engine = new AudioEngine((_, timestamp, _, flags) => { sent.Add((timestamp, flags)); return true; }, false)
{ InputMode = AudioInputMode.AlwaysOn, DeviceBufferMilliseconds = 20 };
engine.AddLocalStream(Stream()); short[] tone = Tone();
engine.FeedPcm(1, tone, 1); engine.ProcessCycle();
engine.ProcessCycle();
engine.FeedPcm(1, tone, 1); engine.ProcessCycle();
Assert.Equal(2, sent.Count); Assert.True((sent[0].Flags & VoiceFrameFlags.Marker) != 0); Assert.Equal(VoiceFrameFlags.None, sent[1].Flags & VoiceFrameFlags.Marker);
for (int i = 0; i < 10; i++) engine.ProcessCycle();
engine.FeedPcm(1, tone, 1); engine.ProcessCycle();
Assert.True((sent[^1].Flags & VoiceFrameFlags.Marker) != 0);
}
[Theory]
[InlineData(5)] [InlineData(10)] [InlineData(20)] [InlineData(40)] [InlineData(60)]
public void RecoveryLookaheadTracksChannelFrameDuration(int frameMilliseconds)
{
using var stream = new ReceiveStream(2, Stream(frameMilliseconds));
Assert.Equal(frameMilliseconds * 48, stream.TargetDepthSamples);
}
[Fact]
public void JitterTargetAdaptsInSampleTimeAndRemainsCapped()
{
var clock = new ManualAudioClock(); StreamInfo info = Stream(); info.Audio.Fec = false;
using var stream = new ReceiveStream(2, info, clock); using var encoder = new OpusEncoder(new() { Bitrate = 32000 });
byte[] packet = new byte[1275]; int length = encoder.Encode(Tone(), packet);
for (uint i = 0; i < 40; i++)
{
clock.Advance(i % 2 == 0 ? 5 : 35);
stream.Enqueue(new(MediaFrameType.Voice, 0, 0, 42, i, i * 960), packet.AsSpan(0, length));
}
int[] output = new int[1920]; stream.Mix(output, false, null);
Assert.InRange(stream.TargetDepthSamples, 960, 5760);
}
[Fact]
public void DredUsesTimestampOffsetForConsecutiveMissingShortFrames()
{
using var probe = new OpusEncoder();
if (!probe.SupportsDeepRedundancy) return;
StreamInfo info = Stream(10, dred: true); using var stream = new ReceiveStream(2, info);
using var encoder = new OpusEncoder(new() { FrameDurationMilliseconds = 10, DeepRedundancy = true, ExpectedPacketLossPercent = 30, Bitrate = 64000 });
byte[] packet = new byte[1275]; short[] tone = new short[480]; int[] output = new int[1920];
for (uint i = 0; i < 50; i++)
{
CodecTests.FillTone(tone, 480, 1, 48000, (int)i); int length = encoder.Encode(tone, packet);
if (i is not (25 or 26)) stream.Enqueue(new(MediaFrameType.Voice, 0, 0, 42, i, i * 480), packet.AsSpan(0, length));
if (i % 2 == 1) { output.AsSpan().Clear(); stream.Mix(output, false, null); }
}
Assert.True(stream.DredFrames >= 2);
}
[Theory]
[InlineData(true)]
[InlineData(false)]
@@ -114,4 +192,12 @@ public class AudioEngineTests
for (int i = 0; i < 15; i++) { send.FeedPcm(1, stereo, 2); send.ProcessCycle(); receive.ProcessCycle(); }
Assert.True(energy > 100000);
}
private sealed class ManualAudioClock : TimeProvider
{
private long milliseconds;
public override long TimestampFrequency => 1000;
public override long GetTimestamp() => milliseconds;
internal void Advance(int value) => milliseconds += value;
}
}