/// <summary>
/// Suspends processing of audio events.
/// </summary>
/// <remarks>
/// <para>
/// To avoid audio artifacts when calling this function, set audio gain to zero before
/// suspending an AudioContext.
/// </para>
/// <para>
/// In some implementations, it can be faster to suspend processing before changing
/// AudioContext state.
/// </para>
/// <para>
/// In some implementations this function may have no effect.
/// </para>
/// </remarks>
/// <exception cref="ObjectDisposedException">Occurs when this function is called after the AudioContext had been disposed.</exception>
/// <seealso cref="Process"/>
/// <seealso cref="IsProcessing"/>
/// <seealso cref="IsSynchronized"/>
public void Suspend()
{
if (disposed)
{
throw new ObjectDisposedException(this.GetType().FullName);
}
Alc.SuspendContext(this.context_handle);
IsProcessing = false;
}
/// <summary>
/// Open the sound device, sets up an audio context, and makes the new context
/// the current context. Note that this method will stop the playback of
/// music that was running prior to the game start. If any error occurs, then
/// the state of the controller is reset.
/// </summary>
/// <returns>True if the sound controller was setup, and false if not.</returns>
private bool OpenSoundController()
{
#if MONOMAC || IOS
alcMacOSXMixerOutputRate(PREFERRED_MIX_RATE);
#endif
try
{
_device = Alc.OpenDevice(string.Empty);
}
catch (Exception ex)
{
_SoundInitException = ex;
return(false);
}
if (CheckALError("Could not open AL device"))
{
return(false);
}
if (_device != IntPtr.Zero)
{
#if ANDROID
// Attach activity event handlers so we can pause and resume all playing sounds
AndroidGameActivity.Paused += Activity_Paused;
AndroidGameActivity.Resumed += Activity_Resumed;
// Query the device for the ideal frequency and update buffer size so
// we can get the low latency sound path.
/*
* The recommended sequence is:
*
* Check for feature "android.hardware.audio.low_latency" using code such as this:
* import android.content.pm.PackageManager;
* ...
* PackageManager pm = getContext().getPackageManager();
* boolean claimsFeature = pm.hasSystemFeature(PackageManager.FEATURE_AUDIO_LOW_LATENCY);
* Check for API level 17 or higher, to confirm use of android.media.AudioManager.getProperty().
* Get the native or optimal output sample rate and buffer size for this device's primary output stream, using code such as this:
* import android.media.AudioManager;
* ...
* AudioManager am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
* String sampleRate = am.getProperty(AudioManager.PROPERTY_OUTPUT_SAMPLE_RATE));
* String framesPerBuffer = am.getProperty(AudioManager.PROPERTY_OUTPUT_FRAMES_PER_BUFFER));
* Note that sampleRate and framesPerBuffer are Strings. First check for null and then convert to int using Integer.parseInt().
* Now use OpenSL ES to create an AudioPlayer with PCM buffer queue data locator.
*
* See http://stackoverflow.com/questions/14842803/low-latency-audio-playback-on-android
*/
int frequency = DEFAULT_FREQUENCY;
int updateSize = DEFAULT_UPDATE_SIZE;
int updateBuffers = DEFAULT_UPDATE_BUFFER_COUNT;
if (Android.OS.Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.JellyBeanMr1)
{
Android.Util.Log.Debug("OAL", Game.Activity.PackageManager.HasSystemFeature(PackageManager.FeatureAudioLowLatency) ? "Supports low latency audio playback." : "Does not support low latency audio playback.");
var audioManager = Game.Activity.GetSystemService(Context.AudioService) as AudioManager;
if (audioManager != null)
{
var result = audioManager.GetProperty(AudioManager.PropertyOutputSampleRate);
if (!string.IsNullOrEmpty(result))
{
frequency = int.Parse(result, CultureInfo.InvariantCulture);
}
result = audioManager.GetProperty(AudioManager.PropertyOutputFramesPerBuffer);
if (!string.IsNullOrEmpty(result))
{
updateSize = int.Parse(result, CultureInfo.InvariantCulture);
}
}
// If 4.4 or higher, then we don't need to double buffer on the application side.
// See http://stackoverflow.com/a/15006327
// Use the explicit value rather than a constant as the 4.2 SDK (the build SDK) does not define a constant for 4.4.
if ((int)Android.OS.Build.VERSION.SdkInt >= 19)
{
updateBuffers = 1;
}
}
else
{
Android.Util.Log.Debug("OAL", "Android 4.2 or higher required for low latency audio playback.");
}
Android.Util.Log.Debug("OAL", "Using sample rate " + frequency + "Hz and " + updateBuffers + " buffers of " + updateSize + " frames.");
// These are missing and non-standard ALC constants
const int AlcFrequency = 0x1007;
const int AlcUpdateSize = 0x1014;
const int AlcUpdateBuffers = 0x1015;
int[] attribute = new[]
{
AlcFrequency, frequency,
AlcUpdateSize, updateSize,
AlcUpdateBuffers, updateBuffers,
0
};
#elif IOS
AudioSession.Initialize();
AudioSession.Interrupted += (sender, e) => {
AudioSession.SetActive(false);
Alc.MakeContextCurrent(ContextHandle.Zero);
Alc.SuspendContext(_context);
};
AudioSession.Resumed += (sender, e) => {
AudioSession.SetActive(true);
Alc.MakeContextCurrent(_context);
Alc.ProcessContext(_context);
};
int[] attribute = new int[0];
#elif !DESKTOPGL
int[] attribute = new int[0];
#endif
#if DESKTOPGL
_acontext = new AudioContext();
_context = Alc.GetCurrentContext();
_oggstreamer = new OggStreamer();
#else
_context = Alc.CreateContext(_device, attribute);
#endif
if (CheckALError("Could not create AL context"))
{
CleanUpOpenAL();
return(false);
}
if (_context != ContextHandle.Zero)
{
Alc.MakeContextCurrent(_context);
if (CheckALError("Could not make AL context current"))
{
CleanUpOpenAL();
return(false);
}
return(true);
}
}
return(false);
}
/// <summary>
/// Open the sound device, sets up an audio context, and makes the new context
/// the current context. Note that this method will stop the playback of
/// music that was running prior to the game start. If any error occurs, then
/// the state of the controller is reset.
/// </summary>
/// <returns>True if the sound controller was setup, and false if not.</returns>
private bool OpenSoundController()
{
try
{
_device = Alc.OpenDevice(string.Empty);
EffectsExtension.device = _device;
}
catch (Exception ex)
{
throw new NoAudioHardwareException("OpenAL device could not be initialized.", ex);
}
AlcHelper.CheckError("Could not open OpenAL device");
if (_device != IntPtr.Zero)
{
#if ANDROID
// Attach activity event handlers so we can pause and resume all playing sounds
MonoGameAndroidGameView.OnPauseGameThread += Activity_Paused;
MonoGameAndroidGameView.OnResumeGameThread += Activity_Resumed;
// Query the device for the ideal frequency and update buffer size so
// we can get the low latency sound path.
/*
* The recommended sequence is:
*
* Check for feature "android.hardware.audio.low_latency" using code such as this:
* import android.content.pm.PackageManager;
* ...
* PackageManager pm = getContext().getPackageManager();
* boolean claimsFeature = pm.hasSystemFeature(PackageManager.FEATURE_AUDIO_LOW_LATENCY);
* Check for API level 17 or higher, to confirm use of android.media.AudioManager.getProperty().
* Get the native or optimal output sample rate and buffer size for this device's primary output stream, using code such as this:
* import android.media.AudioManager;
* ...
* AudioManager am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
* String sampleRate = am.getProperty(AudioManager.PROPERTY_OUTPUT_SAMPLE_RATE));
* String framesPerBuffer = am.getProperty(AudioManager.PROPERTY_OUTPUT_FRAMES_PER_BUFFER));
* Note that sampleRate and framesPerBuffer are Strings. First check for null and then convert to int using Integer.parseInt().
* Now use OpenSL ES to create an AudioPlayer with PCM buffer queue data locator.
*
* See http://stackoverflow.com/questions/14842803/low-latency-audio-playback-on-android
*/
int frequency = DEFAULT_FREQUENCY;
int updateSize = DEFAULT_UPDATE_SIZE;
int updateBuffers = DEFAULT_UPDATE_BUFFER_COUNT;
if (Android.OS.Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.JellyBeanMr1)
{
Android.Util.Log.Debug("OAL", Game.Activity.PackageManager.HasSystemFeature(PackageManager.FeatureAudioLowLatency) ? "Supports low latency audio playback." : "Does not support low latency audio playback.");
var audioManager = Game.Activity.GetSystemService(Context.AudioService) as AudioManager;
if (audioManager != null)
{
var result = audioManager.GetProperty(AudioManager.PropertyOutputSampleRate);
if (!string.IsNullOrEmpty(result))
{
frequency = int.Parse(result, CultureInfo.InvariantCulture);
}
result = audioManager.GetProperty(AudioManager.PropertyOutputFramesPerBuffer);
if (!string.IsNullOrEmpty(result))
{
updateSize = int.Parse(result, CultureInfo.InvariantCulture);
}
}
// If 4.4 or higher, then we don't need to double buffer on the application side.
// See http://stackoverflow.com/a/15006327
if (Android.OS.Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.Kitkat)
{
updateBuffers = 1;
}
}
else
{
Android.Util.Log.Debug("OAL", "Android 4.2 or higher required for low latency audio playback.");
}
Android.Util.Log.Debug("OAL", "Using sample rate " + frequency + "Hz and " + updateBuffers + " buffers of " + updateSize + " frames.");
// These are missing and non-standard ALC constants
const int AlcFrequency = 0x1007;
const int AlcUpdateSize = 0x1014;
const int AlcUpdateBuffers = 0x1015;
int[] attribute = new[]
{
AlcFrequency, frequency,
AlcUpdateSize, updateSize,
AlcUpdateBuffers, updateBuffers,
0
};
#elif IOS
AVAudioSession.SharedInstance().Init();
// NOTE: Do not override AVAudioSessionCategory set by the game developer:
// see https://github.com/MonoGame/MonoGame/issues/6595
EventHandler <AVAudioSessionInterruptionEventArgs> handler = delegate(object sender, AVAudioSessionInterruptionEventArgs e) {
switch (e.InterruptionType)
{
case AVAudioSessionInterruptionType.Began:
AVAudioSession.SharedInstance().SetActive(false);
Alc.MakeContextCurrent(IntPtr.Zero);
Alc.SuspendContext(_context);
break;
case AVAudioSessionInterruptionType.Ended:
AVAudioSession.SharedInstance().SetActive(true);
Alc.MakeContextCurrent(_context);
Alc.ProcessContext(_context);
break;
}
};
AVAudioSession.Notifications.ObserveInterruption(handler);
// Activate the instance or else the interruption handler will not be called.
AVAudioSession.SharedInstance().SetActive(true);
int[] attribute = new int[0];
#else
int[] attribute = new int[0];
#endif
_context = Alc.CreateContext(_device, attribute);
#if DESKTOPGL
_oggstreamer = new OggStreamer();
#endif
AlcHelper.CheckError("Could not create OpenAL context");
if (_context != NullContext)
{
Alc.MakeContextCurrent(_context);
AlcHelper.CheckError("Could not make OpenAL context current");
SupportsIma4 = AL.IsExtensionPresent("AL_EXT_IMA4");
SupportsAdpcm = AL.IsExtensionPresent("AL_SOFT_MSADPCM");
SupportsEfx = AL.IsExtensionPresent("AL_EXT_EFX");
SupportsIeee = AL.IsExtensionPresent("AL_EXT_float32");
return(true);
}
}
return(false);
}
public static void AlcUnitTestFunc()
{
AudioContext context = new AudioContext();
Trace.WriteLine("Testing AudioContext functions.");
Trace.Indent();
// Trace.WriteLine("Suspend()...");
// context.Suspend();
// Trace.Assert(!context.IsProcessing);
//
// Trace.WriteLine("Process()...");
// context.Process();
// Trace.Assert(context.IsProcessing);
//Trace.WriteLine("MakeCurrent()...");
//context.MakeCurrent();
//Trace.Assert(context.IsCurrent);
//Trace.WriteLine("IsCurrent = false...");
//context.IsCurrent = false;
//Trace.Assert(!context.IsCurrent);
//Trace.WriteLine("IsCurrent = true...");
//context.IsCurrent = true;
//Trace.Assert(context.IsCurrent);
Trace.WriteLine("AudioContext.CurrentContext...");
Trace.Assert(AudioContext.CurrentContext == context);
#region Get Attribs
//int AttribCount;
//Alc.GetInteger(context.Device, AlcGetInteger.AttributesSize, sizeof(int), out AttribCount);
//Trace.WriteLine("AttributeSize: " + AttribCount);
//if (AttribCount > 0)
//{
// int[] Attribs = new int[AttribCount];
// Alc.GetInteger(context.Device, AlcGetInteger.AllAttributes, AttribCount, out Attribs[0]);
// for (int i = 0; i < Attribs.Length; i++)
// {
// Trace.Write(Attribs[i]);
// Trace.Write(" ");
// }
// Trace.WriteLine();
//}
#endregion Get Attribs
#if false
AlDevice MyDevice;
AlContext MyContext;
// Initialize Open AL
MyDevice = Alc.OpenDevice(null); // open default device
if (MyDevice != Al.Null)
{
Trace.WriteLine("Device allocation succeeded.");
MyContext = Alc.CreateContext(MyDevice, Al.Null); // create context
if (MyContext != Al.Null)
{
Trace.WriteLine("Context allocation succeeded.");
GetOpenALErrors(MyDevice);
Alc.SuspendContext(MyContext); // disable context
Alc.ProcessContext(MyContext); // enable context. The default state of a context created by alcCreateContext is that it is processing.
Al.Bool result = Alc.MakeContextCurrent(MyContext); // set active context
Trace.WriteLine("MakeContextCurrent succeeded? " + result);
GetOpenALErrors(MyDevice);
Trace.WriteLine("Default: " + Alc.GetString(MyDevice, Enums.AlcGetString.DefaultDeviceSpecifier));
Trace.WriteLine("Device: " + Alc.GetString(MyDevice, Enums.AlcGetString.DeviceSpecifier));
Trace.WriteLine("Extensions: " + Alc.GetString(MyDevice, Enums.AlcGetString.Extensions));
GetOpenALErrors(MyDevice);
#region Get Attribs
int AttribCount;
Alc.GetInteger(MyDevice, Enums.AlcGetInteger.AttributesSize, sizeof(int), out AttribCount);
Trace.WriteLine("AttributeSize: " + AttribCount);
if (AttribCount > 0)
{
int[] Attribs = new int[AttribCount];
Alc.GetInteger(MyDevice, Enums.AlcGetInteger.AttributesSize, AttribCount, out Attribs[0]);
for (int i = 0; i < Attribs.Length; i++)
{
Trace.Write(", " + Attribs[i]);
}
Trace.WriteLine( );
}
#endregion Get Attribs
GetOpenALErrors(MyDevice);
AlDevice currdev = Alc.GetContextsDevice(MyContext);
AlContext currcon = Alc.GetCurrentContext( );
if (MyDevice == currdev)
{
Trace.WriteLine("Devices match.");
}
else
{
Trace.WriteLine("Error: Devices do not match.");
}
if (MyContext == currcon)
{
Trace.WriteLine("Context match.");
}
else
{
Trace.WriteLine("Error: Contexts do not match.");
}
// exit
Alc.MakeContextCurrent(Al.Null); // results in no context being current
Alc.DestroyContext(MyContext);
result = Alc.CloseDevice(MyDevice);
Trace.WriteLine("Result: " + result);
Trace.ReadLine( );
}
else
{
Trace.WriteLine("Context creation failed.");
}
}
else
{
Trace.WriteLine("Failed to find suitable Device.");
}
#endif
/*
* include <stdlib.h>
* include <AL/alut.h>
*
* int
* main (int argc, char **argv)
* {
* ALuint helloBuffer, helloSource;
* alutInit (&argc, argv);
* helloBuffer = alutCreateBufferHelloWorld (); alGenSources (1, &helloSource);
* alSourcei (helloSource, AL_Buffer, helloBuffer);
* alSourcePlay (helloSource);
* alutSleep (1);
* alutExit ();
* return EXIT_SUCCESS;
* }*/
/*
*
* Processing Loop Example:
* // PlaceCamera - places OpenGL camera & updates OpenAL listener buffer
* void AVEnvironment::PlaceCamera()
* {
* // update OpenGL camera position
* glMatrixMode(GL_PROJECTION);
* glLoadIdentity();
* glFrustum(-0.1333, 0.1333, -0.1, 0.1, 0.2, 50.0);
* gluLookAt(listenerPos[0], listenerPos[1], listenerPos[2],
* (listenerPos[0] + sin(listenerAngle)), listenerPos[1],
* (listenerPos[2] - cos(listenerAngle)),
* 0.0, 1.0, 0.0);
* // update OpenAL
* // place listener at camera
* alListener3f(AL_POSITION, listenerPos[0], listenerPos[1], listenerPos[2]);
* float directionvect[6];
* directionvect[0] = (float) sin(listenerAngle);
* directionvect[1] = 0;
* directionvect[2] = (float) cos(listenerAngle);
* directionvect[3] = 0;
* directionvect[4] = 1;
* directionvect[5] = 0;
* alListenerfv(AL_ORIENTATION, directionvect);
* }
*
*/
}
private OpenALSoundController()
{
#if IPHONE
AudioSession.Initialize();
// NOTE: iOS 5.1 simulator throws an exception when setting the category
// to SoloAmbientSound. This could be removed if that bug gets fixed.
try
{
if (AudioSession.OtherAudioIsPlaying)
{
AudioSession.Category = AudioSessionCategory.AmbientSound;
}
else
{
AudioSession.Category = AudioSessionCategory.SoloAmbientSound;
}
}
catch (AudioSessionException) { }
#endif
alcMacOSXMixerOutputRate(PREFERRED_MIX_RATE);
_device = Alc.OpenDevice(string.Empty);
CheckALError("Could not open AL device");
if (_device != IntPtr.Zero)
{
int[] attribute = new int[0];
_context = Alc.CreateContext(_device, attribute);
CheckALError("Could not open AL context");
if (_context != ContextHandle.Zero)
{
Alc.MakeContextCurrent(_context);
CheckALError("Could not make AL context current");
}
}
else
{
return;
}
allSourcesArray = new int[MAX_NUMBER_OF_SOURCES];
AL.GenSources(allSourcesArray);
availableSourcesCollection = new HashSet <int> ();
inUseSourcesCollection = new HashSet <OALSoundBuffer> ();
playingSourcesCollection = new HashSet <OALSoundBuffer> ();
for (int x = 0; x < MAX_NUMBER_OF_SOURCES; x++)
{
availableSourcesCollection.Add(allSourcesArray [x]);
}
#if IPHONE
AudioSession.Interrupted += (sender, e) =>
{
AudioSession.SetActive(false);
Alc.MakeContextCurrent(ContextHandle.Zero);
Alc.SuspendContext(_context);
};
AudioSession.Resumed += (sender, e) =>
{
// That is, without this, the code wont work :(
// It will fail on the next line of code
// Maybe you could ask for an explanation
// to someone at xamarin
System.Threading.Thread.Sleep(100);
AudioSession.SetActive(true);
AudioSession.Category = AudioSessionCategory.SoloAmbientSound;
Alc.MakeContextCurrent(_context);
Alc.ProcessContext(_context);
};
#endif
}
