OpenTK.Audio.AudioCapture Class Reference

Provides methods to instantiate, use and destroy an audio device for recording. Static methods are provided to list available devices known by the driver. More...

List of all members.

Public Member Functions

 AudioCapture ()
 Opens the default device for audio recording. Implicitly set parameters are: 22050Hz, 16Bit Mono, 4096 samples ringbuffer.
 AudioCapture (string deviceName, int frequency, ALFormat sampleFormat, int bufferSize)
 Opens a device for audio recording.
void CheckErrors ()
 Checks for ALC error conditions.
void Start ()
 Start recording samples. The number of available samples can be obtained through the AvailableSamples property. The data can be queried with any ReadSamples(IntPtr, int) method.
void Stop ()
 Stop recording samples. This will not clear previously recorded samples.
void ReadSamples (IntPtr buffer, int sampleCount)
 Fills the specified buffer with samples from the internal capture ring-buffer. This method does not block: it is an error to specify a sampleCount larger than AvailableSamples.
void ReadSamples< TBuffer > (TBuffer[] buffer, int sampleCount)
 Fills the specified buffer with samples from the internal capture ring-buffer. This method does not block: it is an error to specify a sampleCount larger than AvailableSamples.
void Dispose ()
 Closes the device and disposes the instance.

Properties

string CurrentDevice [get]
 The name of the device associated with this instance.
static IList< string > AvailableDevices [get]
 Returns a list of strings containing all known recording devices.
static string DefaultDevice [get]
 Returns the name of the device that will be used as recording default.
AlcError CurrentError [get]
 Returns the ALC error code for this device.
int AvailableSamples [get]
 Returns the number of available samples for capture.
ALFormat SampleFormat [get, set]
 Gets the OpenTK.Audio.ALFormat for this instance.
int SampleFrequency [get, set]
 Gets the sampling rate for this instance.
bool IsRunning [get]
 Gets a value indicating whether this instance is currently capturing samples.

Detailed Description

Provides methods to instantiate, use and destroy an audio device for recording. Static methods are provided to list available devices known by the driver.

Definition at line 42 of file AudioCapture.cs.

Constructor & Destructor Documentation

OpenTK.Audio.AudioCapture.AudioCapture (  ) 

Opens the default device for audio recording. Implicitly set parameters are: 22050Hz, 16Bit Mono, 4096 samples ringbuffer.

Definition at line 70 of file AudioCapture.cs.

00071             : this(AudioCapture.DefaultDevice, 22050, ALFormat.Mono16, 4096)
00072         {
00073         }

OpenTK.Audio.AudioCapture.AudioCapture ( string  deviceName,
int  frequency,
ALFormat  sampleFormat,
int  bufferSize 
)

Opens a device for audio recording.

Parameters:
deviceName The device name.
frequency The frequency that the data should be captured at.
sampleFormat The requested capture buffer format.
bufferSize The size of OpenAL's capture internal ring-buffer. This value expects number of samples, not bytes.

Definition at line 80 of file AudioCapture.cs.

00081         {
00082             if (!AudioDeviceEnumerator.IsOpenALSupported)
00083                 throw new DllNotFoundException("openal32.dll");
00084             if (frequency <= 0)
00085                 throw new ArgumentOutOfRangeException("frequency");
00086             if (bufferSize <= 0)
00087                 throw new ArgumentOutOfRangeException("bufferSize");
00088 
00089             // Try to open specified device. If it fails, try to open default device.
00090             device_name = deviceName;
00091             Handle = Alc.CaptureOpenDevice(deviceName, frequency, sampleFormat, bufferSize);
00092 
00093             if (Handle == IntPtr.Zero)
00094             {
00095                 Debug.WriteLine(ErrorMessage(deviceName, frequency, sampleFormat, bufferSize));
00096                 device_name = "IntPtr.Zero";
00097                 Handle = Alc.CaptureOpenDevice(null, frequency, sampleFormat, bufferSize);
00098             }
00099 
00100             if (Handle == IntPtr.Zero)
00101             {
00102                 Debug.WriteLine(ErrorMessage("IntPtr.Zero", frequency, sampleFormat, bufferSize));
00103                 device_name = AudioDeviceEnumerator.DefaultRecordingDevice;
00104                 Handle = Alc.CaptureOpenDevice(AudioDeviceEnumerator.DefaultRecordingDevice, frequency, sampleFormat, bufferSize);
00105             }
00106 
00107             if (Handle == IntPtr.Zero)
00108             {
00109                 // Everything we tried failed. Capture may not be supported, bail out.
00110                 Debug.WriteLine(ErrorMessage(AudioDeviceEnumerator.DefaultRecordingDevice, frequency, sampleFormat, bufferSize));
00111                 device_name = "None";
00112 
00113                 throw new AudioDeviceException("All attempts to open capture devices returned IntPtr.Zero. See debug log for verbose list.");
00114             }
00115 
00116             // handle is not null, check for some Alc Error
00117             CheckErrors();
00118 
00119             SampleFormat = sampleFormat;
00120             SampleFrequency = frequency;
00121         }

Member Function Documentation

void OpenTK.Audio.AudioCapture.CheckErrors (  ) 

Checks for ALC error conditions.

Exceptions:
OutOfMemoryException Raised when an out of memory error is detected.
AudioValueException Raised when an invalid value is detected.
AudioDeviceException Raised when an invalid device is detected.
AudioContextException Raised when an invalid context is detected.

Definition at line 183 of file AudioCapture.cs.

00184         {
00185             new AudioDeviceErrorChecker(Handle).Dispose();
00186         }

void OpenTK.Audio.AudioCapture.Dispose (  ) 

Closes the device and disposes the instance.

Definition at line 392 of file AudioCapture.cs.

00393         {
00394             this.Dispose(true);
00395             GC.SuppressFinalize(this);
00396         }

void OpenTK.Audio.AudioCapture.ReadSamples ( IntPtr  buffer,
int  sampleCount 
)

Fills the specified buffer with samples from the internal capture ring-buffer. This method does not block: it is an error to specify a sampleCount larger than AvailableSamples.

Parameters:
buffer A pointer to a previously initialized and pinned array.
sampleCount The number of samples to be written to the buffer.

Definition at line 247 of file AudioCapture.cs.

00248         {
00249             Alc.CaptureSamples(Handle, buffer, sampleCount);
00250         }

void OpenTK.Audio.AudioCapture.ReadSamples< TBuffer > ( TBuffer[]  buffer,
int  sampleCount 
)

Fills the specified buffer with samples from the internal capture ring-buffer. This method does not block: it is an error to specify a sampleCount larger than AvailableSamples.

Parameters:
buffer The buffer to fill.
sampleCount The number of samples to be written to the buffer.
Exceptions:
System.ArgumentNullException Raised when buffer is null.
System.ArgumentOutOfRangeException Raised when sampleCount is larger than the buffer.
Type Constraints
TBuffer :struct 
void OpenTK.Audio.AudioCapture.Start (  ) 

Start recording samples. The number of available samples can be obtained through the AvailableSamples property. The data can be queried with any ReadSamples(IntPtr, int) method.

Definition at line 210 of file AudioCapture.cs.

00211         {
00212             Alc.CaptureStart(Handle);
00213             _isrecording = true;
00214         }

void OpenTK.Audio.AudioCapture.Stop (  ) 

Stop recording samples. This will not clear previously recorded samples.

Definition at line 217 of file AudioCapture.cs.

00218         {
00219             Alc.CaptureStop(Handle);
00220             _isrecording = false;
00221         }

Property Documentation

IList<string> OpenTK.Audio.AudioCapture.AvailableDevices [static, get]

Returns a list of strings containing all known recording devices.

Definition at line 150 of file AudioCapture.cs.

int OpenTK.Audio.AudioCapture.AvailableSamples [get]

Returns the number of available samples for capture.

Definition at line 229 of file AudioCapture.cs.

string OpenTK.Audio.AudioCapture.CurrentDevice [get]

The name of the device associated with this instance.

Definition at line 135 of file AudioCapture.cs.

AlcError OpenTK.Audio.AudioCapture.CurrentError [get]

Returns the ALC error code for this device.

Definition at line 194 of file AudioCapture.cs.

string OpenTK.Audio.AudioCapture.DefaultDevice [static, get]

Returns the name of the device that will be used as recording default.

Definition at line 165 of file AudioCapture.cs.

bool OpenTK.Audio.AudioCapture.IsRunning [get]

Gets a value indicating whether this instance is currently capturing samples.

Definition at line 307 of file AudioCapture.cs.

ALFormat OpenTK.Audio.AudioCapture.SampleFormat [get, set]

Gets the OpenTK.Audio.ALFormat for this instance.

Definition at line 285 of file AudioCapture.cs.

int OpenTK.Audio.AudioCapture.SampleFrequency [get, set]

Gets the sampling rate for this instance.

Definition at line 294 of file AudioCapture.cs.

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