org.jitsi.impl.neomedia.jmfext.media.protocol.wasapi

Class AudioCaptureClient

java.lang.Object

org.jitsi.impl.neomedia.jmfext.media.protocol.wasapi.AudioCaptureClient

public class AudioCaptureClient
extends Object

Abstracts the initialization of an IAudioCaptureClient instance from a MediaLocator, the input of data from that IAudioCaptureClient, the buffering of that data, the starting, stopping and closing of the IAudioCaptureClient. Allows WASAPIStream to simultaneously utilize multiple IAudioCaptureClient instances (e.g. in the case of acoustic echo cancellation in which audio is input from both the capture and the render endpoint devices).

Author:

Lyubomir Marinov

Constructor Summary

Constructors

Constructor and Description
AudioCaptureClient(WASAPISystem audioSystem, javax.media.MediaLocator locator, AudioSystem.DataFlow dataFlow, int streamFlags, long hnsBufferDuration, javax.media.format.AudioFormat outFormat, javax.media.protocol.BufferTransferHandler transferHandler) Initializes a new AudioCaptureClient instance.

Method Summary

Modifier and Type	Method and Description
void	close() Releases the resources acquired by this instance throughout its lifetime and prepares it to be garbage collected.
int	read(byte[] buffer, int offset, int length) Reads audio data from this instance into a specific byte array.
int	read(IMediaBuffer iMediaBuffer, int length) Reads audio data from this instance into a specific IMediaBuffer.
void	start() Starts the transfer of media from the IAudioCaptureClient identified by the MediaLocator with which this instance has been initialized.
void	stop() Stops the transfer of media from the IAudioCaptureClient identified by the MediaLocator with which this instance has been initialized.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AudioCaptureClient

public AudioCaptureClient(WASAPISystem audioSystem,
                          javax.media.MediaLocator locator,
                          AudioSystem.DataFlow dataFlow,
                          int streamFlags,
                          long hnsBufferDuration,
                          javax.media.format.AudioFormat outFormat,
                          javax.media.protocol.BufferTransferHandler transferHandler)
                   throws Exception

Initializes a new AudioCaptureClient instance.

Parameters:

audioSystem - the WASAPISystem instance which has contributed locator

locator - a MediaLocator which identifies the audio endpoint device to be opened and read by the new instance

dataFlow - the AudioSystem.DataFlow of the audio endpoint device identified by locator. If AudioSystem.DataFlow.PLAYBACK and streamFlags includes WASAPI.AUDCLNT_STREAMFLAGS_LOOPBACK, allows opening a render endpoint device in loopback mode and inputing the data that is being written on that render endpoint device

streamFlags - zero or more of the AUDCLNT_STREAMFLAGS_XXX flags defined by the WASAPI class

hnsBufferDuration - the base of the duration in milliseconds of the buffer that the audio application will share with the audio engine. If Format.NOT_SPECIFIED, the method uses the default interval between periodic passes by the audio engine.

outFormat - the AudioFormat of the data to be made available by the new instance. Eventually, the IAudioCaptureClient to be represented by the new instance may be initialized with a different AudioFormat in which case the new instance will automatically transcode the data input from the IAudioCaptureClient into the specified outFormat.

transferHandler - the BufferTransferHandler to be invoked when the new instance has made data available to be read via read(byte[], int, int)

Throws:

Exception - if the initialization of the new instance fails

Method Detail

close

public void close()

Releases the resources acquired by this instance throughout its lifetime and prepares it to be garbage collected.

read

public int read(byte[] buffer,
                int offset,
                int length)
         throws IOException

Reads audio data from this instance into a specific byte array.

Parameters:

buffer - the byte array into which the audio data read from this instance is to be written

offset - the offset in buffer at which the writing of the audio data is to start

length - the maximum number of bytes in buffer starting at offset to be written

Returns:

the number of bytes read from this instance and written into the specified buffer

Throws:

IOException - if the reading from this instance or the writing into the specified buffer fails

read

public int read(IMediaBuffer iMediaBuffer,
                int length)
         throws IOException

Reads audio data from this instance into a specific IMediaBuffer.

Parameters:

iMediaBuffer - the IMediaBuffer into which the audio data read from this instance is to be written

length - the maximum number of bytes to read from this instance and write into the specified iMediaBuffer

Returns:

the number of bytes read from this instance and written into the specified iMediaBuffer

Throws:

IOException - if the reading of audio data from this instance or the writing into the specified iMediaBuffer fails

start

public void start()
           throws IOException

Starts the transfer of media from the IAudioCaptureClient identified by the MediaLocator with which this instance has been initialized.

Throws:

IOException - if the starting of the transfer of media fails

stop

public void stop()
          throws IOException

Stops the transfer of media from the IAudioCaptureClient identified by the MediaLocator with which this instance has been initialized.

Throws:

IOException - if the stopping of the transfer of media fails