audio
Class AudioInterfacePCM

java.lang.Object
  audio.AudioInterfacePCM

All Implemented Interfaces:

AudioInterface

public class AudioInterfacePCM
extends java.lang.Object
implements AudioInterface

Implements the audio interface for 16-bit signed linear audio (PCM_SIGNED). It also provides support for CODECs that can convert to and from Signed LIN16.

Author:

Mikica B Kocic, based on hevaily modified and re-documented Tim Panton's (thp@westhawk.co.uk) code from org.asteriskjava.iax.audio.javasound.Audio8k

Nested Class Summary

Nested classes/interfaces inherited from interface audio.AudioInterface

AudioInterface.Packetizer

Field Summary

private java.lang.Thread	audioPlayerThread
private AudioInterface.Packetizer	audioSender
private java.lang.Thread	audioSenderThread
private long	callLength Measured call length in milliseconds
private long	deltaTimePlayerMinusMic
private static int	FRAME_COUNT Audio buffering depth in number of frames
private static int	FRAME_INTERVAL Frame interval in milliseconds
private boolean	jitBufFirst
private long	jitBufFudge
private int	jitBufGet
private int	jitBufPut
private long	lastMicTimestamp
private static int	LLBS Low-level water mark used for de-jittering
private int	micBufGet
private int	micBufPut
private java.lang.Thread	micRecorderThread
private javax.sound.sampled.AudioFormat	mono44k
private javax.sound.sampled.AudioFormat	mono8k
private AudioBuffer[]	playBuffer
private boolean	playerIsEnabled
private boolean	propertyBigBuff Big buffers
private java.lang.String	propertyInputDeviceName Input device name
private java.lang.String	propertyOutputDeviceName Output device name
private boolean	propertyStereoRec Stereo recording
private boolean	providingRingBack
private AudioBuffer[]	recordBuffer
private java.lang.Thread	ringerThread
private byte[]	ringSamples
private long	ringTimer
private byte[]	silenceSamples
private javax.sound.sampled.SourceDataLine	sourceDataLine
private javax.sound.sampled.AudioFormat	stereo8k
private javax.sound.sampled.TargetDataLine	targetDataLine

Constructor Summary

AudioInterfacePCM()
Constructor for the AudioInterfacePCM object

Method Summary

private void	audioPlayerWorker() Writes frames to audio output i.e. source data line
void	cleanUp() Stops threads and cleans-up the instance.
private void	concealMissingDataForAudioOutput(int n) Conceals missing data in the audio output buffer by averaging from samples taken from the the previous and next buffer.
private javax.sound.sampled.DataLine	findDataLineByPref(java.lang.String pref, javax.sound.sampled.AudioFormat af, java.lang.String name, int sbuffsz, java.lang.Class<?> lineClass, java.lang.String debugInfo) Searches for data line of either sort (source/targe) based on the pref string.
private javax.sound.sampled.SourceDataLine	findSourceDataLineByPref(java.lang.String pref, javax.sound.sampled.AudioFormat af, java.lang.String name, int sbuffsz) Searches for source data line according to preferences.
private javax.sound.sampled.TargetDataLine	fintTargetDataLineByPref(java.lang.String pref, javax.sound.sampled.AudioFormat af, java.lang.String name, int sbuffsz) Searches for target data line according to preferences.
private boolean	getAudioIn() Returns audio input (target data line)
private boolean	getAudioOut() Get audio output.
AudioInterface	getByFormat(java.lang.Integer format) Gets audio interface by VoicePDU format
int	getSampleSize() Returns preferred the minimum sample size for use in creating buffers etc.
int	getVoicePduSubclass() Returns our VoicePDU format
private void	initializeRingerSamples() Initializes ringer samples (ring singnal and silecce) samples
private void	micDataRead() Called from micRecorder to record audio samples from microphone.
private void	micRecorderWorker() Records audio samples from the microphone
private void	pduSenderWorker() Sends audio frames to UDP channel at regular intervals (ticks)
long	readWithTimestamp(byte[] buff) Read from the Microphone, into the buffer provided, but only filling getSampSize() bytes.
private void	resample(byte[] src, byte[] dest) Simple PCM down sampler.
private void	ringerWorker() Writes ring signal samples to audio output
private void	sendAudioFrame(long set) Called every FRAMEINTERVAL ms to send audio frame
void	setAudioSender(AudioInterface.Packetizer as) Sets the active audio sender for the recorder
void	startPlay() Starts the audio output worker thread
long	startRecording() Start the audio recording worker thread
void	startRinging() Starts ringing signal
void	stopPlay() Stops the audio output worker thread
void	stopRecording() Stops the audio recording worker thread
void	stopRinging() Stops ringing singnal
void	writeBuffered(byte[] buff, long timestamp) Enqueue packet for playing into de-jitter buffer.
private long	writeBuffersToAudioOutput() Writes de-jittered audio frames to audio output
private long	writeDirectIfAvail(byte[] samples) Writes audio samples to audio output directly (without using jitter buffer).
void	writeDirectly(byte[] buff) Writes directly to source line without buffering

Methods inherited from class java.lang.Object

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

Field Detail

FRAME_COUNT

private static final int FRAME_COUNT

Audio buffering depth in number of frames

See Also:

Constant Field Values

LLBS

private static final int LLBS

Low-level water mark used for de-jittering

See Also:

Constant Field Values

FRAME_INTERVAL

private static final int FRAME_INTERVAL

Frame interval in milliseconds

See Also:

Constant Field Values

propertyStereoRec

private boolean propertyStereoRec

Stereo recording

propertyBigBuff

private boolean propertyBigBuff

Big buffers

propertyInputDeviceName

private java.lang.String propertyInputDeviceName

Input device name

propertyOutputDeviceName

private java.lang.String propertyOutputDeviceName

Output device name

mono8k

private javax.sound.sampled.AudioFormat mono8k

stereo8k

private javax.sound.sampled.AudioFormat stereo8k

mono44k

private javax.sound.sampled.AudioFormat mono44k

targetDataLine

private javax.sound.sampled.TargetDataLine targetDataLine

audioSenderThread

private volatile java.lang.Thread audioSenderThread

micRecorderThread

private volatile java.lang.Thread micRecorderThread

audioSender

private volatile AudioInterface.Packetizer audioSender

recordBuffer

private AudioBuffer[] recordBuffer

micBufPut

private int micBufPut

micBufGet

private int micBufGet

lastMicTimestamp

private long lastMicTimestamp

sourceDataLine

private javax.sound.sampled.SourceDataLine sourceDataLine

audioPlayerThread

private volatile java.lang.Thread audioPlayerThread

playBuffer

private AudioBuffer[] playBuffer

jitBufPut

private int jitBufPut

jitBufGet

private int jitBufGet

jitBufFudge

private long jitBufFudge

jitBufFirst

private boolean jitBufFirst

playerIsEnabled

private boolean playerIsEnabled

deltaTimePlayerMinusMic

private long deltaTimePlayerMinusMic

callLength

private long callLength

Measured call length in milliseconds

ringerThread

private volatile java.lang.Thread ringerThread

ringSamples

private byte[] ringSamples

silenceSamples

private byte[] silenceSamples

providingRingBack

private boolean providingRingBack

ringTimer

private long ringTimer

Constructor Detail

AudioInterfacePCM

public AudioInterfacePCM()

Constructor for the AudioInterfacePCM object

Method Detail

getSampleSize

public int getSampleSize()

Returns preferred the minimum sample size for use in creating buffers etc.

Specified by:

getSampleSize in interface AudioInterface

getVoicePduSubclass

public int getVoicePduSubclass()

Returns our VoicePDU format

Specified by:

getVoicePduSubclass in interface AudioInterface

setAudioSender

public void setAudioSender(AudioInterface.Packetizer as)

Sets the active audio sender for the recorder

Specified by:

setAudioSender in interface AudioInterface

cleanUp

public void cleanUp()

Stops threads and cleans-up the instance.

Specified by:

cleanUp in interface AudioInterface

audioPlayerWorker

private void audioPlayerWorker()

Writes frames to audio output i.e. source data line

writeBuffersToAudioOutput

private long writeBuffersToAudioOutput()

Writes de-jittered audio frames to audio output

concealMissingDataForAudioOutput

private void concealMissingDataForAudioOutput(int n)

Conceals missing data in the audio output buffer by averaging from samples taken from the the previous and next buffer.

writeDirectly

public void writeDirectly(byte[] buff)

Writes directly to source line without buffering

Specified by:

writeDirectly in interface AudioInterface

writeBuffered

public void writeBuffered(byte[] buff,
                          long timestamp)
                   throws java.io.IOException

Enqueue packet for playing into de-jitter buffer.

Specified by:

writeBuffered in interface AudioInterface

Throws:

java.io.IOException

pduSenderWorker

private void pduSenderWorker()

Sends audio frames to UDP channel at regular intervals (ticks)

sendAudioFrame

private void sendAudioFrame(long set)

Called every FRAMEINTERVAL ms to send audio frame

micRecorderWorker

private void micRecorderWorker()

Records audio samples from the microphone

micDataRead

private void micDataRead()

Called from micRecorder to record audio samples from microphone. Blocks as needed.

readWithTimestamp

public long readWithTimestamp(byte[] buff)
                       throws java.io.IOException

Read from the Microphone, into the buffer provided, but only filling getSampSize() bytes. Returns the timestamp of the sample from the audio clock.

Specified by:

readWithTimestamp in interface AudioInterface

Parameters:

buff - audio samples

Returns:

the timestamp of the sample from the audio clock.

Throws:

java.io.IOException - Description of Exception

resample

private void resample(byte[] src,
                      byte[] dest)

Simple PCM down sampler.

Parameters:

src - source buffer with audio samples

dest - destination buffer with audio samples

ringerWorker

private void ringerWorker()

Writes ring signal samples to audio output

writeDirectIfAvail

private long writeDirectIfAvail(byte[] samples)

Writes audio samples to audio output directly (without using jitter buffer).

Returns:

milliseconds to sleep (after which time next write should occur)

initializeRingerSamples

private void initializeRingerSamples()

Initializes ringer samples (ring singnal and silecce) samples

getAudioOut

private boolean getAudioOut()

Get audio output. Initializes source data line.

getAudioIn

private boolean getAudioIn()

Returns audio input (target data line)

findDataLineByPref

private javax.sound.sampled.DataLine findDataLineByPref(java.lang.String pref,
                                                        javax.sound.sampled.AudioFormat af,
                                                        java.lang.String name,
                                                        int sbuffsz,
                                                        java.lang.Class<?> lineClass,
                                                        java.lang.String debugInfo)

Searches for data line of either sort (source/targe) based on the pref string. Uses type to determine the sort ie Target or Source. debugInfo parameter is only used in debug printouts to set the context.

fintTargetDataLineByPref

private javax.sound.sampled.TargetDataLine fintTargetDataLineByPref(java.lang.String pref,
                                                                    javax.sound.sampled.AudioFormat af,
                                                                    java.lang.String name,
                                                                    int sbuffsz)

Searches for target data line according to preferences.

findSourceDataLineByPref

private javax.sound.sampled.SourceDataLine findSourceDataLineByPref(java.lang.String pref,
                                                                    javax.sound.sampled.AudioFormat af,
                                                                    java.lang.String name,
                                                                    int sbuffsz)

Searches for source data line according to preferences.

stopRecording

public void stopRecording()

Stops the audio recording worker thread

Specified by:

stopRecording in interface AudioInterface

startRecording

public long startRecording()

Start the audio recording worker thread

Specified by:

startRecording in interface AudioInterface

startPlay

public void startPlay()

Starts the audio output worker thread

Specified by:

startPlay in interface AudioInterface

stopPlay

public void stopPlay()

Stops the audio output worker thread

Specified by:

stopPlay in interface AudioInterface

getByFormat

public AudioInterface getByFormat(java.lang.Integer format)

Gets audio interface by VoicePDU format

Specified by:

getByFormat in interface AudioInterface

Returns:

AudioInterfacePCM

startRinging

public void startRinging()

Starts ringing signal

Specified by:

startRinging in interface AudioInterface

stopRinging

public void stopRinging()

Stops ringing singnal

Specified by:

stopRinging in interface AudioInterface