audio
Class AudioCodecUlaw

java.lang.Object
  audio.AbstractCODEC
      audio.AudioCodecUlaw

All Implemented Interfaces:

AudioInterface

public class AudioCodecUlaw
extends AbstractCODEC

Converts a 16-bit linear PCM stream from and to 8-bit u-law.

Author:

Mikica B Kocic, based on Craig Reese's and Joe Campbell's C source code.

Nested Class Summary

Nested classes/interfaces inherited from interface audio.AudioInterface

AudioInterface.Packetizer

Field Summary

private static short	BIAS
private static int	CLIP
private static int[]	exp_lut1
private int	sampleSize
private static short[]	ulaw2lin_table
private static boolean	ZEROTRAP

Fields inherited from class audio.AbstractCODEC

audio, inputPcmBuf, outputPcmBuf

Constructor Summary

AudioCodecUlaw(AudioInterfacePCM audio)
Constructs A-Law CODEC above existing PCM audio interface

Method Summary

void	convertFromPCM(byte[] in, byte[] out) Decodes data from PCM, i.e. converts samples from u-Law to PCM format.
void	convertToPCM(byte[] in, byte[] out) Encodes data to PCM, i.e. converts samples from u-Law to CODEC format.
int	getSampleSize() Returns the minimum sample size for use in creating buffers etc.
int	getVoicePduSubclass() Gets the VoicePDU subclass attribute of the AbstractAudio object
static byte	linear2ulaw(int sample) Converts a linear signed 16bit sample to a uLaw byte.
static short	ulaw2linear(byte ulawbyte) Converts an 8-bit u-law value to 16-bit linear PCM

Methods inherited from class audio.AbstractCODEC

cleanUp, getByFormat, readWithTimestamp, setAudioSender, startPlay, startRecording, startRinging, stopPlay, stopRecording, stopRinging, writeBuffered, writeDirectly

Methods inherited from class java.lang.Object

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

Field Detail

sampleSize

private int sampleSize

ZEROTRAP

private static final boolean ZEROTRAP

See Also:

Constant Field Values

BIAS

private static final short BIAS

See Also:

Constant Field Values

CLIP

private static final int CLIP

See Also:

Constant Field Values

exp_lut1

private static final int[] exp_lut1

ulaw2lin_table

private static short[] ulaw2lin_table

Constructor Detail

AudioCodecUlaw

public AudioCodecUlaw(AudioInterfacePCM audio)

Constructs A-Law CODEC above existing PCM audio interface

Method Detail

getVoicePduSubclass

public int getVoicePduSubclass()

Gets the VoicePDU subclass attribute of the AbstractAudio object

Specified by:

getVoicePduSubclass in interface AudioInterface

Specified by:

getVoicePduSubclass in class AbstractCODEC

getSampleSize

public int getSampleSize()

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

convertToPCM

public void convertToPCM(byte[] in,
                         byte[] out)

Encodes data to PCM, i.e. converts samples from u-Law to CODEC format.

Specified by:

convertToPCM in class AbstractCODEC

convertFromPCM

public void convertFromPCM(byte[] in,
                           byte[] out)

Decodes data from PCM, i.e. converts samples from u-Law to PCM format.

Specified by:

convertFromPCM in class AbstractCODEC

linear2ulaw

public static byte linear2ulaw(int sample)

Converts a linear signed 16bit sample to a uLaw byte.

ulaw2linear

public static short ulaw2linear(byte ulawbyte)

Converts an 8-bit u-law value to 16-bit linear PCM