org.xiph.speex
Class PcmWaveWriter

java.lang.Object
  org.xiph.speex.AudioFileWriter
      org.xiph.speex.PcmWaveWriter

public class PcmWaveWriter
extends AudioFileWriter

Writes basic PCM wave files from binary audio data.

Here's an example that writes 2 seconds of silence

 PcmWaveWriter s_wsw = new PcmWaveWriter(2, 44100);
 byte[] silence = new byte[16*2*44100];
 wsw.Open("C:\\out.wav");
 wsw.WriteHeader(); 
 wsw.WriteData(silence, 0, silence.length);
 wsw.WriteData(silence, 0, silence.length);
 wsw.Close(); 
 

Version:

$Revision: 1.2 $

Author:

Jim Lawrence, helloNetwork.com, Marc Gimpel, Wimba S.A. (mgimpel@horizonwimba.com)

Field Summary

private int	channels Defines the number of channels of the audio input (1=mono, 2=stereo).
private boolean	isPCM
private int	mode Defines the encoder mode (0=NB, 1=WB and 2-UWB).
private int	nframes Defines the number of frames per speex packet.
private int	quality
private java.io.RandomAccessFile	raf
private int	sampleRate Defines the sampling rate of the audio input.
private int	size
private boolean	vbr Defines whether or not to use VBR (Variable Bit Rate).
static int[][][]	WAVE_BITS_PER_FRAME Table describing the number of bit per Speex frame, depending on its mode-1 (1=NB, 2=WB, 3=UWB), channels-1 (1=mono, 2=stereo) and the quality setting (0 to 10).
static short	WAVE_FORMAT_PCM Wave type code of PCM
static short	WAVE_FORMAT_SPEEX Wave type code of Speex
static int[][][]	WAVE_FRAME_SIZES Table describing the number of frames per packet in a Speex Wave file, depending on its mode-1 (1=NB, 2=WB, 3=UWB), channels-1 (1=mono, 2=stereo) and the quality setting (0 to 10).

Constructor Summary

PcmWaveWriter()
Constructor.

PcmWaveWriter(int sampleRate, int channels)
Constructor.

PcmWaveWriter(int mode, int quality, int sampleRate, int channels, int nframes, boolean vbr)
Constructor.

Method Summary

private static int	calculateBlockSize(int mode, int channels, int quality) Calculates block size (considering padding).
private static int	calculateEffectiveBitrate(int mode, int channels, int quality) Calculates effective bitrate (considering padding).
void	close() Closes the output file.
void	open(java.io.File file) Open the output file.
void	open(java.lang.String filename) Open the output file.
private void	setPCMFormat(int sampleRate, int channels) Sets the output format for a PCM Wave file.
private void	setSpeexFormat(int mode, int quality, int sampleRate, int channels, int nframes, boolean vbr) Sets the output format for a Speex Wave file.
void	writeHeader(java.lang.String comment) Writes the initial data chunks that start the wave file.
void	writePacket(byte[] data, int offset, int len) Writes a packet of audio.

Methods inherited from class org.xiph.speex.AudioFileWriter

buildOggPageHeader, buildSpeexComment, buildSpeexHeader, writeInt, writeInt, writeInt, writeLong, writeLong, writeOggPageHeader, writeShort, writeShort, writeShort, writeSpeexComment, writeSpeexHeader, writeString

Methods inherited from class java.lang.Object

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

Field Detail

WAVE_FORMAT_PCM

public static final short WAVE_FORMAT_PCM

Wave type code of PCM

See Also:

Constant Field Values

WAVE_FORMAT_SPEEX

public static final short WAVE_FORMAT_SPEEX

Wave type code of Speex

See Also:

Constant Field Values

WAVE_FRAME_SIZES

public static final int[][][] WAVE_FRAME_SIZES

Table describing the number of frames per packet in a Speex Wave file, depending on its mode-1 (1=NB, 2=WB, 3=UWB), channels-1 (1=mono, 2=stereo) and the quality setting (0 to 10). See end of file for exerpt from SpeexACM code for more explanations.

WAVE_BITS_PER_FRAME

public static final int[][][] WAVE_BITS_PER_FRAME

Table describing the number of bit per Speex frame, depending on its mode-1 (1=NB, 2=WB, 3=UWB), channels-1 (1=mono, 2=stereo) and the quality setting (0 to 10). See end of file for exerpt from SpeexACM code for more explanations.

raf

private java.io.RandomAccessFile raf

mode

private int mode

Defines the encoder mode (0=NB, 1=WB and 2-UWB).

quality

private int quality

sampleRate

private int sampleRate

Defines the sampling rate of the audio input.

channels

private int channels

Defines the number of channels of the audio input (1=mono, 2=stereo).

nframes

private int nframes

Defines the number of frames per speex packet.

vbr

private boolean vbr

Defines whether or not to use VBR (Variable Bit Rate).

size

private int size

isPCM

private boolean isPCM

Constructor Detail

PcmWaveWriter

public PcmWaveWriter()

Constructor.

PcmWaveWriter

public PcmWaveWriter(int sampleRate,
                     int channels)

Constructor.

Parameters:

sampleRate - the number of samples per second.

channels - the number of audio channels (1=mono, 2=stereo, ...).

PcmWaveWriter

public PcmWaveWriter(int mode,
                     int quality,
                     int sampleRate,
                     int channels,
                     int nframes,
                     boolean vbr)

Constructor.

Parameters:

mode - the mode of the encoder (0=NB, 1=WB, 2=UWB).

quality -

sampleRate - the number of samples per second.

channels - the number of audio channels (1=mono, 2=stereo, ...).

nframes - the number of frames per speex packet.

vbr -

Method Detail

setPCMFormat

private void setPCMFormat(int sampleRate,
                          int channels)

Sets the output format for a PCM Wave file. Must be called before WriteHeader().

Parameters:

sampleRate - the number of samples per second.

channels - the number of audio channels (1=mono, 2=stereo, ...).

setSpeexFormat

private void setSpeexFormat(int mode,
                            int quality,
                            int sampleRate,
                            int channels,
                            int nframes,
                            boolean vbr)

Sets the output format for a Speex Wave file. Must be called before WriteHeader().

Parameters:

mode - the mode of the encoder (0=NB, 1=WB, 2=UWB).

quality -

sampleRate - the number of samples per second.

channels - the number of audio channels (1=mono, 2=stereo, ...).

nframes - the number of frames per speex packet.

vbr -

close

public void close()
           throws java.io.IOException

Closes the output file. MUST be called to have a correct stream.

Specified by:

close in class AudioFileWriter

Throws:

java.io.IOException - if there was an exception closing the Audio Writer.

open

public void open(java.io.File file)
          throws java.io.IOException

Open the output file.

Specified by:

open in class AudioFileWriter

Parameters:

file - - file to open.

Throws:

java.io.IOException - if there was an exception opening the Audio Writer.

open

public void open(java.lang.String filename)
          throws java.io.IOException

Open the output file.

Specified by:

open in class AudioFileWriter

Parameters:

filename - filename to open.

Throws:

java.io.IOException - if there was an exception opening the Audio Writer.

writeHeader

public void writeHeader(java.lang.String comment)
                 throws java.io.IOException

Writes the initial data chunks that start the wave file. Prepares file for data samples to written.

Specified by:

writeHeader in class AudioFileWriter

Parameters:

comment - ignored by the WAV header.

Throws:

java.io.IOException

writePacket

public void writePacket(byte[] data,
                        int offset,
                        int len)
                 throws java.io.IOException

Writes a packet of audio.

Specified by:

writePacket in class AudioFileWriter

Parameters:

data - audio data

offset - the offset from which to start reading the data.

len - the length of data to read.

Throws:

java.io.IOException

calculateEffectiveBitrate

private static final int calculateEffectiveBitrate(int mode,
                                                   int channels,
                                                   int quality)

Calculates effective bitrate (considering padding). See end of file for exerpt from SpeexACM code for more explanations.

Parameters:

mode -

channels -

quality -

Returns:

effective bitrate (considering padding).

calculateBlockSize

private static final int calculateBlockSize(int mode,
                                            int channels,
                                            int quality)

Calculates block size (considering padding). See end of file for exerpt from SpeexACM code for more explanations.

Parameters:

mode -

channels -

quality -

Returns:

block size (considering padding).