edu.cmu.sphinx.frontend.util

Class StreamDataSource

java.lang.Object

edu.cmu.sphinx.util.props.ConfigurableAdapter

edu.cmu.sphinx.frontend.BaseDataProcessor

edu.cmu.sphinx.frontend.util.StreamDataSource

All Implemented Interfaces:

DataProcessor, Configurable

Direct Known Subclasses:

ConcatFileDataSource

public class StreamDataSource
extends BaseDataProcessor

A StreamDataSource converts data from an InputStream into Data objects. One would call setInputStream to set the input stream, and call getData() to obtain the Data object. The InputStream can be an arbitrary stream, for example a data from the network or from a pipe. StreamDataSource is not aware about incoming data format and assumes that incoming data matches StreamDataSource configuration. By default it's configured to read 16 kHz little-endian 16-bit signed raw data. If data has wrong format the result of the recognition is undefined. Also note that the sample rate of the data must match the sample required by the the acoustic model. If your model decodes 16 kHz files you can't recognize 8kHz data using it. You can use AudioFileDataSource instead to read the file headers and to convert incoming data to the required format automatically.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	bitsPerSample
static java.lang.String	PROP_BIG_ENDIAN_DATA The property specifying whether the input data is big-endian.
static java.lang.String	PROP_BITS_PER_SAMPLE The property for the number of bits per value.
static java.lang.String	PROP_BYTES_PER_READ The property for the number of bytes to read from the InputStream each time.
static java.lang.String	PROP_SAMPLE_RATE The property for the sample rate.
static java.lang.String	PROP_SIGNED_DATA The property specifying whether the input data is signed.
protected int	sampleRate

Fields inherited from class edu.cmu.sphinx.util.props.ConfigurableAdapter

logger

Constructor Summary

Constructors

Constructor and Description
StreamDataSource()
StreamDataSource(int sampleRate, int bytesPerRead, int bitsPerSample, boolean bigEndian, boolean signedData)

Method Summary

Modifier and Type	Method and Description
Data	getData() Reads and returns the next Data from the InputStream of StreamDataSource, return null if no data is read and end of file is reached.
void	initialize() Initializes this DataProcessor.
void	newProperties(PropertySheet ps) This method is called when this configurable component needs to be reconfigured.
void	setInputStream(java.io.InputStream inputStream)
void	setInputStream(java.io.InputStream inputStream, TimeFrame timeFrame) Sets the InputStream from which this StreamDataSource reads.

Methods inherited from class edu.cmu.sphinx.frontend.BaseDataProcessor

getPredecessor, setPredecessor

Methods inherited from class edu.cmu.sphinx.util.props.ConfigurableAdapter

getName, initLogger, toString

Methods inherited from class java.lang.Object

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

Field Detail

PROP_SAMPLE_RATE

@S4Integer(defaultValue=16000)
public static final java.lang.String PROP_SAMPLE_RATE

The property for the sample rate.

See Also:

Constant Field Values

PROP_BYTES_PER_READ

@S4Integer(defaultValue=3200)
public static final java.lang.String PROP_BYTES_PER_READ

The property for the number of bytes to read from the InputStream each time.

See Also:

Constant Field Values

PROP_BITS_PER_SAMPLE

@S4Integer(defaultValue=16)
public static final java.lang.String PROP_BITS_PER_SAMPLE

The property for the number of bits per value.

See Also:

Constant Field Values

PROP_BIG_ENDIAN_DATA

@S4Boolean(defaultValue=false)
public static final java.lang.String PROP_BIG_ENDIAN_DATA

The property specifying whether the input data is big-endian.

See Also:

Constant Field Values

PROP_SIGNED_DATA

@S4Boolean(defaultValue=true)
public static final java.lang.String PROP_SIGNED_DATA

The property specifying whether the input data is signed.

See Also:

Constant Field Values

sampleRate

protected int sampleRate

bitsPerSample

protected int bitsPerSample

Constructor Detail

StreamDataSource

public StreamDataSource(int sampleRate,
                        int bytesPerRead,
                        int bitsPerSample,
                        boolean bigEndian,
                        boolean signedData)

StreamDataSource

public StreamDataSource()

Method Detail

newProperties

public void newProperties(PropertySheet ps)
                   throws PropertyException

Description copied from interface: Configurable

This method is called when this configurable component needs to be reconfigured.

Specified by:

newProperties in interface Configurable

Overrides:

newProperties in class ConfigurableAdapter

Parameters:

ps - a property sheet holding the new data

Throws:

PropertyException - if there is a problem with the properties.

initialize

public void initialize()

Description copied from class: BaseDataProcessor

Initializes this DataProcessor. This is typically called after the DataProcessor has been configured.

Specified by:

initialize in interface DataProcessor

Overrides:

initialize in class BaseDataProcessor

setInputStream

public void setInputStream(java.io.InputStream inputStream)

setInputStream

public void setInputStream(java.io.InputStream inputStream,
                           TimeFrame timeFrame)

Sets the InputStream from which this StreamDataSource reads.

Parameters:

inputStream - the InputStream from which audio data comes

timeFrame - time frame to process

getData

public Data getData()
             throws DataProcessingException

Reads and returns the next Data from the InputStream of StreamDataSource, return null if no data is read and end of file is reached.

Specified by:

getData in interface DataProcessor

Specified by:

getData in class BaseDataProcessor

Returns:

the next Data or null if none is available

Throws:

DataProcessingException - if there is a data processing error