org.openimaj.audio.conversion

Class SampleRateConverter

java.lang.Object

org.openimaj.audio.Audio

org.openimaj.audio.AudioStream

org.openimaj.audio.processor.AudioProcessor

org.openimaj.audio.conversion.SampleRateConverter

All Implemented Interfaces:

Iterable<SampleChunk>

public class SampleRateConverter
extends AudioProcessor

A sample rate conversion audio processing class. There is an enumerator within the class that is publically available for determining the algorithm for sample rate conversion. This defaults to SampleRateConverter.SampleRateConversionAlgorithm.LINEAR_INTERPOLATION.

To use the class, instantiate using the default constructor or the chainable constructor. Both of these constructors take the algorithm for sample rate conversion as well as the output format. The output format must have the same number of bits and same number of channels as the expected input otherwise the process(SampleChunk) method will throw IllegalArgumentException. The input format for the samples is expected to be provided as part of the SampleChunk.

The class itself checks whether the output format and the input format are the same (in which case the sample does not need to be resampled). That means the algorithm implementation does not need to do this.

Author:

David Dupplaw (dpd@ecs.soton.ac.uk)

Created:

18 Jun 2012

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SampleRateConverter.SampleRateConversionAlgorithm An enumerator of the different sample rate conversion algorithms available in this sample rate converter.

Field Summary

Fields inherited from class org.openimaj.audio.Audio

format

Constructor Summary

Constructors

Constructor and Description
SampleRateConverter(AudioStream as, SampleRateConverter.SampleRateConversionAlgorithm converter, AudioFormat outputFormat) Chainable constructor.
SampleRateConverter(SampleRateConverter.SampleRateConversionAlgorithm converter, AudioFormat outputFormat) Default constructor that takes the input conversion

Method Summary

Modifier and Type	Method and Description
SampleChunk	process(SampleChunk sample) Function that takes a sample chunk and processes the chunk.

Methods inherited from class org.openimaj.audio.processor.AudioProcessor

getLength, getUnderlyingStream, nextSampleChunk, process, processingComplete, reset, setUnderlyingStream

Methods inherited from class org.openimaj.audio.AudioStream

iterator, seek

Methods inherited from class org.openimaj.audio.Audio

getFormat, setFormat

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

SampleRateConverter

public SampleRateConverter(SampleRateConverter.SampleRateConversionAlgorithm converter,
                           AudioFormat outputFormat)

Default constructor that takes the input conversion

Parameters:

converter - The converter to use

outputFormat - The output format to convert to

SampleRateConverter

public SampleRateConverter(AudioStream as,
                           SampleRateConverter.SampleRateConversionAlgorithm converter,
                           AudioFormat outputFormat)

Chainable constructor.

Parameters:

as - The audio stream to process

converter - The converter to use

outputFormat - The output format to convert to

Method Detail

process

public SampleChunk process(SampleChunk sample)
                    throws Exception

Function that takes a sample chunk and processes the chunk. It should also return a sample chunk containing the processed data. If wished, the chunk may be side-affected and the input chunk returned. It should not be assumed that the input chunk will be side-affected, but it must be noted that it is possible that it could be. This process function may also return null. If null is returned it means that the rest of the audio stream is not required to be processed by this processing function. Whether the rest of the sample chunks are copied or ignored is up to the caller.

Specified by:

process in class AudioProcessor

Parameters:

sample - The sample chunk to process.

Returns:

A sample chunk containing processed data.

Throws:

Exception - If the processing could not take place

See Also:

AudioProcessor.process(org.openimaj.audio.SampleChunk)