org.openimaj.audio.analysis

Class PeakNormalisationCalculator

java.lang.Object

org.openimaj.audio.Audio

org.openimaj.audio.AudioStream

org.openimaj.audio.processor.AudioProcessor

org.openimaj.audio.analysis.PeakNormalisationCalculator

All Implemented Interfaces:

Iterable<SampleChunk>

public class PeakNormalisationCalculator
extends AudioProcessor

Calculates the scalar necessary to achieve peak value of the loudest part of the given input signal. This scalar can be retrieved using the getVolumeScalar() method which will return the scalar as it has currently been calculated for the stream which has passed. This will only return the correct value for the whole audio stream once the whole audio stream has passed through the processor. This processor will not perform attenuation - that is, the volume scalar will always be greater than 1 (and positive).

The value of the peak volume scalar is compatible with the VolumeAdjustProcessor which can adjust the volume to the maximum peak value.

Version:

$Author$, $Revision$, $Date$

Author:

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

Created:

10 Dec 2012

Field Summary

Fields inherited from class org.openimaj.audio.Audio

format

Constructor Summary

Constructors

Constructor and Description
PeakNormalisationCalculator()

Method Summary

Modifier and Type	Method and Description
float	getVolumeScalar() Returns the calculated peak scalar as it currently stands in the stream.
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

PeakNormalisationCalculator

public PeakNormalisationCalculator()

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)

getVolumeScalar

public float getVolumeScalar()

Returns the calculated peak scalar as it currently stands in the stream. If no audio has passed through the processor, this will return Float.MAX_VALUE otherwise the value will always be positive and greater than 1.

Returns:

The calculated peak scalar.