com.groovemanager.sampled.waveform
Class PeakWaveForm

java.lang.Object
  com.groovemanager.sampled.waveform.AbstractWaveForm
      com.groovemanager.sampled.waveform.PeakWaveForm

All Implemented Interfaces:

WaveForm

Direct Known Subclasses:

DynamicPeakWaveForm

public class PeakWaveForm

extends AbstractWaveForm

A PeakWaveForm is a WaveForm that gets its data out of a number of peak values that have been created once for a file. Each peak value represents a number of sample frames in the original file and consists of a maximum and a minimum value for each cahnnel. Mostly this peak data is stored in a peak file, that is assigned to an audio file by giving it the name of the original file with an added ".gmpk" extension. The file myfile.wav.gmpk is for example the peak file of the file myfile.wav in the same directory.
A PeakWaveForm can also be created out of another WaveForm. In this case, the peak values are created when they are first needed and then stored in memory.

Author:

Manu Robledo

Field Summary

protected byte[]	data The peak data
static java.lang.String	DEFAULT_PEAKFILE_EXTENSION The default extension for peak files
protected WaveForm	source PeakWaveForms can also be created on the fly from a source WaveForm.

Fields inherited from class com.groovemanager.sampled.waveform.AbstractWaveForm

channels, displayWidth, intervallSize, nullWave, position, realLength

Constructor Summary

	PeakWaveForm(byte[] data) Construct a new PeakWaveForm out of the given peak data.
	PeakWaveForm(java.io.File peakFile) Create a new PeakWaveForm out of the given peak file
private	PeakWaveForm(WaveForm source, int newWidth) Private Constructor to be used from getPeak().

Method Summary

static boolean	checkPeakFile(java.io.File f, java.io.File p) Check, if the given peak file is a valid peak file for the given audio file.
static PeakWaveForm	createPeakWaveForm(java.io.File source, org.eclipse.swt.widgets.Shell shell) Get a PeakWaveForm for the given audio file.
protected java.lang.String	getAdditionalToString() Get an additional String describing this WaveForm.
byte[]	getData() Get the whole Peak data as array.
static byte[]	getHeader(int iSize, long lastModified, long realLength, short channels, int snapshots) Create a valid peak file header out of the given data
byte	getMax(int channel) Get the maximum value at the current read position in the given channel
byte	getMin(int channel) Get the minimum value at the current read position in the given channel
static WaveForm	getPeak(WaveForm source, int newWidth, int iSize) Get a PeakWaveForm for the given WaveForm
protected void	readFromFile(java.io.File peakFile) Read the peak data from the given file
WaveForm	subWaveForm(int begin, int length, int width) Get a WaveForm Object that represents the part of this WaveForm specified by begin and length and displays this part in the specified width
static void	writeToStream(WaveForm source, java.io.OutputStream out, long lastModified, int iSize) Write the given source WaveForm as a peak file into a given output.

Methods inherited from class com.groovemanager.sampled.waveform.AbstractWaveForm

canProvide, getChannels, getDisplayableLength, getIntervallSize, getPosition, getRealLength, getRealPosition, getZoomFactor, next, rewind, setPosition, setRealPosition, toString

Methods inherited from class java.lang.Object

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

Field Detail

data

protected byte[] data

The peak data

DEFAULT_PEAKFILE_EXTENSION

public static final java.lang.String DEFAULT_PEAKFILE_EXTENSION

The default extension for peak files

See Also:

Constant Field Values

source

protected WaveForm source

PeakWaveForms can also be created on the fly from a source WaveForm. If this PeakWaveForm has been created in this way, the source WaveForm is stored in this variable

Constructor Detail

PeakWaveForm

public PeakWaveForm(byte[] data)

Construct a new PeakWaveForm out of the given peak data. The first 34 bytes of the data must be a valid peak file header.

Parameters:

data - The peak data

PeakWaveForm

public PeakWaveForm(java.io.File peakFile)
             throws java.io.IOException

Create a new PeakWaveForm out of the given peak file

Parameters:

peakFile - The peak file containing the peak data

Throws:

java.io.IOException - If an I/O Error occured during reading

PeakWaveForm

private PeakWaveForm(WaveForm source,
                     int newWidth)

Private Constructor to be used from getPeak().

Parameters:

source - The source WaveForm

newWidth - The width of the WaveForm to create

Method Detail

checkPeakFile

public static boolean checkPeakFile(java.io.File f,
                                    java.io.File p)

Check, if the given peak file is a valid peak file for the given audio file.

Parameters:

f - The audio file

p - The peak file

Returns:

true, if
- both files exists,
- the peak file´s header data matches the properties of the audio file and
- the peak file´s length matches the peak file´s header data,
false otherwise

createPeakWaveForm

public static PeakWaveForm createPeakWaveForm(java.io.File source,
                                              org.eclipse.swt.widgets.Shell shell)
                                       throws javax.sound.sampled.UnsupportedAudioFileException,
                                              NotFinishedException,
                                              java.io.IOException

Get a PeakWaveForm for the given audio file. If a peak file for this file can be found and if it is a valif peak file, it will be used. Otherwise a peak file for the given audio file will be created and a ProgressMonitor will be shown during the operation.
The peak file for a given audio file will be located in the same directory as the source file and will have the source file´s file name with an additional ".gmpk" extension. If no peak file is found and no peak file can be written to this filename, a temporary file is created in the temp directory.

Parameters:

source - The audio file to create the peak file for

shell - The parent Shell, under which the ProgressMonitor should be opened

Returns:

The PeakWaveForm for the given audio file

Throws:

javax.sound.sampled.UnsupportedAudioFileException - If the audio file´s format cannot be read

NotFinishedException - If no valid peak file was found and the operation for creating it didn´t finish correctly.

java.io.IOException - If an I/O Error occured

getAdditionalToString

protected java.lang.String getAdditionalToString()

Description copied from class: AbstractWaveForm

Get an additional String describing this WaveForm. Will be used in toString()

Overrides:

getAdditionalToString in class AbstractWaveForm

Returns:

An optional String describing special characteristics of this WaveForm

getData

public byte[] getData()

Description copied from interface: WaveForm

Get the whole Peak data as array. This method could take very long for WaveForms which don't store their data in such an array. Should be very fast for peak Wave Forms.

Specified by:

getData in interface WaveForm

Overrides:

getData in class AbstractWaveForm

Returns:

The Peak Data as byte-Array.

See Also:

WaveForm.getData()

getHeader

public static byte[] getHeader(int iSize,
                               long lastModified,
                               long realLength,
                               short channels,
                               int snapshots)

Create a valid peak file header out of the given data

Parameters:

iSize - The interval size

lastModified - The last modification date of the audio file represented by this peak file or -1, if it is not known

realLength - The length of the audio data in the audio file in sample frames

channels - The number of channels of the audio file

snapshots - The number of peak values (snapshots) contained in this peak file

Returns:

A byte-Array of length 34 containing the header data for the peak file

getMax

public byte getMax(int channel)

Description copied from interface: WaveForm

Get the maximum value at the current read position in the given channel

Parameters:

channel - the zero-based index of the channel

Returns:

the maximum value at this position as byte

getMin

public byte getMin(int channel)

Description copied from interface: WaveForm

Get the minimum value at the current read position in the given channel

Parameters:

channel - the zero-based index of the channel

Returns:

the minimum value at this position as byte

getPeak

public static WaveForm getPeak(WaveForm source,
                               int newWidth,
                               int iSize)

Get a PeakWaveForm for the given WaveForm

Parameters:

source - The WaveForm to get a PeakWaveForm for.

newWidth - The width of the new PeakWaveForm

iSize - The interval size to use for the new PeakWaveForm

Returns:

A PeakWaveForm with the given interval size and the given width or the given source WaveForm, if no PeakWaveForm is needed for the desired width.

readFromFile

protected void readFromFile(java.io.File peakFile)
                     throws java.io.IOException

Read the peak data from the given file

Parameters:

peakFile - The file to read from

Throws:

java.io.IOException - If an I/O Error occured during reading

subWaveForm

public WaveForm subWaveForm(int begin,
                            int length,
                            int width)

Description copied from interface: WaveForm

Get a WaveForm Object that represents the part of this WaveForm specified by begin and length and displays this part in the specified width

Specified by:

subWaveForm in interface WaveForm

Overrides:

subWaveForm in class AbstractWaveForm

Parameters:

begin - The offset to the beginning of this WaveForm. May also be negative.

length - The length in steps of this WaveForm that should be represented by the returned WaveForm.

width - The new width in which the part should be displayed.

Returns:

A WaveForm Object that represents the specified Part of this WaveForm and displays it in the given width. Can also be the same Object with adapted attributes

See Also:

WaveForm.subWaveForm(int, int, int)

writeToStream

public static void writeToStream(WaveForm source,
                                 java.io.OutputStream out,
                                 long lastModified,
                                 int iSize)
                          throws java.io.IOException

Write the given source WaveForm as a peak file into a given output. The peak header will also be written.

Parameters:

source - The WaveForm to get the peak data from

out - The OutputStream to write the data to

lastModified - The last modification date of the audio file this peak data belongs to or -1, if it is not known

iSize - The interval size of the WabeForm

Throws:

java.io.IOException - If an I/O Error occurs during writing