org.deepsymmetry.beatlink.data

Class WaveformPreview

java.lang.Object

org.deepsymmetry.beatlink.data.WaveformPreview

public class WaveformPreview
extends Object

Gives a birds-eye view of the audio content of a track, and offers a Swing component for rendering that view as part of a user interface, along with annotations showing the current playback position and cue points, if the appropriate metadata is available.

Author:

James Elliott

Field Summary

Fields

Modifier and Type	Field and Description
DataReference	dataReference The unique identifier that was used to request this waveform preview.
static Color	INTENSE_COLOR The color at which segments of the blue waveform marked most intense are drawn.
boolean	isColor Indicates whether this is an NXS2-style color waveform, or a monochrome (blue) waveform.
static int	LEADING_DBSERVER_COLOR_JUNK_BYTES The number of bytes at the start of the color waveform data to be skipped when that was loaded using the nxs2 ANLZ tag request.
int	maxHeight Holds the maximum height of any point along the waveform, so that it can drawn in a normalized manner to fit its display area.
static Color	NORMAL_COLOR The color at which non-intense blue waveform segments are drawn.
Message	rawMessage The message holding the preview as it was read over the network, if it came from the dbserver.
int	segmentCount The pixel width (number of waveform preview columns) available.

Constructor Summary

Constructors

Constructor and Description
WaveformPreview(DataReference reference, ByteBuffer data, boolean isColor) Constructor when creating from an external caching mechanism.
WaveformPreview(DataReference reference, org.deepsymmetry.cratedigger.pdb.RekordboxAnlz anlzFile) Constructor when received from Crate Digger.

Method Summary

Modifier and Type	Method and Description
JComponent	createViewComponent(TrackMetadata metadata) Create a standard Swing component which can be added to a user interface that will draw this waveform preview, optionally including annotations like the current playback position and minute markers (if you supply TrackMetadata so the total length can be determined), and cue markers (if you also supply a CueList).
ByteBuffer	getData() Get the raw bytes of the waveform preview data
Color	segmentColor(int segment, boolean front) Determine the color of the waveform given an index into it.
int	segmentHeight(int segment, boolean front) Determine the height of the preview given an index into it.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

LEADING_DBSERVER_COLOR_JUNK_BYTES

public static final int LEADING_DBSERVER_COLOR_JUNK_BYTES

The number of bytes at the start of the color waveform data to be skipped when that was loaded using the nxs2 ANLZ tag request. We actually know what these mean, now that we know how to parse EXT files, but we can simply skip them anyway.

See Also:

Constant Field Values

dataReference

public final DataReference dataReference

The unique identifier that was used to request this waveform preview.

rawMessage

public final Message rawMessage

The message holding the preview as it was read over the network, if it came from the dbserver. This can be used to analyze fields that have not yet been reliably understood, and is also used for storing the cue list in a cache file.

isColor

public final boolean isColor

Indicates whether this is an NXS2-style color waveform, or a monochrome (blue) waveform.

segmentCount

public final int segmentCount

The pixel width (number of waveform preview columns) available.

maxHeight

public final int maxHeight

Holds the maximum height of any point along the waveform, so that it can drawn in a normalized manner to fit its display area.

INTENSE_COLOR

public static final Color INTENSE_COLOR

The color at which segments of the blue waveform marked most intense are drawn.

NORMAL_COLOR

public static final Color NORMAL_COLOR

The color at which non-intense blue waveform segments are drawn.

Constructor Detail

WaveformPreview

public WaveformPreview(DataReference reference,
                       org.deepsymmetry.cratedigger.pdb.RekordboxAnlz anlzFile)

Constructor when received from Crate Digger.

Parameters:

reference - the unique database reference that was used to request this waveform preview

anlzFile - the parsed rekordbox track analysis file containing the waveform preview

WaveformPreview

public WaveformPreview(DataReference reference,
                       ByteBuffer data,
                       boolean isColor)

Constructor when creating from an external caching mechanism.

Parameters:

reference - the unique database reference that was used to request this waveform preview

data - the expanded data as will be returned by getData()

isColor - indicates whether the data represents a color preview

Method Detail

getData

public ByteBuffer getData()

Get the raw bytes of the waveform preview data

Returns:

the bytes from which the preview can be drawn, as described in Section 5.8 of the Packet Analysis document.

createViewComponent

public JComponent createViewComponent(TrackMetadata metadata)

Create a standard Swing component which can be added to a user interface that will draw this waveform preview, optionally including annotations like the current playback position and minute markers (if you supply TrackMetadata so the total length can be determined), and cue markers (if you also supply a CueList). The playback position can be

Parameters:

metadata - Information about the track whose waveform we are drawing, so we can translate times into positions

Returns:

the component which will draw the annotated waveform preview

segmentHeight

public int segmentHeight(int segment,
                         boolean front)

Determine the height of the preview given an index into it.

Parameters:

segment - the index of the waveform preview segment to examine

front - if true the height of the front (brighter) segment of a color waveform preview is returned, otherwise the height of the back (dimmer) segment is returned. Has no effect for blue previews.

Returns:

a value from 0 to 31 representing the height of the waveform at that segment, which may be an average of a number of values starting there, determined by the scale

segmentColor

public Color segmentColor(int segment,
                          boolean front)

Determine the color of the waveform given an index into it.

Parameters:

segment - the index of the first waveform byte to examine

front - if true the front (brighter) segment of a color waveform preview is returned, otherwise the back (dimmer) segment is returned. Has no effect for blue previews.

Returns:

the color of the waveform at that segment, which may be based on an average of a number of values starting there, determined by the scale

toString

public String toString()

Overrides:

toString in class Object