org.deepsymmetry.beatlink

Class Beat

java.lang.Object

org.deepsymmetry.beatlink.DeviceUpdate

org.deepsymmetry.beatlink.Beat

public class Beat
extends DeviceUpdate

A device update that announces the start of a new beat on a DJ Link network. Even though beats contain far less detailed information than status updates, they can be passed to VirtualCdj.getLatestStatusFor(DeviceUpdate) to find the current detailed status for that device, as long as the Virtual CDJ is active.

Author:

James Elliott

Constructor Summary

Constructors

Constructor and Description
Beat(DatagramPacket packet) Constructor sets all the immutable interpreted fields based on the packet content.

Method Summary

Modifier and Type	Method and Description
int	getBeatWithinBar() Get the position within a measure of music at which this beat falls (a value from 1 to 4, where 1 represents the down beat).
int	getBpm() Get the track BPM at the time of the beat.
double	getEffectiveTempo() Get the effective tempo reflected by this update, which reflects both its track BPM and pitch as needed.
int	getPitch() Get the device pitch at the time of the beat.
boolean	isBeatWithinBarMeaningful() Returns true if this beat is coming from a device where getBeatWithinBar() can reasonably be expected to have musical significance, because it respects the way a track was configured within rekordbox.
boolean	isTempoMaster() Was this beat sent by the current tempo master?
String	toString()

Methods inherited from class org.deepsymmetry.beatlink.DeviceUpdate

getAddress, getDeviceName, getDeviceNumber, getPacketBytes, getTimestamp

Methods inherited from class java.lang.Object

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

Constructor Detail

Beat

public Beat(DatagramPacket packet)

Constructor sets all the immutable interpreted fields based on the packet content.

Parameters:

packet - the beat announcement packet that was received

Method Detail

getPitch

public int getPitch()

Get the device pitch at the time of the beat. This is an integer ranging from 0 to 2097152, which corresponds to a range between completely stopping playback to playing at twice normal tempo. The equivalent percentage value can be obtained by passing the pitch to Util.pitchToPercentage(long), and the corresponding fractional scaling value by passing it to Util.pitchToMultiplier(long).

Specified by:

getPitch in class DeviceUpdate

Returns:

the raw device pitch

getBpm

public int getBpm()

Get the track BPM at the time of the beat. This is an integer representing the BPM times 100, so a track running at 120.5 BPM would be represented by the value 12050.

Specified by:

getBpm in class DeviceUpdate

Returns:

the track BPM to two decimal places multiplied by 100

getBeatWithinBar

public int getBeatWithinBar()

Get the position within a measure of music at which this beat falls (a value from 1 to 4, where 1 represents the down beat). This value will be accurate for players when the track was properly configured within rekordbox (and if the music follows a standard House 4/4 time signature). The mixer makes no effort to synchronize down beats with players, however, so this value is meaningless when coming from the mixer.

Specified by:

getBeatWithinBar in class DeviceUpdate

Returns:

the beat number within the current measure of music

isBeatWithinBarMeaningful

public boolean isBeatWithinBarMeaningful()

Returns true if this beat is coming from a device where getBeatWithinBar() can reasonably be expected to have musical significance, because it respects the way a track was configured within rekordbox.

If the VirtualCdj is running, we can check the latest status update received from this device to get a definitive answer. Otherwise we guess based on the device number; mixers seem to fall in the range 33 and up.

Specified by:

isBeatWithinBarMeaningful in class DeviceUpdate

Returns:

true for status packets from players, false for status packets from mixers

toString

public String toString()

Overrides:

toString in class DeviceUpdate

isTempoMaster

public boolean isTempoMaster()

Was this beat sent by the current tempo master?

Specified by:

isTempoMaster in class DeviceUpdate

Returns:

true if the device that sent this beat is the master

Throws:

IllegalStateException - if the VirtualCdj is not running.

getEffectiveTempo

public double getEffectiveTempo()

Description copied from class: DeviceUpdate

Get the effective tempo reflected by this update, which reflects both its track BPM and pitch as needed.

Specified by:

getEffectiveTempo in class DeviceUpdate

Returns:

the beats per minute this device is reporting