org.deepsymmetry.beatlink

Class DeviceUpdate

java.lang.Object

org.deepsymmetry.beatlink.DeviceUpdate

Direct Known Subclasses:

Beat, CdjStatus, MixerStatus

public abstract class DeviceUpdate
extends Object

Represents a device status update seen on a DJ Link network.

Author:

James Elliott

Constructor Summary

Constructors

Constructor and Description
DeviceUpdate(DatagramPacket packet, String name, int length) Constructor sets all the immutable interpreted fields based on the packet content.

Method Summary

Modifier and Type	Method and Description
InetAddress	getAddress() Get the address of the device from which this update was seen.
abstract int	getBeatWithinBar() Get the position within a measure of music at which the most recent beat fell (a value from 1 to 4, where 1 represents the down beat).
abstract int	getBpm() Get the playback BPM at the time of the update.
String	getDeviceName() Get the name reported by the device sending the update.
int	getDeviceNumber() Get the player/device number reporting the update.
abstract double	getEffectiveTempo() Get the effective tempo reflected by this update, which reflects both its track BPM and pitch as needed.
byte[]	getPacketBytes() Get the raw data bytes of the device update packet.
abstract int	getPitch() Get the device pitch at the time of the update.
long	getTimestamp() Get the timestamp recording when the device update was received.
abstract boolean	isBeatWithinBarMeaningful() Returns true if this update 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.
abstract boolean	isTempoMaster() Is this device reporting itself to be the current tempo master?
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

DeviceUpdate

public DeviceUpdate(DatagramPacket packet,
                    String name,
                    int length)

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

Parameters:

packet - the device update packet that was received

name - the type of packet that is being processed, in case a problem needs to be reported

length - the expected length of the packet

Method Detail

getAddress

public InetAddress getAddress()

Get the address of the device from which this update was seen.

Returns:

the network address from which the update was sent

getTimestamp

public long getTimestamp()

Get the timestamp recording when the device update was received.

Returns:

the nanosecond timestamp at which we received this update

getDeviceName

public String getDeviceName()

Get the name reported by the device sending the update.

Returns:

the device name

getDeviceNumber

public int getDeviceNumber()

Get the player/device number reporting the update.

Returns:

the player number found in the update packet

getPacketBytes

public byte[] getPacketBytes()

Get the raw data bytes of the device update packet.

Returns:

the data sent by the device to update its status

getPitch

public abstract int getPitch()

Get the device pitch at the time of the update. 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). Mixers always report a pitch of +0%, so tempo changes are purely reflected in the BPM value.

Returns:

the raw effective device pitch at the time of the update

getBpm

public abstract int getBpm()

Get the playback BPM at the time of the update. This is an integer representing the BPM times 100, so a track running at 120.5 BPM would be represented by the value 12050. Mixers always report a pitch of +0%, so tempo changes are purely reflected in the BPM value.

When the CDJ has just started up and no track has been loaded, it will report a BPM of 65535.

Returns:

the track BPM to two decimal places multiplied by 100

isTempoMaster

public abstract boolean isTempoMaster()

Is this device reporting itself to be the current tempo master?

Returns:

true if the device that sent this update is the master

Throws:

IllegalStateException - if the VirtualCdj is not running.

getEffectiveTempo

public abstract double getEffectiveTempo()

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

Returns:

the beats per minute this device is reporting

getBeatWithinBar

public abstract int getBeatWithinBar()

Get the position within a measure of music at which the most recent beat fell (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. The usefulness of this value can be checked with isBeatWithinBarMeaningful().

Returns:

the beat number within the current measure of music

isBeatWithinBarMeaningful

public abstract boolean isBeatWithinBarMeaningful()

Returns true if this update 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.

Returns:

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

toString

public String toString()

Overrides:

toString in class Object