MidiBuffer Class Reference

Holds a sequence of time-stamped midi events. More...

Public Member Functions
	MidiBuffer () noexcept=default
	Creates an empty MidiBuffer.
	MidiBuffer (const MidiMessage &message) noexcept
	Creates a MidiBuffer containing a single midi message.
void	clear () noexcept
	Removes all events from the buffer.
void	clear (int start, int numSamples)
	Removes all events between two times from the buffer.
bool	isEmpty () const noexcept
	Returns true if the buffer is empty.
int	getNumEvents () const noexcept
	Counts the number of events in the buffer.
bool	addEvent (const MidiMessage &midiMessage, int sampleNumber)
	Adds an event to the buffer.
bool	addEvent (const void *rawMidiData, int maxBytesOfMidiData, int sampleNumber)
	Adds an event to the buffer from raw midi data.
void	addEvents (const MidiBuffer &otherBuffer, int startSample, int numSamples, int sampleDeltaToAdd)
	Adds some events from another buffer to this one.
int	getFirstEventTime () const noexcept
	Returns the sample number of the first event in the buffer.
int	getLastEventTime () const noexcept
	Returns the sample number of the last event in the buffer.
void	swapWith (MidiBuffer &) noexcept
	Exchanges the contents of this buffer with another one.
void	ensureSize (size_t minimumNumBytes)
	Preallocates some memory for the buffer to use.
MidiBufferIterator	begin () const noexcept
	Get a read-only iterator pointing to the beginning of this buffer.
MidiBufferIterator	end () const noexcept
	Get a read-only iterator pointing one past the end of this buffer.
MidiBufferIterator	cbegin () const noexcept
	Get a read-only iterator pointing to the beginning of this buffer.
MidiBufferIterator	cend () const noexcept
	Get a read-only iterator pointing one past the end of this buffer.
MidiBufferIterator	findNextSamplePosition (int samplePosition) const noexcept
	Get an iterator pointing to the first event with a timestamp greater-than or equal-to samplePosition.

Public Attributes
Array< uint8 >	data
	The raw data holding this buffer.

Detailed Description

Holds a sequence of time-stamped midi events.

Analogous to the AudioBuffer, this holds a set of midi events with integer time-stamps. The buffer is kept sorted in order of the time-stamps.

If you're working with a sequence of midi events that may need to be manipulated or read/written to a midi file, then MidiMessageSequence is probably a more appropriate container. MidiBuffer is designed for lower-level streams of raw midi data.

See also

MidiMessage

Constructor & Destructor Documentation

MidiBuffer() [1/2]

MidiBuffer::MidiBuffer ( )

defaultnoexcept

Creates an empty MidiBuffer.

Referenced by addEvents(), findNextSamplePosition(), MidiBuffer(), and swapWith().

MidiBuffer() [2/2]

MidiBuffer::MidiBuffer ( const MidiMessage & message )

explicitnoexcept

Creates a MidiBuffer containing a single midi message.

References MidiBuffer().

Member Function Documentation

clear() [1/2]

void MidiBuffer::clear ( )

noexcept

Removes all events from the buffer.

References clear().

Referenced by clear(), and clear().

clear() [2/2]

void MidiBuffer::clear	(	int	start,
		int	numSamples )

Removes all events between two times from the buffer.

All events for which (start <= event position < start + numSamples) will be removed.

References clear().

isEmpty()

bool MidiBuffer::isEmpty ( ) const

noexcept

Returns true if the buffer is empty.

To actually retrieve the events, use a MidiBufferIterator object

References isEmpty().

Referenced by isEmpty().

getNumEvents()

int MidiBuffer::getNumEvents ( ) const

noexcept

Counts the number of events in the buffer.

This is actually quite a slow operation, as it has to iterate through all the events, so you might prefer to call isEmpty() if that's all you need to know.

References getNumEvents().

Referenced by getNumEvents().

addEvent() [1/2]

bool MidiBuffer::addEvent	(	const MidiMessage &	midiMessage,
		int	sampleNumber )

Adds an event to the buffer.

The sample number will be used to determine the position of the event in the buffer, which is always kept sorted. The MidiMessage's timestamp is ignored.

If an event is added whose sample position is the same as one or more events already in the buffer, the new event will be placed after the existing ones.

To retrieve events, use a MidiBufferIterator object.

Returns true on success, or false on failure.

References addEvent().

Referenced by addEvent(), and addEvent().

addEvent() [2/2]

bool MidiBuffer::addEvent	(	const void *	rawMidiData,
		int	maxBytesOfMidiData,
		int	sampleNumber )

Adds an event to the buffer from raw midi data.

The sample number will be used to determine the position of the event in the buffer, which is always kept sorted.

If an event is added whose sample position is the same as one or more events already in the buffer, the new event will be placed after the existing ones.

The event data will be inspected to calculate the number of bytes in length that the midi event really takes up, so maxBytesOfMidiData may be longer than the data that actually gets stored. E.g. if you pass in a note-on and a length of 4 bytes, it'll actually only store 3 bytes. If the midi data is invalid, it might not add an event at all.

To retrieve events, use a MidiBufferIterator object.

Returns true on success, or false on failure.

References addEvent().

addEvents()

void MidiBuffer::addEvents	(	const MidiBuffer &	otherBuffer,
		int	startSample,
		int	numSamples,
		int	sampleDeltaToAdd )

Adds some events from another buffer to this one.

Parameters

otherBuffer	the buffer containing the events you want to add
startSample	the lowest sample number in the source buffer for which events should be added. Any source events whose timestamp is less than this will be ignored
numSamples	the valid range of samples from the source buffer for which events should be added - i.e. events in the source buffer whose timestamp is greater than or equal to (startSample + numSamples) will be ignored. If this value is less than 0, all events after startSample will be taken.
sampleDeltaToAdd	a value which will be added to the source timestamps of the events that are added to this buffer

References addEvents(), and MidiBuffer().

Referenced by addEvents().

getFirstEventTime()

int MidiBuffer::getFirstEventTime ( ) const

noexcept

Returns the sample number of the first event in the buffer.

If the buffer's empty, this will just return 0.

References getFirstEventTime().

Referenced by getFirstEventTime().

getLastEventTime()

int MidiBuffer::getLastEventTime ( ) const

noexcept

Returns the sample number of the last event in the buffer.

If the buffer's empty, this will just return 0.

References getLastEventTime().

Referenced by getLastEventTime().

swapWith()

void MidiBuffer::swapWith ( MidiBuffer & )

noexcept

Exchanges the contents of this buffer with another one.

This is a quick operation, because no memory allocating or copying is done, it just swaps the internal state of the two buffers.

References MidiBuffer(), and swapWith().

Referenced by swapWith().

ensureSize()

void MidiBuffer::ensureSize

(

size_t

minimumNumBytes

)

Preallocates some memory for the buffer to use.

This helps to avoid needing to reallocate space when the buffer has messages added to it.

References ensureSize().

Referenced by ensureSize().

begin()

MidiBufferIterator MidiBuffer::begin ( ) const

noexcept

Get a read-only iterator pointing to the beginning of this buffer.

References begin(), and cbegin().

Referenced by begin().

end()

MidiBufferIterator MidiBuffer::end ( ) const

noexcept

Get a read-only iterator pointing one past the end of this buffer.

References cend().

cbegin()

MidiBufferIterator MidiBuffer::cbegin ( ) const

noexcept

Get a read-only iterator pointing to the beginning of this buffer.

References data.

Referenced by begin().

cend()

MidiBufferIterator MidiBuffer::cend ( ) const

noexcept

Get a read-only iterator pointing one past the end of this buffer.

References data.

Referenced by end().

findNextSamplePosition()

MidiBufferIterator MidiBuffer::findNextSamplePosition ( int samplePosition ) const

noexcept

Get an iterator pointing to the first event with a timestamp greater-than or equal-to samplePosition.

References JUCE_API, and MidiBuffer().

Member Data Documentation

data

Array<uint8> MidiBuffer::data

The raw data holding this buffer.

Obviously access to this data is provided at your own risk. Its internal format could change in future, so don't write code that relies on it!

Referenced by cbegin(), and cend().