MIDIFile 0.1.0

构造函数

MIDI.MIDIFile文件初始化（self，filename）

^{tt1}$

the name of an SMF file to read and parse. Raises an exception if the file does not exist / cannot be read.

方法

MIDI.MIDIFile.parse(self)	Parse the file. Determines the file’s type and populates an array of content tracks, each of which contains one track from the file and is represented by a MIDI.Track instance.
MIDI.MIDIFile.__len__(self)	The number of tracks in the file (0 if ^{tt3}$ has not yet been invoked).
MIDI.MIDIFile.__iter__(self)	Iterates over the tracks in the file
MIDI.MIDIFile.__get_item__(self, ^{tt4}$)	A MIDI.Track object, representing the ^{tt4}$’th track in the file (or throws a RangeError if ^{tt4}$ is out of range)
MIDI.MIDIFile.__str__(self)	Useful information about the file as a whole, number of tracks and their sizes

属性

如果self是MIDI.MIDI文件实例

self.format	int	The MIDI format of the loaded file. Possible values are 0, 1 and 2 (or None if the ^{tt3}$ method has not yet been invoked). See page 134 of the MIDI Specification v1.0.
self.division	uint16	Time quantum of the MIDI data encoded in the file (or ^{tt8}$ if the ^{tt3}$ method has not yet been invoked). Interpretation depends on the value: < 32768 : equals number of ticks per quarter-note; often equal to ^{tt10}$ >=32786 : number of subdivisions of a second as defined in the SMTPE Standard and on pages 116- of the MIDI Specification v1.0. Equals 32768 + 256 f + t where f identifies one of the standard MIDI time code formats, and signifies the number of frames per second, while f is the numbef of subdivisions within a frame (common values are 4, 8, 10, 80 and 100).

构造函数

迷笛音轨初始化（self，data，containsTiming = True）

参数：

^{tt11}$	binary string or array	data comprising one track from an SMF file, or a sequence of MIDI messages
^{tt14}$	boolean	True if ^{tt11}$ consists of MIDI events interleaved with timestamps (as in an SMF file); False if it is a sequence of MIDI messages

所以，举个例子

track=Track(data,containsTiming=True)

initialises ^{tt16}$ for parsing ^{tt11}$ representing a track taken from an SMF file; while

track=Track(data,containsTiming=False)

initialises ^{tt16}$ for parsing ^{tt11}$ consisting of a sequence of one or more raw MIDI events, e.g. captured from an observed MIDI stream, or sent to the application by a MIDI controller.

方法

MIDI.Track.parse(self)	Parse the track into an array of events, ordered based on their appearance in the track. Events are represented by instances of MIDI.Events.Event.
MIDI.Track.__len__(self)	Returns the number of messages in the track (0 if ^{tt3}$ has not yet been invoked).
MIDI.Track.__iter__(self)	Iterates over the events / messages in the track, in the order in which they appeared.
MIDI.Track.__get_item__(self, ^{tt4}$)	Returns a MIDI.Events.Event instance representing the ^{tt4}$’th event in the track (or throws a RangeError if ^{tt4}$ is out of range).
MIDI.Track.__str__(self)	Returns string representations of all the track’s events, concatenated and separated by newline ^{tt24}$.

构造函数

MIDI.Events.Event.__init__(self, ^{tt25}$, ^{tt26}$)

Arguments:

^{tt25}$	uint64	MIDI timestamp for the time of the event’s occurrence, relative to some arbitrary zero.
^{tt26}$	binary string or array	bytes making up the event.

方法

MIDI.Events.Event.__len__(self)	The total length of the event.
MIDI.Events.Event.__str__(self)	String representation of the event. By default, a representation of the raw bytes as a binary string.

属性

如果self是MIDI.Events.事件实例

self.time	the timestamp with which the event instance was initialised; measured in units of the quantum of time defined by the value of the ^{tt29}$ property of the MIDI.MIDIFile instance containing the track of which this event forms a part.
self.header	the event’s initial byte, which serves to identify its kind.
self.data	binary string or array containing the event’s body, i.e. its data content, with the header byte and other formatting removed

此类的专门化描述了特定类型的SMF事件，提供了各种动态生成的只读属性，描述了特定于它们的属性。具体如下：

Meta Events

提供有关曲目的信息，例如歌词、节奏等，用类型^{str1}表示$MIDI.Events.MetaEvent，它具有以下附加属性：

^{tt30}$

is the meta event’s kind, expressed as a member of the enumeration MIDI.Events.meta.MetaEventKinds for defined message types (see pages 137-139 of the MIDI Specification v1.0 for a complete list) , and None otherwise

其他参数仅适用于以下特定事件类型：

Property	Description	Meta Event Type(s)
^{tt31}$	general text	Text, Copyright_Notice, Track_Name, Instrument_Name, Lyric, Marker, Cue_Point
^{tt32}$	sequence number	Sequence_Number
^{tt33}$	channel number	MIDI_Channel_Prefix
^{tt34}$	tempo	Set_Tempo
^{tt35}$	hours	SMTPE_Offset
^{tt36}$	minutes	SMTPE_Offset
^{tt37}$	seconds	SMTPE_Offset
^{tt38}$	frames	SMTPE_Offset
^{tt39}$	time signature top number	Time_Signature
^{tt40}$	time signature bottom number	Time_Signature
^{tt41}$	number of MIDI clocks per tick	Time_Signature
^{tt42}$	what it says	Time_Signature

系统事件

告诉MIDI乐器如何执行音轨，并用^{str 1}类型表示$MIDI.Events.SysExEvent。每个系统事件都包含一条MIDI System消息。如果self是^{str 1}的实例$MIDI.Events.SysExEvent然后：

^{tt44}$

uint8

is the MIDI system message’s kind, expressed as an integer 0 - 15; it is equal to ^{tt45}$

MIDI事件

告诉MIDI乐器在执行曲目时要播放什么，并用类型^{str 1}表示$MIDI.Events.MIDIEvent。所有实例都有以下字段：

^{tt46}$	uint8	The message command type, as defined in the MIDI Specification v1.0. Equal to ^{tt47}$
^{tt33}$	uint8	The channel that the message relates to. Equal to ^{tt45}$
^{tt30}$	message type specific	Instance of a class representing this particular kind of MIDI message; depending on ^{tt46}$

根据消息类型，ev.message的值如下：

NOTE-OFF or NOTE-ON (^{tt53}$)

^{tt54}$	ON if this is a NOTE-ON message; OFF if it is a NOTE-OFF message
^{tt55}$	The note to which the message refers
^{tt56}$	The velocity with which the note is applied

按键压力（command = 0xa0）

^{tt55}$	The note to which the message refers
^{tt59}$	The pressure with which the note is applied

控件更改（command = 0xb0）

^{tt46}$	The control that should be changed; represented either as a named object, for known controls, or as an unsigned integer for others
^{tt59}$	The new value of the control; converted to ON / OFF, etc for known controls, left as an unsigned integer for others

程序更改（command = 0xc0）

^{tt64}$	always equal to “Program”
^{tt65}$	The new program number

通道压力（command = 0xd0）

^{tt64}$	always equal to “Pressure”
^{tt65}$	The new pressure value for the channel as an unsigned integer

PITCH BEND CHANGE（command = 0xe0）

^{tt64}$	always equal to “BEND”
^{tt65}$	The new pitch bend for the channel as a signed integer b such that -2048 <= b <= 2047