class SF::Music
inherits SF::SoundStream
#
Streamed music played from an audio file
Musics are sounds that are streamed rather than completely
loaded in memory. This is especially useful for compressed
musics that usually take hundreds of MB when they are
uncompressed: by streaming it instead of loading it entirely,
you avoid saturating the memory and have almost no loading delay.
This implies that the underlying resource (file, stream or
memory buffer) must remain valid for the lifetime of the
SF::Music object.
Apart from that, a SF::Music has almost the same features as
the SF::SoundBuffer / SF::Sound pair: you can play/pause/stop
it, request its parameters (channels, sample rate), change
the way it is played (pitch, volume, 3D position, ...), etc.
As a sound stream, a music is played in its own thread in order
not to block the rest of the program. This means that you can
leave the music alone after calling play(), it will manage itself
very well.
Usage example:
# Declare a new music
music = SF::Music.new
# Open it from an audio file
if !music.open_from_file("music.ogg")
# error...
end
# Change some parameters
music.set_position(0, 1, 10) # change its 3D position
music.pitch = 2 # increase the pitch
music.volume = 50 # reduce the volume
music.loop = true # make it loop
# Play it
music.play
See also: SF::Sound, SF::SoundStream
Constructors#
.from_file(*args, **kwargs) : self#
Shorthand for music = Music.new; music.open_from_file(...); music
Raises InitError on failure
.from_memory(*args, **kwargs) : self#
Shorthand for music = Music.new; music.open_from_memory(...); music
Raises InitError on failure
.from_stream(*args, **kwargs) : self#
Shorthand for music = Music.new; music.open_from_stream(...); music
Raises InitError on failure
Methods#
#loop_points : Music::TimeSpan#
Get the positions of the of the sound's looping sequence
Returns: Loop Time position class.
Warning
Since loop_points=() performs some adjustments on the
provided values and rounds them to internal samples, a call to
loop_points() is not guaranteed to return the same times passed
into a previous call to loop_points=(). However, it is guaranteed
to return times that will map to the valid internal samples of
this Music if they are later passed to loop_points=().
See also: loop_points=
#loop_points=(time_points : Music::TimeSpan)#
Sets the beginning and duration of the sound's looping sequence using SF::Time
loop_points=() allows for specifying the beginning offset and the duration of the loop such that, when the music
is enabled for looping, it will seamlessly seek to the beginning whenever it
encounters the end of the duration. Valid ranges for time_points.offset and time_points.length are
[0, Dur) and (0, Dur-offset] respectively, where Dur is the value returned by duration().
Note that the EOF "loop point" from the end to the beginning of the stream is still honored,
in case the caller seeks to a point after the end of the loop range. This function can be
safely called at any point after a stream is opened, and will be applied to a playing sound
without affecting the current playing offset.
Warning
Setting the loop points while the stream's status is Paused
will set its status to Stopped. The playing offset will be unaffected.
- time_points - The definition of the loop. Can be any time points within the sound's length
See also: loop_points
#on_get_data : Slice(Int16) | ::Nil#
Request a new chunk of audio samples from the stream source
This function fills the chunk from the next samples to read from the audio file.
- data - Chunk of data to fill
Returns: True to continue playback, false to stop
#on_loop : Int64#
Change the current playing position in the stream source to the loop offset
This is called by the underlying SoundStream whenever it needs us to reset the seek position for a loop. We then determine whether we are looping on a loop point or the end-of-file, perform the seek, and return the new position.
Returns: The seek position after looping (or -1 if there's no loop)
#on_seek(time_offset : Time)#
Change the current playing position in the stream source
- time_offset - New playing position, from the beginning of the music
#open_from_file(filename : String) : Bool#
Open a music from an audio file
This function doesn't start playing the music (call play()
to do so).
See the documentation of SF::InputSoundFile for the list
of supported formats.
Warning
Since the music is not loaded at once but rather
streamed continuously, the file must remain accessible until
the SF::Music object loads a new music or is destroyed.
- filename - Path of the music file to open
Returns: True if loading succeeded, false if it failed
See also: open_from_memory, open_from_stream
#open_from_memory(data : Slice) : Bool#
Open a music from an audio file in memory
This function doesn't start playing the music (call play()
to do so).
See the documentation of SF::InputSoundFile for the list
of supported formats.
Warning
Since the music is not loaded at once but rather streamed
continuously, the data buffer must remain accessible until
the SF::Music object loads a new music or is destroyed. That is,
you can't deallocate the buffer right after calling this function.
- data - Slice containing the file data in memory
Returns: True if loading succeeded, false if it failed
See also: open_from_file, open_from_stream
#open_from_stream(stream : InputStream) : Bool#
Open a music from an audio file in a custom stream
This function doesn't start playing the music (call play()
to do so).
See the documentation of SF::InputSoundFile for the list
of supported formats.
Warning
Since the music is not loaded at once but rather
streamed continuously, the stream must remain accessible
until the SF::Music object loads a new music or is destroyed.
- stream - Source stream to read from
Returns: True if loading succeeded, false if it failed
See also: open_from_file, open_from_memory