| Title: | Audio Interface for R |
|---|---|
| Description: | Interfaces to audio devices (mainly sample-based) from R to allow recording and playback of audio. Built-in devices include Windows MM, Mac OS X AudioUnits and PortAudio (the last one is very experimental). |
| Authors: | Simon Urbanek <[email protected]> |
| Maintainer: | Simon Urbanek <[email protected]> |
| License: | MIT + file LICENSE |
| Version: | 0.1-11 |
| Built: | 2024-11-01 11:17:07 UTC |
| Source: | https://github.com/s-u/audio |
audio.drivers lists all currently loaded and available audio
drivers.
current.audio.driver returns the name of the currently active
audio driver or NULL if no audio drivers is available.
set.audio.driver selects an audio driver as the current
driver.
load.audio.driver attempts to load a modular audio driver and,
if succeessful, makes it the current audio driver.
audio.drivers() current.audio.driver() set.audio.driver(name) load.audio.driver(path)audio.drivers() current.audio.driver() set.audio.driver(name) load.audio.driver(path)
name |
name of the driver to load (as it appears in the
|
path |
path to the dynamic module to load |
The audio package comes with several built-in audio drivers (currently "wmm": WindowsMultiMedia for MS Windows, "macosx": AudioUnits for Mac OS X and "portaudio": PortAudio for unix), but it also supports 3rd-party drivers to be loaded (e.g. from other packages).
All operations that create new audio instances (play
and record) use the current audio driver. The audio
package allows the user to switch between different audio
drivers. Each audio instance is tied to the driver it was created
with even if the current driver was changed in the meantime.
Drivers are references by its short name listed in the name
column in the list of available drivers (obtainable via
audio.drivers).
An audio driver is any shared module that provides a C function
create_audio_driver which returns a pointer to a populated
structure audio_driver as defined in driver.h.
audio.drivers returns a data frame lising all availbale
drivers
set.audio.driver and current.audio.driver return the
name of the active driver or NULL if no drivers ar avaliable.
load.audio.driver returns the name of the loaded driver.
audio.drivers()audio.drivers()
audioInstances supports most methods relevant to them. See
the corresponding generics help for details.
Noteworthy is that $data is the canonical way to get data
associated with an audio instance - i.e. played or recorded content.
## S3 method for class 'audioInstance' x$name ## S3 method for class 'audioInstance' resume(x, ...) ## S3 method for class 'audioInstance' pause(x, ...) ## S3 method for class 'audioInstance' rewind(x, ...) ## S3 method for class 'audioInstance' close(con, ...) ## S3 method for class 'audioInstance' play(x, ...) ## S3 method for class 'audioInstance' print(x, ...)## S3 method for class 'audioInstance' x$name ## S3 method for class 'audioInstance' resume(x, ...) ## S3 method for class 'audioInstance' pause(x, ...) ## S3 method for class 'audioInstance' rewind(x, ...) ## S3 method for class 'audioInstance' close(con, ...) ## S3 method for class 'audioInstance' play(x, ...) ## S3 method for class 'audioInstance' print(x, ...)
x |
audio instance |
name |
name of the attribute - currently only "data" is supported |
con |
audio instance (the name is unfortuantely defined in the |
... |
ignored |
audioSample is a class encapsulating digitalized (sampled)
audio data. Essentiually it tags numeric vectors and matrices with
additional audio information (most importantly sample rate).
audioSample is the designated constructor of such objects.
Instances of the audioSample are numeric vectors or matrices
with the following additional attributes:
ratesample rate (in Hz), mandatory
bitsresolution of the source (in bits), optional
If the object itself is a vector, it contains only one channel. Otherwise it is a matrix with as many rows as there are channels (hence 2 for stereo).
as.audioSample generic converts an object into an audio
sample object. The default method is very similar to the constructor
except that it attempts to infer the parameters from the object's
attributes if they are not specified. Thus they are optional although
they don't have visible defaults.
audioSample(x, rate=44100, bits=16, clip = TRUE) as.audioSample(x, ...) ## Default S3 method: as.audioSample(x, rate, bits, clip, ...) ## S3 method for class 'Sample' as.audioSample(x, ...)audioSample(x, rate=44100, bits=16, clip = TRUE) as.audioSample(x, ...) ## Default S3 method: as.audioSample(x, rate, bits, clip, ...) ## S3 method for class 'Sample' as.audioSample(x, ...)
x |
object to convert or initilize with |
rate |
sample rate |
bits |
resolution of the source. It doesn't affect the data itself and is only used for playback and export. |
clip |
boolean value determining whether the source should be clipped to a range between -1 and 1. Values outside this range result in undefined behavior. |
... |
parameters passed to the object-specific method |
audioSample and as.audioSample return an audio sample
object.
x <- audioSample(sin(1:8000/10), 8000) play(x)x <- audioSample(sin(1:8000/10), 8000) play(x)
audioSample methods behave in the same way as the underlying
methods of numeric vectors and matrices except that they preserve
the attributes and class of the objects.
## S3 method for class 'audioSample' x$name ## S3 replacement method for class 'audioSample' x$name <- value ## S3 method for class 'audioSample' x[..., drop = FALSE] ## S3 method for class 'audioSample' as.Sample(x, ...) ## S3 method for class 'audioSample' print(x, ...)## S3 method for class 'audioSample' x$name ## S3 replacement method for class 'audioSample' x$name <- value ## S3 method for class 'audioSample' x[..., drop = FALSE] ## S3 method for class 'audioSample' as.Sample(x, ...) ## S3 method for class 'audioSample' print(x, ...)
x |
sample object |
name |
name of the attribute to get/set |
value |
value to set |
drop |
see |
... |
parameters passed to the object-specific method |
x <- audioSample(sin(1:8000/10), 8000) x$rate x[1:10]x <- audioSample(sin(1:8000/10), 8000) x$rate x[1:10]
pause pauses (stops) audio recording or playback
rewind rewinds audio recording or playback, i.e., makes the
beginning of the source (or target) object the current audio
position.
resume resumes previously paused audio recording or playback
pause(x, ...) rewind(x, ...) resume(x, ...)pause(x, ...) rewind(x, ...) resume(x, ...)
x |
instance object |
... |
optional arguments passed to the method specific to the object |
All functions return TRUE on success and FALSE on failure. All methods are generics and intended to apply to similar asynchronous operations (e.g. movie playback etc.).
play plays audio
play(x, ...) ## S3 method for class 'audioSample' play(x, rate, ...) ## S3 method for class 'Sample' play(x, ...) ## Default S3 method: play(x, rate = 44100, ...)play(x, ...) ## S3 method for class 'audioSample' play(x, rate, ...) ## S3 method for class 'Sample' play(x, ...) ## Default S3 method: play(x, rate = 44100, ...)
x |
data to play |
rate |
sample rate - it is inferred from the object (where possible) if not specified |
... |
optional arguments passed to the method specific to the object being played |
Returns an audio instance object which can be used to control the playback subsequently.
play(sin(1:10000/20))play(sin(1:10000/20))
record record audio using the current audio device
record(where, rate, channels)record(where, rate, channels)
where |
object to record into or the number of samples to record |
rate |
sample rate. If ommitted it will be taken from the |
channels |
number of channels to record. If ommitted it will be taken from the |
The record function creates an audio instance of the current
audio driver to start audio recording. The recording is performed
asynchronously and the function returns immediately after the
recording is started.
where can either be a numeric vector of the storage mode
‘double’ and length greater than 1 or a numberic vector of length
one specifying the number of samples to record. The the former case
the audio data is recorded directly to the vector, in the latter
case a new object (initialized with NA) is created internally
(and thus only accessible using a$data where a is the
audio instance).
The recording is automatically stopped after the where object
has been completely filled. Nonetheless pause can be
used to stop the recoding at any time.
Returns an audio instance object which can be used to control the recording subsequently.
x <- rep(NA_real_, 16000) # start recording into x record(x, 8000, 1) # monitor the recording progress par(ask=FALSE) # for continuous plotting while (is.na(x[length(x)])) plot(x, type='l', ylim=c(-1, 1)) # play the recorded audio play(x)x <- rep(NA_real_, 16000) # start recording into x record(x, 8000, 1) # monitor the recording progress par(ask=FALSE) # for continuous plotting while (is.na(x[length(x)])) plot(x, type='l', ylim=c(-1, 1)) # play the recorded audio play(x)
wait waits until an event occurs or times out
wait(x, ...) ## Default S3 method: wait(x, timeout, ...) ## S3 method for class 'audioInstance' wait(x, timeout=NA, ...)wait(x, ...) ## Default S3 method: wait(x, timeout, ...) ## S3 method for class 'audioInstance' wait(x, timeout=NA, ...)
x |
event to wait for |
timeout |
longest period to wait for (in seconds, real number). A value of 0 causes |
... |
optional arguments passed to the method specific to the object being monitored |
The default method allows x to specify the timeout, i.e., if timeout is not specified and x is numeric then the timeout is set to x.
Returns the result.
# play a sound and wait until the playback is done wait(play(sin(1:10000/20))) # wait for 2.5 seconds unconditionally wait(2.5)# play a sound and wait until the playback is done wait(play(sin(1:10000/20))) # wait for 2.5 seconds unconditionally wait(2.5)
load.wave loads a sample from a WAVE file
save.wave saves a sample into a WAVE file
load.wave(where) save.wave(what, where)load.wave(where) save.wave(what, where)
where |
file name of the file to load from or save to |
what |
audioSample object to save |
WAVE is a RIFF (Resource Interchange File Format) widely used for storage of uncompressed audio data. It is often identified by the extension .WAV on DOS-legacy systems (such as Windows). Although WAVE files may contain compressed data, the above functions only support plain, uncompressed PCM data.
load.wave returns an object of the class audioSample as loaded from the WAVE file
save.wave always returns NULL