Package 'openmpt'

Control the volume of a module

Description

Functions to control the global volume of a module, or that of specific channels in the module.

Usage

channel_mute_status(mod, channel, ...)

channel_mute_status(mod, channel, ...) <- value

channel_volume(mod, channel, ...)

channel_volume(mod, channel, ...) <- value

global_volume(mod, ...)

global_volume(mod, ...) <- value

Arguments

mod	A tracker module object of class openmpt.
channel	Channel index (integer starting at 0) for which to request or control the volume.
...	Ignored
value	Replacement value. In case of 'status' functions a logical value, in case of 'volume' functions a numeric value.

Value

Returns the volume (status), or the updated object in case of an assign operation (⁠<-⁠).

Examples

mod <- demo_mod()

channel_mute_status(mod, 0L)

## Mute the first channel in the module
channel_mute_status(mod, 0L) <- TRUE

## Second channel volume at 50%
channel_volume(mod, 1L) <- 0.5

## global volume at 90%
global_volume(mod, 1L) <- 0.9

---

Convert a ModPlug Tracker module to an audio file

Description

Renders ModPlug Tracker music to an audio file and encodes it to a desired output format (e.g. .mp3, .ogg, etc) using av::av_audio_convert().

Usage

convert_mod(
  mod,
  file,
  start_order = 0L,
  start_row = 0L,
  sample_rate = 44100L,
  verbose = FALSE,
  ...
)

Arguments

mod	A tracker module object of class openmpt
file	Output audio file where the rendered audio is stored. The file name extension is used to determine the type of encoding to be applied.
start_order	Starting position (integer index starting at 0) in the pattern sequence table.
start_row	Starting row (integer index starting at 0) of the pattern table.
sample_rate	Output sample rate in Hz (samples per seconds).
verbose	Passed on to av::av_audio_convert().
...	Ignored

Value

Returns NULL invisibly

Examples

mod <- demo_mod()

destination <- tempfile(fileext = ".mp3")

convert_mod(mod, destination)

---

Loads demo module included with the package

Description

Reads the file cyberrid.mod. It is a ProTracker file create by Jester. It is redistributed under the Attribution Non-commercial Share Alike license. The music was part of an Amiga computer demo named 'Extension' and was originally released in 1993.

Usage

demo_mod()

Value

Returns the demo module tracker object of class openmpt

Examples

mod <- demo_mod()

---

Get ModPlug Tracker module duration

Description

Get the duration of the song from a openmpt class module object in seconds.

Usage

get_duration_seconds(mod, ...)

Arguments

mod	A tracker module object of class openmpt.
...	Ignored

Value

Returns a numeric value indicating the song duration in seconds.

Examples

mod <- demo_mod()
get_duration_seconds(mod)

---

Get ModPlug Tracker module meta data

Description

Get meta data of a tracker module such as its "type", "title" and "tracker". Use get_metadata_keys() to get the available keys for a module object.

Usage

get_metadata(mod, key = "title", ...)

get_metadata_keys(mod, ...)

Arguments

mod	A tracker module object of class openmpt.
key	A key as listed by get_metadata_keys().
...	Ignored

Value

A list of available keys in case of get_metadata_keys(), the requested information in case of get_metadata().

Examples

mod <- demo_mod()
get_metadata_keys(mod)

get_metadata(mod, "tracker")

---

Retrieve information about the OpenMPT library

Description

A wrapper for the get function in libopenmpt (see API documentation)

Usage

openmpt_info(key = "library_version", ...)

Arguments

key	A key character string indicating which information to retrieve. can be "library_version", "library_features" and many others. See API documentation) for all possible values.
...	Ignored

Value

Returns a character string with the requested information.

Examples

openmpt_info("library_version")
openmpt_info("library_features")
openmpt_info("url")

---

Get a specific ModPlug pattern table

Description

Collects a specific pattern table from a tracker module and presents it as a matrix of formatted character strings.

Usage

pattern(mod, pattern = 0L, width = 0L, pad = TRUE, ...)

Arguments

mod	A tracker module object of class openmpt.
pattern	The pattern index (starting at 0) of the pattern to get.
width	The maximum number of characters the string should contain. 0 means no limit.
pad	If TRUE, the string will be resized to the exact length provided in the width parameter.
...	Ignored

Value

A matrix of pattern cells formatted as character strings. Each column represents an audio channel.

Examples

mod <- demo_mod()
pattern(mod)

---

Control the pitch and tempo of a module

Description

Functions to control the pitch and tempo of a module.

Usage

pitch_factor(mod, ...)

pitch_factor(mod, ...) <- value

tempo_factor(mod, ...)

tempo_factor(mod, ...) <- value

Arguments

mod	A tracker module object of class openmpt.
...	Ignored
value	Replacement value. A numeric factor with which to adjust the tempo or pitch of a module

Value

Returns current factor, or the updated object in case of an assign operation (⁠<-⁠).

Examples

mod <- demo_mod()

## Increase the module pitch with a factor 2
pitch_factor(mod) <- 2

## Increase the module tempo with a factor 2
tempo_factor(mod) <- 2

---

Play a ModPlug Tracker module

Description

Renders a module tracker object of class openmpt and plays it instantaneously.

Usage

play(mod, sample_rate = 44100L, progress = "vu", ...)

Arguments

mod	A tracker module object of class openmpt.
sample_rate	Output sample rate when playing the module.
progress	Progress printed to console while playing. Should be one of "vu" (indicative volume meter), "time" (shows timer) or "none" (don't show progress). If your audio is stuttering you might want to set this to "none" to save processing speed.
...	Ignored

Value

Returns NULL invisibly.

Examples

## Not run: 
mod <- demo_mod()
play(mod)

## End(Not run)

---

Get and set ModPlug Tracker module position

Description

Get or set the position of the music player. rewind() moves the position to the start of the song.

Usage

position_seconds(mod, ...)

position_seconds(mod, ...) <- value

rewind(mod, ...)

set_position_order_row(mod, order, row, ...)

Arguments

mod	A tracker module object of class openmpt.
...	Ignored
value	Position in seconds to move the player to. The value is rounded to its nearest order and row position.
order	Index of the position in the pattern sequence table (starts at 0).
row	Index of the row in the current pattern table (starts at 0).

Value

Returns NULL invisibly, or the updated object in case of the assign operator (⁠<-⁠).

Examples

mod <- demo_mod()
position_seconds(mod)
position_seconds(mod) <- 10.2
set_position_order_row(mod, 1, 4)
rewind(mod)

---

Implementation of basic S3 generics

Description

Implementation of basic S3 generics such as print().

Usage

## S3 method for class 'openmpt'
print(x, ...)

## S3 method for class 'openmpt'
format(x, ...)

Arguments

x	Object to apply the method to.
...	Ignored.

Value

In case of print and format a formatted string with basic information about the module is returned.

---

Read Open ModPlug module

Description

Read any of the music tracker module file formats supported by libopenmpt: https://wiki.openmpt.org/Manual:_Module_formats.

Usage

read_mod(file, ...)

Arguments

file	File path or URL to read the file from. Binary connections are also supported.
...	Ignored

Value

A modplug class object. It is an external pointer, pointing to the module object in memory. It can be used for rendering audio.

Examples

## You can read from files
mod1 <- read_mod(system.file("cyberrid", "cyberrid.mod", package = "openmpt"))


## but also URLs
mod2 <- read_mod("https://api.modarchive.org/downloads.php?moduleid=41529#elektric_funk.mod")

---