class WaveFile::SamplerLoop

Provides a way to indicate the data about sampler loop points in a file's “smpl” chunk. That is, information about how a sampler could loop between a sample range while playing this *.wav as a note. If a *.wav file contains a “smpl” chunk, then Reader.sampler_info.loops will return an array of SamplerLoop objects with the relevant info.

Public

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Attributes

end_sample_frame[R]

Returns ↑

Returns the last sample frame of the loop.

fraction[R]

A value >= 0.0 and < 1.0 which specifies a fraction of a sample at which to loop. This allows a loop to be fine tuned at a resolution finer than one sample.

id[R]

Returns ↑

Returns a numeric ID which identifies the specific loop

play_count[R]

Returns ↑

Returns the number of times to loop. Will be an Integer 1 or greater, or Float::INFINITY.

start_sample_frame[R]

Returns ↑

Returns the first sample frame of the loop.

type[R]

Returns ↑

Returns a symbol indicating which direction the loop should run. The possible values are :forward, :alternating, :backward, or a positive Integer. Integer values 3 or greater are allowed by the *.wav file spec, but don't necessarily have a defined meaning.

Public Class Methods

new(id: required("id"), type: required("type"), start_sample_frame: required("start_sample_frame"), end_sample_frame: required("end_sample_frame"), fraction: required("fraction"), play_count: required("play_count")) click to toggle source

Constructs a new SamplerLoop instance.

id

A numeric ID which identifies the specific loop. Should be an Integer 0 or greater.

type

Indicates which direction the loop should run. Should either be one of the symbols :forward, :alternating, :backward, or a positive Integer. If an Integer, then 0 will be normalized to :forward, 1 to :alternating, 2 to :backward. Integer values 3 or greater are allowed by the *.wav file spec, but don't necessarily have a defined meaning.

start_sample_frame

The first sample frame in the loop.

end_sample_frame

The last sample frame in the loop.

fraction

A Float >= 0.0 and < 1.0 which specifies a fraction of a sample at which to start the loop. This allows a loop start to be fine tuned at a resolution finer than one sample.

play_count

The number of times to loop. Can be an Integer 0 or greater, or Float::INFINITY. A value of 0 will be normalized to Float::INFINITY, because in the file format a value of 0 means to repeat the loop indefinitely.

Returns ↑

Raises InvalidSamplerLoopError if the given arguments can't be written to a *.wav file.

# File lib/wavefile/sampler_loop.rb, line 40
def initialize(id: required("id"),
              type: required("type"),
              start_sample_frame: required("start_sample_frame"),
              end_sample_frame: required("end_sample_frame"),
              fraction: required("fraction"),
              play_count: required("play_count"))
  type = normalize_type(type)
  if play_count == 0
    play_count = Float::INFINITY
  end

  validate_32_bit_integer_field(id, "id")
  validate_loop_type(type)
  validate_32_bit_integer_field(start_sample_frame, "start_sample_frame")
  validate_32_bit_integer_field(end_sample_frame, "end_sample_frame")
  validate_fraction(fraction)
  validate_play_count(play_count)

  @id = id
  @type = type
  @start_sample_frame = start_sample_frame
  @end_sample_frame = end_sample_frame
  @fraction = fraction
  @play_count = play_count
end