class WaveFile::SamplerInfo

Provides a way to indicate the data contained in a “smpl” chunk. That is, information about how the *.wav file could be used by a sampler, such as the file’s MIDI note or loop points. If a *.wav file contains a “smpl” chunk, then Reader#sampler_info will return an instance of this object with the relevant info.

Public

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Attributes

fine_tuning_cents[R]

Returns¶ ↑

Returns the number of cents >= 0.0 and < 100.0 the note should be tuned up from the midi_note field. 100 cents is equal to one semitone. For example, if this value is 50, and midi_note is 60, then the sample is tuned half-way between MIDI note 60 and 61. If the value is 0, then the sample has no fine tuning.

loops[R]

Returns¶ ↑

Returns an Array of 0 or more SamplerLoop objects containing loop point info. Loop point info can indicate that (for example) the sampler should loop between a given sample range as long as the sample is played.

manufacturer_id[R]

Returns¶ ↑

Returns the ID of the manufacturer that this sample is intended for. If it’s not intended for a sampler from a particular manufacturer, this should be 0. See the list at www.midi.org/specifications-old/item/manufacturer-id-numbers

midi_note[R]

Returns¶ ↑

Returns the MIDI note number of the sample, which normally should be between 0 and 127.

product_id[R]

Returns¶ ↑

Returns the ID of the product made by the manufacturer this sample is intended for. If not intended for a particular product, this should be 0.

sample_nanoseconds[R]

Returns¶ ↑

Returns the length of each sample in nanoseconds, which is typically determined by converting 1 / sample rate (in seconds) into nanoseconds. For example, with a sample rate of 44100 this would be 22675 nanoseconds. However, this can be set to an arbitrary value to allow for fine tuning.

sampler_specific_data[R]

Returns¶ ↑

Returns a String of data specific to the intended target sampler, or nil if there is no sampler specific data. This is returned as a raw String because the structure of this data depends on the specific sampler. If you want to use it, you’ll need to unpack the String yourself.

smpte_format[R]

Returns¶ ↑

Returns the SMPTE format (0, 24, 25, 29 or 30)

smpte_offset[R]

Returns¶ ↑

Returns a SMPTETimecode representing the SMPTE time offset.

Public Class Methods

new(manufacturer_id: required("manufacturer_id"), product_id: required("product_id"), sample_nanoseconds: required("sample_nanoseconds"), midi_note: required("midi_note"), fine_tuning_cents: required("fine_tuning_cents"), smpte_format: required("smpte_format"), smpte_offset: required("smpte_offset"), loops: required("loops"), sampler_specific_data: required("sampler_specific_data")) click to toggle source

Constructs a new SamplerInfo instance.

manufacturer_id: the ID of the manufacturer that this sample is intended for. If it’s not intended for a sampler from a particular manufacturer, this should be 0. See the list at www.midi.org/specifications-old/item/manufacturer-id-numbers
product_id: the ID of the product made by the manufacturer this sample is intended for. If not intended for a particular product, this should be 0.
sample_nanoseconds: the length of each sample in nanoseconds, which is typically determined by converting 1 / sample rate (in seconds) into nanoseconds. For example, with a sample rate of 44100 this would be 22675 nanoseconds. However, this can be set to an arbitrary value to allow for fine tuning.
midi_note: the MIDI note number of the sample. Should be between 0 and 127.
fine_tuning_cents: the number of cents >= 0.0 and < 100.0 the note should be tuned up from the midi_note field. 100 cents is equal to one semitone. For example, if this value is 50.0, and midi_note is 60, then the sample is tuned half-way between MIDI note 60 and 61. If the value is 0, then the sample has no fine tuning.
smpte_format: the SMPTE format. Should be 0, 24, 25, 29 or 30.
smpte_offset: a SMPTETimecode representing the SMPTE time offset.
loops: an Array of 0 or more SamplerLoop objects containing loop point info. Loop point info can indicate that (for example) the sampler should loop between a given sample range as long as the sample is played.
sampler_specific_data: a String of data specific to the intended target sampler, or nil if there is no sampler specific data.

Returns¶ ↑

Raises InvalidSamplerInfoError if the given arguments are can’t be written to a *.wav file.

# File lib/wavefile/sampler_info.rb, line 46
def initialize(manufacturer_id: required("manufacturer_id"),
               product_id: required("product_id"),
               sample_nanoseconds: required("sample_nanoseconds"),
               midi_note: required("midi_note"),
               fine_tuning_cents: required("fine_tuning_cents"),
               smpte_format: required("smpte_format"),
               smpte_offset: required("smpte_offset"),
               loops: required("loops"),
               sampler_specific_data: required("sampler_specific_data"))
  validate_32_bit_integer_field(manufacturer_id, "manufacturer_id")
  validate_32_bit_integer_field(product_id, "product_id")
  validate_32_bit_integer_field(sample_nanoseconds, "sample_nanoseconds")
  validate_32_bit_integer_field(midi_note, "midi_note")
  validate_fine_tuning_cents(fine_tuning_cents)
  validate_32_bit_integer_field(smpte_format, "smpte_format")
  validate_smpte_offset(smpte_offset)
  validate_loops(loops)
  validate_sampler_specific_data(sampler_specific_data)

  @manufacturer_id = manufacturer_id
  @product_id = product_id
  @sample_nanoseconds = sample_nanoseconds
  @midi_note = midi_note
  @fine_tuning_cents = fine_tuning_cents
  @smpte_format = smpte_format
  @smpte_offset = smpte_offset
  @loops = loops
  @sampler_specific_data = sampler_specific_data
end