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# frozen_string_literal: true
module Aubio
class Pitches
def initialize(aubio_source, params)
# TODO: cleanup param dups
@sample_rate = params[:sample_rate] || 44_100
@window_size = params[:window_size] || 1024
@hop_size = params[:hop_size] || 512
# Set the tolerance for the pitch detection algorithm.
# Typical values range between 0.2 and 0.9.
# Pitch candidates found with a confidence less than this threshold will not be selected.
# The higher the threshold, the more confidence in the candidates.
@confidence_thresh = params[:confidence_thresh] || 0.9
@pitch_method = params[:pitch_method] || 'yinfast'
@source = aubio_source
@pitch = Api.new_aubio_pitch(@pitch_method, @window_size, @hop_size, @sample_rate)
Api.aubio_pitch_set_unit(@pitch, 'midi')
Api.aubio_pitch_set_tolerance(@pitch, @confidence_thresh)
# create output for source
@sample_buffer = Api.new_fvec(@hop_size)
# create output for pitch and beat
@out_fvec = Api.new_fvec(1)
end
def each
return enum_for(:each) unless block_given?
total_frames_counter = 0
read_buffer = FFI::MemoryPointer.new(:int)
last_pitch = 0
loop do
# Perform pitch calculation
Api.aubio_source_do(@source, @sample_buffer, read_buffer)
Api.aubio_pitch_do(@pitch, @sample_buffer, @out_fvec)
# Retrieve result
pitch = Api.fvec_get_sample(@out_fvec, 0)
confidence = Api.aubio_pitch_get_confidence(@pitch)
no_of_bytes_read = read_buffer.read_int
total_frames_counter += no_of_bytes_read
if ((last_pitch - pitch).abs >= 1) && (confidence > @confidence_thresh)
output = {
pitch: pitch,
confidence: confidence,
start: (total_frames_counter == 0 ? 1 : 0),
end: 0
}
yield output
end
last_pitch = pitch
next unless no_of_bytes_read != @hop_size
# there's no more audio to look at
# Let's output one last pitch to mark the end of the file
total_time = total_frames_counter.to_f / @sample_rate.to_f
output = {
pitch: pitch,
confidence: confidence,
start: 0,
end: 1
}
yield output
# clean up
Api.del_aubio_pitch(@pitch)
Api.del_fvec(@sample_buffer)
Api.del_fvec(@out_fvec)
break
end
end
end
end
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