Class: SRC::Resample

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby-libsamplerate/resample.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(input_rate, output_rate, channels = 1, type = SRC_SINC_FASTEST) ⇒ Resample

Returns a new instance of Resample.



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# File 'lib/ruby-libsamplerate/resample.rb', line 5

def initialize(input_rate, output_rate, channels=1, type=SRC_SINC_FASTEST)
	@input_rate = input_rate
	@output_rate = output_rate
	@channels = channels

	error = FFI::MemoryPointer.new :int, 1
	@state = SRC.src_new type, channels, error
end

Instance Attribute Details

#channels ⇒ Object

Returns the value of attribute channels.



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# File 'lib/ruby-libsamplerate/resample.rb', line 3

def channels
  @channels
end

#input_rate ⇒ Object

Returns the value of attribute input_rate.



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# File 'lib/ruby-libsamplerate/resample.rb', line 3

def input_rate
  @input_rate
end

#output_rate ⇒ Object

Returns the value of attribute output_rate.



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# File 'lib/ruby-libsamplerate/resample.rb', line 3

def output_rate
  @output_rate
end

Instance Method Details

#destroy ⇒ Object 



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# File 'lib/ruby-libsamplerate/resample.rb', line 48

def destroy
	SRC.src_delete @state
end

#process(data) ⇒ Object 



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# File 'lib/ruby-libsamplerate/resample.rb', line 18

def process(data)
	size = data.size
	frames = size / @channels
	rs_frames = (frames * src_ratio).to_i
	rs_size = rs_frames * @channels

	input = FFI::MemoryPointer.new :float, size
	output = FFI::MemoryPointer.new :float, rs_size
	input.write_array_of_float data

	src_data = Data.new
	src_data[:data_in] = input
	src_data[:input_frames] = frames
	src_data[:data_out] = output
	src_data[:output_frames] = rs_frames
	src_data[:src_ratio] = src_ratio
	src_data[:end_of_input] = 0

	res = SRC.src_process @state, src_data

	raise SRCError.from_int res unless res == 0

	frames_written = src_data[:output_frames_gen]
	src_data[:data_out].read_array_of_float frames_written * @channels
end

#reset ⇒ Object 



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# File 'lib/ruby-libsamplerate/resample.rb', line 44

def reset
	SRC.src_reset @state
end

#src_ratio ⇒ Object 



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# File 'lib/ruby-libsamplerate/resample.rb', line 14

def src_ratio
	@output_rate.to_f / @input_rate.to_f
end