Пример #1
0
func Main(ctx sound.Context, channels ...chan float64) {
	flag.Parse()
	runtime.GOMAXPROCS(NumThreads)

	// Make a copy of the argument array before we modify it.
	channels2 := make([]chan float64, len(channels))
	copy(channels2, channels)
	channels = channels2

	// Measure the duration of the first channel
	var durationStream chan float64
	channels[0], durationStream = ctx.Fork2(channels[0])
	durationChan := make(chan time.Duration, 1)
	go func() {
		durationChan <- ctx.Duration(durationStream)
	}()

	so := getOutput(ctx)

	// Write the output
	startTime := time.Now()
	err := so.Write(ctx.SampleRate, channels)
	endTime := time.Now()

	if err != nil {
		fmt.Printf("Error: %s\n", err.Error())
	}

	outSecs := float64(<-durationChan) / float64(time.Second)
	realSecs := float64(endTime.Sub(startTime)) / float64(time.Second)
	fmt.Printf("Generated %.3f seconds of audio in %.3f seconds (ratio %.3f).\n", outSecs, realSecs, outSecs/realSecs)
}
Пример #2
0
func SequenceBass(ctx sound.Context) (seq *sound.Sequencer) {
	melody := GenerateBassMelody()
	seq = sound.NewSequencer(ctx)

	var pos time.Duration

	for i := 0; i < NumBars; i++ {
		if rand.Float64() < 0.05 {
			freqInput := ctx.Const((<-melody).Frequency())
			note := PlayBassNote(ctx, freqInput, NoteDuration*3)
			seq.Add(pos, note)

		} else if rand.Float64() < 0.05 {
			freqInput1, freqInput2 := ctx.Fork2(ctx.Const((<-melody).Frequency()))
			note1 := PlayBassNote(ctx, freqInput1, NoteDuration)
			note2 := PlayBassNote(ctx, freqInput2, NoteDuration)
			seq.Add(pos, note1)
			seq.Add(pos+NoteDuration*2, note2)

		} else {
			freqInput := ctx.Const((<-melody).Frequency())
			note := PlayBassNote(ctx, freqInput, NoteDuration)
			seq.Add(pos, note)
		}

		pos += NoteDuration * 3
	}

	return seq
}
Пример #3
0
func Generate(ctx sound.Context) (left, right chan float64) {
	treble := SequenceTreble(ctx).Play()
	bass := SequenceBass(ctx).Play()

	trebleLeft, trebleRight := ctx.Fork2(treble)
	bassLeft, bassRight := ctx.Fork2(bass)

	left = ctx.TakeDuration(
		ctx.Add(
			ctx.Mul(trebleLeft, ctx.Const(0.3)),
			ctx.Mul(bassLeft, ctx.Const(0.4)),
		),
		NoteDuration*NumBars*3+time.Second*2,
		true,
	)

	right = ctx.TakeDuration(
		ctx.Add(
			ctx.Mul(trebleRight, ctx.Const(0.4)),
			ctx.Mul(bassRight, ctx.Const(0.3)),
		),
		NoteDuration*NumBars*3+time.Second*2,
		true,
	)

	return left, right
}
Пример #4
0
func FilterFormant(ctx sound.Context, input chan float64, centre, q, gain float64) (output chan float64) {
	lowerCutoff := (centre - (centre / q)) / 0.772
	upperCutoff := (centre + (centre / q)) / 1.29

	input, formant := ctx.Fork2(input)
	formant = filter.Chebyshev(ctx, formant, filter.HighPass, lowerCutoff, 0.5, 2)
	formant = filter.Chebyshev(ctx, formant, filter.LowPass, upperCutoff, 0.5, 2)
	formant = ctx.Mul(formant, ctx.Const(gain-1.0))
	return ctx.Add(input, formant)
}
Пример #5
0
func Generate(ctx sound.Context) (left, right chan float64) {
	stream := ctx.TakeDuration(
		ctx.Mul(
			ctx.Sine(
				FrequencyEnvelope(ctx),
			),
			ctx.Const(0.7),
		),
		NoteDuration*8,
		true, // Wait for a zero crossing
	)
	return ctx.Fork2(stream)
}
Пример #6
0
func playMelodySynth(ctx sound.Context, freqInput chan float64) (stream chan float64) {
	freqInput1, freqInput2 := ctx.Fork2(freqInput)

	return ctx.Add(
		ctx.Mul(
			ctx.Square(
				freqInput1,
				ctx.Const(0.5),
			),
			ctx.Const(0.75),
		),
		ctx.Mul(
			ctx.Saw(
				ctx.Mul(freqInput2, ctx.Const(2)),
			),
			ctx.Const(0.25),
		),
	)
}
Пример #7
0
func PlayTrebleNote(ctx sound.Context, freqInput chan float64, duration time.Duration) (stream chan float64) {
	freqInput1, freqInput2 := ctx.Fork2(freqInput)

	return ctx.TakeDuration(
		ctx.Add(
			ctx.Mul(
				ctx.Square(
					freqInput1,
					ctx.Const(0.5),
				),
				ctx.Const(0.75),
			),
			ctx.Mul(
				ctx.Saw(
					ctx.Mul(freqInput2, ctx.Const(2)),
				),
				ctx.Const(0.25),
			),
		),
		duration,
		true,
	)
}
Пример #8
0
// input should be finite and preferably short (e.g. one cycle of a triangle wave)
func KarplusStrong(ctx sound.Context, input chan float64, delaySamples uint, cutoff float64, decay float64) (output chan float64) {
	feedback := make(chan float64, ctx.StreamBufferSize)

	// Mix the input with the feedback.
	output = ctx.Add(input, feedback)

	// Fork off a copy of the output.
	output, outputCopy := ctx.Fork2(output)

	// The copy is first passed through a delay line...
	outputCopy = delay(ctx, outputCopy, delaySamples)

	// ...then filtered...
	//outputCopy = filter.Chebyshev(ctx, outputCopy, filter.LowPass, cutoff, 0.5, 2)
	outputCopy = filter.RC(ctx, outputCopy, filter.LowPass, cutoff)

	// ...and finally attenuated slightly.
	outputCopy = ctx.Mul(outputCopy, ctx.Const(decay))

	// The filtered output copy is fed back into the system.
	go pipe(outputCopy, feedback)

	return output
}
Пример #9
0
func Generate(ctx sound.Context) (left, right chan float64) {
	rand.Seed(time.Now().UnixNano())

	melodyParts := make(chan chan float64)
	bassParts := make(chan chan float64)

	go func() {
		for {
			var octave int
			x := rand.Float64()
			if x < 0.3 {
				octave = 4
			} else {
				octave = 5
			}

			root := music.MakeNote(music.D, octave)
			scale := music.Scale{Root: root, Intervals: music.HarmonicMinor}

			var n int
			x = rand.Float64()
			if x < 0.2 {
				n = 3
			} else if x < 0.4 {
				n = 6
			} else if x < 0.6 {
				n = 12
			} else if x < 0.8 {
				n = 18
			} else {
				n = 24
			}

			melodyParts <- genMelodyArpeggio(ctx, scale, n)
		}
	}()

	go func() {
		for {
			var octave int
			x := rand.Float64()
			if x < 0.3 {
				octave = 3
			} else {
				octave = 2
			}

			root := music.MakeNote(music.D, octave)
			scale := music.Scale{Root: root, Intervals: music.HarmonicMinor}

			var n int
			x = rand.Float64()
			if x < 0.2 {
				n = 3
			} else if x < 0.4 {
				n = 6
			} else if x < 0.6 {
				n = 9
			} else if x < 0.8 {
				n = 12
			} else {
				n = 18
			}

			bassParts <- genBassArpeggio(ctx, scale, n)
		}
	}()

	melody := playMelodySynth(ctx, ctx.AppendStream(melodyParts))
	bass := playBassSynth(ctx, ctx.AppendStream(bassParts))

	melodyLeft, melodyRight := ctx.Fork2(melody)
	bassLeft, bassRight := ctx.Fork2(bass)

	left = ctx.TakeDuration(
		ctx.Add(
			ctx.Mul(melodyLeft, ctx.Const(0.4)),
			ctx.Mul(bassLeft, ctx.Const(0.6)),
		),
		time.Second*300,
		true,
	)

	right = ctx.TakeDuration(
		ctx.Add(
			ctx.Mul(melodyRight, ctx.Const(0.6)),
			ctx.Mul(bassRight, ctx.Const(0.4)),
		),
		time.Second*300,
		true,
	)

	return left, right
}