Merge pull request #1 from kardianos/main

meltysynth: make main and tests more robust

main.go

@@ -2,6 +2,10 @@ package main
 
 import (
 	"encoding/binary"
+	"flag"
+	"fmt"
+	"io"
+	"log"
 	"math"
 	"os"
 	"time"
@@ -10,21 +14,60 @@ import (
 )
 
 func main() {
-
-	simpleChord()
-	flourish()
+	err := run()
+	if err != nil {
+		log.Fatal(err)
+	}
 }
 
-func simpleChord() {
+func run() error {
+	sf2Path := flag.String("sf2", "", "Sound font file location")
+	outPath := flag.String("o", "out.pcm", "file to write pcm file to")
+	midiPath := flag.String("midi", "", `midi file to synth, or "chord" for example`)
+	flag.Parse()
+
+	if len(*sf2Path) == 0 {
+		flag.PrintDefaults()
+		return fmt.Errorf("missing sf2 path")
+	}
+	if len(*outPath) == 0 {
+		flag.PrintDefaults()
+		return fmt.Errorf("missing output path")
+	}
+	if len(*midiPath) == 0 {
+		flag.PrintDefaults()
+		return fmt.Errorf("missing midi path")
+	}
 
-	// Load the SoundFont.
-	sf2, _ := os.Open("TimGM6mb.sf2")
-	soundFont, _ := meltysynth.NewSoundFont(sf2)
+	sf2, err := os.Open(*sf2Path)
+	if err != nil {
+		return err
+	}
+	soundFont, err := meltysynth.NewSoundFont(sf2)
 	sf2.Close()
+	if err != nil {
+		return err
+	}
+
+	switch *midiPath {
+	default:
+		err = midi(soundFont, *midiPath, *outPath)
+	case "chord":
+		err = simpleChord(soundFont, *outPath)
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}
 
+func simpleChord(soundFont *meltysynth.SoundFont, outputFile string) error {
 	// Create the synthesizer.
 	settings := meltysynth.NewSynthesizerSettings(44100)
-	synthesizer, _ := meltysynth.NewSynthesizer(soundFont, settings)
+	synthesizer, err := meltysynth.NewSynthesizer(soundFont, settings)
+	if err != nil {
+		return err
+	}
 
 	// Play some notes (middle C, E, G).
 	synthesizer.NoteOn(0, 60, 100)
@@ -39,24 +82,27 @@ func simpleChord() {
 	// Render the waveform.
 	synthesizer.Render(left, right)
 
-	writePcmInterleavedInt16(left, right, "simpleChord.pcm")
+	return writeFile(left, right, outputFile)
 }
 
-func flourish() {
-
-	// Load the SoundFont.
-	sf2, _ := os.Open("TimGM6mb.sf2")
-	soundFont, _ := meltysynth.NewSoundFont(sf2)
-	sf2.Close()
-
+func midi(soundFont *meltysynth.SoundFont, midiFilePath string, outputFile string) error {
 	// Create the synthesizer.
 	settings := meltysynth.NewSynthesizerSettings(44100)
-	synthesizer, _ := meltysynth.NewSynthesizer(soundFont, settings)
+	synthesizer, err := meltysynth.NewSynthesizer(soundFont, settings)
+	if err != nil {
+		return err
+	}
 
 	// Load the MIDI file.
-	mid, _ := os.Open("C:\\Windows\\Media\\flourish.mid")
-	midiFile, _ := meltysynth.NewMidiFile(mid)
+	mid, err := os.Open(midiFilePath)
+	if err != nil {
+		return err
+	}
+	midiFile, err := meltysynth.NewMidiFile(mid)
 	mid.Close()
+	if err != nil {
+		return err
+	}
 
 	// Create the MIDI sequencer.
 	sequencer := meltysynth.NewMidiFileSequencer(synthesizer)
@@ -70,14 +116,22 @@ func flourish() {
 	// Render the waveform.
 	sequencer.Render(left, right)
 
-	writePcmInterleavedInt16(left, right, "flourish.pcm")
+	return writeFile(left, right, outputFile)
 }
 
-func writePcmInterleavedInt16(left []float32, right []float32, path string) {
+func writeFile(left []float32, right []float32, filename string) error {
+	f, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
 
-	length := len(left)
+	return writePCMInterleavedInt16(left, right, f)
+}
 
-	max := 0.0
+func writePCMInterleavedInt16(left []float32, right []float32, pcm io.Writer) error {
+	length := len(left)
+	var max float64
 
 	for i := 0; i < length; i++ {
 		absLeft := math.Abs(float64(left[i]))
@@ -99,7 +153,5 @@ func writePcmInterleavedInt16(left []float32, right []float32, path string) {
 		data[2*i+1] = int16(a * right[i])
 	}
 
-	pcm, _ := os.Create(path)
-	binary.Write(pcm, binary.LittleEndian, data)
-	pcm.Close()
+	return binary.Write(pcm, binary.LittleEndian, data)
 }

meltysynth/array_math.go

@@ -1,15 +1,13 @@
 package meltysynth
 
 func arrayMultiplyAdd(a float32, x []float32, dst []float32) {
-
 	dstLen := len(dst)
 	for i := 0; i < dstLen; i++ {
 		dst[i] += a * x[i]
 	}
 }
 
 func arrayMultiplyAddSlope(a float32, step float32, x []float32, dst []float32) {
-
 	dstLen := len(dst)
 	for i := 0; i < dstLen; i++ {
 		dst[i] += a * x[i]

meltysynth/binaryreader_ex.go

@@ -7,7 +7,6 @@ import (
 )
 
 func readFourCC(r io.Reader) (string, error) {
-
 	var data [4]byte
 	n, err := r.Read(data[:])
 	if err != nil {
@@ -28,7 +27,6 @@ func readFourCC(r io.Reader) (string, error) {
 }
 
 func readFixedLengthString(r io.Reader, length int32) (string, error) {
-
 	var data []byte = make([]byte, length)
 	n, err := r.Read(data[:])
 	if err != nil {
@@ -49,8 +47,7 @@ func readFixedLengthString(r io.Reader, length int32) (string, error) {
 }
 
 func readIntVariableLength(r io.Reader) (int32, error) {
-
-	acc := int32(0)
+	var acc int32
 	count := 0
 	for {
 		var value byte

meltysynth/biquad_filter.go

@@ -34,42 +34,35 @@ func (bf *biQuadFilter) clearBuffer() {
 }
 
 func (bf *biQuadFilter) setLowPassFilter(cutoffFrequency float32, resonance float32) {
+	if cutoffFrequency >= 0.499*float32(bf.synthesizer.SampleRate) {
+		bf.active = false
+		return
+	}
+	bf.active = true
 
-	if cutoffFrequency < 0.499*float32(bf.synthesizer.SampleRate) {
-
-		bf.active = true
-
-		// This equation gives the Q value which makes the desired resonance peak.
-		// The error of the resultant peak height is less than 3%.
-		q := resonance - resonancePeakOffset/(1+6*(resonance-1))
-
-		w := 2 * math.Pi * float64(cutoffFrequency) / float64(bf.synthesizer.SampleRate)
-		cosw := math.Cos(w)
-		alpha := math.Sin(w) / float64(2*q)
-
-		b0 := (1 - cosw) / 2
-		b1 := 1 - cosw
-		b2 := (1 - cosw) / 2
-		a0 := 1 + alpha
-		a1 := -2 * cosw
-		a2 := 1 - alpha
+	// This equation gives the Q value which makes the desired resonance peak.
+	// The error of the resultant peak height is less than 3%.
+	q := resonance - resonancePeakOffset/(1+6*(resonance-1))
 
-		bf.setCoefficients(float32(a0), float32(a1), float32(a2), float32(b0), float32(b1), float32(b2))
+	w := 2 * math.Pi * float64(cutoffFrequency) / float64(bf.synthesizer.SampleRate)
+	cosw := math.Cos(w)
+	alpha := math.Sin(w) / float64(2*q)
 
-	} else {
+	b0 := (1 - cosw) / 2
+	b1 := 1 - cosw
+	b2 := (1 - cosw) / 2
+	a0 := 1 + alpha
+	a1 := -2 * cosw
+	a2 := 1 - alpha
 
-		bf.active = false
-	}
+	bf.setCoefficients(float32(a0), float32(a1), float32(a2), float32(b0), float32(b1), float32(b2))
 }
 
 func (bf *biQuadFilter) process(block []float32) {
-
 	blockLength := len(block)
 
 	if bf.active {
-
 		for t := 0; t < blockLength; t++ {
-
 			input := block[t]
 			output := bf.a0*input + bf.a1*bf.x1 + bf.a2*bf.x2 - bf.a3*bf.y1 - bf.a4*bf.y2
 
@@ -80,9 +73,7 @@ func (bf *biQuadFilter) process(block []float32) {
 
 			block[t] = output
 		}
-
 	} else {
-
 		bf.x2 = block[blockLength-2]
 		bf.x1 = block[blockLength-1]
 		bf.y2 = bf.x2

meltysynth/channel.go

@@ -25,7 +25,6 @@ type channel struct {
 }
 
 func newChannel(s *Synthesizer, isPercussionChannel bool) *channel {
-
 	result := new(channel)
 
 	result.synthesizer = s
@@ -37,7 +36,6 @@ func newChannel(s *Synthesizer, isPercussionChannel bool) *channel {
 }
 
 func (ch *channel) reset() {
-
 	if ch.isPercussionChannel {
 		ch.bankNumber = 128
 	} else {
@@ -64,7 +62,6 @@ func (ch *channel) reset() {
 }
 
 func (ch *channel) resetAllControllers() {
-
 	ch.modulation = 0
 	ch.expression = 127 << 7
 	ch.holdPedal = false
@@ -75,7 +72,6 @@ func (ch *channel) resetAllControllers() {
 }
 
 func (ch *channel) setBank(value int32) {
-
 	ch.bankNumber = value
 
 	if ch.isPercussionChannel {

meltysynth/generator.go

@@ -12,7 +12,6 @@ type generator struct {
 }
 
 func readGeneratorsFromChunk(r io.Reader, size int32) ([]generator, error) {
-
 	var n int
 	var err error
 
@@ -21,11 +20,9 @@ func readGeneratorsFromChunk(r io.Reader, size int32) ([]generator, error) {
 	}
 
 	count := size/4 - 1
-
 	generators := make([]generator, count)
 
 	for i := int32(0); i < count; i++ {
-
 		var gen generator
 
 		var generatorType uint16

meltysynth/instrument.go

@@ -10,11 +10,9 @@ type Instrument struct {
 }
 
 func createInstrument(info *instrumentInfo, zones []*zone, samples []*SampleHeader) (*Instrument, error) {
-
 	var err error
 
 	result := new(Instrument)
-
 	result.Name = info.name
 
 	zoneCount := info.zoneEndIndex - info.zoneStartIndex + 1

meltysynth/instrument_info.go

@@ -13,19 +13,16 @@ type instrumentInfo struct {
 }
 
 func readInstrumentsFromChunk(r io.Reader, size int32) ([]*instrumentInfo, error) {
-
 	var err error
 
 	if size%22 != 0 {
 		return nil, errors.New("the instrument list is invalid")
 	}
 
 	count := size / 22
-
 	instruments := make([]*instrumentInfo, count)
 
 	for i := int32(0); i < count; i++ {
-
 		instrument := new(instrumentInfo)
 
 		instrument.name, err = readFixedLengthString(r, 20)

meltysynth/instrument_region.go

@@ -11,7 +11,6 @@ type InstrumentRegion struct {
 }
 
 func createInstrumentRegion(inst *Instrument, global *zone, local *zone, samples []*SampleHeader) (*InstrumentRegion, error) {
-
 	result := new(InstrumentRegion)
 
 	result.gs[gen_InitialFilterCutoffFrequency] = 13500
@@ -52,7 +51,6 @@ func createInstrumentRegion(inst *Instrument, global *zone, local *zone, samples
 }
 
 func createInstrumentRegions(inst *Instrument, zones []*zone, samples []*SampleHeader) ([]*InstrumentRegion, error) {
-
 	var err error
 
 	// Is the first one the global zone?
@@ -71,9 +69,7 @@ func createInstrumentRegions(inst *Instrument, zones []*zone, samples []*SampleH
 			}
 		}
 		return regions, nil
-
 	} else {
-
 		// No global zone.
 		count := len(zones)
 		regions := make([]*InstrumentRegion, count)
@@ -88,7 +84,6 @@ func createInstrumentRegions(inst *Instrument, zones []*zone, samples []*SampleH
 }
 
 func (region *InstrumentRegion) setParameter(param generator) {
-
 	index := param.generatorType
 
 	// Unknown generators should be ignored.