Add audio/wav package

examples/_resources/audio/license.md

@@ -1,8 +1,19 @@
 # License
 
+## jab.wav
+
+```
+http://soundbible.com/995-Jab.html
+
+Recorded by Mike Koenig
+Attribution 3.0: https://creativecommons.org/licenses/by/3.0/
+```
+
 ## ragtime.ogg
 
 ```
+https://soundcloud.com/jacaranda-trilhas-sonoras/james-scott-01-frog-legs-rag
+
 Title:  Frog Legs Rag (1906, piano roll)
 Artist: James Scott
 Album:  Frog Legs: Ragtime Era Favorites

examples/audio/main.go

@@ -15,8 +15,10 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"image/color"
+	"io"
 	"log"
 	"time"
 
@@ -24,6 +26,7 @@ import (
 	"github.com/hajimehoshi/ebiten/ebitenutil"
 	"github.com/hajimehoshi/ebiten/exp/audio"
 	"github.com/hajimehoshi/ebiten/exp/audio/vorbis"
+	"github.com/hajimehoshi/ebiten/exp/audio/wav"
 )
 
 const (
@@ -58,8 +61,10 @@ type Player struct {
 
 var (
 	audioContext     *audio.Context
-	player           *Player
+	musicPlayer      *Player
-	playerCh         = make(chan *Player)
+	seStream         *wav.Stream
+	musicCh          = make(chan *Player)
+	seCh             = make(chan *wav.Stream)
 	mouseButtonState = map[ebiten.MouseButton]int{}
 	keyState         = map[ebiten.Key]int{}
 )
@@ -71,6 +76,33 @@ func playerBarRect() (x, y, w, h int) {
 	return
 }
 
+func (p *Player) updateSE() error {
+	if seStream == nil {
+		return nil
+	}
+	if !ebiten.IsKeyPressed(ebiten.KeyP) {
+		keyState[ebiten.KeyP] = 0
+		return nil
+	}
+	keyState[ebiten.KeyP]++
+	if keyState[ebiten.KeyP] != 1 {
+		return nil
+	}
+	// Clone the stream
+	b := &bytes.Buffer{}
+	if _, err := seStream.Seek(0, 0); err != nil {
+		return err
+	}
+	if _, err := io.Copy(b, seStream); err != nil {
+		return err
+	}
+	sePlayer, err := audioContext.NewPlayer(bytes.NewReader(b.Bytes()))
+	if err != nil {
+		return err
+	}
+	return sePlayer.Play()
+}
+
 func (p *Player) updatePlayPause() error {
 	if p.audioPlayer == nil {
 		return nil
@@ -115,17 +147,26 @@ func (p *Player) updateBar() error {
 
 func update(screen *ebiten.Image) error {
 	audioContext.Update()
-	if player == nil {
+	if musicPlayer == nil {
 		select {
-		case player = <-playerCh:
+		case musicPlayer = <-musicCh:
 		default:
 		}
 	}
-	if player != nil {
+	if seStream == nil {
-		if err := player.updateBar(); err != nil {
+		select {
+		case seStream = <-seCh:
+		default:
+		}
+	}
+	if musicPlayer != nil {
+		if err := musicPlayer.updateBar(); err != nil {
 			return err
 		}
-		if err := player.updatePlayPause(); err != nil {
+		if err := musicPlayer.updatePlayPause(); err != nil {
+			return err
+		}
+		if err := musicPlayer.updateSE(); err != nil {
 			return err
 		}
 	}
@@ -135,8 +176,8 @@ func update(screen *ebiten.Image) error {
 	op.GeoM.Translate(float64(x), float64(y))
 	screen.DrawImage(playerBarImage, op)
 	currentTimeStr := "00:00"
-	if player != nil {
+	if musicPlayer != nil {
-		c := player.audioPlayer.Current()
+		c := musicPlayer.audioPlayer.Current()
 
 		// Current Time
 		m := (c / time.Minute) % 100
@@ -145,7 +186,7 @@ func update(screen *ebiten.Image) error {
 
 		// Bar
 		cw, ch := playerCurrentImage.Size()
-		cx := int(time.Duration(w)*c/player.total) + x - cw/2
+		cx := int(time.Duration(w)*c/musicPlayer.total) + x - cw/2
 		cy := y - (ch-h)/2
 		op := &ebiten.DrawImageOptions{}
 		op.GeoM.Translate(float64(cx), float64(cy))
@@ -154,8 +195,9 @@ func update(screen *ebiten.Image) error {
 
 	msg := fmt.Sprintf(`FPS: %0.2f
 Press S to toggle Play/Pause
+Press P to play SE
 %s`, ebiten.CurrentFPS(), currentTimeStr)
-	if player == nil {
+	if musicPlayer == nil {
 		msg += "\nNow Loading..."
 	}
 	ebitenutil.DebugPrint(screen, msg)
@@ -163,16 +205,26 @@ Press S to toggle Play/Pause
 }
 
 func main() {
-	// Use a FLAC file so far: I couldn't find any good OGG/Vorbis decoder in pure Go.
+	wavF, err := ebitenutil.OpenFile("_resources/audio/jab.wav")
-	f, err := ebitenutil.OpenFile("_resources/audio/ragtime.ogg")
+	if err != nil {
+		log.Fatal(err)
+	}
+	oggF, err := ebitenutil.OpenFile("_resources/audio/ragtime.ogg")
 	if err != nil {
 		log.Fatal(err)
 	}
-	// TODO: sampleRate should be obtained from the ogg file.
 	audioContext = audio.NewContext(22050)
-	// TODO: This doesn't work synchronously on browsers because of decoding. Fix this.
 	go func() {
-		s, err := vorbis.Decode(audioContext, f)
+		s, err := wav.Decode(audioContext, wavF)
+		if err != nil {
+			log.Fatal(err)
+			return
+		}
+		seCh <- s
+		close(seCh)
+	}()
+	go func() {
+		s, err := vorbis.Decode(audioContext, oggF)
 		if err != nil {
 			log.Fatal(err)
 			return
@@ -182,11 +234,12 @@ func main() {
 			log.Fatal(err)
 			return
 		}
-		playerCh <- &Player{
+		musicCh <- &Player{
 			audioPlayer: p,
 			total:       s.Len(),
 		}
-		close(playerCh)
+		close(musicCh)
+		// TODO: Is this goroutine-safe?
 		p.Play()
 	}()
 	if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Audio (Ebiten Demo)"); err != nil {

exp/audio/wav/decode.go

@@ -0,0 +1,86 @@
+// Copyright 2016 Hajime Hoshi
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package wav
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"time"
+
+	"github.com/hajimehoshi/ebiten/exp/audio"
+)
+
+const (
+	headerSize = 44
+	riffHeader = "RIFF"
+	waveHeader = "WAVE"
+)
+
+type Stream struct {
+	buf        *bytes.Reader
+	sampleRate int
+}
+
+func (s *Stream) Read(p []byte) (int, error) {
+	return s.buf.Read(p)
+}
+
+func (s *Stream) Seek(offset int64, whence int) (int64, error) {
+	return s.buf.Seek(offset, whence)
+}
+
+func (s *Stream) Len() time.Duration {
+	const bytesPerSample = 4
+	return time.Duration(s.buf.Len()/bytesPerSample) * time.Second / time.Duration(s.sampleRate)
+}
+
+func Decode(context *audio.Context, src io.Reader) (*Stream, error) {
+	buf := make([]byte, headerSize)
+	n, err := io.ReadFull(src, buf)
+	if n != headerSize {
+		return nil, fmt.Errorf("wav: invalid header")
+	}
+	if err != nil {
+		return nil, err
+	}
+	if !bytes.Equal(buf[0:4], []byte(riffHeader)) {
+		return nil, fmt.Errorf("wav: invalid header: RIFF not found")
+	}
+	if !bytes.Equal(buf[8:12], []byte(waveHeader)) {
+		return nil, fmt.Errorf("wav: invalid header: WAVE not found")
+	}
+	channels, depth := buf[22], buf[34]
+	if channels != 2 {
+		return nil, fmt.Errorf("wav: invalid header: channel num must be 2")
+	}
+	if depth != 16 {
+		return nil, fmt.Errorf("wav: invalid header: depth must be 16")
+	}
+	sampleRate := int(buf[24]) | int(buf[25])<<8 | int(buf[26])<<16 | int(buf[27]<<24)
+	if context.SampleRate() != sampleRate {
+		return nil, fmt.Errorf("wav: sample rate must be %d but %d", context.SampleRate(), sampleRate)
+	}
+	b, err := ioutil.ReadAll(src)
+	if err != nil {
+		return nil, err
+	}
+	s := &Stream{
+		buf:        bytes.NewReader(b),
+		sampleRate: sampleRate,
+	}
+	return s, nil
+}