[WIP] Add facility to read samples from byte arrays

bind/api.go

@@ -1,10 +1,11 @@
-// Package bind is for modular binding of mix to audio interface
 package bind
 
 import (
 	"io"
 	"time"
 
+	riff "github.com/youpy/go-riff"
+
 	"github.com/go-mix/mix/bind/hardware/null"
 	"github.com/go-mix/mix/bind/opt"
 	"github.com/go-mix/mix/bind/sample"
@@ -65,6 +66,19 @@ func LoadWAV(file string) ([]sample.Sample, *spec.AudioSpec) {
 	}
 }
 
+// LoadWAVFromReader loads WAV data from an io.Reader+io.ReaderAt into a buffer
+func LoadWAVFromReader(r riff.RIFFReader) ([]sample.Sample, *spec.AudioSpec) {
+	switch useLoader {
+	case opt.InputWAV:
+		return wav.LoadFromReader(r)
+	case opt.InputSOX:
+		// SOX doesn't support io.Reader, fall back to WAV
+		return wav.LoadFromReader(r)
+	default:
+		return make([]sample.Sample, 0), &spec.AudioSpec{}
+	}
+}
+
 // Teardown to close all hardware bindings
 func Teardown() {
 	switch useOutput {

bind/wav/wav.go

@@ -5,6 +5,8 @@ import (
 	"io"
 	"os"
 
+	riff "github.com/youpy/go-riff"
+
 	"github.com/go-mix/mix/bind/sample"
 	"github.com/go-mix/mix/bind/spec"
 )
@@ -15,7 +17,12 @@ func Load(path string) (out []sample.Sample, specs *spec.AudioSpec) {
 		panic("File not found: " + path)
 	}
 	file, _ := os.Open(path)
-	reader, err := NewReader(file)
+	return LoadFromReader(file)
+}
+
+// LoadFromReader loads WAV data from an io.Reader+io.ReaderAt into memory
+func LoadFromReader(r riff.RIFFReader) (out []sample.Sample, specs *spec.AudioSpec) {
+	reader, err := NewReader(r)
 	if err != nil {
 		panic(err)
 	}

bind/wav/wav_test.go

@@ -2,9 +2,32 @@
 package wav
 
 import (
+	"bytes"
+	"io/ioutil"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestLoad(t *testing.T) {
 	// TODO
 }
+
+func TestLoadFromReader(t *testing.T) {
+	// Read a test WAV file
+	wavData, err := ioutil.ReadFile("../../lib/source/testdata/Signed16bitLittleEndian44100HzMono.wav")
+	assert.NoError(t, err)
+
+	// Create a bytes.Reader which implements both io.Reader and io.ReaderAt
+	reader := bytes.NewReader(wavData)
+
+	// Load from reader
+	samples, spec := LoadFromReader(reader)
+
+	// Verify we got samples and spec
+	assert.NotNil(t, samples)
+	assert.NotNil(t, spec)
+	assert.Greater(t, len(samples), 0)
+	assert.Greater(t, spec.Freq, float64(0))
+	assert.Greater(t, spec.Channels, 0)
+}

go.sum

@@ -1,11 +1,16 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/krig/go-sox v0.0.0-20180617124112-7d2f8ae31981 h1:ir4NRMjkkSP63kAOiFDTQN3dcs0o6c0f1cfpe9V8JT0=
 github.com/krig/go-sox v0.0.0-20180617124112-7d2f8ae31981/go.mod h1:0uPmTzngejep+JBRxvlmijKKMexuskpMCzWFp+oFzc4=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/youpy/go-riff v0.0.0-20131220112943-557d78c11efb h1:RDh7U5Di6o7fblIBe7rVi9KnrcOXUbLwvvLLdP2InSI=
 github.com/youpy/go-riff v0.0.0-20131220112943-557d78c11efb/go.mod h1:83nxdDV4Z9RzrTut9losK7ve4hUnxUR8ASSz4BsKXwQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/pkg/profile.v1 v1.3.0 h1:zQjfg5nVj3xAlW4eOk1IjKDjQ+SfQwcQXm+M1IemyYo=
 gopkg.in/pkg/profile.v1 v1.3.0/go.mod h1:knhHpoyiu3zB9bR/uG9+s8jTFrCOFA3g9Xkh/NCDzJ4=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

lib/source/source.go

@@ -1,9 +1,11 @@
-// Package source models a single audio source
 package source
 
 import (
+	"io"
 	"math"
 
+	riff "github.com/youpy/go-riff"
+
 	"github.com/go-mix/mix/bind"
 	"github.com/go-mix/mix/bind/debug"
 	"github.com/go-mix/mix/bind/sample"
@@ -26,6 +28,28 @@ func New(URL string) *Source {
 	return s
 }
 
+// NewFromReader creates a Source from an io.Reader+io.ReaderAt containing WAV data
+func NewFromReader(r riff.RIFFReader) *Source {
+	s := &Source{
+		state: STAGED,
+		URL:   "<reader>",
+	}
+	s.loadFromReader(r)
+	return s
+}
+
+// NewFromSamples creates a Source from pre-loaded sample data
+func NewFromSamples(samples []sample.Sample, audioSpec *spec.AudioSpec) *Source {
+	s := &Source{
+		state:     READY,
+		URL:       "<samples>",
+		sample:    samples,
+		audioSpec: audioSpec,
+		maxTz:     spec.Tz(len(samples)),
+	}
+	return s
+}
+
 // Source stores a series of Samples in Channels across Time, for audio playback.
 type Source struct {
 	URL string
@@ -103,6 +127,17 @@ func (s *Source) load() {
 	s.state = READY
 }
 
+func (s *Source) loadFromReader(r riff.RIFFReader) {
+	s.state = LOADING
+	s.sample, s.audioSpec = bind.LoadWAVFromReader(r)
+	if s.audioSpec == nil {
+		// TODO: handle errors loading from reader
+		debug.Printf("could not load WAV from reader\n")
+	}
+	s.maxTz = spec.Tz(len(s.sample))
+	s.state = READY
+}
+
 // volume (0 to 1), and pan (-1 to +1)
 // TODO: ensure implicit panning of source channels! e.g. 2 channels is full left, full right.
 func volume(channel float64, volume float64, pan float64) sample.Value {