add aac utilities

pkg/aac/mpeg4audioconfig_test.go

@@ -0,0 +1,155 @@
+package aac
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var configCases = []struct {
+	name string
+	enc  []byte
+	dec  MPEG4AudioConfig
+}{
+	{
+		"aac-lc 44.1khz mono",
+		[]byte{0x12, 0x08, 0x56, 0xe5, 0x00},
+		MPEG4AudioConfig{
+			Type:              MPEG4AudioTypeAACLC,
+			SampleRate:        44100,
+			ChannelCount:      1,
+			AOTSpecificConfig: []byte{0x0A, 0xDC, 0xA0},
+		},
+	},
+	{
+		"aac-lc 48khz stereo",
+		[]byte{17, 144},
+		MPEG4AudioConfig{
+			Type:         MPEG4AudioTypeAACLC,
+			SampleRate:   48000,
+			ChannelCount: 2,
+		},
+	},
+	{
+		"aac-lc 96khz stereo",
+		[]byte{0x10, 0x10, 0x56, 0xE5, 0x00},
+		MPEG4AudioConfig{
+			Type:              MPEG4AudioTypeAACLC,
+			SampleRate:        96000,
+			ChannelCount:      2,
+			AOTSpecificConfig: []byte{0x0A, 0xDC, 0xA0},
+		},
+	},
+	{
+		"aac-lc 44.1khz 5.1",
+		[]byte{0x12, 0x30},
+		MPEG4AudioConfig{
+			Type:         MPEG4AudioTypeAACLC,
+			SampleRate:   44100,
+			ChannelCount: 6,
+		},
+	},
+	{
+		"aac-lc 53khz stereo",
+		[]byte{0x17, 0x80, 0x67, 0x84, 0x10},
+		MPEG4AudioConfig{
+			Type:         MPEG4AudioTypeAACLC,
+			SampleRate:   53000,
+			ChannelCount: 2,
+		},
+	},
+}
+
+func TestConfigDecode(t *testing.T) {
+	for _, ca := range configCases {
+		t.Run(ca.name, func(t *testing.T) {
+			var dec MPEG4AudioConfig
+			err := dec.Decode(ca.enc)
+			require.NoError(t, err)
+			require.Equal(t, ca.dec, dec)
+		})
+	}
+}
+
+func TestConfigDecodeErrors(t *testing.T) {
+	for _, ca := range []struct {
+		name string
+		byts []byte
+		err  string
+	}{
+		{
+			"empty",
+			[]byte{},
+			"EOF",
+		},
+		{
+			"unsupported type",
+			[]byte{18 << 3},
+			"unsupported type: 18",
+		},
+		{
+			"sample rate missing",
+			[]byte{0x12},
+			"EOF",
+		},
+		{
+			"sample rate invalid",
+			[]byte{0x17, 0},
+			"invalid sample rate index (14)",
+		},
+		{
+			"explicit sample rate missing",
+			[]byte{0x17, 0x80, 0x67},
+			"EOF",
+		},
+		{
+			"channel configuration invalid",
+			[]byte{0x11, 0xF0},
+			"invalid channel configuration (14)",
+		},
+		{
+			"channel configuration zero",
+			[]byte{0x11, 0x80},
+			"not yet supported",
+		},
+	} {
+		t.Run(ca.name, func(t *testing.T) {
+			var dec MPEG4AudioConfig
+			err := dec.Decode(ca.byts)
+			require.Equal(t, ca.err, err.Error())
+		})
+	}
+}
+
+func TestConfigEncode(t *testing.T) {
+	for _, ca := range configCases {
+		t.Run(ca.name, func(t *testing.T) {
+			enc, err := ca.dec.Encode()
+			require.NoError(t, err)
+			require.Equal(t, ca.enc, enc)
+		})
+	}
+}
+
+func TestConfigEncodeErrors(t *testing.T) {
+	for _, ca := range []struct {
+		name string
+		conf MPEG4AudioConfig
+		err  string
+	}{
+		{
+			"invalid channel config",
+			MPEG4AudioConfig{
+				Type:         2,
+				SampleRate:   44100,
+				ChannelCount: 0,
+			},
+			"invalid channel count (0)",
+		},
+	} {
+		t.Run(ca.name, func(t *testing.T) {
+			_, err := ca.conf.Encode()
+			require.Equal(t, ca.err, err.Error())
+		})
+	}
+}