move codec utilities into dedicated packages

pkg/codecaac/mpeg4audioconfig_test.go

@@ -0,0 +1,52 @@
+package codecaac
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var configCases = []struct {
+	name string
+	enc  []byte
+	dec  MPEG4AudioConfig
+}{
+	{
+		name: "aac-lc 48khz stereo",
+		enc:  []byte{17, 144},
+		dec: MPEG4AudioConfig{
+			Type:         MPEG4AudioTypeAACLC,
+			SampleRate:   48000,
+			ChannelCount: 2,
+		},
+	},
+	{
+		name: "aac-lc 96khz stereo",
+		enc:  []byte{0x10, 0x10, 0x56, 0xE5, 0x00},
+		dec: MPEG4AudioConfig{
+			Type:         MPEG4AudioTypeAACLC,
+			SampleRate:   96000,
+			ChannelCount: 2,
+		},
+	},
+	{
+		name: "aac-lc 44.1khz 5.1",
+		enc:  []byte{0x12, 0x30},
+		dec: MPEG4AudioConfig{
+			Type:         MPEG4AudioTypeAACLC,
+			SampleRate:   44100,
+			ChannelCount: 6,
+		},
+	},
+}
+
+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)
+		})
+	}
+}