container/flv/audio_test.go: added test TestAudioTagBytes

Wrote test TestAudioTagBytes to check that we can correctly get a []byte representation of an
AudioTag.

container/flv/flv_test.go

@@ -73,5 +73,39 @@ func TestVideoTagBytes(t *testing.T) {
 }
 
 func TestAudioTagBytes(t *testing.T) {
+	tests := []struct {
+		tag      AudioTag
+		expected []byte
+	}{
+		{
+			tag: AudioTag{
+				TagType:           AudioTagType,
+				DataSize:          8,
+				Timestamp:         1234,
+				TimestampExtended: 56,
+				SoundFormat:       AACAudioFormat,
+				SoundRate:         3,
+				SoundSize:         true,
+				SoundType:         true,
+				Data:              []byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07},
+			},
+			expected: []byte{
+				0x08,             // TagType.
+				0x00, 0x00, 0x08, // DataSize.
+				0x00, 0x04, 0xd2, // Timestamp.
+				0x38,             // TimestampExtended.
+				0x00, 0x00, 0x00, // StreamID. (always 0)
+				0xaf,                                     // SoundFormat=1010,SoundRate=11,SoundSize=1,SoundType=1
+				0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, // AudioData.
+				0x00, 0x00, 0x00, 0x00, // previousTagSize.
+			},
+		},
+	}
 
+	for testNum, test := range tests {
+		got := test.tag.Bytes()
+		if !bytes.Equal(got, test.expected) {
+			t.Errorf("did not get expected result for test: %v.\n Got: %v\n Want: %v\n", testNum, got, test.expected)
+		}
+	}
 }