mpeg4audio: fix regression due to #219 (#223)

pkg/codecs/mpeg4audio/audio_specific_config.go

@@ -22,6 +22,7 @@ type AudioSpecificConfig struct {
 	ExtensionType       ObjectType
 	ExtensionSampleRate int
 
+	// GASpecificConfig
 	FrameLengthFlag    bool
 	DependsOnCoreCoder bool
 	CoreCoderDelay     uint16
@@ -35,15 +36,6 @@ func (c *AudioSpecificConfig) Unmarshal(buf []byte) error {
 		return err
 	}
 
-	n := pos / 8
-	if pos%8 != 0 {
-		n++
-	}
-
-	if n != len(buf) {
-		return fmt.Errorf("detected unread bytes")
-	}
-
 	return nil
 }
 
@@ -121,7 +113,7 @@ func (c *AudioSpecificConfig) UnmarshalFromPos(buf []byte, pos *int) error {
 			c.ExtensionSampleRate = int(tmp)
 
 		default:
-			return fmt.Errorf("invalid extension sample rate index (%d)", extensionSamplingFrequencyIndex)
+			return fmt.Errorf("invalid extension sample rate index: %d", extensionSamplingFrequencyIndex)
 		}
 
 		tmp, err = bits.ReadBits(buf, pos, 5)
@@ -135,6 +127,8 @@ func (c *AudioSpecificConfig) UnmarshalFromPos(buf []byte, pos *int) error {
 		}
 	}
 
+	// GASpecificConfig
+
 	c.FrameLengthFlag, err = bits.ReadFlag(buf, pos)
 	if err != nil {
 		return err
@@ -159,7 +153,7 @@ func (c *AudioSpecificConfig) UnmarshalFromPos(buf []byte, pos *int) error {
 	}
 
 	if extensionFlag {
-		return fmt.Errorf("unsupported")
+		return fmt.Errorf("extensionFlag is unsupported")
 	}
 
 	return nil

pkg/codecs/mpeg4audio/audio_specific_config_test.go

@@ -122,6 +122,31 @@ func TestAudioSpecificConfigUnmarshal(t *testing.T) {
 	}
 }
 
+func TestAudioSpecificConfigUnmarshalAdditional(t *testing.T) {
+	for _, ca := range []struct {
+		name string
+		enc  []byte
+		dec  AudioSpecificConfig
+	}{
+		{
+			"additional bytes",
+			[]byte{0x11, 0x90, 0x08, 0x10},
+			AudioSpecificConfig{
+				Type:         ObjectTypeAACLC,
+				SampleRate:   48000,
+				ChannelCount: 2,
+			},
+		},
+	} {
+		t.Run(ca.name, func(t *testing.T) {
+			var dec AudioSpecificConfig
+			err := dec.Unmarshal(ca.enc)
+			require.NoError(t, err)
+			require.Equal(t, ca.dec, dec)
+		})
+	}
+}
+
 func TestAudioSpecificConfigMarshal(t *testing.T) {
 	for _, ca := range audioSpecificConfigCases {
 		t.Run(ca.name, func(t *testing.T) {