nativeaudio

commit e8bf58c33b5795abb6799a7ed58d65fbc570c14b
parent 852abf67ebee4d6f5007240ef33c78a8fb2b3d43
Author: Jack Mordaunt <jackmordaunt.dev@gmail.com>
Date:   Wed, 16 Sep 2026 21:26:39 -0400

audio: [Windows] release COM objects after they are created

`defer x.Release()` evaluates the receiver at the defer statement. Every
Media Foundation object was deferred before the call that assigned it,
so each Release ran against a nil pointer and did nothing. The byte
stream, attributes, source reader and both media types leaked on every
decode. Deferring after the creating call succeeds fixes the leak and
also avoids a Release on a pointer that was never assigned when the call
fails.

Diffstat:
M
audio_windows.go
 | 
17
++++++-----------

1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/audio_windows.go b/audio_windows.go
@@ -71,19 +71,17 @@ func decode(compressed []byte) (uncompressed []byte, format Format, err error) {
 
 	// We need to adapt the generic IStream to a Media Foundation stream type.
 	var mfByteStream *IMFByteStream
-	defer mfByteStream.Release()
-
 	if err := MFCreateMFByteStreamOnStream(stream, &mfByteStream); err != nil {
 		return nil, format, fmt.Errorf("creating MFByteStream from IStream: %w", err)
 	}
+	defer mfByteStream.Release()
 
 	// Attributes to configure the source reader with; specifically, enable hardware codecs.
 	var attributes *IMFAttributes
-	defer attributes.Release()
-
 	if err := MFCreateAttributes(&attributes, 1); err != nil {
 		return nil, format, fmt.Errorf("creating attributes to apply to source reader: %w", err)
 	}
+	defer attributes.Release()
 
 	if err := attributes.SetUINT32(&MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, 1); err != nil {
 		return nil, format, fmt.Errorf("enabling hardware transforms: %w", err)
@@ -91,11 +89,10 @@ func decode(compressed []byte) (uncompressed []byte, format Format, err error) {
 
 	// Create the source reader using the byte stream.
 	var mfSourceReader *IMFSourceReader
-	defer mfSourceReader.Release()
-
 	if err := MFCreateSourceReaderFromByteStream(mfByteStream, attributes, &mfSourceReader); err != nil {
 		return nil, format, fmt.Errorf("creating IMFSourceReader from IMFByteStream: %w", err)
 	}
+	defer mfSourceReader.Release()
 
 	if err := configureAudioStream(mfSourceReader); err != nil {
 		return nil, format, fmt.Errorf("configuring audio stream: %w", err)
@@ -119,12 +116,11 @@ func decode(compressed []byte) (uncompressed []byte, format Format, err error) {
 // configureAudioStream selects the first audio stream and configures it output PCM.
 func configureAudioStream(pReader *IMFSourceReader) error {
 	var pPartialType *IMFMediaType
-	defer pPartialType.Release()
-
-	// Create a partial media pUncompressedAutioTypee that specifies uncompressed PCM audio.
+	// Create a partial media type that specifies uncompressed PCM audio.
 	if err := MFCreateMediaType(&pPartialType); err != nil {
 		return fmt.Errorf("creating media type: %w", err)
 	}
+	defer pPartialType.Release()
 
 	if err := pPartialType.SetGUID(&MF_MT_MAJOR_TYPE, &MFMediaType_Audio); err != nil {
 		return fmt.Errorf("setting major type: %w", err)
@@ -153,12 +149,11 @@ func configureAudioStream(pReader *IMFSourceReader) error {
 // getSourceReaderFormat returns the audio format configured for the source reader.
 func getSourceReaderFormat(sr *IMFSourceReader) (f Format, _ error) {
 	var mfMediaType *IMFMediaType
-	defer mfMediaType.Release()
-
 	// Get the complete uncompressed format.
 	if err := sr.GetCurrentMediaType(MF_SOURCE_READER_FIRST_AUDIO_STREAM, &mfMediaType); err != nil {
 		return f, fmt.Errorf("getting the current media type: %w", err)
 	}
+	defer mfMediaType.Release()
 
 	return getFormat(mfMediaType)
 }