diff --git a/src/encoder/plugins/VorbisEncoderPlugin.cxx b/src/encoder/plugins/VorbisEncoderPlugin.cxx
index ecc784a47..3cc941220 100644
--- a/src/encoder/plugins/VorbisEncoderPlugin.cxx
+++ b/src/encoder/plugins/VorbisEncoderPlugin.cxx
@@ -58,7 +58,7 @@ struct vorbis_encoder {
 static constexpr Domain vorbis_encoder_domain("vorbis_encoder");
 
 static bool
-vorbis_encoder_configure(struct vorbis_encoder *encoder,
+vorbis_encoder_configure(struct vorbis_encoder &encoder,
 			 const config_param &param, Error &error)
 {
 	const char *value = param.GetBlockValue("quality");
@@ -66,10 +66,10 @@ vorbis_encoder_configure(struct vorbis_encoder *encoder,
 		/* a quality was configured (VBR) */
 
 		char *endptr;
-		encoder->quality = ParseDouble(value, &endptr);
+		encoder.quality = ParseDouble(value, &endptr);
 
-		if (*endptr != '\0' || encoder->quality < -1.0 ||
-		    encoder->quality > 10.0) {
+		if (*endptr != '\0' || encoder.quality < -1.0 ||
+		    encoder.quality > 10.0) {
 			error.Format(config_domain,
 				     "quality \"%s\" is not a number in the "
 				     "range -1 to 10",
@@ -92,11 +92,11 @@ vorbis_encoder_configure(struct vorbis_encoder *encoder,
 			return false;
 		}
 
-		encoder->quality = -2.0;
+		encoder.quality = -2.0;
 
 		char *endptr;
-		encoder->bitrate = ParseInt(value, &endptr);
-		if (*endptr != '\0' || encoder->bitrate <= 0) {
+		encoder.bitrate = ParseInt(value, &endptr);
+		if (*endptr != '\0' || encoder.bitrate <= 0) {
 			error.Set(config_domain,
 				  "bitrate should be a positive integer");
 			return false;
@@ -112,7 +112,7 @@ vorbis_encoder_init(const config_param &param, Error &error)
 	vorbis_encoder *encoder = new vorbis_encoder();
 
 	/* load configuration from "param" */
-	if (!vorbis_encoder_configure(encoder, param, error)) {
+	if (!vorbis_encoder_configure(*encoder, param, error)) {
 		/* configuration has failed, roll back and return error */
 		delete encoder;
 		return nullptr;
@@ -132,63 +132,63 @@ vorbis_encoder_finish(Encoder *_encoder)
 }
 
 static bool
-vorbis_encoder_reinit(struct vorbis_encoder *encoder, Error &error)
+vorbis_encoder_reinit(struct vorbis_encoder &encoder, Error &error)
 {
-	vorbis_info_init(&encoder->vi);
+	vorbis_info_init(&encoder.vi);
 
-	if (encoder->quality >= -1.0) {
+	if (encoder.quality >= -1.0) {
 		/* a quality was configured (VBR) */
 
-		if (0 != vorbis_encode_init_vbr(&encoder->vi,
-						encoder->audio_format.channels,
-						encoder->audio_format.sample_rate,
-						encoder->quality * 0.1)) {
+		if (0 != vorbis_encode_init_vbr(&encoder.vi,
+						encoder.audio_format.channels,
+						encoder.audio_format.sample_rate,
+						encoder.quality * 0.1)) {
 			error.Set(vorbis_encoder_domain,
 				  "error initializing vorbis vbr");
-			vorbis_info_clear(&encoder->vi);
+			vorbis_info_clear(&encoder.vi);
 			return false;
 		}
 	} else {
 		/* a bit rate was configured */
 
-		if (0 != vorbis_encode_init(&encoder->vi,
-					    encoder->audio_format.channels,
-					    encoder->audio_format.sample_rate, -1.0,
-					    encoder->bitrate * 1000, -1.0)) {
+		if (0 != vorbis_encode_init(&encoder.vi,
+					    encoder.audio_format.channels,
+					    encoder.audio_format.sample_rate, -1.0,
+					    encoder.bitrate * 1000, -1.0)) {
 			error.Set(vorbis_encoder_domain,
 				  "error initializing vorbis encoder");
-			vorbis_info_clear(&encoder->vi);
+			vorbis_info_clear(&encoder.vi);
 			return false;
 		}
 	}
 
-	vorbis_analysis_init(&encoder->vd, &encoder->vi);
-	vorbis_block_init(&encoder->vd, &encoder->vb);
-	encoder->stream.Initialize(GenerateOggSerial());
+	vorbis_analysis_init(&encoder.vd, &encoder.vi);
+	vorbis_block_init(&encoder.vd, &encoder.vb);
+	encoder.stream.Initialize(GenerateOggSerial());
 
 	return true;
 }
 
 static void
-vorbis_encoder_headerout(struct vorbis_encoder *encoder, vorbis_comment *vc)
+vorbis_encoder_headerout(struct vorbis_encoder &encoder, vorbis_comment &vc)
 {
 	ogg_packet packet, comments, codebooks;
 
-	vorbis_analysis_headerout(&encoder->vd, vc,
+	vorbis_analysis_headerout(&encoder.vd, &vc,
 				  &packet, &comments, &codebooks);
 
-	encoder->stream.PacketIn(packet);
-	encoder->stream.PacketIn(comments);
-	encoder->stream.PacketIn(codebooks);
+	encoder.stream.PacketIn(packet);
+	encoder.stream.PacketIn(comments);
+	encoder.stream.PacketIn(codebooks);
 }
 
 static void
-vorbis_encoder_send_header(struct vorbis_encoder *encoder)
+vorbis_encoder_send_header(struct vorbis_encoder &encoder)
 {
 	vorbis_comment vc;
 
 	vorbis_comment_init(&vc);
-	vorbis_encoder_headerout(encoder, &vc);
+	vorbis_encoder_headerout(encoder, vc);
 	vorbis_comment_clear(&vc);
 }
 
@@ -197,11 +197,11 @@ vorbis_encoder_open(Encoder *_encoder,
 		    AudioFormat &audio_format,
 		    Error &error)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 
 	audio_format.format = SampleFormat::FLOAT;
 
-	encoder->audio_format = audio_format;
+	encoder.audio_format = audio_format;
 
 	if (!vorbis_encoder_reinit(encoder, error))
 		return false;
@@ -212,67 +212,67 @@ vorbis_encoder_open(Encoder *_encoder,
 }
 
 static void
-vorbis_encoder_clear(struct vorbis_encoder *encoder)
+vorbis_encoder_clear(struct vorbis_encoder &encoder)
 {
-	encoder->stream.Deinitialize();
-	vorbis_block_clear(&encoder->vb);
-	vorbis_dsp_clear(&encoder->vd);
-	vorbis_info_clear(&encoder->vi);
+	encoder.stream.Deinitialize();
+	vorbis_block_clear(&encoder.vb);
+	vorbis_dsp_clear(&encoder.vd);
+	vorbis_info_clear(&encoder.vi);
 }
 
 static void
 vorbis_encoder_close(Encoder *_encoder)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 
 	vorbis_encoder_clear(encoder);
 }
 
 static void
-vorbis_encoder_blockout(struct vorbis_encoder *encoder)
+vorbis_encoder_blockout(struct vorbis_encoder &encoder)
 {
-	while (vorbis_analysis_blockout(&encoder->vd, &encoder->vb) == 1) {
-		vorbis_analysis(&encoder->vb, nullptr);
-		vorbis_bitrate_addblock(&encoder->vb);
+	while (vorbis_analysis_blockout(&encoder.vd, &encoder.vb) == 1) {
+		vorbis_analysis(&encoder.vb, nullptr);
+		vorbis_bitrate_addblock(&encoder.vb);
 
 		ogg_packet packet;
-		while (vorbis_bitrate_flushpacket(&encoder->vd, &packet))
-			encoder->stream.PacketIn(packet);
+		while (vorbis_bitrate_flushpacket(&encoder.vd, &packet))
+			encoder.stream.PacketIn(packet);
 	}
 }
 
 static bool
 vorbis_encoder_flush(Encoder *_encoder, gcc_unused Error &error)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 
-	encoder->stream.Flush();
+	encoder.stream.Flush();
 	return true;
 }
 
 static bool
 vorbis_encoder_pre_tag(Encoder *_encoder, gcc_unused Error &error)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 
-	vorbis_analysis_wrote(&encoder->vd, 0);
+	vorbis_analysis_wrote(&encoder.vd, 0);
 	vorbis_encoder_blockout(encoder);
 
 	/* reinitialize vorbis_dsp_state and vorbis_block to reset the
 	   end-of-stream marker */
-	vorbis_block_clear(&encoder->vb);
-	vorbis_dsp_clear(&encoder->vd);
-	vorbis_analysis_init(&encoder->vd, &encoder->vi);
-	vorbis_block_init(&encoder->vd, &encoder->vb);
+	vorbis_block_clear(&encoder.vb);
+	vorbis_dsp_clear(&encoder.vd);
+	vorbis_analysis_init(&encoder.vd, &encoder.vi);
+	vorbis_block_init(&encoder.vd, &encoder.vb);
 
-	encoder->stream.Flush();
+	encoder.stream.Flush();
 	return true;
 }
 
 static void
-copy_tag_to_vorbis_comment(vorbis_comment *vc, const Tag *tag)
+copy_tag_to_vorbis_comment(vorbis_comment *vc, const Tag &tag)
 {
-	for (const auto &item : *tag) {
+	for (const auto &item : tag) {
 		char *name = g_ascii_strup(tag_item_names[item.type], -1);
 		vorbis_comment_add_tag(vc, name, item.value);
 		g_free(name);
@@ -283,21 +283,21 @@ static bool
 vorbis_encoder_tag(Encoder *_encoder, const Tag *tag,
 		   gcc_unused Error &error)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 	vorbis_comment comment;
 
 	/* write the vorbis_comment object */
 
 	vorbis_comment_init(&comment);
-	copy_tag_to_vorbis_comment(&comment, tag);
+	copy_tag_to_vorbis_comment(&comment, *tag);
 
 	/* reset ogg_stream_state and begin a new stream */
 
-	encoder->stream.Reinitialize(GenerateOggSerial());
+	encoder.stream.Reinitialize(GenerateOggSerial());
 
 	/* send that vorbis_comment to the ogg_stream_state */
 
-	vorbis_encoder_headerout(encoder, &comment);
+	vorbis_encoder_headerout(encoder, comment);
 	vorbis_comment_clear(&comment);
 
 	return true;
@@ -317,19 +317,19 @@ vorbis_encoder_write(Encoder *_encoder,
 		     const void *data, size_t length,
 		     gcc_unused Error &error)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 
-	unsigned num_frames = length / encoder->audio_format.GetFrameSize();
+	unsigned num_frames = length / encoder.audio_format.GetFrameSize();
 
 	/* this is for only 16-bit audio */
 
-	interleaved_to_vorbis_buffer(vorbis_analysis_buffer(&encoder->vd,
+	interleaved_to_vorbis_buffer(vorbis_analysis_buffer(&encoder.vd,
 							    num_frames),
 				     (const float *)data,
 				     num_frames,
-				     encoder->audio_format.channels);
+				     encoder.audio_format.channels);
 
-	vorbis_analysis_wrote(&encoder->vd, num_frames);
+	vorbis_analysis_wrote(&encoder.vd, num_frames);
 	vorbis_encoder_blockout(encoder);
 	return true;
 }
@@ -337,9 +337,9 @@ vorbis_encoder_write(Encoder *_encoder,
 static size_t
 vorbis_encoder_read(Encoder *_encoder, void *dest, size_t length)
 {
-	struct vorbis_encoder *encoder = (struct vorbis_encoder *)_encoder;
+	struct vorbis_encoder &encoder = *(struct vorbis_encoder *)_encoder;
 
-	return encoder->stream.PageOut(dest, length);
+	return encoder.stream.PageOut(dest, length);
 }
 
 static const char *