diff --git a/Core/HW/Atrac3Standalone.cpp b/Core/HW/Atrac3Standalone.cpp
index a195e02a49..dc73b46cc0 100644
--- a/Core/HW/Atrac3Standalone.cpp
+++ b/Core/HW/Atrac3Standalone.cpp
@@ -16,12 +16,25 @@ inline int16_t clamp16(float f) {
 // Test case for ATRAC3: Mega Man Maverick Hunter X, PSP menu sound
 class Atrac3Audio : public AudioDecoder {
 public:
-	Atrac3Audio(PSPAudioType audioType) : audioType_(audioType) {
+	Atrac3Audio(PSPAudioType audioType, int channels, size_t blockAlign, const uint8_t *extraData, size_t extraDataSize) : audioType_(audioType) {
 		if (audioType == PSP_CODEC_AT3PLUS) {
 			ctx_ = avcodec_alloc_context3(&ff_atrac3p_decoder);
 		} else {
 			ctx_ = avcodec_alloc_context3(&ff_atrac3_decoder);
 		}
+		if (audioType_ == PSP_CODEC_AT3) {
+			_dbg_assert_(ctx_);
+			_dbg_assert_(!codecOpen_);
+			ctx_->extradata = (uint8_t *)av_mallocz(extraDataSize);
+			ctx_->extradata_size = (int)extraDataSize;
+			ctx_->block_align = (int)blockAlign;
+			codecOpen_ = false;
+			if (extraData != nullptr) {
+				memcpy(ctx_->extradata, extraData, extraDataSize);
+			}
+		} else {
+			ctx_->block_align = (int)blockAlign;
+		}
 		for (int i = 0; i < 2; i++) {
 			buffers_[i] = new float[4096];
 		}
@@ -52,6 +65,10 @@ public:
 			codecOpen_ = true;
 		}
 
+		if (inbytes != ctx_->block_align) {
+			WARN_LOG(ME, "Atrac3Audio::Decode: Unexpected block align %d (expected %d)", inbytes, ctx_->block_align);
+		}
+
 		// We just call the decode function directly without going through the whole packet machinery.
 		int got_frame = 0;
 		int result;
@@ -96,20 +113,6 @@ public:
 		// Hmm. ignore for now.
 	}
 
-	void SetExtraData(const uint8_t *data, int size, int wav_bytes_per_packet) override {
-		// if (audioType_ == PSP_CODEC_AT3PLUS) {
-			_dbg_assert_(ctx_);
-			_dbg_assert_(!codecOpen_);
-			ctx_->extradata = (uint8_t *)av_mallocz(size);
-			ctx_->extradata_size = size;
-			ctx_->block_align = wav_bytes_per_packet;
-			codecOpen_ = false;
-			if (data != nullptr) {
-				memcpy(ctx_->extradata, data, size);
-			}
-		//}
-	}
-
 	PSPAudioType GetAudioType() const override { return audioType_; }
 
 private:
@@ -124,6 +127,9 @@ private:
 	PSPAudioType audioType_;
 };
 
-AudioDecoder *CreateAtrac3Audio(PSPAudioType audioType) {
-	return new Atrac3Audio(audioType);
+AudioDecoder *CreateAtrac3Audio(int channels, size_t blockAlign, const uint8_t *extraData, size_t extraDataSize) {
+	return new Atrac3Audio(PSP_CODEC_AT3, channels, blockAlign, extraData, extraDataSize);
+}
+AudioDecoder *CreateAtrac3PlusAudio(int channels, size_t blockAlign) {
+	return new Atrac3Audio(PSP_CODEC_AT3PLUS, channels, blockAlign, nullptr, 0);
 }
diff --git a/Core/HW/Atrac3Standalone.h b/Core/HW/Atrac3Standalone.h
index 713b1a21a2..a86fae1729 100644
--- a/Core/HW/Atrac3Standalone.h
+++ b/Core/HW/Atrac3Standalone.h
@@ -2,4 +2,5 @@
 
 #include "SimpleAudioDec.h"
 
-AudioDecoder *CreateAtrac3Audio(PSPAudioType audioType);
+AudioDecoder *CreateAtrac3Audio(int channels, size_t blockAlign, const uint8_t *extraData, size_t extraDataSize);
+AudioDecoder *CreateAtrac3PlusAudio(int channels, size_t blockAlign);
diff --git a/Core/HW/SimpleAudioDec.cpp b/Core/HW/SimpleAudioDec.cpp
index 0f72ae0469..83b79ec975 100644
--- a/Core/HW/SimpleAudioDec.cpp
+++ b/Core/HW/SimpleAudioDec.cpp
@@ -117,8 +117,6 @@ public:
 		return srcPos;
 	}
 
-	// Not save stated, only used by UI.  Used for ATRAC3 (non+) files.
-	void SetExtraData(const uint8_t *data, int size, int wav_bytes_per_packet) override;
 	void SetChannels(int channels) override;
 
 	// These two are only here because of save states.
@@ -144,13 +142,14 @@ private:
 	bool codecOpen_;
 };
 
-AudioDecoder *CreateAudioDecoder(PSPAudioType audioType, int sampleRateHz, int channels) {
+AudioDecoder *CreateAudioDecoder(PSPAudioType audioType, int sampleRateHz, int channels, size_t blockAlign, const uint8_t *extraData, size_t extraDataSize) {
 	switch (audioType) {
 	case PSP_CODEC_MP3:
 		return new MiniMp3Audio();
 	case PSP_CODEC_AT3:
+		return CreateAtrac3Audio(channels, blockAlign, extraData, extraDataSize);
 	case PSP_CODEC_AT3PLUS:
-		return CreateAtrac3Audio(audioType);
+		return CreateAtrac3PlusAudio(channels, blockAlign);
 	default:
 		// Only AAC falls back to FFMPEG now.
 		return new SimpleAudio(audioType, sampleRateHz, channels);
@@ -240,21 +239,6 @@ bool SimpleAudio::OpenCodec(int block_align) {
 #endif  // USE_FFMPEG
 }
 
-void SimpleAudio::SetExtraData(const uint8_t *data, int size, int wav_bytes_per_packet) {
-#ifdef USE_FFMPEG
-	if (codecCtx_) {
-		codecCtx_->extradata = (uint8_t *)av_mallocz(size);
-		codecCtx_->extradata_size = size;
-		codecCtx_->block_align = wav_bytes_per_packet;
-		codecOpen_ = false;
-
-		if (data != nullptr) {
-			memcpy(codecCtx_->extradata, data, size);
-		}
-	}
-#endif
-}
-
 void SimpleAudio::SetChannels(int channels) {
 	if (channels_ == channels) {
 		// Do nothing, already set.
diff --git a/Core/HW/SimpleAudioDec.h b/Core/HW/SimpleAudioDec.h
index e4c2cf0116..8ee4e45aa1 100644
--- a/Core/HW/SimpleAudioDec.h
+++ b/Core/HW/SimpleAudioDec.h
@@ -47,7 +47,6 @@ public:
 	virtual int GetSourcePos() const = 0;
 
 	virtual void SetChannels(int channels) = 0;
-	virtual void SetExtraData(const uint8_t *data, int size, int wav_bytes_per_packet) {}
 
 	// Just metadata.
 	void SetCtxPtr(uint32_t ptr) { ctxPtr = ptr; }
@@ -60,7 +59,7 @@ private:
 void AudioClose(AudioDecoder **ctx);
 const char *GetCodecName(int codec);  // audioType
 bool IsValidCodec(PSPAudioType codec);
-AudioDecoder *CreateAudioDecoder(PSPAudioType audioType, int sampleRateHz = 44100, int channels = 2);
+AudioDecoder *CreateAudioDecoder(PSPAudioType audioType, int sampleRateHz = 44100, int channels = 2, size_t blockAlign = 0, const uint8_t *extraData = nullptr, size_t extraDataSize = 0);
 
 class AuCtx {
 public:
diff --git a/UI/BackgroundAudio.cpp b/UI/BackgroundAudio.cpp
index 471d245476..fc528274fa 100644
--- a/UI/BackgroundAudio.cpp
+++ b/UI/BackgroundAudio.cpp
@@ -189,10 +189,17 @@ public:
 
 		wave_.Read(file_);
 
-		decoder_ = CreateAudioDecoder((PSPAudioType)wave_.codec, wave_.sample_rate, wave_.num_channels);
+		uint8_t *extraData = nullptr;
+		size_t extraDataSize = 0;
+		size_t blockSize = 0;
 		if (wave_.codec == PSP_CODEC_AT3) {
-			decoder_->SetExtraData(&wave_.at3_extradata[2], 14, wave_.raw_bytes_per_frame);
+			extraData = &wave_.at3_extradata[2];
+			extraDataSize = 14;
+			blockSize = wave_.raw_bytes_per_frame;
+		} else if (wave_.codec == PSP_CODEC_AT3PLUS) {
+			blockSize = wave_.raw_bytes_per_frame;
 		}
+		decoder_ = CreateAudioDecoder((PSPAudioType)wave_.codec, wave_.sample_rate, wave_.num_channels, blockSize, extraData, extraDataSize);
 		INFO_LOG(AUDIO, "read ATRAC, frames: %d, rate %d", wave_.numFrames, wave_.sample_rate);
 	}