[XMA] Added multiple versions of XMA decoders

- Fake: No decoding
- Master: 1:1 from base version of Xenia
- Old: Master with improvements
- New: Completely new decoder with better stability (but not compability)

Co-authored-by: Herman S. <429230+has207@users.noreply.github.com>

src/xenia/apu/xma_context_fake.h

@@ -0,0 +1,66 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2025 Xenia Canary. All rights reserved.                          *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_APU_XMA_CONTEXT_FAKE_H_
+#define XENIA_APU_XMA_CONTEXT_FAKE_H_
+
+#include <array>
+#include <atomic>
+#include <mutex>
+#include <queue>
+
+#include "xenia/apu/xma_context.h"
+#include "xenia/base/bit_stream.h"
+#include "xenia/base/ring_buffer.h"
+#include "xenia/memory.h"
+#include "xenia/xbox.h"
+
+namespace xe {
+namespace apu {
+
+class XmaContextFake : public XmaContext {
+ public:
+  static constexpr uint32_t kBitsPerPacketHeader = 32;
+  static constexpr uint32_t kMaxFrameSizeinBits = 0x4000 - kBitsPerPacketHeader;
+
+  explicit XmaContextFake();
+  ~XmaContextFake() override;
+
+  int Setup(uint32_t id, Memory* memory, uint32_t guest_ptr) override;
+  bool Work() override;
+
+  void Enable() override;
+  bool Block(bool poll) override;
+  void Clear() override;
+  void Disable() override;
+  void Release() override;
+
+ private:
+  void ProcessPacket(XMA_CONTEXT_DATA* data);
+  void Consume(RingBuffer* output_rb, XMA_CONTEXT_DATA* data);
+  void UpdateLoopStatus(XMA_CONTEXT_DATA* data);
+  RingBuffer PrepareOutputRingBuffer(XMA_CONTEXT_DATA* data);
+
+  static void SwapInputBuffer(XMA_CONTEXT_DATA* data);
+  static int GetSampleRate(int id);
+  uint8_t* GetCurrentInputBuffer(XMA_CONTEXT_DATA* data);
+  static uint32_t GetCurrentInputBufferSize(XMA_CONTEXT_DATA* data);
+
+  // Fake frame data - generate silence
+  std::array<uint8_t, kBytesPerFrameChannel * 2> fake_frame_;
+
+  // Minimal state tracking
+  int32_t remaining_subframe_blocks_in_output_buffer_ = 0;
+  uint8_t current_frame_remaining_subframes_ = 0;
+};
+
+}  // namespace apu
+}  // namespace xe
+
+#endif  // XENIA_APU_XMA_CONTEXT_FAKE_H_