Moved the XMA decoder out of AudioSystem and into its own world (plus minor code cleanup in the process).

src/xenia/apu/xma_context.h

@@ -0,0 +1,169 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2015 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_APU_XMA_CONTEXT_H_
+#define XENIA_APU_XMA_CONTEXT_H_
+
+#include <atomic>
+#include <mutex>
+#include <queue>
+
+#include "xenia/emulator.h"
+#include "xenia/xbox.h"
+
+// XMA audio format:
+// From research, XMA appears to be based on WMA Pro with
+// a few (very slight) modifications.
+// XMA2 is fully backwards-compatible with XMA1.
+
+// Helpful resources:
+// https://github.com/koolkdev/libertyv/blob/master/libav_wrapper/xma2dec.c
+// http://hcs64.com/mboard/forum.php?showthread=14818
+// https://github.com/hrydgard/minidx9/blob/master/Include/xma2defs.h
+
+// Forward declarations
+struct AVCodec;
+struct AVCodecContext;
+struct AVFrame;
+struct AVPacket;
+
+namespace xe {
+namespace apu {
+
+// This is stored in guest space in big-endian order.
+// We load and swap the whole thing to splat here so that we can
+// use bitfields.
+// This could be important:
+// http://www.fmod.org/questions/question/forum-15859
+// Appears to be dumped in order (for the most part)
+
+struct XMA_CONTEXT_DATA {
+  static const uint32_t kBytesPerPacket = 2048;
+  static const uint32_t kSamplesPerFrame = 512;
+  static const uint32_t kSamplesPerSubframe = 128;
+
+  static const uint32_t kOutputBytesPerBlock = 256;
+  static const uint32_t kOutputMaxSizeBytes = 31 * kOutputBytesPerBlock;
+
+  // DWORD 0
+  uint32_t input_buffer_0_packet_count : 12; // XMASetInputBuffer0, number of
+                                             // 2KB packets. Max 4095 packets.
+                                             // These packets form a block.
+  uint32_t loop_count : 8;                   // +12bit, XMASetLoopData NumLoops
+  uint32_t input_buffer_0_valid : 1;         // +20bit, XMAIsInputBuffer0Valid
+  uint32_t input_buffer_1_valid : 1;         // +21bit, XMAIsInputBuffer1Valid
+  uint32_t output_buffer_block_count : 5;    // +22bit SizeWrite 256byte blocks
+  uint32_t output_buffer_write_offset : 5;   // +27bit
+                                             // XMAGetOutputBufferWriteOffset
+                                             // AKA OffsetWrite
+
+  // DWORD 1
+  uint32_t input_buffer_1_packet_count : 12; // XMASetInputBuffer1, number of
+                                             // 2KB packets. Max 4095 packets.
+                                             // These packets form a block.
+  uint32_t loop_subframe_end : 2;            // +12bit, XMASetLoopData
+  uint32_t unk_dword_1_a : 3;                // ? might be loop_subframe_skip
+  uint32_t loop_subframe_skip : 3;           // +17bit, XMASetLoopData might be
+                                             // subframe_decode_count
+  uint32_t subframe_decode_count : 4;  // +20bit might be subframe_skip_count
+  uint32_t unk_dword_1_b : 3;          // ? NumSubframesToSkip/NumChannels(?)
+  uint32_t sample_rate : 2;            // +27bit enum of sample rates
+  uint32_t is_stereo : 1;              // +29bit
+  uint32_t unk_dword_1_c : 1;          // +30bit
+  uint32_t output_buffer_valid : 1;    // +31bit, XMAIsOutputBufferValid
+
+  // DWORD 2
+  uint32_t input_buffer_read_offset : 26;  // XMAGetInputBufferReadOffset
+  uint32_t unk_dword_2 : 6;                // ErrorStatus/ErrorSet (?)
+
+  // DWORD 3
+  uint32_t loop_start : 26;  // XMASetLoopData LoopStartOffset
+  uint32_t unk_dword_3 : 6;  // ? ParserErrorStatus/ParserErrorSet(?)
+
+  // DWORD 4
+  uint32_t loop_end : 26;        // XMASetLoopData LoopEndOffset
+  uint32_t packet_metadata : 5;  // XMAGetPacketMetadata
+  uint32_t current_buffer : 1;   // ?
+
+  // DWORD 5
+  uint32_t input_buffer_0_ptr;  // physical address
+  // DWORD 6
+  uint32_t input_buffer_1_ptr;  // physical address
+  // DWORD 7
+  uint32_t output_buffer_ptr;  // physical address
+  // DWORD 8
+  uint32_t overlap_add_ptr;  // PtrOverlapAdd(?)
+
+  // DWORD 9
+  // +0bit, XMAGetOutputBufferReadOffset AKA WriteBufferOffsetRead
+  uint32_t output_buffer_read_offset : 5;
+  uint32_t unk_dword_9 : 27;  // StopWhenDone/InterruptWhenDone(?)
+
+  // DWORD 10-15
+  uint32_t unk_dwords_10_15[6]; // reserved?
+
+  XMA_CONTEXT_DATA(const void* ptr) {
+    xe::copy_and_swap(reinterpret_cast<uint32_t*>(this),
+                      reinterpret_cast<const uint32_t*>(ptr),
+                      sizeof(XMA_CONTEXT_DATA) / 4);
+  }
+
+  void Store(void* ptr) {
+    xe::copy_and_swap(reinterpret_cast<uint32_t*>(ptr),
+                      reinterpret_cast<const uint32_t*>(this),
+                      sizeof(XMA_CONTEXT_DATA) / 4);
+  }
+};
+static_assert_size(XMA_CONTEXT_DATA, 64);
+
+class XmaContext {
+  public:
+    XmaContext();
+    ~XmaContext();
+
+    int Initialize();
+
+    int PreparePacket(uint8_t* input, size_t seq_offset, size_t size,
+                      int sample_rate, int channels);
+    void DiscardPacket();
+
+    int DecodePacket(uint8_t* output, size_t offset, size_t size);
+
+    uint32_t guest_ptr() { return guest_ptr_; }
+    xe::mutex& lock() { return lock_; } // TODO(gibbed): remove this
+    bool in_use() { return in_use_; }
+    bool kicked() { return kicked_; }
+
+    void set_guest_ptr(uint32_t guest_ptr) { guest_ptr_ = guest_ptr; }
+    void set_in_use(bool in_use) { in_use_ = in_use; }
+    void set_kicked(bool kicked) { kicked_ = kicked; }
+
+  private:
+    uint32_t guest_ptr_;
+    xe::mutex lock_;
+    bool in_use_;
+    bool kicked_;
+
+    // libav structures
+    AVCodec* codec_;
+    AVCodecContext* context_;
+    AVFrame* decoded_frame_;
+    AVPacket* packet_;
+
+    size_t current_frame_pos_;
+    uint8_t* current_frame_;
+    uint32_t frame_samples_size_;
+
+    uint8_t packet_data_[XMA_CONTEXT_DATA::kBytesPerPacket];
+};
+
+} // namespace apu
+} // namespace xe
+
+#endif  // XENIA_APU_XMA_CONTEXT_H_