DSPHLE: add support for dynamic range compression

The CPU-side AX library enables it by default and uses hardcoded parameters.
CMD_COMPRESSOR_TABLE_ADDR (0x0A) was incorrect. It's always a nop on the
GameCube and was probably confused with the Wii version.

Source/Core/Core/HW/DSPHLE/UCodes/AX.cpp

@@ -23,7 +23,8 @@
 
 namespace DSP::HLE
 {
-AXUCode::AXUCode(DSPHLE* dsphle, u32 crc) : UCodeInterface(dsphle, crc), m_cmdlist_size(0)
+AXUCode::AXUCode(DSPHLE* dsphle, u32 crc)
+    : UCodeInterface(dsphle, crc), m_cmdlist_size(0), m_compressor_pos(0)
 {
   INFO_LOG_FMT(DSPHLE, "Instantiating AXUCode: crc={:08x}", crc);
 }
@@ -181,13 +182,11 @@ void AXUCode::HandleCommandList()
       MixAUXSamples(1, 0, HILO_TO_32(addr));
       break;
 
-    case CMD_COMPRESSOR_TABLE_ADDR:
+    case CMD_UNK_0A:
-      curr_idx += 2;
-      break;
     case CMD_UNK_0B:
-      break;  // TODO: check other versions
     case CMD_UNK_0C:
-      break;  // TODO: check other versions
+      // nop in all 6 known ucodes we handle here
+      break;
 
     case CMD_MORE:
       addr_hi = m_cmdlist[curr_idx++];
@@ -224,16 +223,16 @@ void AXUCode::HandleCommandList()
       SetOppositeLR(HILO_TO_32(addr));
       break;
 
-    case CMD_UNK_12:
+    case CMD_COMPRESSOR:
     {
-      u16 samp_val = m_cmdlist[curr_idx++];
+      // 0x4e8a8b21 doesn't have this command, but it doesn't range-check
-      u16 idx = m_cmdlist[curr_idx++];
+      // the value properly and ends up jumping into a mixer function
+      ASSERT(m_crc != 0x4e8a8b21);
+      u16 threshold = m_cmdlist[curr_idx++];
+      u16 frames = m_cmdlist[curr_idx++];
       addr_hi = m_cmdlist[curr_idx++];
       addr_lo = m_cmdlist[curr_idx++];
-      // TODO
+      RunCompressor(threshold, frames, HILO_TO_32(addr), 5);
-      // suppress warnings:
-      (void)samp_val;
-      (void)idx;
       break;
     }
 
@@ -508,6 +507,52 @@ void AXUCode::SetMainLR(u32 src_addr)
   }
 }
 
+void AXUCode::RunCompressor(u16 threshold, u16 release_frames, u32 table_addr, u32 millis)
+{
+  // check for L/R samples exceeding the threshold
+  bool triggered = false;
+  for (u32 i = 0; i < 32 * millis; ++i)
+  {
+    if (std::abs(m_samples_left[i]) > int(threshold) ||
+        std::abs(m_samples_right[i]) > int(threshold))
+    {
+      triggered = true;
+      break;
+    }
+  }
+
+  const u32 frame_byte_size = 32 * millis * sizeof(s16);
+  u32 table_offset = 0;
+  if (triggered)
+  {
+    // one attack frame based on previous frame
+    table_offset = m_compressor_pos * frame_byte_size;
+    // next frame will start release
+    m_compressor_pos = release_frames;
+  }
+  else if (m_compressor_pos)
+  {
+    // release
+    --m_compressor_pos;
+    // the release ramps are located after the attack ramps
+    constexpr u32 ATTACK_ENTRY_COUNT = 11;
+    table_offset = (ATTACK_ENTRY_COUNT + m_compressor_pos) * frame_byte_size;
+  }
+  else
+  {
+    return;
+  }
+
+  // apply the selected ramp
+  u16* ramp = (u16*)HLEMemory_Get_Pointer(table_addr + table_offset);
+  for (u32 i = 0; i < 32 * millis; ++i)
+  {
+    u16 coef = Common::swap16(*ramp++);
+    m_samples_left[i] = (s64(m_samples_left[i]) * coef) >> 15;
+    m_samples_right[i] = (s64(m_samples_right[i]) * coef) >> 15;
+  }
+}
+
 void AXUCode::OutputSamples(u32 lr_addr, u32 surround_addr)
 {
   int surround_buffer[5 * 32];

Source/Core/Core/HW/DSPHLE/UCodes/AX.h

@@ -98,6 +98,8 @@ protected:
   bool m_coeffs_available;
   s16 m_coeffs[0x800];
 
+  u16 m_compressor_pos;
+
   void LoadResamplingCoefficients();
 
   // Copy a command list from memory to our temp buffer
@@ -138,6 +140,7 @@ protected:
   void MixAUXSamples(int aux_id, u32 write_addr, u32 read_addr);
   void UploadLRS(u32 dst_addr);
   void SetMainLR(u32 src_addr);
+  void RunCompressor(u16 threshold, u16 release_stages, u32 table_addr, u32 millis);
   void OutputSamples(u32 out_addr, u32 surround_addr);
   void MixAUXBLR(u32 ul_addr, u32 dl_addr);
   void SetOppositeLR(u32 src_addr);
@@ -160,7 +163,7 @@ private:
     CMD_SET_LR = 0x07,
     CMD_UNK_08 = 0x08,
     CMD_MIX_AUXB_NOWRITE = 0x09,
-    CMD_COMPRESSOR_TABLE_ADDR = 0x0A,
+    CMD_UNK_0A = 0x0A,
     CMD_UNK_0B = 0x0B,
     CMD_UNK_0C = 0x0C,
     CMD_MORE = 0x0D,
@@ -168,7 +171,7 @@ private:
     CMD_END = 0x0F,
     CMD_MIX_AUXB_LR = 0x10,
     CMD_SET_OPPOSITE_LR = 0x11,
-    CMD_UNK_12 = 0x12,
+    CMD_COMPRESSOR = 0x12,
     CMD_SEND_AUX_AND_MIX = 0x13,
   };
 };

Source/Core/Core/HW/DSPHLE/UCodes/AXWii.cpp

@@ -113,11 +113,15 @@ void AXWiiUCode::HandleCommandList()
         break;
       }
 
-      // TODO(delroth): figure this one out, it's used by almost every
+      case CMD_COMPRESSOR_OLD:
-      // game I've tested so far.
+      {
-      case CMD_UNK_0B_OLD:
+        u16 threshold = m_cmdlist[curr_idx++];
-        curr_idx += 4;
+        u16 frames = m_cmdlist[curr_idx++];
+        addr_hi = m_cmdlist[curr_idx++];
+        addr_lo = m_cmdlist[curr_idx++];
+        RunCompressor(threshold, frames, HILO_TO_32(addr), 3);
         break;
+      }
 
       case CMD_OUTPUT_OLD:
       case CMD_OUTPUT_DPL2_OLD:
@@ -206,11 +210,15 @@ void AXWiiUCode::HandleCommandList()
         break;
       }
 
-      // TODO(delroth): figure this one out, it's used by almost every
+      case CMD_COMPRESSOR:
-      // game I've tested so far.
+      {
-      case CMD_UNK_0A:
+        u16 threshold = m_cmdlist[curr_idx++];
-        curr_idx += 4;
+        u16 frames = m_cmdlist[curr_idx++];
+        addr_hi = m_cmdlist[curr_idx++];
+        addr_lo = m_cmdlist[curr_idx++];
+        RunCompressor(threshold, frames, HILO_TO_32(addr), 3);
         break;
+      }
 
       case CMD_OUTPUT:
       case CMD_OUTPUT_DPL2:

Source/Core/Core/HW/DSPHLE/UCodes/AXWii.h

@@ -82,7 +82,7 @@ private:
     CMD_MIX_AUXC = 0x07,
     CMD_UPL_AUXA_MIX_LRSC = 0x08,
     CMD_UPL_AUXB_MIX_LRSC = 0x09,
-    CMD_UNK_0A = 0x0A,
+    CMD_COMPRESSOR = 0x0A,
     CMD_OUTPUT = 0x0B,
     CMD_OUTPUT_DPL2 = 0x0C,
     CMD_WM_OUTPUT = 0x0D,
@@ -105,7 +105,7 @@ private:
     CMD_MIX_AUXC_OLD = 0x08,
     CMD_UPL_AUXA_MIX_LRSC_OLD = 0x09,
     CMD_UPL_AUXB_MIX_LRSC_OLD = 0x0a,
-    CMD_UNK_0B_OLD = 0x0B,
+    CMD_COMPRESSOR_OLD = 0x0B,
     CMD_OUTPUT_OLD = 0x0C,  // no volume!
     CMD_OUTPUT_DPL2_OLD = 0x0D,
     CMD_WM_OUTPUT_OLD = 0x0E,