Swapped FFDShow's DPL2 decoder by FreeSurround

Added class in AudioCommon for the surround decoder

Source/Core/AudioCommon/AudioCommon.vcxproj

@@ -45,6 +45,7 @@
     <ClCompile Include="NullSoundStream.cpp" />
     <ClCompile Include="OpenALStream.cpp" />
     <ClCompile Include="WASAPIStream.cpp" />
+    <ClCompile Include="SurroundDecoder.cpp" />
     <ClCompile Include="WaveFile.cpp" />
     <ClCompile Include="XAudio2Stream.cpp" />
     <ClCompile Include="XAudio2_7Stream.cpp">
@@ -65,6 +66,7 @@
     <ClInclude Include="PulseAudioStream.h" />
     <ClInclude Include="SoundStream.h" />
     <ClInclude Include="WASAPIStream.h" />
+    <ClInclude Include="SurroundDecoder.h" />
     <ClInclude Include="WaveFile.h" />
     <ClInclude Include="XAudio2Stream.h" />
     <ClInclude Include="XAudio2_7Stream.h" />
@@ -79,6 +81,9 @@
     <ProjectReference Include="$(CoreDir)Common\Common.vcxproj">
       <Project>{2e6c348c-c75c-4d94-8d1e-9c1fcbf3efe4}</Project>
     </ProjectReference>
+    <ProjectReference Include="$(ExternalsDir)FreeSurround\FreeSurround.vcxproj">
+      <Project>{8498f2fa-5ca6-4169-9971-de5b1fe6132c}</Project>
+    </ProjectReference>
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

Source/Core/AudioCommon/AudioCommon.vcxproj.filters

@@ -30,6 +30,7 @@
     <ClCompile Include="WASAPIStream.cpp">
       <Filter>SoundStreams</Filter>
     </ClCompile>
+    <ClCompile Include="SurroundDecoder.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="AudioCommon.h" />
@@ -68,6 +69,7 @@
     <ClInclude Include="WASAPIStream.h">
       <Filter>SoundStreams</Filter>
     </ClInclude>
+    <ClInclude Include="SurroundDecoder.h" />
   </ItemGroup>
   <ItemGroup>
     <Text Include="CMakeLists.txt" />

Source/Core/AudioCommon/CMakeLists.txt

@@ -5,6 +5,7 @@ add_library(audiocommon
   CubebUtils.cpp
   DPL2Decoder.cpp
   Mixer.cpp
+  SurroundDecoder.cpp
   NullSoundStream.cpp
   WaveFile.cpp
 )
@@ -69,4 +70,4 @@ if(WIN32)
   endif()
 endif()
 
-target_link_libraries(audiocommon PRIVATE cubeb SoundTouch)
+target_link_libraries(audiocommon PRIVATE cubeb SoundTouch FreeSurround)

Source/Core/AudioCommon/Mixer.cpp

@@ -7,7 +7,6 @@
 #include <cmath>
 #include <cstring>
 
-#include "AudioCommon/DPL2Decoder.h"
 #include "Common/ChunkFile.h"
 #include "Common/CommonTypes.h"
 #include "Common/Logging/Log.h"
@@ -16,10 +15,10 @@
 #include "Core/ConfigManager.h"
 
 Mixer::Mixer(unsigned int BackendSampleRate)
-    : m_sampleRate(BackendSampleRate), m_stretcher(BackendSampleRate)
+    : m_sampleRate(BackendSampleRate), m_stretcher(BackendSampleRate),
+      m_surround_decoder(BackendSampleRate, SURROUND_BLOCK_SIZE)
 {
   INFO_LOG(AUDIO_INTERFACE, "Mixer is initialized");
-  DPL2Reset();
 }
 
 Mixer::~Mixer()
@@ -167,20 +166,23 @@ unsigned int Mixer::MixSurround(float* samples, unsigned int num_samples)
   if (!num_samples)
     return 0;
 
-  memset(samples, 0, num_samples * 6 * sizeof(float));
+  memset(samples, 0, num_samples * SURROUND_CHANNELS * sizeof(float));
 
-  // Mix() may also use m_scratch_buffer internally, but is safe because it alternates reads and
-  // writes.
-  unsigned int available_samples = Mix(m_scratch_buffer.data(), num_samples);
-  for (size_t i = 0; i < static_cast<size_t>(available_samples) * 2; ++i)
+  size_t needed_frames = m_surround_decoder.QueryFramesNeededForSurroundOutput(num_samples);
+
+  // Mix() may also use m_scratch_buffer internally, but is safe because it alternates reads
+  // and writes.
+  size_t available_frames = Mix(m_scratch_buffer.data(), static_cast<u32>(needed_frames));
+  if (available_frames != needed_frames)
   {
-    m_float_conversion_buffer[i] =
-        m_scratch_buffer[i] / static_cast<float>(std::numeric_limits<short>::max());
+    ERROR_LOG(AUDIO, "Error decoding surround frames.");
+    return 0;
   }
 
-  DPL2Decode(m_float_conversion_buffer.data(), available_samples, samples);
+  m_surround_decoder.PutFrames(m_scratch_buffer.data(), needed_frames);
+  m_surround_decoder.ReceiveFrames(samples, num_samples);
 
-  return available_samples;
+  return num_samples;
 }
 
 void Mixer::MixerFifo::PushSamples(const short* samples, unsigned int num_samples)

Source/Core/AudioCommon/Mixer.h

@@ -8,6 +8,7 @@
 #include <atomic>
 
 #include "AudioCommon/AudioStretcher.h"
+#include "AudioCommon/SurroundDecoder.h"
 #include "AudioCommon/WaveFile.h"
 #include "Common/CommonTypes.h"
 
@@ -52,6 +53,9 @@ private:
   static constexpr float CONTROL_FACTOR = 0.2f;
   static constexpr u32 CONTROL_AVG = 32;  // In freq_shift per FIFO size offset
 
+  const unsigned int SURROUND_CHANNELS = 6;
+  const unsigned int SURROUND_BLOCK_SIZE = 512;
+
   class MixerFifo final
   {
   public:
@@ -86,8 +90,8 @@ private:
 
   bool m_is_stretching = false;
   AudioCommon::AudioStretcher m_stretcher;
+  AudioCommon::SurroundDecoder m_surround_decoder;
   std::array<short, MAX_SAMPLES * 2> m_scratch_buffer;
-  std::array<float, MAX_SAMPLES * 2> m_float_conversion_buffer;
 
   WaveFileWriter m_wave_writer_dtk;
   WaveFileWriter m_wave_writer_dsp;

Source/Core/AudioCommon/SurroundDecoder.cpp

@@ -0,0 +1,93 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <FreeSurround/FreeSurroundDecoder.h>
+#include <limits>
+
+#include "AudioCommon/SurroundDecoder.h"
+
+namespace AudioCommon
+{
+constexpr size_t STEREO_CHANNELS = 2;
+constexpr size_t SURROUND_CHANNELS = 6;
+
+SurroundDecoder::SurroundDecoder(u32 sample_rate, u32 frame_block_size)
+    : m_sample_rate(sample_rate), m_frame_block_size(frame_block_size)
+{
+  m_fsdecoder = std::make_unique<DPL2FSDecoder>();
+  m_fsdecoder->Init(cs_5point1, m_frame_block_size, m_sample_rate);
+}
+
+SurroundDecoder::~SurroundDecoder() = default;
+
+void SurroundDecoder::Clear()
+{
+  m_fsdecoder->flush();
+  m_decoded_fifo.clear();
+}
+
+// Currently only 6 channels are supported.
+size_t SurroundDecoder::QueryFramesNeededForSurroundOutput(const size_t output_frames) const
+{
+  if (m_decoded_fifo.size() < output_frames * SURROUND_CHANNELS)
+  {
+    // Output stereo frames needed to have at least the desired number of surround frames
+    size_t frames_needed = output_frames - m_decoded_fifo.size() / SURROUND_CHANNELS;
+    return frames_needed + m_frame_block_size - frames_needed % m_frame_block_size;
+  }
+
+  return 0;
+}
+
+// Receive and decode samples
+void SurroundDecoder::PutFrames(const short* in, const size_t num_frames_in)
+{
+  // Maybe check if it is really power-of-2?
+  s64 remaining_frames = static_cast<s64>(num_frames_in);
+  size_t frame_index = 0;
+
+  while (remaining_frames > 0)
+  {
+    // Convert to float
+    for (size_t i = 0, end = m_frame_block_size * STEREO_CHANNELS; i < end; ++i)
+    {
+      m_float_conversion_buffer[i] = in[i + frame_index * STEREO_CHANNELS] /
+                                     static_cast<float>(std::numeric_limits<short>::max());
+    }
+
+    // Decode
+    const float* dpl2_fs = m_fsdecoder->decode(m_float_conversion_buffer.data());
+
+    // Add to ring buffer and fix channel mapping
+    // Maybe modify FreeSurround to output the correct mapping?
+    // FreeSurround:
+    // FL | FC | FR | BL | BR | LFE
+    // Most backends:
+    // FL | FR | FC | LFE | BL | BR
+    for (size_t i = 0; i < m_frame_block_size; ++i)
+    {
+      m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 0]);  // LEFTFRONT
+      m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 2]);  // RIGHTFRONT
+      m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 1]);  // CENTREFRONT
+      m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 5]);  // sub/lfe
+      m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 3]);  // LEFTREAR
+      m_decoded_fifo.push(dpl2_fs[i * SURROUND_CHANNELS + 4]);  // RIGHTREAR
+    }
+
+    remaining_frames = remaining_frames - static_cast<int>(m_frame_block_size);
+    frame_index = frame_index + m_frame_block_size;
+  }
+}
+
+void SurroundDecoder::ReceiveFrames(float* out, const size_t num_frames_out)
+{
+  // Copy to output array with desired num_frames_out
+  for (size_t i = 0, num_samples_output = num_frames_out * SURROUND_CHANNELS;
+       i < num_samples_output; ++i)
+  {
+    out[i] = m_decoded_fifo.pop_front();
+  }
+}
+
+}  // namespace AudioCommon

Source/Core/AudioCommon/SurroundDecoder.h

@@ -0,0 +1,36 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <memory>
+
+#include "Common/CommonTypes.h"
+#include "Common/FixedSizeQueue.h"
+
+class DPL2FSDecoder;
+
+namespace AudioCommon
+{
+class SurroundDecoder
+{
+public:
+  explicit SurroundDecoder(u32 sample_rate, u32 frame_block_size);
+  ~SurroundDecoder();
+  size_t QueryFramesNeededForSurroundOutput(const size_t output_frames) const;
+  void PutFrames(const short* in, const size_t num_frames_in);
+  void ReceiveFrames(float* out, const size_t num_frames_out);
+  void Clear();
+
+private:
+  u32 m_sample_rate;
+  u32 m_frame_block_size;
+
+  std::unique_ptr<DPL2FSDecoder> m_fsdecoder;
+  std::array<float, 32768> m_float_conversion_buffer;
+  FixedSizeQueue<float, 32768> m_decoded_fifo;
+};
+
+}  // AudioCommon