Revert #3970 #4177 (#4187)

3970 revert fixes crash caused by scheduler
4177 fix mario galaxy and metroid prime 4 not booting

Co-authored-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4187
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

4 files changed, 287 insertions, 274 deletions

diff --git a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
index af37fb4685..45a69eca03 100644
--- a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
+++ b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.cpp
@@ -29,96 +29,8 @@ void AudioRenderer::Start() {
     CreateSinkStreams();
 
     mailbox.Initialize(AppMailboxId::AudioRenderer);
-    // Main AudioRenderer thread, responsible for processing the command lists.
-    main_thread = std::jthread([this](std::stop_token stop_token) {
-        Common::SetCurrentThreadName("DSP_AudioRenderer_Main");
-        Common::SetCurrentThreadPriority(Common::ThreadPriority::High);
 
-        // TODO: Create buffer map/unmap thread + mailbox
-        // TODO: Create gMix devices, initialize them here
-
-        if (mailbox.Receive(Direction::DSP) != Message::InitializeOK) {
-            LOG_ERROR(Service_Audio, "ADSP Audio Renderer -- Failed to receive initialize message from host!");
-            return;
-        }
-
-        mailbox.Send(Direction::Host, Message::InitializeOK);
-
-        // 0.12 seconds (2,304,000 / 19,200,000)
-        constexpr u64 max_process_time{2'304'000ULL};
-        while (!stop_token.stop_requested()) {
-            auto msg{mailbox.Receive(Direction::DSP)};
-            switch (msg) {
-            case Message::Shutdown:
-                mailbox.Send(Direction::Host, Message::Shutdown);
-                return;
-
-            case Message::Render: {
-                if (system.IsShuttingDown()) {
-                    std::this_thread::sleep_for(std::chrono::milliseconds(200));
-                    mailbox.Send(Direction::Host, Message::RenderResponse);
-                    continue;
-                }
-                std::array<bool, MaxRendererSessions> buffers_reset{};
-                std::array<u64, MaxRendererSessions> render_times_taken{};
-                const auto start_time{system.CoreTiming().GetGlobalTimeUs().count()};
-
-                for (u32 index = 0; index < MaxRendererSessions; index++) {
-                    auto& command_buffer{command_buffers[index]};
-                    auto& command_list_processor{command_list_processors[index]};
-
-                    // Check this buffer is valid, as it may not be used.
-                    if (command_buffer.buffer != 0) {
-                        // If there are no remaining commands (from the previous list),
-                        // this is a new command list, initialize it.
-                        if (command_buffer.remaining_command_count == 0) {
-                            command_list_processor.Initialize(system, *command_buffer.process,
-                                command_buffer.buffer,
-                                command_buffer.size, streams[index]);
-                        }
-
-                        if (command_buffer.reset_buffer && !buffers_reset[index]) {
-                            streams[index]->ClearQueue();
-                            buffers_reset[index] = true;
-                        }
-
-                        u64 max_time{max_process_time};
-                        if (index == 1 && command_buffer.applet_resource_user_id ==
-                                            command_buffers[0].applet_resource_user_id) {
-                            max_time = max_process_time - render_times_taken[0];
-                            if (render_times_taken[0] > max_process_time) {
-                                max_time = 0;
-                            }
-                        }
-
-                        max_time = (std::min)(command_buffer.time_limit, max_time);
-                        command_list_processor.SetProcessTimeMax(max_time);
-
-                        if (index == 0) {
-                            streams[index]->WaitFreeSpace(stop_token);
-                        }
-
-                        // Process the command list
-                        {
-                            render_times_taken[index] =
-                                command_list_processor.Process(index) - start_time;
-                        }
-
-                        const auto end_time{system.CoreTiming().GetGlobalTimeUs().count()};
-
-                        command_buffer.remaining_command_count =
-                            command_list_processor.GetRemainingCommandCount();
-                        command_buffer.render_time_taken_us = end_time - start_time;
-                    }
-                }
-                mailbox.Send(Direction::Host, Message::RenderResponse);
-            } break;
-            default:
-                LOG_WARNING(Service_Audio, "ADSP AudioRenderer received an invalid message, msg={:02X}!", msg);
-                break;
-            }
-        }
-    });
+    main_thread = std::jthread([this](std::stop_token stop_token) { Main(stop_token); });
 
     mailbox.Send(Direction::DSP, Message::InitializeOK);
     if (mailbox.Receive(Direction::Host) != Message::InitializeOK) {
@@ -217,4 +129,95 @@ void AudioRenderer::CreateSinkStreams() {
     }
 }
 
+void AudioRenderer::Main(std::stop_token stop_token) {
+    Common::SetCurrentThreadName("DSP_AudioRenderer_Main");
+    Common::SetCurrentThreadPriority(Common::ThreadPriority::High);
+
+    // TODO: Create buffer map/unmap thread + mailbox
+    // TODO: Create gMix devices, initialize them here
+
+    if (mailbox.Receive(Direction::DSP) != Message::InitializeOK) {
+        LOG_ERROR(Service_Audio, "ADSP Audio Renderer -- Failed to receive initialize message from host!");
+        return;
+    }
+
+    mailbox.Send(Direction::Host, Message::InitializeOK);
+
+    // 0.12 seconds (2,304,000 / 19,200,000)
+    constexpr u64 max_process_time{2'304'000ULL};
+
+    while (!stop_token.stop_requested()) {
+        auto msg{mailbox.Receive(Direction::DSP)};
+        switch (msg) {
+        case Message::Shutdown:
+            mailbox.Send(Direction::Host, Message::Shutdown);
+            return;
+
+        case Message::Render: {
+            if (system.IsShuttingDown()) {
+                std::this_thread::sleep_for(std::chrono::milliseconds(200));
+                mailbox.Send(Direction::Host, Message::RenderResponse);
+                continue;
+            }
+            std::array<bool, MaxRendererSessions> buffers_reset{};
+            std::array<u64, MaxRendererSessions> render_times_taken{};
+            const auto start_time{system.CoreTiming().GetGlobalTimeUs().count()};
+
+            for (u32 index = 0; index < MaxRendererSessions; index++) {
+                auto& command_buffer{command_buffers[index]};
+                auto& command_list_processor{command_list_processors[index]};
+
+                // Check this buffer is valid, as it may not be used.
+                if (command_buffer.buffer != 0) {
+                    // If there are no remaining commands (from the previous list),
+                    // this is a new command list, initialize it.
+                    if (command_buffer.remaining_command_count == 0) {
+                        command_list_processor.Initialize(system, *command_buffer.process,
+                            command_buffer.buffer,
+                            command_buffer.size, streams[index]);
+                    }
+
+                    if (command_buffer.reset_buffer && !buffers_reset[index]) {
+                        streams[index]->ClearQueue();
+                        buffers_reset[index] = true;
+                    }
+
+                    u64 max_time{max_process_time};
+                    if (index == 1 && command_buffer.applet_resource_user_id ==
+                                          command_buffers[0].applet_resource_user_id) {
+                        max_time = max_process_time - render_times_taken[0];
+                        if (render_times_taken[0] > max_process_time) {
+                            max_time = 0;
+                        }
+                    }
+
+                    max_time = (std::min)(command_buffer.time_limit, max_time);
+                    command_list_processor.SetProcessTimeMax(max_time);
+
+                    if (index == 0) {
+                        streams[index]->WaitFreeSpace(stop_token);
+                    }
+
+                    // Process the command list
+                    {
+                        render_times_taken[index] =
+                            command_list_processor.Process(index) - start_time;
+                    }
+
+                    const auto end_time{system.CoreTiming().GetGlobalTimeUs().count()};
+
+                    command_buffer.remaining_command_count =
+                        command_list_processor.GetRemainingCommandCount();
+                    command_buffer.render_time_taken_us = end_time - start_time;
+                }
+            }
+            mailbox.Send(Direction::Host, Message::RenderResponse);
+        } break;
+        default:
+            LOG_WARNING(Service_Audio, "ADSP AudioRenderer received an invalid message, msg={:02X}!", msg);
+            break;
+        }
+    }
+}
+
 } // namespace AudioCore::ADSP::AudioRenderer
diff --git a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
index a7a21e76af..4e128187a7 100644
--- a/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
+++ b/src/audio_core/adsp/apps/audio_renderer/audio_renderer.h
@@ -83,6 +83,11 @@ public:
 
 private:
     /**
+     * Main AudioRenderer thread, responsible for processing the command lists.
+     */
+    void Main(std::stop_token stop_token);
+
+    /**
      * Creates the streams which will receive the processed samples.
      */
     void CreateSinkStreams();
diff --git a/src/audio_core/adsp/apps/opus/opus_decoder.cpp b/src/audio_core/adsp/apps/opus/opus_decoder.cpp
index 1ce81d287a..8a009c04c7 100644
--- a/src/audio_core/adsp/apps/opus/opus_decoder.cpp
+++ b/src/audio_core/adsp/apps/opus/opus_decoder.cpp
@@ -37,9 +37,7 @@ bool IsValidMultiStreamStreamCounts(s32 total_stream_count, s32 stereo_stream_co
 } // namespace
 
 OpusDecoder::OpusDecoder(Core::System& system_) : system{system_} {
-    init_thread = std::jthread([this](std::stop_token stop_token) {
-        Init(stop_token);
-    });
+    init_thread = std::jthread([this](std::stop_token stop_token) { Init(stop_token); });
 }
 
 OpusDecoder::~OpusDecoder() {
@@ -66,203 +64,206 @@ u32 OpusDecoder::Receive(Direction dir, std::stop_token stop_token) {
     return mailbox.Receive(dir, stop_token);
 }
 
-void OpusDecoder::Init(std::stop_token rc_stop_token) {
+void OpusDecoder::Init(std::stop_token stop_token) {
     Common::SetCurrentThreadName("DSP_OpusDecoder_Init");
 
-    if (Receive(Direction::DSP, rc_stop_token) != Message::Start) {
-        LOG_ERROR(Service_Audio, "DSP OpusDecoder failed to receive Start message. Opus initialization failed.");
+    if (Receive(Direction::DSP, stop_token) != Message::Start) {
+        LOG_ERROR(Service_Audio,
+                  "DSP OpusDecoder failed to receive Start message. Opus initialization failed.");
         return;
     }
-    // Main OpusDecoder thread, responsible for processing the incoming Opus packets.
-    main_thread = std::jthread([this](std::stop_token stop_token) {
-        Common::SetCurrentThreadName("DSP_OpusDecoder_Main");
-        while (!stop_token.stop_requested()) {
-            auto msg = Receive(Direction::DSP, stop_token);
-            switch (msg) {
-            case Shutdown:
-                Send(Direction::Host, Message::ShutdownOK);
-                return;
-
-            case GetWorkBufferSize: {
-                auto channel_count = static_cast<s32>(shared_memory->host_send_data[0]);
-
-                ASSERT(IsValidChannelCount(channel_count));
-
-                shared_memory->dsp_return_data[0] = OpusDecodeObject::GetWorkBufferSize(channel_count);
-                Send(Direction::Host, Message::GetWorkBufferSizeOK);
-            } break;
-
-            case InitializeDecodeObject: {
-                auto buffer = shared_memory->host_send_data[0];
-                auto buffer_size = shared_memory->host_send_data[1];
-                auto sample_rate = static_cast<s32>(shared_memory->host_send_data[2]);
-                auto channel_count = static_cast<s32>(shared_memory->host_send_data[3]);
-
-                ASSERT(sample_rate >= 0);
-                ASSERT(IsValidChannelCount(channel_count));
-                ASSERT(buffer_size >= OpusDecodeObject::GetWorkBufferSize(channel_count));
-
-                auto& decoder_object = OpusDecodeObject::Initialize(buffer, buffer);
-                shared_memory->dsp_return_data[0] =
-                    decoder_object.InitializeDecoder(sample_rate, channel_count);
-
-                Send(Direction::Host, Message::InitializeDecodeObjectOK);
-            } break;
-
-            case ShutdownDecodeObject: {
-                auto buffer = shared_memory->host_send_data[0];
-                [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
-
-                auto& decoder_object = OpusDecodeObject::Initialize(buffer, buffer);
-                shared_memory->dsp_return_data[0] = decoder_object.Shutdown();
-
-                Send(Direction::Host, Message::ShutdownDecodeObjectOK);
-            } break;
-
-            case DecodeInterleaved: {
-                auto start_time = system.CoreTiming().GetGlobalTimeUs();
-
-                auto buffer = shared_memory->host_send_data[0];
-                auto input_data = shared_memory->host_send_data[1];
-                auto input_data_size = shared_memory->host_send_data[2];
-                auto output_data = shared_memory->host_send_data[3];
-                auto output_data_size = shared_memory->host_send_data[4];
-                auto final_range = static_cast<u32>(shared_memory->host_send_data[5]);
-                auto reset_requested = shared_memory->host_send_data[6];
-
-                u32 decoded_samples{0};
-
-                auto& decoder_object = OpusDecodeObject::Initialize(buffer, buffer);
-                s32 error_code{OPUS_OK};
-                if (reset_requested) {
-                    error_code = decoder_object.ResetDecoder();
-                }
+    main_thread = std::jthread([this](std::stop_token st) { Main(st); });
+    running = true;
+    Send(Direction::Host, Message::StartOK);
+}
 
-                if (error_code == OPUS_OK) {
-                    error_code = decoder_object.Decode(decoded_samples, output_data, output_data_size,
-                                                    input_data, input_data_size);
-                }
+void OpusDecoder::Main(std::stop_token stop_token) {
+    Common::SetCurrentThreadName("DSP_OpusDecoder_Main");
 
-                if (error_code == OPUS_OK) {
-                    if (final_range && decoder_object.GetFinalRange() != final_range) {
-                        error_code = OPUS_INVALID_PACKET;
-                    }
-                }
+    while (!stop_token.stop_requested()) {
+        auto msg = Receive(Direction::DSP, stop_token);
+        switch (msg) {
+        case Shutdown:
+            Send(Direction::Host, Message::ShutdownOK);
+            return;
 
-                auto end_time = system.CoreTiming().GetGlobalTimeUs();
-                shared_memory->dsp_return_data[0] = error_code;
-                shared_memory->dsp_return_data[1] = decoded_samples;
-                shared_memory->dsp_return_data[2] = (end_time - start_time).count();
-
-                Send(Direction::Host, Message::DecodeInterleavedOK);
-            } break;
-
-            case MapMemory: {
-                [[maybe_unused]] auto buffer = shared_memory->host_send_data[0];
-                [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
-                Send(Direction::Host, Message::MapMemoryOK);
-            } break;
-
-            case UnmapMemory: {
-                [[maybe_unused]] auto buffer = shared_memory->host_send_data[0];
-                [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
-                Send(Direction::Host, Message::UnmapMemoryOK);
-            } break;
-
-            case GetWorkBufferSizeForMultiStream: {
-                auto total_stream_count = static_cast<s32>(shared_memory->host_send_data[0]);
-                auto stereo_stream_count = static_cast<s32>(shared_memory->host_send_data[1]);
-
-                ASSERT(IsValidMultiStreamStreamCounts(total_stream_count, stereo_stream_count));
-
-                shared_memory->dsp_return_data[0] = OpusMultiStreamDecodeObject::GetWorkBufferSize(
-                    total_stream_count, stereo_stream_count);
-                Send(Direction::Host, Message::GetWorkBufferSizeForMultiStreamOK);
-            } break;
-
-            case InitializeMultiStreamDecodeObject: {
-                auto buffer = shared_memory->host_send_data[0];
-                auto buffer_size = shared_memory->host_send_data[1];
-                auto sample_rate = static_cast<s32>(shared_memory->host_send_data[2]);
-                auto channel_count = static_cast<s32>(shared_memory->host_send_data[3]);
-                auto total_stream_count = static_cast<s32>(shared_memory->host_send_data[4]);
-                auto stereo_stream_count = static_cast<s32>(shared_memory->host_send_data[5]);
-                // Nintendo seem to have a bug here, they try to use &host_send_data[6] for the channel
-                // mappings, but [6] is never set, and there is not enough room in the argument data for
-                // more than 40 channels, when 255 are possible.
-                // It also means the mapping values are undefined, though likely always 0,
-                // and the mappings given by the game are ignored. The mappings are copied to this
-                // dedicated buffer host side, so let's do as intended.
-                auto mappings = shared_memory->channel_mapping.data();
-
-                ASSERT(IsValidMultiStreamStreamCounts(total_stream_count, stereo_stream_count));
-                ASSERT(sample_rate >= 0);
-                ASSERT(buffer_size >= OpusMultiStreamDecodeObject::GetWorkBufferSize(
-                                        total_stream_count, stereo_stream_count));
-
-                auto& decoder_object = OpusMultiStreamDecodeObject::Initialize(buffer, buffer);
-                shared_memory->dsp_return_data[0] = decoder_object.InitializeDecoder(
-                    sample_rate, total_stream_count, channel_count, stereo_stream_count, mappings);
-
-                Send(Direction::Host, Message::InitializeMultiStreamDecodeObjectOK);
-            } break;
-
-            case ShutdownMultiStreamDecodeObject: {
-                auto buffer = shared_memory->host_send_data[0];
-                [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
-
-                auto& decoder_object = OpusMultiStreamDecodeObject::Initialize(buffer, buffer);
-                shared_memory->dsp_return_data[0] = decoder_object.Shutdown();
-
-                Send(Direction::Host, Message::ShutdownMultiStreamDecodeObjectOK);
-            } break;
-
-            case DecodeInterleavedForMultiStream: {
-                auto start_time = system.CoreTiming().GetGlobalTimeUs();
-
-                auto buffer = shared_memory->host_send_data[0];
-                auto input_data = shared_memory->host_send_data[1];
-                auto input_data_size = shared_memory->host_send_data[2];
-                auto output_data = shared_memory->host_send_data[3];
-                auto output_data_size = shared_memory->host_send_data[4];
-                auto final_range = static_cast<u32>(shared_memory->host_send_data[5]);
-                auto reset_requested = shared_memory->host_send_data[6];
-
-                u32 decoded_samples{0};
-
-                auto& decoder_object = OpusMultiStreamDecodeObject::Initialize(buffer, buffer);
-                s32 error_code{OPUS_OK};
-                if (reset_requested) {
-                    error_code = decoder_object.ResetDecoder();
-                }
+        case GetWorkBufferSize: {
+            auto channel_count = static_cast<s32>(shared_memory->host_send_data[0]);
 
-                if (error_code == OPUS_OK) {
-                    error_code = decoder_object.Decode(decoded_samples, output_data, output_data_size,
-                                                    input_data, input_data_size);
-                }
+            ASSERT(IsValidChannelCount(channel_count));
+
+            shared_memory->dsp_return_data[0] = OpusDecodeObject::GetWorkBufferSize(channel_count);
+            Send(Direction::Host, Message::GetWorkBufferSizeOK);
+        } break;
+
+        case InitializeDecodeObject: {
+            auto buffer = shared_memory->host_send_data[0];
+            auto buffer_size = shared_memory->host_send_data[1];
+            auto sample_rate = static_cast<s32>(shared_memory->host_send_data[2]);
+            auto channel_count = static_cast<s32>(shared_memory->host_send_data[3]);
+
+            ASSERT(sample_rate >= 0);
+            ASSERT(IsValidChannelCount(channel_count));
+            ASSERT(buffer_size >= OpusDecodeObject::GetWorkBufferSize(channel_count));
+
+            auto& decoder_object = OpusDecodeObject::Initialize(buffer, buffer);
+            shared_memory->dsp_return_data[0] =
+                decoder_object.InitializeDecoder(sample_rate, channel_count);
+
+            Send(Direction::Host, Message::InitializeDecodeObjectOK);
+        } break;
+
+        case ShutdownDecodeObject: {
+            auto buffer = shared_memory->host_send_data[0];
+            [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
+
+            auto& decoder_object = OpusDecodeObject::Initialize(buffer, buffer);
+            shared_memory->dsp_return_data[0] = decoder_object.Shutdown();
+
+            Send(Direction::Host, Message::ShutdownDecodeObjectOK);
+        } break;
+
+        case DecodeInterleaved: {
+            auto start_time = system.CoreTiming().GetGlobalTimeUs();
 
-                if (error_code == OPUS_OK) {
-                    if (final_range && decoder_object.GetFinalRange() != final_range) {
-                        error_code = OPUS_INVALID_PACKET;
-                    }
+            auto buffer = shared_memory->host_send_data[0];
+            auto input_data = shared_memory->host_send_data[1];
+            auto input_data_size = shared_memory->host_send_data[2];
+            auto output_data = shared_memory->host_send_data[3];
+            auto output_data_size = shared_memory->host_send_data[4];
+            auto final_range = static_cast<u32>(shared_memory->host_send_data[5]);
+            auto reset_requested = shared_memory->host_send_data[6];
+
+            u32 decoded_samples{0};
+
+            auto& decoder_object = OpusDecodeObject::Initialize(buffer, buffer);
+            s32 error_code{OPUS_OK};
+            if (reset_requested) {
+                error_code = decoder_object.ResetDecoder();
+            }
+
+            if (error_code == OPUS_OK) {
+                error_code = decoder_object.Decode(decoded_samples, output_data, output_data_size,
+                                                   input_data, input_data_size);
+            }
+
+            if (error_code == OPUS_OK) {
+                if (final_range && decoder_object.GetFinalRange() != final_range) {
+                    error_code = OPUS_INVALID_PACKET;
                 }
+            }
 
-                auto end_time = system.CoreTiming().GetGlobalTimeUs();
-                shared_memory->dsp_return_data[0] = error_code;
-                shared_memory->dsp_return_data[1] = decoded_samples;
-                shared_memory->dsp_return_data[2] = (end_time - start_time).count();
+            auto end_time = system.CoreTiming().GetGlobalTimeUs();
+            shared_memory->dsp_return_data[0] = error_code;
+            shared_memory->dsp_return_data[1] = decoded_samples;
+            shared_memory->dsp_return_data[2] = (end_time - start_time).count();
+
+            Send(Direction::Host, Message::DecodeInterleavedOK);
+        } break;
+
+        case MapMemory: {
+            [[maybe_unused]] auto buffer = shared_memory->host_send_data[0];
+            [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
+            Send(Direction::Host, Message::MapMemoryOK);
+        } break;
+
+        case UnmapMemory: {
+            [[maybe_unused]] auto buffer = shared_memory->host_send_data[0];
+            [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
+            Send(Direction::Host, Message::UnmapMemoryOK);
+        } break;
+
+        case GetWorkBufferSizeForMultiStream: {
+            auto total_stream_count = static_cast<s32>(shared_memory->host_send_data[0]);
+            auto stereo_stream_count = static_cast<s32>(shared_memory->host_send_data[1]);
+
+            ASSERT(IsValidMultiStreamStreamCounts(total_stream_count, stereo_stream_count));
+
+            shared_memory->dsp_return_data[0] = OpusMultiStreamDecodeObject::GetWorkBufferSize(
+                total_stream_count, stereo_stream_count);
+            Send(Direction::Host, Message::GetWorkBufferSizeForMultiStreamOK);
+        } break;
+
+        case InitializeMultiStreamDecodeObject: {
+            auto buffer = shared_memory->host_send_data[0];
+            auto buffer_size = shared_memory->host_send_data[1];
+            auto sample_rate = static_cast<s32>(shared_memory->host_send_data[2]);
+            auto channel_count = static_cast<s32>(shared_memory->host_send_data[3]);
+            auto total_stream_count = static_cast<s32>(shared_memory->host_send_data[4]);
+            auto stereo_stream_count = static_cast<s32>(shared_memory->host_send_data[5]);
+            // Nintendo seem to have a bug here, they try to use &host_send_data[6] for the channel
+            // mappings, but [6] is never set, and there is not enough room in the argument data for
+            // more than 40 channels, when 255 are possible.
+            // It also means the mapping values are undefined, though likely always 0,
+            // and the mappings given by the game are ignored. The mappings are copied to this
+            // dedicated buffer host side, so let's do as intended.
+            auto mappings = shared_memory->channel_mapping.data();
+
+            ASSERT(IsValidMultiStreamStreamCounts(total_stream_count, stereo_stream_count));
+            ASSERT(sample_rate >= 0);
+            ASSERT(buffer_size >= OpusMultiStreamDecodeObject::GetWorkBufferSize(
+                                      total_stream_count, stereo_stream_count));
+
+            auto& decoder_object = OpusMultiStreamDecodeObject::Initialize(buffer, buffer);
+            shared_memory->dsp_return_data[0] = decoder_object.InitializeDecoder(
+                sample_rate, total_stream_count, channel_count, stereo_stream_count, mappings);
+
+            Send(Direction::Host, Message::InitializeMultiStreamDecodeObjectOK);
+        } break;
+
+        case ShutdownMultiStreamDecodeObject: {
+            auto buffer = shared_memory->host_send_data[0];
+            [[maybe_unused]] auto buffer_size = shared_memory->host_send_data[1];
+
+            auto& decoder_object = OpusMultiStreamDecodeObject::Initialize(buffer, buffer);
+            shared_memory->dsp_return_data[0] = decoder_object.Shutdown();
+
+            Send(Direction::Host, Message::ShutdownMultiStreamDecodeObjectOK);
+        } break;
+
+        case DecodeInterleavedForMultiStream: {
+            auto start_time = system.CoreTiming().GetGlobalTimeUs();
+
+            auto buffer = shared_memory->host_send_data[0];
+            auto input_data = shared_memory->host_send_data[1];
+            auto input_data_size = shared_memory->host_send_data[2];
+            auto output_data = shared_memory->host_send_data[3];
+            auto output_data_size = shared_memory->host_send_data[4];
+            auto final_range = static_cast<u32>(shared_memory->host_send_data[5]);
+            auto reset_requested = shared_memory->host_send_data[6];
+
+            u32 decoded_samples{0};
+
+            auto& decoder_object = OpusMultiStreamDecodeObject::Initialize(buffer, buffer);
+            s32 error_code{OPUS_OK};
+            if (reset_requested) {
+                error_code = decoder_object.ResetDecoder();
+            }
 
-                Send(Direction::Host, Message::DecodeInterleavedForMultiStreamOK);
-            } break;
+            if (error_code == OPUS_OK) {
+                error_code = decoder_object.Decode(decoded_samples, output_data, output_data_size,
+                                                   input_data, input_data_size);
+            }
 
-            default:
-                LOG_ERROR(Service_Audio, "Invalid OpusDecoder command {}", msg);
-                continue;
+            if (error_code == OPUS_OK) {
+                if (final_range && decoder_object.GetFinalRange() != final_range) {
+                    error_code = OPUS_INVALID_PACKET;
+                }
             }
+
+            auto end_time = system.CoreTiming().GetGlobalTimeUs();
+            shared_memory->dsp_return_data[0] = error_code;
+            shared_memory->dsp_return_data[1] = decoded_samples;
+            shared_memory->dsp_return_data[2] = (end_time - start_time).count();
+
+            Send(Direction::Host, Message::DecodeInterleavedForMultiStreamOK);
+        } break;
+
+        default:
+            LOG_ERROR(Service_Audio, "Invalid OpusDecoder command {}", msg);
+            continue;
         }
-    });
-    running = true;
-    Send(Direction::Host, Message::StartOK);
+    }
 }
 
 } // namespace AudioCore::ADSP::OpusDecoder
diff --git a/src/audio_core/adsp/apps/opus/opus_decoder.h b/src/audio_core/adsp/apps/opus/opus_decoder.h
index d554586703..5b3f22bf4c 100644
--- a/src/audio_core/adsp/apps/opus/opus_decoder.h
+++ b/src/audio_core/adsp/apps/opus/opus_decoder.h
@@ -72,6 +72,10 @@ private:
      * Initializing thread, launched at audio_core boot to avoid blocking the main emu boot thread.
      */
     void Init(std::stop_token stop_token);
+    /**
+     * Main OpusDecoder thread, responsible for processing the incoming Opus packets.
+     */
+    void Main(std::stop_token stop_token);
 
     /// Core system
     Core::System& system;