audio_renderer: Add support for 6 channel mixing and correct the default case

src/audio_core/audio_renderer.cpp

@@ -73,6 +73,20 @@ private:
     EffectInStatus info{};
 };
 
+class AudioRenderer::ChannelState {
+public:
+    const ChannelInfoIn& GetInfo() const {
+        return info;
+    }
+
+    ChannelInfoIn& GetInfo() {
+        return info;
+    }
+
+private:
+    ChannelInfoIn info{};
+};
+
 AudioRenderer::AudioRenderer(Core::Timing::CoreTiming& core_timing, Core::Memory::Memory& memory_,
                              AudioRendererParameter params,
                              std::shared_ptr<Kernel::WritableEvent> buffer_event,
@@ -134,6 +148,15 @@ std::vector<u8> AudioRenderer::UpdateAudioRenderer(const std::vector<u8>& input_
         voice_offset += sizeof(VoiceInfo);
     }
 
+    std::size_t channel_offset{sizeof(UpdateDataHeader) + config.behavior_size +
+                               config.memory_pools_size};
+    channels.resize((voice_offset - channel_offset) / sizeof(ChannelInfoIn));
+    for (auto& channel : channels) {
+        std::memcpy(&channel.GetInfo(), input_params.data() + channel_offset,
+                    sizeof(ChannelInfoIn));
+        channel_offset += sizeof(ChannelInfoIn);
+    }
+
     std::size_t effect_offset{sizeof(UpdateDataHeader) + config.behavior_size +
                               config.memory_pools_size + config.voice_resource_size +
                               config.voices_size};
@@ -332,6 +355,19 @@ static constexpr s16 ClampToS16(s32 value) {
     return static_cast<s16>(std::clamp(value, -32768, 32767));
 }
 
+static std::size_t GetMixVolumeIndex(const VoiceInfo& voice_info, std::size_t offset) {
+    switch (voice_info.channel_count) {
+    case 1:
+        return 0;
+    case 2:
+    case 6:
+        return offset % 2;
+    default:
+        UNIMPLEMENTED_MSG("Unimplemented channel_count={}", voice_info.channel_count);
+        return 0;
+    }
+}
+
 void AudioRenderer::QueueMixedBuffer(Buffer::Tag tag) {
     constexpr std::size_t BUFFER_SIZE{512};
     std::vector<s16> buffer(BUFFER_SIZE * stream->GetNumChannels());
@@ -352,10 +388,16 @@ void AudioRenderer::QueueMixedBuffer(Buffer::Tag tag) {
 
             samples_remaining -= samples.size() / stream->GetNumChannels();
 
+            // TODO(FearlessTobi): Implement Surround mixing
+            const auto& mix_volumes{channels[voice.GetInfo().id].GetInfo().mix_volume};
             for (const auto& sample : samples) {
                 const s32 buffer_sample{buffer[offset]};
-                buffer[offset++] =
-                    ClampToS16(buffer_sample + static_cast<s32>(sample * voice.GetInfo().volume));
+
+                // Index 0 is for the left channel, 1 is for the right channel
+                const float mix_volume{mix_volumes[GetMixVolumeIndex(voice.GetInfo(), offset)]};
+
+                buffer[offset++] = ClampToS16(
+                    buffer_sample + static_cast<s32>(sample * voice.GetInfo().volume * mix_volume));
             }
         }
     }

src/audio_core/audio_renderer.h

@@ -148,6 +148,14 @@ struct VoiceOutStatus {
 };
 static_assert(sizeof(VoiceOutStatus) == 0x10, "VoiceOutStatus has wrong size");
 
+struct ChannelInfoIn {
+    u32_le id;
+    std::array<float_le, 24> mix_volume;
+    bool is_used;
+    INSERT_PADDING_BYTES(11);
+};
+static_assert(sizeof(ChannelInfoIn) == 0x70, "ChannelInfoIn has wrong size");
+
 struct AuxInfo {
     std::array<u8, 24> input_mix_buffers;
     std::array<u8, 24> output_mix_buffers;
@@ -235,11 +243,13 @@ public:
     Stream::State GetStreamState() const;
 
 private:
+    class ChannelState;
     class EffectState;
     class VoiceState;
 
     AudioRendererParameter worker_params;
     std::shared_ptr<Kernel::WritableEvent> buffer_event;
+    std::vector<ChannelState> channels;
     std::vector<VoiceState> voices;
     std::vector<EffectState> effects;
     std::unique_ptr<AudioOut> audio_out;