[audio_core/hid] Audio REV12+15 support + HID fixes (#2719)

This fixes newer updates / games.

Implements partial audio rev15, rev13, rev12 and HID issues on SDK20+ games.

Credits to LotP (Ryubing) and Zephyron (Citron) for their research and implementation.

Co-authored-by: Zephyron <zephyron@citron-emu.org>
Co-authored-by: Shinmegumi <shinmegumi@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2719
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Co-authored-by: unknown <sahyno1996@gmail.com>
Co-committed-by: unknown <sahyno1996@gmail.com>

1 files changed, 103 insertions, 14 deletions

diff --git a/src/audio_core/renderer/splitter/splitter_context.cpp b/src/audio_core/renderer/splitter/splitter_context.cpp
index fb118e981e..1ba5daebe9 100644
--- a/src/audio_core/renderer/splitter/splitter_context.cpp
+++ b/src/audio_core/renderer/splitter/splitter_context.cpp
@@ -35,12 +35,16 @@ SplitterDestinationData& SplitterContext::GetData(const u32 index) {
 
 void SplitterContext::Setup(std::span<SplitterInfo> splitter_infos_, const u32 splitter_info_count_,
                             SplitterDestinationData* splitter_destinations_,
-                            const u32 destination_count_, const bool splitter_bug_fixed_) {
+                            const u32 destination_count_, const bool splitter_bug_fixed_,
+                            const BehaviorInfo& behavior) {
     splitter_infos = splitter_infos_;
     info_count = splitter_info_count_;
     splitter_destinations = splitter_destinations_;
     destinations_count = destination_count_;
     splitter_bug_fixed = splitter_bug_fixed_;
+    splitter_prev_volume_reset_supported = behavior.IsSplitterPrevVolumeResetSupported();
+    splitter_biquad_param_supported = behavior.IsBiquadFilterParameterForSplitterEnabled();
+    splitter_float_coeff_supported = behavior.IsSplitterDestinationV2bSupported();
 }
 
 bool SplitterContext::UsingSplitter() const {
@@ -84,7 +88,7 @@ bool SplitterContext::Initialize(const BehaviorInfo& behavior,
         }
 
         Setup(splitter_infos, params.splitter_infos, splitter_destinations,
-              params.splitter_destinations, behavior.IsSplitterBugFixed());
+              params.splitter_destinations, behavior.IsSplitterBugFixed(), behavior);
     }
     return true;
 }
@@ -137,19 +141,104 @@ u32 SplitterContext::UpdateInfo(const u8* input, u32 offset, const u32 splitter_
 
 u32 SplitterContext::UpdateData(const u8* input, u32 offset, const u32 count) {
     for (u32 i = 0; i < count; i++) {
-        auto data_header{
-            reinterpret_cast<const SplitterDestinationData::InParameter*>(input + offset)};
-
-        if (data_header->magic != GetSplitterSendDataMagic()) {
-            continue;
-        }
-
-        if (data_header->id < 0 || data_header->id > destinations_count) {
-            continue;
+        // Version selection based on feature flags:
+        // - REV12: integer biquad params (Version2a)
+        // - REV15: float coeff/biquad v2b
+        // - older: no biquad fields
+        if (!splitter_biquad_param_supported) {
+            const auto* data_header =
+                reinterpret_cast<const SplitterDestinationData::InParameter*>(input + offset);
+
+            if (data_header->magic != GetSplitterSendDataMagic()) {
+                continue;
+            }
+            if (data_header->id < 0 || data_header->id > destinations_count) {
+                continue;
+            }
+
+            auto modified_params = *data_header;
+            if (!splitter_prev_volume_reset_supported) {
+                modified_params.reset_prev_volume = false;
+            }
+            splitter_destinations[data_header->id].Update(modified_params);
+            offset += sizeof(SplitterDestinationData::InParameter);
+        } else if (!splitter_float_coeff_supported) {
+            // Version 2a: struct contains legacy fixed-point biquad filter fields (REV12+)
+            const auto* data_header_v2a =
+                reinterpret_cast<const SplitterDestinationData::InParameterVersion2a*>(input +
+                                                                                       offset);
+
+            if (data_header_v2a->magic != GetSplitterSendDataMagic()) {
+                continue;
+            }
+            if (data_header_v2a->id < 0 || data_header_v2a->id > destinations_count) {
+                continue;
+            }
+
+            // Map common fields to the base format
+            SplitterDestinationData::InParameter mapped{};
+            mapped.magic = data_header_v2a->magic;
+            mapped.id = data_header_v2a->id;
+            mapped.mix_volumes = data_header_v2a->mix_volumes;
+            mapped.mix_id = data_header_v2a->mix_id;
+            mapped.in_use = data_header_v2a->in_use;
+            mapped.reset_prev_volume =
+                splitter_prev_volume_reset_supported ? data_header_v2a->reset_prev_volume : false;
+
+            auto& destination = splitter_destinations[data_header_v2a->id];
+            destination.Update(mapped);
+
+            // Convert legacy fixed-point biquad params into float representation
+            auto biquad_filters = destination.GetBiquadFilters();
+            for (size_t filter_idx = 0; filter_idx < MaxBiquadFilters; filter_idx++) {
+                const auto& legacy = data_header_v2a->biquad_filters[filter_idx];
+                auto& out = biquad_filters[filter_idx];
+                out.enabled = legacy.enabled;
+                // s16 fixed-point scale: use Q14 like voices (b and a are s16, 1.0 ~= 1<<14)
+                constexpr float scale = 1.0f / static_cast<float>(1 << 14);
+                out.numerator[0] = static_cast<float>(legacy.b[0]) * scale;
+                out.numerator[1] = static_cast<float>(legacy.b[1]) * scale;
+                out.numerator[2] = static_cast<float>(legacy.b[2]) * scale;
+                out.denominator[0] = static_cast<float>(legacy.a[0]) * scale;
+                out.denominator[1] = static_cast<float>(legacy.a[1]) * scale;
+            }
+
+            offset += static_cast<u32>(sizeof(SplitterDestinationData::InParameterVersion2a));
+        } else {
+            // Version 2b: struct contains extra biquad filter fields with float coeffs
+            const auto* data_header_v2b =
+                reinterpret_cast<const SplitterDestinationData::InParameterVersion2b*>(input +
+                                                                                       offset);
+
+            if (data_header_v2b->magic != GetSplitterSendDataMagic()) {
+                continue;
+            }
+            if (data_header_v2b->id < 0 || data_header_v2b->id > destinations_count) {
+                continue;
+            }
+
+            // Map common fields to the old format
+            SplitterDestinationData::InParameter mapped{};
+            mapped.magic = data_header_v2b->magic;
+            mapped.id = data_header_v2b->id;
+            mapped.mix_volumes = data_header_v2b->mix_volumes;
+            mapped.mix_id = data_header_v2b->mix_id;
+            mapped.in_use = data_header_v2b->in_use;
+            mapped.reset_prev_volume =
+                splitter_prev_volume_reset_supported ? data_header_v2b->reset_prev_volume : false;
+
+            // Store biquad filters from V2b (REV15+)
+            auto& destination = splitter_destinations[data_header_v2b->id];
+            destination.Update(mapped);
+
+            // Copy biquad filter parameters
+            auto biquad_filters = destination.GetBiquadFilters();
+            for (size_t filter_idx = 0; filter_idx < MaxBiquadFilters; filter_idx++) {
+                biquad_filters[filter_idx] = data_header_v2b->biquad_filters[filter_idx];
+            }
+
+            offset += static_cast<u32>(sizeof(SplitterDestinationData::InParameterVersion2b));
         }
-
-        splitter_destinations[data_header->id].Update(*data_header);
-        offset += sizeof(SplitterDestinationData::InParameter);
     }
 
     return offset;