From ffbba74c91e2200868047f76ab5c452bb9aa338d Mon Sep 17 00:00:00 2001
From: Kelebek1 <eeeedddccc@hotmail.co.uk>
Date: Wed, 13 Dec 2023 06:26:20 +0000
Subject: [PATCH 1/2] Have GetActiveChannelCount return the system channels
instead of host device channels
---
src/audio_core/sink/cubeb_sink.cpp | 3 +-
src/audio_core/sink/sdl2_sink.cpp | 3 +-
src/audio_core/sink/sink.h | 12 +++++++
src/audio_core/sink/sink_stream.cpp | 43 +++++++++++++++----------
src/core/hle/service/audio/audren_u.cpp | 2 +-
5 files changed, 43 insertions(+), 20 deletions(-)
diff --git a/src/audio_core/sink/cubeb_sink.cpp b/src/audio_core/sink/cubeb_sink.cpp
index 51a23fe158..d97ca2a406 100644
--- a/src/audio_core/sink/cubeb_sink.cpp
+++ b/src/audio_core/sink/cubeb_sink.cpp
@@ -253,8 +253,9 @@ CubebSink::~CubebSink() {
#endif
}
-SinkStream* CubebSink::AcquireSinkStream(Core::System& system, u32 system_channels,
+SinkStream* CubebSink::AcquireSinkStream(Core::System& system, u32 system_channels_,
const std::string& name, StreamType type) {
+ system_channels = system_channels_;
SinkStreamPtr& stream = sink_streams.emplace_back(std::make_unique<CubebSinkStream>(
ctx, device_channels, system_channels, output_device, input_device, name, type, system));
diff --git a/src/audio_core/sink/sdl2_sink.cpp b/src/audio_core/sink/sdl2_sink.cpp
index 96e0efce2e..7dd155ff0c 100644
--- a/src/audio_core/sink/sdl2_sink.cpp
+++ b/src/audio_core/sink/sdl2_sink.cpp
@@ -168,8 +168,9 @@ SDLSink::SDLSink(std::string_view target_device_name) {
SDLSink::~SDLSink() = default;
-SinkStream* SDLSink::AcquireSinkStream(Core::System& system, u32 system_channels,
+SinkStream* SDLSink::AcquireSinkStream(Core::System& system, u32 system_channels_,
const std::string&, StreamType type) {
+ system_channels = system_channels_;
SinkStreamPtr& stream = sink_streams.emplace_back(std::make_unique<SDLSinkStream>(
device_channels, system_channels, output_device, input_device, type, system));
return stream.get();
diff --git a/src/audio_core/sink/sink.h b/src/audio_core/sink/sink.h
index f28c6d1268..e22e8c3e56 100644
--- a/src/audio_core/sink/sink.h
+++ b/src/audio_core/sink/sink.h
@@ -85,9 +85,21 @@ public:
*/
virtual void SetSystemVolume(f32 volume) = 0;
+ /**
+ * Get the number of channels the game has set, can be different to the host hardware's support.
+ * Either 2 or 6.
+ *
+ * @return Number of device channels.
+ */
+ u32 GetSystemChannels() const {
+ return system_channels;
+ }
+
protected:
/// Number of device channels supported by the hardware
u32 device_channels{2};
+ /// Number of channels the game is sending
+ u32 system_channels{2};
};
using SinkPtr = std::unique_ptr<Sink>;
diff --git a/src/audio_core/sink/sink_stream.cpp b/src/audio_core/sink/sink_stream.cpp
index 2a09db599e..97866f417b 100644
--- a/src/audio_core/sink/sink_stream.cpp
+++ b/src/audio_core/sink/sink_stream.cpp
@@ -40,29 +40,38 @@ void SinkStream::AppendBuffer(SinkBuffer& buffer, std::span<s16> samples) {
if (system_channels == 6 && device_channels == 2) {
// We're given 6 channels, but our device only outputs 2, so downmix.
- static constexpr std::array<f32, 4> down_mix_coeff{1.0f, 0.707f, 0.251f, 0.707f};
+ // Front = 1.0
+ // Center = 0.596
+ // Back = 0.707
+ // LFE = 0.354
+ // 1.0 + 0.596 + 0.707 + 0.354 = 2.657, 1/2.657 = 0.37636f downscale coefficient
+ static constexpr std::array<f32, 4> down_mix_coeff{0.37636f, 0.22431056f, 0.13323144f,
+ 0.26608652f};
for (u32 read_index = 0, write_index = 0; read_index < samples.size();
read_index += system_channels, write_index += device_channels) {
+ const auto fl =
+ static_cast<f32>(samples[read_index + static_cast<u32>(Channels::FrontLeft)]);
+ const auto fr =
+ static_cast<f32>(samples[read_index + static_cast<u32>(Channels::FrontRight)]);
+ const auto c =
+ static_cast<f32>(samples[read_index + static_cast<u32>(Channels::Center)]);
+ const auto lfe =
+ static_cast<f32>(samples[read_index + static_cast<u32>(Channels::LFE)]);
+ const auto bl =
+ static_cast<f32>(samples[read_index + static_cast<u32>(Channels::BackLeft)]);
+ const auto br =
+ static_cast<f32>(samples[read_index + static_cast<u32>(Channels::BackRight)]);
+
const auto left_sample{
- ((Common::FixedPoint<49, 15>(
- samples[read_index + static_cast<u32>(Channels::FrontLeft)]) *
- down_mix_coeff[0] +
- samples[read_index + static_cast<u32>(Channels::Center)] * down_mix_coeff[1] +
- samples[read_index + static_cast<u32>(Channels::LFE)] * down_mix_coeff[2] +
- samples[read_index + static_cast<u32>(Channels::BackLeft)] * down_mix_coeff[3]) *
- volume)
- .to_int()};
+ static_cast<s32>((fl * down_mix_coeff[0] + c * down_mix_coeff[1] +
+ lfe * down_mix_coeff[2] + bl * down_mix_coeff[3]) *
+ volume)};
const auto right_sample{
- ((Common::FixedPoint<49, 15>(
- samples[read_index + static_cast<u32>(Channels::FrontRight)]) *
- down_mix_coeff[0] +
- samples[read_index + static_cast<u32>(Channels::Center)] * down_mix_coeff[1] +
- samples[read_index + static_cast<u32>(Channels::LFE)] * down_mix_coeff[2] +
- samples[read_index + static_cast<u32>(Channels::BackRight)] * down_mix_coeff[3]) *
- volume)
- .to_int()};
+ static_cast<s32>((fr * down_mix_coeff[0] + c * down_mix_coeff[1] +
+ lfe * down_mix_coeff[2] + br * down_mix_coeff[3]) *
+ volume)};
samples[write_index + static_cast<u32>(Channels::FrontLeft)] =
static_cast<s16>(std::clamp(left_sample, min, max));
diff --git a/src/core/hle/service/audio/audren_u.cpp b/src/core/hle/service/audio/audren_u.cpp
index 2f09cade55..23e56c77a6 100644
--- a/src/core/hle/service/audio/audren_u.cpp
+++ b/src/core/hle/service/audio/audren_u.cpp
@@ -359,7 +359,7 @@ private:
void GetActiveChannelCount(HLERequestContext& ctx) {
const auto& sink{system.AudioCore().GetOutputSink()};
- u32 channel_count{sink.GetDeviceChannels()};
+ u32 channel_count{sink.GetSystemChannels()};
LOG_DEBUG(Service_Audio, "(STUBBED) called. Channels={}", channel_count);
From 6851e93296969e1f990ebc12e2a46026dc34ccce Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Sat, 16 Dec 2023 12:54:40 -0500
Subject: [PATCH 2/2] audio: skip coefficient normalization for downmix
---
src/audio_core/sink/sink_stream.cpp | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/src/audio_core/sink/sink_stream.cpp b/src/audio_core/sink/sink_stream.cpp
index 97866f417b..c047b06683 100644
--- a/src/audio_core/sink/sink_stream.cpp
+++ b/src/audio_core/sink/sink_stream.cpp
@@ -42,11 +42,9 @@ void SinkStream::AppendBuffer(SinkBuffer& buffer, std::span<s16> samples) {
// We're given 6 channels, but our device only outputs 2, so downmix.
// Front = 1.0
// Center = 0.596
- // Back = 0.707
// LFE = 0.354
- // 1.0 + 0.596 + 0.707 + 0.354 = 2.657, 1/2.657 = 0.37636f downscale coefficient
- static constexpr std::array<f32, 4> down_mix_coeff{0.37636f, 0.22431056f, 0.13323144f,
- 0.26608652f};
+ // Back = 0.707
+ static constexpr std::array<f32, 4> down_mix_coeff{1.0, 0.596f, 0.354f, 0.707f};
for (u32 read_index = 0, write_index = 0; read_index < samples.size();
read_index += system_channels, write_index += device_channels) {