From 2688ed93f09732dfe3a718f56a4e34b4c8b55216 Mon Sep 17 00:00:00 2001
From: PJB3005 <pieterjan.briers+git@gmail.com>
Date: Tue, 17 Mar 2026 00:03:35 +0100
Subject: [PATCH] Audio processing in f32

---
 src/dusk/audio/DuskAudioSystem.cpp | 16 +++++++---------
 src/dusk/audio/DuskDsp.cpp         | 28 +++++++++++++++++-----------
 src/dusk/audio/DuskDsp.hpp         |  2 +-
 3 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/src/dusk/audio/DuskAudioSystem.cpp b/src/dusk/audio/DuskAudioSystem.cpp
index ae23b995f3..1d625a8101 100644
--- a/src/dusk/audio/DuskAudioSystem.cpp
+++ b/src/dusk/audio/DuskAudioSystem.cpp
@@ -67,8 +67,9 @@ void SDLCALL GetNewAudio(
     }
 }
 
+#if 0
 static std::ofstream outRaw("guh.raw", std::ios_base::out | std::ios_base::binary);
-static std::ofstream outRawF32("guh.f32.raw", std::ios_base::out | std::ios_base::binary);
+#endif
 
 int RenderNewAudioFrame() {
     JASCriticalSection section;
@@ -82,7 +83,9 @@ int RenderNewAudioFrame() {
         JASAudioThread::snIntCount -= 1;
     }
 
+#if 0
     outRaw.flush();
+#endif
 
     return static_cast<u16>(countSubframes) * DSP_SUBFRAME_SIZE;
 }
@@ -93,14 +96,9 @@ void RenderAudioSubframe() {
     JASDriver::updateDSP();
     DspRender(subFrame);
 
-    std::array<f32, DSP_SUBFRAME_SIZE> guh = {};
-    for (int i = 0; i < DSP_SUBFRAME_SIZE; i++) {
-        guh[i] = (f32)subFrame[i] / (f32)0x7FFF;
-    }
-
+#if 0
     outRaw.write((const char*)subFrame.data(), sizeof(subFrame));
-    outRawF32.write((const char*)guh.data(), sizeof(guh));
+#endif
 
-    SDL_PutAudioStreamData(PlaybackStream, guh.data(), sizeof(guh));
-    // SDL_PutAudioStreamData(PlaybackStream, subFrame.data(), sizeof(subFrame));
+    SDL_PutAudioStreamData(PlaybackStream, subFrame.data(), sizeof(subFrame));
 }
diff --git a/src/dusk/audio/DuskDsp.cpp b/src/dusk/audio/DuskDsp.cpp
index 3c5679e9df..a901cc0cdc 100644
--- a/src/dusk/audio/DuskDsp.cpp
+++ b/src/dusk/audio/DuskDsp.cpp
@@ -80,7 +80,7 @@ static void ResetChannel(JASDsp::TChannel& channel, ChannelAuxData& aux) {
 
 static void MixSubframe(DspSubframe& dst, const DspSubframe& src) {
     for (int i = 0; i < dst.size(); i++) {
-        dst[i] = static_cast<s16>(dst[i] + src[i]);
+        dst[i] += src[i];
     }
 }
 
@@ -197,7 +197,7 @@ static void RenderChannel(
         ResetChannel(channel, channelAux);
     }
 
-    int wantRead = static_cast<int>(subframe.size() * sizeof(s16));
+    int wantRead = static_cast<int>(subframe.size() * sizeof(subframe[0]));
     auto read = SDL_GetAudioStreamData(
         channelAux.resampleStream,
         subframe.data(),
@@ -207,27 +207,33 @@ static void RenderChannel(
         channel.mIsFinished = true;
     }
 
+    u16 volume;
+    if (channel.mAutoMixerBeenSet) {
+        volume = channel.mAutoMixerVolume;
+    } else {
+        volume = channel.mOutputChannels[0].mTargetVolume;
+    }
+    f32 ratio = static_cast<f32>(volume) / static_cast<f32>(JASDriver::getChannelLevel_dsp());
     for (auto& sample : subframe) {
-        u16 volume;
-        if (channel.mAutoMixerBeenSet) {
-            volume = channel.mAutoMixerVolume;
-        } else {
-            volume = channel.mOutputChannels[0].mTargetVolume;
-        }
-        sample = (s16)((s64)sample * volume / JASDriver::getChannelLevel_dsp());
+        sample *= ratio;
     }
 }
 
 void dusk::audio::DspInit() {
-    constexpr SDL_AudioSpec spec = {
+    constexpr SDL_AudioSpec srcSpec = {
         SDL_AUDIO_S16,
         1,
         SampleRate
     };
+    constexpr SDL_AudioSpec dstSpec = {
+        SDL_AUDIO_F32,
+        1,
+        SampleRate
+    };
 
     for (int i = 0; i < DSP_CHANNELS; i++) {
         auto& aux = ChannelAux[i];
-        aux.resampleStream = SDL_CreateAudioStream(&spec, &spec);
+        aux.resampleStream = SDL_CreateAudioStream(&srcSpec, &dstSpec);
 
         SDL_SetAudioStreamGetCallback(
             aux.resampleStream,
diff --git a/src/dusk/audio/DuskDsp.hpp b/src/dusk/audio/DuskDsp.hpp
index 186f7de677..76a4ef2e14 100644
--- a/src/dusk/audio/DuskDsp.hpp
+++ b/src/dusk/audio/DuskDsp.hpp
@@ -17,7 +17,7 @@ namespace dusk::audio {
 
     extern ChannelAuxData ChannelAux[DSP_CHANNELS];
 
-    using DspSubframe = std::array<s16, DSP_SUBFRAME_SIZE>;
+    using DspSubframe = std::array<f32, DSP_SUBFRAME_SIZE>;
 
     void DspInit();
     void DspRender(DspSubframe& subframe);