switch to software volume scaling (it's bad tho i need daniel to do maths for me please)

src/audio/bt_audio_output.cpp

@@ -7,9 +7,9 @@
 #include "bt_audio_output.hpp"
 
 #include <algorithm>
+#include <cmath>
 #include <cstddef>
 #include <cstdint>
-#include <cmath>
 #include <memory>
 #include <variant>
 
@@ -32,7 +32,7 @@ namespace audio {
 BluetoothAudioOutput::BluetoothAudioOutput(StreamBufferHandle_t s,
                                            drivers::Bluetooth& bt,
                                            tasks::WorkerPool& p)
-    : IAudioOutput(s), bluetooth_(bt), bg_worker_(p), volume_(10) {}
+    : IAudioOutput(s), bluetooth_(bt), bg_worker_(p), volume_() {}
 
 BluetoothAudioOutput::~BluetoothAudioOutput() {}
 
@@ -44,10 +44,16 @@ auto BluetoothAudioOutput::changeMode(Modes mode) -> void {
   }
 }
 
-auto BluetoothAudioOutput::SetVolumeImbalance(int_fast8_t balance) -> void {}
+auto BluetoothAudioOutput::SetVolumeImbalance(int_fast8_t balance) -> void {
+  // FIXME: Support two separate scaling factors in the bluetooth driver.
+}
 
 auto BluetoothAudioOutput::SetVolume(uint16_t v) -> void {
-  volume_ = std::clamp<uint16_t>(v, 0, 0x7f);
+  volume_ = std::clamp<uint16_t>(v, 0, 100);
+  bg_worker_.Dispatch<void>([&]() {
+    float factor = volume_ / 100.;
+    bluetooth_.SetVolumeFactor(factor);
+  });
 }
 
 auto BluetoothAudioOutput::GetVolume() -> uint16_t {
@@ -55,20 +61,19 @@ auto BluetoothAudioOutput::GetVolume() -> uint16_t {
 }
 
 auto BluetoothAudioOutput::GetVolumePct() -> uint_fast8_t {
-  return static_cast<uint_fast8_t>(round(static_cast<int>(volume_) * 100.0 / 0x7f));
+  return static_cast<uint_fast8_t>(round(static_cast<int>(volume_)));
 }
 
 auto BluetoothAudioOutput::SetVolumePct(uint_fast8_t val) -> bool {
   if (val > 100) {
     return false;
   }
-  uint16_t vol = (val * (0x7f))/100;
-  SetVolume(vol);
+  SetVolume(val);
   return true;
 }
 
 auto BluetoothAudioOutput::GetVolumeDb() -> int_fast16_t {
-  double pct = GetVolumePct()/100.0;
+  double pct = GetVolumePct() / 100.0;
   if (pct <= 0) {
     pct = 0.01;
   }
@@ -82,11 +87,11 @@ auto BluetoothAudioOutput::SetVolumeDb(int_fast16_t val) -> bool {
 }
 
 auto BluetoothAudioOutput::AdjustVolumeUp() -> bool {
-  if (volume_ == 0x7f) {
+  if (volume_ == 100) {
     return false;
   }
   volume_++;
-  bg_worker_.Dispatch<void>([&]() { bluetooth_.SetVolume(volume_); });
+  SetVolume(volume_);
   return true;
 }
 
@@ -95,7 +100,7 @@ auto BluetoothAudioOutput::AdjustVolumeDown() -> bool {
     return false;
   }
   volume_--;
-  bg_worker_.Dispatch<void>([&]() { bluetooth_.SetVolume(volume_); });
+  SetVolume(volume_);
   return true;
 }
 

src/audio/include/bt_audio_output.hpp

@@ -54,7 +54,8 @@ class BluetoothAudioOutput : public IAudioOutput {
  private:
   drivers::Bluetooth& bluetooth_;
   tasks::WorkerPool& bg_worker_;
-  uint8_t volume_;
+
+  uint16_t volume_;
 };
 
 }  // namespace audio

src/drivers/bluetooth.cpp

@@ -25,6 +25,7 @@
 #include "freertos/portmacro.h"
 #include "freertos/projdefs.h"
 #include "freertos/timers.h"
+#include "sample.hpp"
 #include "tinyfsm/include/tinyfsm.hpp"
 
 #include "bluetooth_types.hpp"
@@ -37,6 +38,8 @@ namespace drivers {
 [[maybe_unused]] static constexpr char kTag[] = "bluetooth";
 
 DRAM_ATTR static StreamBufferHandle_t sStream = nullptr;
+DRAM_ATTR static std::atomic<float> sVolumeFactor = 1.f;
+
 static tasks::WorkerPool* sBgWorker;
 
 auto gap_cb(esp_bt_gap_cb_event_t event, esp_bt_gap_cb_param_t* param) -> void {
@@ -69,7 +72,16 @@ IRAM_ATTR auto a2dp_data_cb(uint8_t* buf, int32_t buf_size) -> int32_t {
   if (stream == nullptr) {
     return 0;
   }
-  return xStreamBufferReceive(stream, buf, buf_size, 0);
+  size_t bytes_received = xStreamBufferReceive(stream, buf, buf_size, 0);
+
+  // Apply software volume scaling.
+  int16_t* samples = reinterpret_cast<int16_t*>(buf);
+  float factor = sVolumeFactor.load();
+  for (size_t i = 0; i < bytes_received / 2; i++) {
+    samples[i] *= factor;
+  }
+
+  return bytes_received;
 }
 
 Bluetooth::Bluetooth(NvsStorage& storage, tasks::WorkerPool& bg_worker) {
@@ -150,10 +162,8 @@ auto Bluetooth::SetSource(StreamBufferHandle_t src) -> void {
       bluetooth::events::SourceChanged{});
 }
 
-auto Bluetooth::SetVolume(uint8_t vol) -> void {
-  auto lock = bluetooth::BluetoothState::lock();
-  tinyfsm::FsmList<bluetooth::BluetoothState>::dispatch(
-      bluetooth::events::ChangeVolume{.volume = vol});
+auto Bluetooth::SetVolumeFactor(float f) -> void {
+  sVolumeFactor = f;
 }
 
 auto Bluetooth::SetEventHandler(std::function<void(bluetooth::Event)> cb)
@@ -654,17 +664,6 @@ void Connected::react(const events::SourceChanged& ev) {
   }
 }
 
-void Connected::react(const events::ChangeVolume& ev) {
-  esp_err_t err = esp_avrc_ct_send_set_absolute_volume_cmd(
-      transaction_num_++, std::clamp<uint8_t>(ev.volume, 0, 0x7f));
-  if (err != ESP_OK) {
-    ESP_LOGW(kTag, "send vol failed %u", err);
-  }
-  if (transaction_num_ > ESP_AVRC_TRANS_LABEL_MAX) {
-    transaction_num_ = 0;
-  }
-}
-
 void Connected::react(const events::internal::Gap& ev) {
   sScanner_->HandleGapEvent(ev);
   switch (ev.type) {

src/drivers/include/bluetooth.hpp

@@ -43,7 +43,7 @@ class Bluetooth {
   auto PreferredDevice() -> std::optional<bluetooth::MacAndName>;
 
   auto SetSource(StreamBufferHandle_t) -> void;
-  auto SetVolume(uint8_t) -> void;
+  auto SetVolumeFactor(float) -> void;
 
   auto SetEventHandler(std::function<void(bluetooth::Event)> cb) -> void;
 };
@@ -60,9 +60,6 @@ struct SourceChanged : public tinyfsm::Event {};
 struct DeviceDiscovered : public tinyfsm::Event {
   const Device& device;
 };
-struct ChangeVolume : public tinyfsm::Event {
-  const uint8_t volume;
-};
 
 namespace internal {
 struct Gap : public tinyfsm::Event {
@@ -131,7 +128,6 @@ class BluetoothState : public tinyfsm::Fsm<BluetoothState> {
   virtual void react(const events::ConnectTimedOut& ev){};
   virtual void react(const events::PreferredDeviceChanged& ev){};
   virtual void react(const events::SourceChanged& ev){};
-  virtual void react(const events::ChangeVolume&) {}
 
   virtual void react(const events::DeviceDiscovered&);
 
@@ -204,7 +200,6 @@ class Connected : public BluetoothState {
 
   void react(const events::PreferredDeviceChanged& ev) override;
   void react(const events::SourceChanged& ev) override;
-  void react(const events::ChangeVolume&) override;
 
   void react(const events::Disable& ev) override;
   void react(const events::internal::Gap& ev) override;