Performance tweaks for smoother tunes

- Pin the decoder task to APP_CORE to reduce context switches
 - Increase sample buffer sizes

src/audio/audio_converter.cpp

@@ -24,7 +24,7 @@
 static constexpr char kTag[] = "mixer";
 
 static constexpr std::size_t kSourceBufferLength = 8 * 1024;
-static constexpr std::size_t kSampleBufferLength = 240 * 2;
+static constexpr std::size_t kSampleBufferLength = 240 * 2 * 4;
 
 namespace audio {
 

src/audio/audio_decoder.cpp

@@ -46,7 +46,7 @@ namespace audio {
 
 static const char* kTag = "audio_dec";
 
-static constexpr std::size_t kCodecBufferLength = 240 * 4;
+static constexpr std::size_t kCodecBufferLength = 240 * 4 * 4;
 
 Timer::Timer(const codecs::ICodec::OutputFormat& format)
     : current_seconds_(0),
@@ -79,7 +79,7 @@ auto Timer::AddSamples(std::size_t samples) -> void {
 auto Decoder::Start(std::shared_ptr<IAudioSource> source,
                     std::shared_ptr<SampleConverter> sink) -> Decoder* {
   Decoder* task = new Decoder(source, sink);
-  tasks::StartPersistent<tasks::Type::kAudio>([=]() { task->Main(); });
+  tasks::StartPersistent<tasks::Type::kAudio>(1, [=]() { task->Main(); });
   return task;
 }
 

src/audio/i2s_audio_output.cpp

@@ -37,7 +37,7 @@ static constexpr uint16_t kMaxVolume = 0x1ff;
 static constexpr uint16_t kMinVolume = 0b0;
 static constexpr uint16_t kMaxVolumeBeforeClipping = 0x185;
 static constexpr uint16_t kLineLevelVolume = 0x13d;
-static constexpr uint16_t kDefaultVolume = 0x128;
+static constexpr uint16_t kDefaultVolume = 0x100;
 
 static constexpr size_t kDrainBufferSize = 8 * 1024;
 

src/ui/lvgl_task.cpp

@@ -49,7 +49,7 @@
 namespace ui {
 
 static const char* kTag = "lv_task";
-static const TickType_t kMaxFrameRate = pdMS_TO_TICKS(66);
+static const TickType_t kMaxFrameRate = pdMS_TO_TICKS(100);
 
 static int sTimerId;
 static SemaphoreHandle_t sFrameSemaphore;

src/ui/widget_top_bar.cpp

@@ -58,23 +58,23 @@ auto TopBar::Update(const State& state) -> void {
       lv_label_set_text(playback_, "-");
       break;
     case PlaybackState::kPaused:
-      lv_label_set_text(playback_, "");
+      lv_label_set_text(playback_, LV_SYMBOL_PAUSE);
       break;
     case PlaybackState::kPlaying:
-      lv_label_set_text(playback_, "");
+      lv_label_set_text(playback_, LV_SYMBOL_PLAY);
       break;
   }
 
   if (state.battery_percent >= 95) {
-    lv_label_set_text(battery_, "");
+    lv_label_set_text(battery_, LV_SYMBOL_BATTERY_FULL);
   } else if (state.battery_percent >= 70) {
-    lv_label_set_text(battery_, "");
+    lv_label_set_text(battery_, LV_SYMBOL_BATTERY_1);
   } else if (state.battery_percent >= 40) {
-    lv_label_set_text(battery_, "");
+    lv_label_set_text(battery_, LV_SYMBOL_BATTERY_2);
   } else if (state.battery_percent >= 10) {
-    lv_label_set_text(battery_, "");
+    lv_label_set_text(battery_, LV_SYMBOL_BATTERY_3);
   } else {
-    lv_label_set_text(battery_, "");
+    lv_label_set_text(battery_, LV_SYMBOL_BATTERY_EMPTY);
   }
 }