Rename the main audio tasks to be more sensible

3 files changed, 29 insertions, 19 deletions

diff --git a/src/audio/include/sink_mixer.hpp b/src/audio/include/audio_converter.hpp
index d046f835..81532969 100644
--- a/src/audio/include/sink_mixer.hpp
+++ b/src/audio/include/audio_converter.hpp
@@ -18,19 +18,21 @@
 namespace audio {
 
 /*
- * Handles the final downmix + resample + quantisation stage of audio,
- * generation sending the result directly to an IAudioOutput.
+ * Handle to a persistent task that converts samples between formats (sample
+ * rate, channels, bits per sample), in order to put samples in the preferred
+ * format of the current output device. The resulting samples are forwarded
+ * to the output device's sink stream.
  */
-class SinkMixer {
+class SampleConverter {
  public:
-  SinkMixer();
-  ~SinkMixer();
+  SampleConverter();
+  ~SampleConverter();
 
   auto SetOutput(std::shared_ptr<IAudioOutput>) -> void;
 
-  auto MixAndSend(cpp::span<sample::Sample>,
-                  const IAudioOutput::Format& format,
-                  bool is_eos) -> void;
+  auto ConvertSamples(cpp::span<sample::Sample>,
+                      const IAudioOutput::Format& format,
+                      bool is_eos) -> void;
 
  private:
   auto Main() -> void;
diff --git a/src/audio/include/audio_task.hpp b/src/audio/include/audio_decoder.hpp
index 08c5769c..1759f6e4 100644
--- a/src/audio/include/audio_task.hpp
+++ b/src/audio/include/audio_decoder.hpp
@@ -9,15 +9,18 @@
 #include <cstdint>
 #include <memory>
 
+#include "audio_converter.hpp"
 #include "audio_sink.hpp"
 #include "audio_source.hpp"
 #include "codec.hpp"
-#include "sink_mixer.hpp"
 #include "track.hpp"
 #include "types.hpp"
 
 namespace audio {
 
+/*
+ * Sample-based timer for the current elapsed playback time.
+ */
 class Timer {
  public:
   Timer(const codecs::ICodec::OutputFormat& format);
@@ -32,25 +35,30 @@ class Timer {
   uint32_t total_duration_seconds_;
 };
 
-class AudioTask {
+/*
+ * Handle to a persistent task that takes bytes from the given source, decodes
+ * them into sample::Sample (normalised to 16 bit signed PCM), and then
+ * forwards the resulting stream to the given converter.
+ */
+class Decoder {
  public:
   static auto Start(std::shared_ptr<IAudioSource> source,
-                    std::shared_ptr<SinkMixer> mixer) -> AudioTask*;
+                    std::shared_ptr<SampleConverter> converter) -> Decoder*;
 
   auto Main() -> void;
 
-  AudioTask(const AudioTask&) = delete;
-  AudioTask& operator=(const AudioTask&) = delete;
+  Decoder(const Decoder&) = delete;
+  Decoder& operator=(const Decoder&) = delete;
 
  private:
-  AudioTask(std::shared_ptr<IAudioSource> source,
-            std::shared_ptr<SinkMixer> mixer);
+  Decoder(std::shared_ptr<IAudioSource> source,
+          std::shared_ptr<SampleConverter> converter);
 
   auto BeginDecoding(std::shared_ptr<codecs::IStream>) -> bool;
   auto ContinueDecoding() -> bool;
 
   std::shared_ptr<IAudioSource> source_;
-  std::shared_ptr<SinkMixer> mixer_;
+  std::shared_ptr<SampleConverter> converter_;
 
   std::shared_ptr<codecs::IStream> stream_;
   std::unique_ptr<codecs::ICodec> codec_;
diff --git a/src/audio/include/audio_fsm.hpp b/src/audio/include/audio_fsm.hpp
index 6c785426..430bc298 100644
--- a/src/audio/include/audio_fsm.hpp
+++ b/src/audio/include/audio_fsm.hpp
@@ -13,8 +13,8 @@
 #include "audio_sink.hpp"
 #include "tinyfsm.hpp"
 
+#include "audio_decoder.hpp"
 #include "audio_events.hpp"
-#include "audio_task.hpp"
 #include "bt_audio_output.hpp"
 #include "database.hpp"
 #include "display.hpp"
@@ -68,9 +68,9 @@ class AudioState : public tinyfsm::Fsm<AudioState> {
   static std::shared_ptr<drivers::I2SDac> sDac;
   static std::weak_ptr<database::Database> sDatabase;
 
-  static std::unique_ptr<AudioTask> sTask;
   static std::shared_ptr<FatfsAudioInput> sFileSource;
-  static std::shared_ptr<SinkMixer> sMixer;
+  static std::unique_ptr<Decoder> sDecoder;
+  static std::shared_ptr<SampleConverter> sSampleConverter;
   static std::shared_ptr<IAudioOutput> sOutput;
 
   static TrackQueue* sTrackQueue;