6 files changed, 81 insertions, 46 deletions

diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index c9124688..261f7c79 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -38,7 +38,7 @@ class IAudioSink {
   virtual auto AdjustVolumeUp() -> bool = 0;
   virtual auto AdjustVolumeDown() -> bool = 0;
 
-  virtual auto Configure(const StreamInfo::Format& format) -> bool = 0;
+  virtual auto Configure(const StreamInfo::Pcm& format) -> bool = 0;
   virtual auto Send(const cpp::span<std::byte>& data) -> void = 0;
 
   auto stream() -> StreamBufferHandle_t { return stream_; }
diff --git a/src/audio/include/audio_source.hpp b/src/audio/include/audio_source.hpp
index e062fd1a..115f8bf4 100644
--- a/src/audio/include/audio_source.hpp
+++ b/src/audio/include/audio_source.hpp
@@ -8,6 +8,7 @@
 
 #include <stdint.h>
 
+#include <bitset>
 #include <memory>
 
 #include "freertos/FreeRTOS.h"
@@ -22,12 +23,25 @@ class IAudioSource {
  public:
   virtual ~IAudioSource() {}
 
+  class Flags {
+   public:
+    Flags(bool is_start, bool is_end) {
+      flags_[0] = is_start;
+      flags_[1] = is_start;
+    }
+
+    auto is_start() -> bool { return flags_[0]; }
+    auto is_end() -> bool { return flags_[1]; }
+
+   private:
+    std::bitset<2> flags_;
+  };
+
   /*
    * Synchronously fetches data from this source.
    */
-  virtual auto Read(std::function<bool(StreamInfo::Format)>,
-                    std::function<size_t(cpp::span<const std::byte>)>,
-                    TickType_t) -> void = 0;
+  virtual auto Read(std::function<void(Flags, InputStream&)>, TickType_t)
+      -> void = 0;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_task.hpp b/src/audio/include/audio_task.hpp
index f80c8878..ae4c2221 100644
--- a/src/audio/include/audio_task.hpp
+++ b/src/audio/include/audio_task.hpp
@@ -14,6 +14,7 @@
 #include "audio_source.hpp"
 #include "codec.hpp"
 #include "pipeline.hpp"
+#include "stream_info.hpp"
 
 namespace audio {
 
@@ -27,10 +28,13 @@ class Timer {
   auto AddBytes(std::size_t) -> void;
 
  private:
+  auto bytes_to_samples(uint32_t) -> uint32_t;
+
   StreamInfo::Pcm format_;
 
   uint32_t current_seconds_;
   uint32_t current_sample_in_second_;
+
   uint32_t total_duration_seconds_;
 };
 
@@ -43,14 +47,24 @@ class AudioTask {
  private:
   AudioTask(IAudioSource* source, IAudioSink* sink);
 
+  auto HandleNewStream(const InputStream&) -> bool;
+
+  auto BeginDecoding(InputStream&) -> bool;
+  auto ContinueDecoding(InputStream&) -> bool;
+  auto FinishDecoding(InputStream&) -> void;
+
+  auto ForwardPcmStream(StreamInfo::Pcm&, cpp::span<const std::byte>) -> bool;
+
+  auto ConfigureSink(const StreamInfo::Pcm&) -> bool;
+
   IAudioSource* source_;
   IAudioSink* sink_;
   std::unique_ptr<codecs::ICodec> codec_;
   std::unique_ptr<Timer> timer_;
 
-  bool is_new_stream_;
+  bool has_begun_decoding_;
   std::optional<StreamInfo::Format> current_input_format_;
-  std::optional<StreamInfo::Format> current_output_format_;
+  std::optional<StreamInfo::Pcm> current_output_format_;
 
   std::byte* sample_buffer_;
   std::size_t sample_buffer_len_;
diff --git a/src/audio/include/fatfs_audio_input.hpp b/src/audio/include/fatfs_audio_input.hpp
index a1b9689b..e13e49e2 100644
--- a/src/audio/include/fatfs_audio_input.hpp
+++ b/src/audio/include/fatfs_audio_input.hpp
@@ -89,9 +89,8 @@ class FatfsAudioInput : public IAudioSource {
   auto SetPath(const std::string&) -> void;
   auto SetPath() -> void;
 
-  auto Read(std::function<bool(StreamInfo::Format)>,
-            std::function<size_t(cpp::span<const std::byte>)>,
-            TickType_t) -> void override;
+  auto Read(std::function<void(Flags, InputStream&)>, TickType_t)
+      -> void override;
 
   FatfsAudioInput(const FatfsAudioInput&) = delete;
   FatfsAudioInput& operator=(const FatfsAudioInput&) = delete;
@@ -118,11 +117,7 @@ class FatfsAudioInput : public IAudioSource {
   StreamBufferHandle_t streamer_buffer_;
   std::unique_ptr<FileStreamer> streamer_;
 
-  StreamInfo file_buffer_info_;
-  std::size_t file_buffer_len_;
-  std::byte* file_buffer_;
-
-  RawStream file_buffer_stream_;
+  std::unique_ptr<RawStream> input_buffer_;
 
   // Mutex guarding the current file/stream associated with this source. Must be
   // held during readings, and before altering the current file.
@@ -130,7 +125,7 @@ class FatfsAudioInput : public IAudioSource {
 
   std::unique_ptr<database::FutureFetcher<std::optional<std::string>>>
       pending_path_;
-  std::optional<StreamInfo::Format> current_format_;
+  bool is_first_read_;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/i2s_audio_output.hpp b/src/audio/include/i2s_audio_output.hpp
index 583a5d6a..d42efc42 100644
--- a/src/audio/include/i2s_audio_output.hpp
+++ b/src/audio/include/i2s_audio_output.hpp
@@ -34,7 +34,7 @@ class I2SAudioOutput : public IAudioSink {
   auto AdjustVolumeUp() -> bool override;
   auto AdjustVolumeDown() -> bool override;
 
-  auto Configure(const StreamInfo::Format& format) -> bool override;
+  auto Configure(const StreamInfo::Pcm& format) -> bool override;
   auto Send(const cpp::span<std::byte>& data) -> void override;
 
   I2SAudioOutput(const I2SAudioOutput&) = delete;
diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index 00aa1110..77789c24 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <sys/_stdint.h>
 #include <cstdint>
 #include <optional>
 #include <string>
@@ -25,25 +26,26 @@
 
 namespace audio {
 
-struct StreamInfo {
+class StreamInfo {
+ public:
+  StreamInfo() : bytes_in_stream_(0), total_length_bytes_(), format_() {}
+
   // The number of bytes that are available for consumption within this
   // stream's buffer.
-  std::size_t bytes_in_stream{0};
-
-  bool is_producer_finished = true;
-
-  bool is_consumer_finished = true;
-
-  std::optional<std::uint32_t> duration_seconds;
+  auto bytes_in_stream() -> std::size_t& { return bytes_in_stream_; }
+  auto bytes_in_stream() const -> std::size_t { return bytes_in_stream_; }
 
-  std::optional<std::uint32_t> seek_to_seconds{};
+  auto total_length_bytes() -> std::optional<std::uint32_t>& {
+    return total_length_bytes_;
+  }
+  auto total_length_bytes() const -> std::optional<std::uint32_t> {
+    return total_length_bytes_;
+  }
 
   struct Encoded {
     // The codec that this stream is associated with.
     codecs::StreamType type;
 
-    std::optional<std::size_t> duration_bytes;
-
     bool operator==(const Encoded&) const = default;
   };
 
@@ -59,33 +61,48 @@ struct StreamInfo {
   };
 
   typedef std::variant<std::monostate, Encoded, Pcm> Format;
-  Format format{};
+  auto format() const -> const Format& { return format_; }
+  auto set_format(Format f) -> void { format_ = f; }
+
+  template <typename T>
+  auto format_as() const -> std::optional<T> {
+    if (std::holds_alternative<T>(format_)) {
+      return std::get<T>(format_);
+    }
+    return {};
+  }
 
   bool operator==(const StreamInfo&) const = default;
+
+ private:
+  std::size_t bytes_in_stream_;
+  std::optional<std::uint32_t> total_length_bytes_;
+  Format format_{};
 };
 
+class InputStream;
+class OutputStream;
+
 class RawStream {
  public:
-  StreamInfo* info;
-  cpp::span<std::byte> data;
+  explicit RawStream(std::size_t size);
+  ~RawStream();
 
-  RawStream(StreamInfo* i, cpp::span<std::byte> d) : info(i), data(d) {}
+  auto info() -> StreamInfo& { return info_; }
+  auto data() -> cpp::span<std::byte>;
+
+ private:
+  StreamInfo info_;
+  std::size_t buffer_size_;
+  std::byte* buffer_;
 };
 
-/*
- * A byte buffer + associated metadata, which is not allowed to modify any of
- * the underlying data.
- */
 class InputStream {
  public:
   explicit InputStream(RawStream* s) : raw_(s) {}
 
   void consume(std::size_t bytes) const;
 
-  bool is_producer_finished() const;
-
-  void mark_consumer_finished() const;
-
   const StreamInfo& info() const;
 
   cpp::span<const std::byte> data() const;
@@ -100,18 +117,13 @@ class OutputStream {
 
   void add(std::size_t bytes) const;
 
-  bool prepare(const StreamInfo::Format& new_format);
-
-  void set_duration(std::size_t);
+  void prepare(const StreamInfo::Format& new_format,
+               std::optional<uint32_t> length);
 
   const StreamInfo& info() const;
 
   cpp::span<std::byte> data() const;
 
-  bool is_consumer_finished() const;
-
-  void mark_producer_finished() const;
-
  private:
   RawStream* raw_;
 };