From a9531c86a433c8b7ae1f77ff0266c27c39eca7f4 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Fri, 10 Mar 2023 11:28:33 +1100
Subject: mostly single task pipeline

---
 src/audio/include/audio_decoder.hpp     | 19 ++++------
 src/audio/include/audio_element.hpp     | 58 ++----------------------------
 src/audio/include/audio_playback.hpp    | 13 +++----
 src/audio/include/audio_task.hpp        | 31 +++++++++++++---
 src/audio/include/fatfs_audio_input.hpp | 17 ++++-----
 src/audio/include/i2s_audio_output.hpp  | 17 ++++-----
 src/audio/include/pipeline.hpp          | 42 ++++++++++++++++++++++
 src/audio/include/stream_info.hpp       | 63 +++++++++++++++++++++++++++++----
 8 files changed, 153 insertions(+), 107 deletions(-)
 create mode 100644 src/audio/include/pipeline.hpp

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_decoder.hpp b/src/audio/include/audio_decoder.hpp
index 47642469..be8daf99 100644
--- a/src/audio/include/audio_decoder.hpp
+++ b/src/audio/include/audio_decoder.hpp
@@ -3,6 +3,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <vector>
 
 #include "chunk.hpp"
 #include "ff.h"
@@ -10,6 +11,7 @@
 
 #include "audio_element.hpp"
 #include "codec.hpp"
+#include "stream_info.hpp"
 
 namespace audio {
 
@@ -22,28 +24,21 @@ class AudioDecoder : public IAudioElement {
   AudioDecoder();
   ~AudioDecoder();
 
-  auto StackSizeBytes() const -> std::size_t override { return 10 * 1024; };
-
-  auto HasUnprocessedInput() -> bool override;
-  auto IsOverBuffered() -> bool override;
-
-  auto ProcessStreamInfo(const StreamInfo& info) -> void override;
-  auto ProcessChunk(const cpp::span<std::byte>& chunk) -> void override;
-  auto ProcessEndOfStream() -> void override;
-  auto Process() -> void override;
+  auto Process(std::vector<Stream>* inputs, MutableStream* output)
+      -> void override;
 
   AudioDecoder(const AudioDecoder&) = delete;
   AudioDecoder& operator=(const AudioDecoder&) = delete;
 
  private:
-  memory::Arena arena_;
   std::unique_ptr<codecs::ICodec> current_codec_;
   std::optional<StreamInfo> stream_info_;
-  std::optional<ChunkReader> chunk_reader_;
 
-  bool has_sent_stream_info_;
+  bool has_set_stream_info_;
   bool has_samples_to_send_;
   bool needs_more_input_;
+
+  auto ProcessStreamInfo(const StreamInfo& info) -> bool;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_element.hpp b/src/audio/include/audio_element.hpp
index 91036348..c9192e4a 100644
--- a/src/audio/include/audio_element.hpp
+++ b/src/audio/include/audio_element.hpp
@@ -40,62 +40,8 @@ class IAudioElement {
   IAudioElement();
   virtual ~IAudioElement();
 
-  /*
-   * Returns the stack size in bytes that this element requires. This should
-   * be tuned according to the observed stack size of each element, as different
-   * elements have fairly different stack requirements (particular decoders).
-   */
-  virtual auto StackSizeBytes() const -> std::size_t { return 4096; };
-
-  /* Returns this element's input buffer. */
-  auto InputEventQueue() const -> QueueHandle_t { return input_events_; }
-  /* Returns this element's output buffer. */
-  auto OutputEventQueue() const -> QueueHandle_t { return output_events_; }
-  auto OutputEventQueue(const QueueHandle_t q) -> void { output_events_ = q; }
-
-  virtual auto HasUnprocessedInput() -> bool = 0;
-
-  virtual auto IsOverBuffered() -> bool { return false; }
-
-  auto HasUnflushedOutput() -> bool { return !buffered_output_.empty(); }
-  auto FlushBufferedOutput() -> bool;
-
-  /*
-   * Called when a StreamInfo message is received. Used to configure this
-   * element in preperation for incoming chunks.
-   */
-  virtual auto ProcessStreamInfo(const StreamInfo& info) -> void = 0;
-
-  /*
-   * Called when a ChunkHeader message is received. Includes the data associated
-   * with this chunk of stream data. This method should return the number of
-   * bytes in this chunk that were actually used; leftover bytes will be
-   * prepended to the next call.
-   */
-  virtual auto ProcessChunk(const cpp::span<std::byte>& chunk) -> void = 0;
-
-  virtual auto ProcessEndOfStream() -> void = 0;
-
-  virtual auto ProcessLogStatus() -> void {}
-
-  /*
-   * Called when there has been no data received over the input buffer for some
-   * time. This could be used to synthesize output, or to save memory by
-   * releasing unused resources.
-   */
-  virtual auto Process() -> void = 0;
-
- protected:
-  auto SendOrBufferEvent(std::unique_ptr<StreamEvent> event) -> bool;
-
-  // Queue for events coming into this element. Owned by us.
-  QueueHandle_t input_events_;
-  // Queue for events going into the next element. Not owned by us, may be null
-  // if we're not yet in a pipeline.
-  // FIXME: it would be nicer if this was non-nullable.
-  QueueHandle_t output_events_;
-  // Output events that have been generated, but are yet to be sent downstream.
-  std::deque<std::unique_ptr<StreamEvent>> buffered_output_;
+  virtual auto Process(std::vector<Stream>* inputs, MutableStream* output)
+      -> void = 0;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_playback.hpp b/src/audio/include/audio_playback.hpp
index a1bea64f..507e6f73 100644
--- a/src/audio/include/audio_playback.hpp
+++ b/src/audio/include/audio_playback.hpp
@@ -5,7 +5,9 @@
 #include <string>
 #include <vector>
 
+#include "audio_task.hpp"
 #include "esp_err.h"
+#include "fatfs_audio_input.hpp"
 #include "result.hpp"
 #include "span.hpp"
 
@@ -23,12 +25,10 @@ namespace audio {
 class AudioPlayback {
  public:
   enum Error { ERR_INIT_ELEMENT, ERR_MEM };
-  static auto create(drivers::GpioExpander* expander,
-                     std::shared_ptr<drivers::SdStorage> storage)
+  static auto create(drivers::GpioExpander* expander)
       -> cpp::result<std::unique_ptr<AudioPlayback>, Error>;
 
-  // TODO(jacqueline): configure on the fly once we have things to configure.
-  AudioPlayback();
+  AudioPlayback(FatfsAudioInput *file_input);
   ~AudioPlayback();
 
   /*
@@ -44,9 +44,10 @@ class AudioPlayback {
   AudioPlayback& operator=(const AudioPlayback&) = delete;
 
  private:
-  auto ConnectElements(IAudioElement* src, IAudioElement* sink) -> void;
+  FatfsAudioInput *file_source;
 
-  QueueHandle_t input_handle_;
+  std::vector<std::unique_ptr<IAudioElement>> all_elements_;
+  std::unique_ptr<task::Handle> pipeline_;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_task.hpp b/src/audio/include/audio_task.hpp
index df70ebaa..8db99850 100644
--- a/src/audio/include/audio_task.hpp
+++ b/src/audio/include/audio_task.hpp
@@ -6,17 +6,38 @@
 
 #include "audio_element.hpp"
 #include "freertos/portmacro.h"
+#include "pipeline.hpp"
 
 namespace audio {
 
+namespace task {
 struct AudioTaskArgs {
-  std::shared_ptr<IAudioElement>& element;
+  Pipeline* pipeline;
+  QueueHandle_t input;
 };
 
-auto StartAudioTask(const std::string& name,
-                    std::optional<BaseType_t> core_id,
-                    std::shared_ptr<IAudioElement> element) -> void;
+extern "C" void AudioTaskMain(void* args);
 
-void AudioTaskMain(void* args);
+enum Command { PLAY, PAUSE, QUIT };
+
+class Handle {
+ public:
+  explicit Handle(QueueHandle_t input);
+  ~Handle();
+
+  auto SetStreamInfo() -> void;
+  auto Play() -> void;
+  auto Pause() -> void;
+  auto Quit() -> void;
+
+  auto OutputBuffer() -> StreamBufferHandle_t;
+
+ private:
+  QueueHandle_t input;
+};
+
+auto Start(Pipeline* pipeline) -> Handle*;
+
+}  // namespace task
 
 }  // namespace audio
diff --git a/src/audio/include/fatfs_audio_input.hpp b/src/audio/include/fatfs_audio_input.hpp
index 9f2d676c..b3a6d843 100644
--- a/src/audio/include/fatfs_audio_input.hpp
+++ b/src/audio/include/fatfs_audio_input.hpp
@@ -3,41 +3,36 @@
 #include <cstdint>
 #include <memory>
 #include <string>
+#include <vector>
 
 #include "arena.hpp"
 #include "chunk.hpp"
 #include "freertos/FreeRTOS.h"
 
+#include "ff.h"
 #include "freertos/message_buffer.h"
 #include "freertos/queue.h"
 #include "span.hpp"
 
 #include "audio_element.hpp"
-#include "storage.hpp"
 #include "stream_buffer.hpp"
 
 namespace audio {
 
 class FatfsAudioInput : public IAudioElement {
  public:
-  explicit FatfsAudioInput(std::shared_ptr<drivers::SdStorage> storage);
+  explicit FatfsAudioInput();
   ~FatfsAudioInput();
 
-  auto HasUnprocessedInput() -> bool override;
-  auto IsOverBuffered() -> bool override;
+  auto OpenFile(const std::string& path) -> void;
 
-  auto ProcessStreamInfo(const StreamInfo& info) -> void override;
-  auto ProcessChunk(const cpp::span<std::byte>& chunk) -> void override;
-  auto ProcessEndOfStream() -> void override;
-  auto Process() -> void override;
+  auto Process(std::vector<Stream>* inputs, MutableStream* output)
+      -> void override;
 
   FatfsAudioInput(const FatfsAudioInput&) = delete;
   FatfsAudioInput& operator=(const FatfsAudioInput&) = delete;
 
  private:
-  memory::Arena arena_;
-  std::shared_ptr<drivers::SdStorage> storage_;
-
   FIL current_file_;
   bool is_file_open_;
 };
diff --git a/src/audio/include/i2s_audio_output.hpp b/src/audio/include/i2s_audio_output.hpp
index 2bea091b..57881b35 100644
--- a/src/audio/include/i2s_audio_output.hpp
+++ b/src/audio/include/i2s_audio_output.hpp
@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <memory>
+#include <vector>
 
 #include "audio_element.hpp"
 #include "chunk.hpp"
@@ -9,6 +10,7 @@
 
 #include "dac.hpp"
 #include "gpio_expander.hpp"
+#include "stream_info.hpp"
 
 namespace audio {
 
@@ -22,14 +24,8 @@ class I2SAudioOutput : public IAudioElement {
                  std::unique_ptr<drivers::AudioDac> dac);
   ~I2SAudioOutput();
 
-  auto HasUnprocessedInput() -> bool override;
-  auto IsOverBuffered() -> bool override;
-
-  auto ProcessStreamInfo(const StreamInfo& info) -> void override;
-  auto ProcessChunk(const cpp::span<std::byte>& chunk) -> void override;
-  auto ProcessEndOfStream() -> void override;
-  auto ProcessLogStatus() -> void override;
-  auto Process() -> void override;
+  auto Process(std::vector<Stream>* inputs, MutableStream* output)
+      -> void override;
 
   I2SAudioOutput(const I2SAudioOutput&) = delete;
   I2SAudioOutput& operator=(const I2SAudioOutput&) = delete;
@@ -40,8 +36,9 @@ class I2SAudioOutput : public IAudioElement {
   drivers::GpioExpander* expander_;
   std::unique_ptr<drivers::AudioDac> dac_;
 
-  std::optional<ChunkReader> chunk_reader_;
-  cpp::span<std::byte> latest_chunk_;
+  std::optional<StreamInfo::Pcm> current_config_;
+
+  auto ProcessStreamInfo(const StreamInfo& info) -> bool;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/pipeline.hpp b/src/audio/include/pipeline.hpp
new file mode 100644
index 00000000..42f70828
--- /dev/null
+++ b/src/audio/include/pipeline.hpp
@@ -0,0 +1,42 @@
+#pragma once
+
+#include <memory>
+#include <optional>
+#include <string>
+
+#include "freertos/portmacro.h"
+
+#include "audio_element.hpp"
+#include "himem.hpp"
+#include "stream_info.hpp"
+
+namespace audio {
+
+static const std::size_t kPipelineBufferSize = 32 * 1024;
+
+class Pipeline {
+ public:
+  Pipeline(IAudioElement* output);
+  ~Pipeline();
+  auto AddInput(IAudioElement* input) -> Pipeline*;
+
+  auto OutputElement() const -> IAudioElement*;
+
+  auto NumInputs() const -> std::size_t;
+
+  auto InStreams(std::vector<MappableRegion<kPipelineBufferSize>>*,
+                 std::vector<MutableStream>*) -> void;
+
+  auto OutStream(MappableRegion<kPipelineBufferSize>*) -> MutableStream;
+
+  auto GetIterationOrder() -> std::vector<Pipeline*>;
+
+ private:
+  IAudioElement* root_;
+  std::vector<std::unique_ptr<Pipeline>> subtrees_;
+
+  HimemAlloc<kPipelineBufferSize> output_buffer_;
+  StreamInfo output_info_;
+};
+
+}  // namespace audio
diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index bf67364f..47f65649 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -4,19 +4,68 @@
 #include <optional>
 #include <string>
 #include <string_view>
+#include <variant>
 
-#include "cbor.h"
 #include "result.hpp"
-#include "sys/_stdint.h"
+#include "span.hpp"
+#include "types.hpp"
 
 namespace audio {
 
 struct StreamInfo {
-  std::optional<std::string> path;
-  std::optional<uint8_t> channels;
-  std::optional<uint8_t> bits_per_sample;
-  std::optional<uint16_t> sample_rate;
-  std::optional<size_t> chunk_size;
+  // The number of bytes that are available for consumption within this
+  // stream's buffer.
+  std::size_t bytes_in_stream;
+
+  // The total length of this stream, in case its source is finite (e.g. a
+  // file on disk). May be absent for endless streams (internet streams,
+  // generated audio, etc.)
+  std::optional<std::size_t> length_bytes;
+
+  struct Encoded {
+    // The codec that this stream is associated with.
+    codecs::StreamType type;
+
+    bool operator==(const Encoded&) const = default;
+  };
+
+  struct Pcm {
+    // Number of channels in this stream.
+    uint8_t channels;
+    // Number of bits per sample.
+    uint8_t bits_per_sample;
+    // The sample rate.
+    uint16_t sample_rate;
+
+    bool operator==(const Pcm&) const = default;
+  };
+
+  std::variant<Encoded, Pcm> data;
+
+  bool operator==(const StreamInfo&) const = default;
+};
+
+class MutableStream {
+ public:
+  StreamInfo* info;
+  cpp::span<std::byte> data;
+
+  MutableStream(StreamInfo* i, cpp::span<std::byte> d)
+      : info(i), data(d) {}
+};
+
+/*
+ * A byte buffer + associated metadata, which is not allowed to modify any of
+ * the underlying data.
+ */
+class Stream {
+ public:
+  explicit Stream(const MutableStream& s) : info(*s.info), data(s.data) {}
+
+  const StreamInfo& info;
+  // `data` itself left mutable for signalling how much of the stream was
+  // consumed
+  cpp::span<const std::byte> data;
 };
 
 }  // namespace audio
-- 
cgit v1.2.3


From 7c6fd654f50e6665efa4226c6b927f9762734182 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Sat, 1 Apr 2023 13:22:21 +1100
Subject: New pipeline building, still needs proper control

---
 src/audio/include/audio_decoder.hpp     |  8 ++--
 src/audio/include/audio_element.hpp     |  8 ++--
 src/audio/include/audio_playback.hpp    | 10 ++---
 src/audio/include/audio_sink.hpp        | 22 +++++++++++
 src/audio/include/audio_task.hpp        | 34 +++++++---------
 src/audio/include/fatfs_audio_input.hpp |  3 +-
 src/audio/include/i2s_audio_output.hpp  | 11 +++---
 src/audio/include/pipeline.hpp          |  7 ++--
 src/audio/include/stream_info.hpp       | 69 +++++++++++++++++++++++++++------
 9 files changed, 117 insertions(+), 55 deletions(-)
 create mode 100644 src/audio/include/audio_sink.hpp

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_decoder.hpp b/src/audio/include/audio_decoder.hpp
index be8daf99..6a1b5177 100644
--- a/src/audio/include/audio_decoder.hpp
+++ b/src/audio/include/audio_decoder.hpp
@@ -24,7 +24,7 @@ class AudioDecoder : public IAudioElement {
   AudioDecoder();
   ~AudioDecoder();
 
-  auto Process(std::vector<Stream>* inputs, MutableStream* output)
+  auto Process(const std::vector<InputStream>& inputs, OutputStream* output)
       -> void override;
 
   AudioDecoder(const AudioDecoder&) = delete;
@@ -32,11 +32,9 @@ class AudioDecoder : public IAudioElement {
 
  private:
   std::unique_ptr<codecs::ICodec> current_codec_;
-  std::optional<StreamInfo> stream_info_;
-
-  bool has_set_stream_info_;
+  std::optional<StreamInfo::Format> current_input_format_;
+  std::optional<StreamInfo::Format> current_output_format_;
   bool has_samples_to_send_;
-  bool needs_more_input_;
 
   auto ProcessStreamInfo(const StreamInfo& info) -> bool;
 };
diff --git a/src/audio/include/audio_element.hpp b/src/audio/include/audio_element.hpp
index c9192e4a..5884f7b2 100644
--- a/src/audio/include/audio_element.hpp
+++ b/src/audio/include/audio_element.hpp
@@ -37,11 +37,11 @@ static const size_t kEventQueueSize = 8;
  */
 class IAudioElement {
  public:
-  IAudioElement();
-  virtual ~IAudioElement();
+  IAudioElement() {}
+  virtual ~IAudioElement() {}
 
-  virtual auto Process(std::vector<Stream>* inputs, MutableStream* output)
-      -> void = 0;
+  virtual auto Process(const std::vector<InputStream>& inputs,
+                       OutputStream* output) -> void = 0;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_playback.hpp b/src/audio/include/audio_playback.hpp
index 507e6f73..88dc29aa 100644
--- a/src/audio/include/audio_playback.hpp
+++ b/src/audio/include/audio_playback.hpp
@@ -8,6 +8,7 @@
 #include "audio_task.hpp"
 #include "esp_err.h"
 #include "fatfs_audio_input.hpp"
+#include "i2s_audio_output.hpp"
 #include "result.hpp"
 #include "span.hpp"
 
@@ -28,7 +29,7 @@ class AudioPlayback {
   static auto create(drivers::GpioExpander* expander)
       -> cpp::result<std::unique_ptr<AudioPlayback>, Error>;
 
-  AudioPlayback(FatfsAudioInput *file_input);
+  explicit AudioPlayback(std::unique_ptr<I2SAudioOutput> output);
   ~AudioPlayback();
 
   /*
@@ -44,10 +45,9 @@ class AudioPlayback {
   AudioPlayback& operator=(const AudioPlayback&) = delete;
 
  private:
-  FatfsAudioInput *file_source;
-
-  std::vector<std::unique_ptr<IAudioElement>> all_elements_;
-  std::unique_ptr<task::Handle> pipeline_;
+  std::unique_ptr<FatfsAudioInput> file_source_;
+  std::unique_ptr<I2SAudioOutput> i2s_output_;
+  std::vector<std::unique_ptr<IAudioElement>> elements_;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
new file mode 100644
index 00000000..ed7eb02b
--- /dev/null
+++ b/src/audio/include/audio_sink.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "audio_element.hpp"
+#include "stream_info.hpp"
+namespace audio {
+
+class IAudioSink {
+ private:
+  static const std::size_t kDrainBufferSize = 8 * 1024;
+  StreamBufferHandle_t buffer_;
+
+ public:
+  IAudioSink() : buffer_(xStreamBufferCreate(kDrainBufferSize, 1)) {}
+  virtual ~IAudioSink() { vStreamBufferDelete(buffer_); }
+
+  virtual auto Configure(const StreamInfo::Format& format) -> bool = 0;
+  virtual auto Send(const cpp::span<std::byte>& data) -> void = 0;
+
+  auto buffer() const -> StreamBufferHandle_t { return buffer_; }
+};
+
+}  // namespace audio
diff --git a/src/audio/include/audio_task.hpp b/src/audio/include/audio_task.hpp
index 8db99850..a7b7a0fa 100644
--- a/src/audio/include/audio_task.hpp
+++ b/src/audio/include/audio_task.hpp
@@ -5,38 +5,32 @@
 #include <string>
 
 #include "audio_element.hpp"
+#include "audio_sink.hpp"
+#include "dac.hpp"
 #include "freertos/portmacro.h"
 #include "pipeline.hpp"
+#include "stream_buffer.hpp"
 
 namespace audio {
 
 namespace task {
+
+enum Command { PLAY, PAUSE, QUIT };
+
 struct AudioTaskArgs {
   Pipeline* pipeline;
-  QueueHandle_t input;
+  IAudioSink* sink;
+};
+struct AudioDrainArgs {
+  IAudioSink* sink;
+  std::atomic<Command>* command;
 };
 
 extern "C" void AudioTaskMain(void* args);
+extern "C" void AudioDrainMain(void* args);
 
-enum Command { PLAY, PAUSE, QUIT };
-
-class Handle {
- public:
-  explicit Handle(QueueHandle_t input);
-  ~Handle();
-
-  auto SetStreamInfo() -> void;
-  auto Play() -> void;
-  auto Pause() -> void;
-  auto Quit() -> void;
-
-  auto OutputBuffer() -> StreamBufferHandle_t;
-
- private:
-  QueueHandle_t input;
-};
-
-auto Start(Pipeline* pipeline) -> Handle*;
+auto StartPipeline(Pipeline* pipeline, IAudioSink* sink) -> void;
+auto StartDrain(IAudioSink* sink) -> void;
 
 }  // namespace task
 
diff --git a/src/audio/include/fatfs_audio_input.hpp b/src/audio/include/fatfs_audio_input.hpp
index b3a6d843..24f62e3c 100644
--- a/src/audio/include/fatfs_audio_input.hpp
+++ b/src/audio/include/fatfs_audio_input.hpp
@@ -16,6 +16,7 @@
 
 #include "audio_element.hpp"
 #include "stream_buffer.hpp"
+#include "stream_info.hpp"
 
 namespace audio {
 
@@ -26,7 +27,7 @@ class FatfsAudioInput : public IAudioElement {
 
   auto OpenFile(const std::string& path) -> void;
 
-  auto Process(std::vector<Stream>* inputs, MutableStream* output)
+  auto Process(const std::vector<InputStream>& inputs, OutputStream* output)
       -> void override;
 
   FatfsAudioInput(const FatfsAudioInput&) = delete;
diff --git a/src/audio/include/i2s_audio_output.hpp b/src/audio/include/i2s_audio_output.hpp
index 57881b35..77019228 100644
--- a/src/audio/include/i2s_audio_output.hpp
+++ b/src/audio/include/i2s_audio_output.hpp
@@ -5,6 +5,7 @@
 #include <vector>
 
 #include "audio_element.hpp"
+#include "audio_sink.hpp"
 #include "chunk.hpp"
 #include "result.hpp"
 
@@ -14,18 +15,18 @@
 
 namespace audio {
 
-class I2SAudioOutput : public IAudioElement {
+class I2SAudioOutput : public IAudioSink {
  public:
   enum Error { DAC_CONFIG, I2S_CONFIG, STREAM_INIT };
   static auto create(drivers::GpioExpander* expander)
-      -> cpp::result<std::shared_ptr<I2SAudioOutput>, Error>;
+      -> cpp::result<std::unique_ptr<I2SAudioOutput>, Error>;
 
   I2SAudioOutput(drivers::GpioExpander* expander,
                  std::unique_ptr<drivers::AudioDac> dac);
   ~I2SAudioOutput();
 
-  auto Process(std::vector<Stream>* inputs, MutableStream* output)
-      -> void override;
+  auto Configure(const StreamInfo::Format& format) -> bool override;
+  auto Send(const cpp::span<std::byte>& data) -> void override;
 
   I2SAudioOutput(const I2SAudioOutput&) = delete;
   I2SAudioOutput& operator=(const I2SAudioOutput&) = delete;
@@ -37,8 +38,6 @@ class I2SAudioOutput : public IAudioElement {
   std::unique_ptr<drivers::AudioDac> dac_;
 
   std::optional<StreamInfo::Pcm> current_config_;
-
-  auto ProcessStreamInfo(const StreamInfo& info) -> bool;
 };
 
 }  // namespace audio
diff --git a/src/audio/include/pipeline.hpp b/src/audio/include/pipeline.hpp
index 42f70828..2e9247bc 100644
--- a/src/audio/include/pipeline.hpp
+++ b/src/audio/include/pipeline.hpp
@@ -3,6 +3,7 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <vector>
 
 #include "freertos/portmacro.h"
 
@@ -16,7 +17,7 @@ static const std::size_t kPipelineBufferSize = 32 * 1024;
 
 class Pipeline {
  public:
-  Pipeline(IAudioElement* output);
+  explicit Pipeline(IAudioElement* output);
   ~Pipeline();
   auto AddInput(IAudioElement* input) -> Pipeline*;
 
@@ -25,9 +26,9 @@ class Pipeline {
   auto NumInputs() const -> std::size_t;
 
   auto InStreams(std::vector<MappableRegion<kPipelineBufferSize>>*,
-                 std::vector<MutableStream>*) -> void;
+                 std::vector<RawStream>*) -> void;
 
-  auto OutStream(MappableRegion<kPipelineBufferSize>*) -> MutableStream;
+  auto OutStream(MappableRegion<kPipelineBufferSize>*) -> RawStream;
 
   auto GetIterationOrder() -> std::vector<Pipeline*>;
 
diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index 47f65649..5622517f 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -4,6 +4,8 @@
 #include <optional>
 #include <string>
 #include <string_view>
+#include <type_traits>
+#include <utility>
 #include <variant>
 
 #include "result.hpp"
@@ -35,37 +37,82 @@ struct StreamInfo {
     // Number of bits per sample.
     uint8_t bits_per_sample;
     // The sample rate.
-    uint16_t sample_rate;
+    uint32_t sample_rate;
 
     bool operator==(const Pcm&) const = default;
   };
 
-  std::variant<Encoded, Pcm> data;
+  typedef std::variant<Encoded, Pcm> Format;
+  Format format;
 
   bool operator==(const StreamInfo&) const = default;
 };
 
-class MutableStream {
+class RawStream {
  public:
   StreamInfo* info;
   cpp::span<std::byte> data;
+  bool is_incomplete;
 
-  MutableStream(StreamInfo* i, cpp::span<std::byte> d)
-      : info(i), data(d) {}
+  RawStream(StreamInfo* i, cpp::span<std::byte> d)
+      : info(i), data(d), is_incomplete(false) {}
 };
 
 /*
  * A byte buffer + associated metadata, which is not allowed to modify any of
  * the underlying data.
  */
-class Stream {
+class InputStream {
  public:
-  explicit Stream(const MutableStream& s) : info(*s.info), data(s.data) {}
+  explicit InputStream(RawStream* s) : raw_(s) {}
 
-  const StreamInfo& info;
-  // `data` itself left mutable for signalling how much of the stream was
-  // consumed
-  cpp::span<const std::byte> data;
+  void consume(std::size_t bytes) const {
+    auto new_data = raw_->data.subspan(bytes);
+    std::move(new_data.begin(), new_data.end(), raw_->data.begin());
+    raw_->info->bytes_in_stream = new_data.size_bytes();
+  }
+
+  void mark_incomplete() const { raw_->is_incomplete = true; }
+
+  const StreamInfo& info() const { return *raw_->info; }
+
+  cpp::span<const std::byte> data() const {
+    return raw_->data.first(raw_->info->bytes_in_stream);
+  }
+
+ private:
+  RawStream* raw_;
+};
+
+class OutputStream {
+ public:
+  explicit OutputStream(RawStream* s) : raw_(s) {}
+
+  void add(std::size_t bytes) const { raw_->info->bytes_in_stream += bytes; }
+
+  bool prepare(const StreamInfo::Format& new_format) {
+    if (new_format == raw_->info->format) {
+      raw_->info->format = new_format;
+      return true;
+    }
+    if (raw_->is_incomplete) {
+      raw_->info->format = new_format;
+      raw_->info->bytes_in_stream = 0;
+      return true;
+    }
+    return false;
+  }
+
+  const StreamInfo& info() const { return *raw_->info; }
+
+  cpp::span<std::byte> data() const {
+    return raw_->data.subspan(raw_->info->bytes_in_stream);
+  }
+
+  bool is_incomplete() const { return raw_->is_incomplete; }
+
+ private:
+  RawStream* raw_;
 };
 
 }  // namespace audio
-- 
cgit v1.2.3


From 3836768bb8b95188e6657ab69027d1d9e4b13a77 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Mon, 3 Apr 2023 14:06:30 +1000
Subject: new pipeline working(?), but the dac eludes me

---
 src/audio/include/audio_sink.hpp       |  1 +
 src/audio/include/i2s_audio_output.hpp |  1 +
 src/audio/include/stream_info.hpp      | 13 ++++++++-----
 3 files changed, 10 insertions(+), 5 deletions(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index ed7eb02b..ad63ec2e 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -15,6 +15,7 @@ class IAudioSink {
 
   virtual auto Configure(const StreamInfo::Format& format) -> bool = 0;
   virtual auto Send(const cpp::span<std::byte>& data) -> void = 0;
+  virtual auto Log() -> void {}
 
   auto buffer() const -> StreamBufferHandle_t { return buffer_; }
 };
diff --git a/src/audio/include/i2s_audio_output.hpp b/src/audio/include/i2s_audio_output.hpp
index 77019228..31510a91 100644
--- a/src/audio/include/i2s_audio_output.hpp
+++ b/src/audio/include/i2s_audio_output.hpp
@@ -27,6 +27,7 @@ class I2SAudioOutput : public IAudioSink {
 
   auto Configure(const StreamInfo::Format& format) -> bool override;
   auto Send(const cpp::span<std::byte>& data) -> void override;
+  auto Log() -> void override;
 
   I2SAudioOutput(const I2SAudioOutput&) = delete;
   I2SAudioOutput& operator=(const I2SAudioOutput&) = delete;
diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index 5622517f..5a36384c 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -17,12 +17,12 @@ namespace audio {
 struct StreamInfo {
   // The number of bytes that are available for consumption within this
   // stream's buffer.
-  std::size_t bytes_in_stream;
+  std::size_t bytes_in_stream{0};
 
   // The total length of this stream, in case its source is finite (e.g. a
   // file on disk). May be absent for endless streams (internet streams,
   // generated audio, etc.)
-  std::optional<std::size_t> length_bytes;
+  std::optional<std::size_t> length_bytes{};
 
   struct Encoded {
     // The codec that this stream is associated with.
@@ -42,8 +42,8 @@ struct StreamInfo {
     bool operator==(const Pcm&) const = default;
   };
 
-  typedef std::variant<Encoded, Pcm> Format;
-  Format format;
+  typedef std::variant<std::monostate, Encoded, Pcm> Format;
+  Format format{};
 
   bool operator==(const StreamInfo&) const = default;
 };
@@ -91,8 +91,11 @@ class OutputStream {
   void add(std::size_t bytes) const { raw_->info->bytes_in_stream += bytes; }
 
   bool prepare(const StreamInfo::Format& new_format) {
-    if (new_format == raw_->info->format) {
+    if (std::holds_alternative<std::monostate>(raw_->info->format)) {
       raw_->info->format = new_format;
+      raw_->info->bytes_in_stream = 0;
+    }
+    if (new_format == raw_->info->format) {
       return true;
     }
     if (raw_->is_incomplete) {
-- 
cgit v1.2.3


From 25c5896dc5c239e3a175c6c8fc5d7368946adeb6 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Thu, 6 Apr 2023 16:19:02 +1000
Subject: add some bounds checking asserts

---
 src/audio/include/stream_info.hpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index 5a36384c..6256f2ee 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -67,6 +67,7 @@ class InputStream {
   explicit InputStream(RawStream* s) : raw_(s) {}
 
   void consume(std::size_t bytes) const {
+    assert(raw_->info->bytes_in_stream >= bytes);
     auto new_data = raw_->data.subspan(bytes);
     std::move(new_data.begin(), new_data.end(), raw_->data.begin());
     raw_->info->bytes_in_stream = new_data.size_bytes();
@@ -88,7 +89,10 @@ class OutputStream {
  public:
   explicit OutputStream(RawStream* s) : raw_(s) {}
 
-  void add(std::size_t bytes) const { raw_->info->bytes_in_stream += bytes; }
+  void add(std::size_t bytes) const {
+    assert(raw_->info->bytes_in_stream + bytes <= raw_->data.size_bytes());
+    raw_->info->bytes_in_stream += bytes;
+  }
 
   bool prepare(const StreamInfo::Format& new_format) {
     if (std::holds_alternative<std::monostate>(raw_->info->format)) {
-- 
cgit v1.2.3


From 561f9d2a07ee6ee1c2f18dc375125f87ea7b0d55 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Wed, 19 Apr 2023 13:00:42 +1000
Subject: Ensure the sink buffer is large enough to not fully drain during
 playback

---
 src/audio/include/audio_sink.hpp  |  3 ++-
 src/audio/include/stream_info.hpp | 52 ++++++++++-----------------------------
 2 files changed, 15 insertions(+), 40 deletions(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index ad63ec2e..03a4690d 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -6,7 +6,8 @@ namespace audio {
 
 class IAudioSink {
  private:
-  static const std::size_t kDrainBufferSize = 8 * 1024;
+  // TODO: tune. at least about 12KiB seems right for mp3
+  static const std::size_t kDrainBufferSize = 24 * 1024;
   StreamBufferHandle_t buffer_;
 
  public:
diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index 6256f2ee..28095935 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -66,20 +66,13 @@ class InputStream {
  public:
   explicit InputStream(RawStream* s) : raw_(s) {}
 
-  void consume(std::size_t bytes) const {
-    assert(raw_->info->bytes_in_stream >= bytes);
-    auto new_data = raw_->data.subspan(bytes);
-    std::move(new_data.begin(), new_data.end(), raw_->data.begin());
-    raw_->info->bytes_in_stream = new_data.size_bytes();
-  }
+  void consume(std::size_t bytes) const;
 
-  void mark_incomplete() const { raw_->is_incomplete = true; }
+  void mark_incomplete() const;
 
-  const StreamInfo& info() const { return *raw_->info; }
+  const StreamInfo& info() const;
 
-  cpp::span<const std::byte> data() const {
-    return raw_->data.first(raw_->info->bytes_in_stream);
-  }
+  cpp::span<const std::byte> data() const;
 
  private:
   RawStream* raw_;
@@ -89,34 +82,15 @@ class OutputStream {
  public:
   explicit OutputStream(RawStream* s) : raw_(s) {}
 
-  void add(std::size_t bytes) const {
-    assert(raw_->info->bytes_in_stream + bytes <= raw_->data.size_bytes());
-    raw_->info->bytes_in_stream += bytes;
-  }
-
-  bool prepare(const StreamInfo::Format& new_format) {
-    if (std::holds_alternative<std::monostate>(raw_->info->format)) {
-      raw_->info->format = new_format;
-      raw_->info->bytes_in_stream = 0;
-    }
-    if (new_format == raw_->info->format) {
-      return true;
-    }
-    if (raw_->is_incomplete) {
-      raw_->info->format = new_format;
-      raw_->info->bytes_in_stream = 0;
-      return true;
-    }
-    return false;
-  }
-
-  const StreamInfo& info() const { return *raw_->info; }
-
-  cpp::span<std::byte> data() const {
-    return raw_->data.subspan(raw_->info->bytes_in_stream);
-  }
-
-  bool is_incomplete() const { return raw_->is_incomplete; }
+  void add(std::size_t bytes) const;
+
+  bool prepare(const StreamInfo::Format& new_format);
+
+  const StreamInfo& info() const;
+
+  cpp::span<std::byte> data() const;
+
+  bool is_incomplete() const;
 
  private:
   RawStream* raw_;
-- 
cgit v1.2.3


From 4c77950e702a329f3136456a932efbea36e03d42 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Wed, 19 Apr 2023 16:45:50 +1000
Subject: Pipeline working and outputting correctly, but noisy

---
 src/audio/include/audio_sink.hpp | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index 03a4690d..a11a9c92 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -1,6 +1,9 @@
 #pragma once
 
+#include <stdint.h>
 #include "audio_element.hpp"
+#include "esp_heap_caps.h"
+#include "freertos/FreeRTOS.h"
 #include "stream_info.hpp"
 namespace audio {
 
@@ -8,17 +11,30 @@ class IAudioSink {
  private:
   // TODO: tune. at least about 12KiB seems right for mp3
   static const std::size_t kDrainBufferSize = 24 * 1024;
-  StreamBufferHandle_t buffer_;
+  uint8_t *buffer_;
+  StaticStreamBuffer_t *metadata_;
+  StreamBufferHandle_t *handle_;
 
  public:
-  IAudioSink() : buffer_(xStreamBufferCreate(kDrainBufferSize, 1)) {}
-  virtual ~IAudioSink() { vStreamBufferDelete(buffer_); }
+  IAudioSink() :
+    buffer_(reinterpret_cast<uint8_t*>(heap_caps_malloc(kDrainBufferSize, MALLOC_CAP_DMA))),
+    metadata_(reinterpret_cast<StaticStreamBuffer_t*>(heap_caps_malloc(sizeof(StaticStreamBuffer_t), MALLOC_CAP_DMA))),
+    handle_(reinterpret_cast<StreamBufferHandle_t*>(heap_caps_malloc(sizeof(StreamBufferHandle_t), MALLOC_CAP_DMA))) {
+      *handle_ = xStreamBufferCreateStatic(kDrainBufferSize, 1, buffer_, metadata_);
+    }
+
+  virtual ~IAudioSink() {
+    vStreamBufferDelete(*handle_);
+    free(buffer_);
+    free(handle_);
+    free(metadata_);
+  }
 
   virtual auto Configure(const StreamInfo::Format& format) -> bool = 0;
   virtual auto Send(const cpp::span<std::byte>& data) -> void = 0;
   virtual auto Log() -> void {}
 
-  auto buffer() const -> StreamBufferHandle_t { return buffer_; }
+  auto buffer() -> StreamBufferHandle_t* { return handle_; }
 };
 
 }  // namespace audio
-- 
cgit v1.2.3


From 731b2cfa77a063e98da8fa26acc1e7ed1de8c169 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Thu, 20 Apr 2023 11:25:43 +1000
Subject: working isr-based sink, but still grainy

---
 src/audio/include/audio_sink.hpp | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index a11a9c92..eaed04ec 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -11,22 +11,26 @@ class IAudioSink {
  private:
   // TODO: tune. at least about 12KiB seems right for mp3
   static const std::size_t kDrainBufferSize = 24 * 1024;
-  uint8_t *buffer_;
-  StaticStreamBuffer_t *metadata_;
-  StreamBufferHandle_t *handle_;
+  uint8_t* buffer_;
+  StaticStreamBuffer_t* metadata_;
+  StreamBufferHandle_t handle_;
 
  public:
-  IAudioSink() :
-    buffer_(reinterpret_cast<uint8_t*>(heap_caps_malloc(kDrainBufferSize, MALLOC_CAP_DMA))),
-    metadata_(reinterpret_cast<StaticStreamBuffer_t*>(heap_caps_malloc(sizeof(StaticStreamBuffer_t), MALLOC_CAP_DMA))),
-    handle_(reinterpret_cast<StreamBufferHandle_t*>(heap_caps_malloc(sizeof(StreamBufferHandle_t), MALLOC_CAP_DMA))) {
-      *handle_ = xStreamBufferCreateStatic(kDrainBufferSize, 1, buffer_, metadata_);
-    }
+  IAudioSink()
+      : buffer_(reinterpret_cast<uint8_t*>(
+            heap_caps_malloc(kDrainBufferSize,
+                             MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT))),
+        metadata_(reinterpret_cast<StaticStreamBuffer_t*>(
+            heap_caps_malloc(sizeof(StaticStreamBuffer_t),
+                             MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT))),
+        handle_(xStreamBufferCreateStatic(kDrainBufferSize,
+                                          1,
+                                          buffer_,
+                                          metadata_)) {}
 
   virtual ~IAudioSink() {
-    vStreamBufferDelete(*handle_);
+    vStreamBufferDelete(handle_);
     free(buffer_);
-    free(handle_);
     free(metadata_);
   }
 
@@ -34,7 +38,7 @@ class IAudioSink {
   virtual auto Send(const cpp::span<std::byte>& data) -> void = 0;
   virtual auto Log() -> void {}
 
-  auto buffer() -> StreamBufferHandle_t* { return handle_; }
+  auto buffer() -> StreamBufferHandle_t { return handle_; }
 };
 
 }  // namespace audio
-- 
cgit v1.2.3


From 27c63ebb957aa5b942939aea33431ac50d101a26 Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Thu, 20 Apr 2023 21:25:22 +1000
Subject: Switch to an MVP-ready 16bit three wire DAC setup

---
 src/audio/include/audio_sink.hpp | 2 +-
 src/audio/include/pipeline.hpp   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_sink.hpp b/src/audio/include/audio_sink.hpp
index eaed04ec..7a535c35 100644
--- a/src/audio/include/audio_sink.hpp
+++ b/src/audio/include/audio_sink.hpp
@@ -10,7 +10,7 @@ namespace audio {
 class IAudioSink {
  private:
   // TODO: tune. at least about 12KiB seems right for mp3
-  static const std::size_t kDrainBufferSize = 24 * 1024;
+  static const std::size_t kDrainBufferSize = 48 * 1024;
   uint8_t* buffer_;
   StaticStreamBuffer_t* metadata_;
   StreamBufferHandle_t handle_;
diff --git a/src/audio/include/pipeline.hpp b/src/audio/include/pipeline.hpp
index 2e9247bc..7a658a38 100644
--- a/src/audio/include/pipeline.hpp
+++ b/src/audio/include/pipeline.hpp
@@ -13,7 +13,7 @@
 
 namespace audio {
 
-static const std::size_t kPipelineBufferSize = 32 * 1024;
+static const std::size_t kPipelineBufferSize = 64 * 1024;
 
 class Pipeline {
  public:
-- 
cgit v1.2.3


From 7083459cf3c62c32d0c039a4665e702d70a27bba Mon Sep 17 00:00:00 2001
From: jacqueline <me@jacqueline.id.au>
Date: Fri, 21 Apr 2023 15:27:57 +1000
Subject: wrap driver instance ownership + di in a class

---
 src/audio/include/audio_playback.hpp   | 7 ++-----
 src/audio/include/i2s_audio_output.hpp | 8 ++------
 2 files changed, 4 insertions(+), 11 deletions(-)

(limited to 'src/audio/include')

diff --git a/src/audio/include/audio_playback.hpp b/src/audio/include/audio_playback.hpp
index 88dc29aa..cd4be3e7 100644
--- a/src/audio/include/audio_playback.hpp
+++ b/src/audio/include/audio_playback.hpp
@@ -6,6 +6,7 @@
 #include <vector>
 
 #include "audio_task.hpp"
+#include "driver_cache.hpp"
 #include "esp_err.h"
 #include "fatfs_audio_input.hpp"
 #include "i2s_audio_output.hpp"
@@ -25,11 +26,7 @@ namespace audio {
  */
 class AudioPlayback {
  public:
-  enum Error { ERR_INIT_ELEMENT, ERR_MEM };
-  static auto create(drivers::GpioExpander* expander)
-      -> cpp::result<std::unique_ptr<AudioPlayback>, Error>;
-
-  explicit AudioPlayback(std::unique_ptr<I2SAudioOutput> output);
+  explicit AudioPlayback(drivers::DriverCache* drivers);
   ~AudioPlayback();
 
   /*
diff --git a/src/audio/include/i2s_audio_output.hpp b/src/audio/include/i2s_audio_output.hpp
index 31510a91..07430777 100644
--- a/src/audio/include/i2s_audio_output.hpp
+++ b/src/audio/include/i2s_audio_output.hpp
@@ -17,12 +17,8 @@ namespace audio {
 
 class I2SAudioOutput : public IAudioSink {
  public:
-  enum Error { DAC_CONFIG, I2S_CONFIG, STREAM_INIT };
-  static auto create(drivers::GpioExpander* expander)
-      -> cpp::result<std::unique_ptr<I2SAudioOutput>, Error>;
-
   I2SAudioOutput(drivers::GpioExpander* expander,
-                 std::unique_ptr<drivers::AudioDac> dac);
+                 std::shared_ptr<drivers::AudioDac> dac);
   ~I2SAudioOutput();
 
   auto Configure(const StreamInfo::Format& format) -> bool override;
@@ -36,7 +32,7 @@ class I2SAudioOutput : public IAudioSink {
   auto SetVolume(uint8_t volume) -> void;
 
   drivers::GpioExpander* expander_;
-  std::unique_ptr<drivers::AudioDac> dac_;
+  std::shared_ptr<drivers::AudioDac> dac_;
 
   std::optional<StreamInfo::Pcm> current_config_;
 };
-- 
cgit v1.2.3