Use the sync apis for I2S output

src/audio/audio_decoder.cpp

@@ -21,7 +21,7 @@ namespace audio {
 
 static const char* kTag = "DEC";
 
-static const std::size_t kSamplesPerChunk = 256;
+static const std::size_t kSamplesPerChunk = 1024;
 
 AudioDecoder::AudioDecoder()
     : IAudioElement(),
@@ -89,14 +89,12 @@ auto AudioDecoder::ProcessEndOfStream() -> void {
   needs_more_input_ = true;
   current_codec_.reset();
 
-  SendOrBufferEvent(
+  SendOrBufferEvent(std::unique_ptr<StreamEvent>(
-      std::unique_ptr<StreamEvent>(
       StreamEvent::CreateEndOfStream(input_events_)));
 }
 
 auto AudioDecoder::Process() -> cpp::result<void, AudioProcessingError> {
   if (has_samples_to_send_) {
-    ESP_LOGI(kTag, "sending samples");
     // Writing samples is relatively quick (it's just a bunch of memcopy's), so
     // do them all at once.
     while (has_samples_to_send_ && !IsOverBuffered()) {
@@ -132,7 +130,6 @@ auto AudioDecoder::Process() -> cpp::result<void, AudioProcessingError> {
   }
 
   if (!needs_more_input_) {
-    ESP_LOGI(kTag, "decoding frame");
     auto res = current_codec_->ProcessNextFrame();
     if (res.has_error()) {
       // todo

src/audio/audio_task.cpp

@@ -38,8 +38,9 @@ auto StartAudioTask(const std::string& name,
 
   ESP_LOGI(kTag, "starting audio task %s", name.c_str());
   if (core_id) {
-    xTaskCreatePinnedToCore(&AudioTaskMain, name.c_str(), element->StackSizeBytes(), args,
+    xTaskCreatePinnedToCore(&AudioTaskMain, name.c_str(),
-                kTaskPriorityAudio, task_handle.get(), *core_id);
+                            element->StackSizeBytes(), args, kTaskPriorityAudio,
+                            task_handle.get(), *core_id);
   } else {
     xTaskCreate(&AudioTaskMain, name.c_str(), element->StackSizeBytes(), args,
                 kTaskPriorityAudio, task_handle.get());

src/audio/fatfs_audio_input.cpp

@@ -73,8 +73,7 @@ auto FatfsAudioInput::ProcessEndOfStream() -> void {
   if (is_file_open_) {
     f_close(&current_file_);
     is_file_open_ = false;
-      SendOrBufferEvent(
+    SendOrBufferEvent(std::unique_ptr<StreamEvent>(
-          std::unique_ptr<StreamEvent>(
         StreamEvent::CreateEndOfStream(input_events_)));
   }
 }
@@ -85,7 +84,6 @@ auto FatfsAudioInput::Process() -> cpp::result<void, AudioProcessingError> {
         StreamEvent::CreateChunkData(input_events_, kChunkSize));
     UINT bytes_read = 0;
 
-    ESP_LOGI(kTag, "reading from file");
     FRESULT result = f_read(&current_file_, dest_event->chunk_data.raw_bytes,
                             kChunkSize, &bytes_read);
     if (result != FR_OK) {
@@ -93,13 +91,11 @@ auto FatfsAudioInput::Process() -> cpp::result<void, AudioProcessingError> {
       return cpp::fail(IO_ERROR);
     }
 
-    ESP_LOGI(kTag, "sending file data (%u bytes)", bytes_read);
     dest_event->chunk_data.bytes =
         dest_event->chunk_data.bytes.first(bytes_read);
     SendOrBufferEvent(std::move(dest_event));
 
     if (bytes_read < kChunkSize || f_eof(&current_file_)) {
-      ESP_LOGI(kTag, "closing file");
       f_close(&current_file_);
       is_file_open_ = false;
     }

src/audio/i2s_audio_output.cpp

@@ -43,22 +43,12 @@ I2SAudioOutput::I2SAudioOutput(drivers::GpioExpander* expander,
       volume_(255),
       is_soft_muted_(false),
       chunk_reader_(),
-      latest_chunk_(),
+      latest_chunk_() {}
-      dma_size_(),
-      dma_queue_(nullptr) {}
 
-I2SAudioOutput::~I2SAudioOutput() {
+I2SAudioOutput::~I2SAudioOutput() {}
-  if (dma_queue_ != nullptr) {
-    ClearDmaQueue();
-  }
-  // TODO: power down the DAC.
-}
 
 auto I2SAudioOutput::HasUnprocessedInput() -> bool {
-  if (dma_queue_ == nullptr || !dma_size_) {
+  return latest_chunk_.size() > 0;
-    return false;
-  }
-  return latest_chunk_.size() >= *dma_size_;
 }
 
 auto I2SAudioOutput::ProcessStreamInfo(const StreamInfo& info)
@@ -108,77 +98,30 @@ auto I2SAudioOutput::ProcessStreamInfo(const StreamInfo& info)
       return cpp::fail(UNSUPPORTED_STREAM);
   }
 
-  QueueHandle_t new_dma_queue =
+  dac_->Reconfigure(bps, sample_rate);
-      xQueueCreate(kDmaQueueLength, sizeof(std::byte*));
-
-  dma_size_ = dac_->Reconfigure(bps, sample_rate, new_dma_queue);
-
-  if (dma_queue_ != nullptr) {
-    ClearDmaQueue();
-  }
-  dma_queue_ = new_dma_queue;
 
   return {};
 }
 
 auto I2SAudioOutput::ProcessChunk(const cpp::span<std::byte>& chunk)
     -> cpp::result<std::size_t, AudioProcessingError> {
-  ESP_LOGI(kTag, "received new samples");
   latest_chunk_ = chunk_reader_->HandleNewData(chunk);
   return 0;
 }
 
 auto I2SAudioOutput::ProcessEndOfStream() -> void {
-  if (chunk_reader_ && dma_size_) {
+  SendOrBufferEvent(std::unique_ptr<StreamEvent>(
-    auto leftovers = chunk_reader_->GetLeftovers();
-    if (leftovers.size() > 0 && leftovers.size() < *dma_size_) {
-      std::byte* dest = static_cast<std::byte*>(malloc(*dma_size_));
-      cpp::span dest_span(dest, *dma_size_);
-
-      std::copy(leftovers.begin(), leftovers.end(), dest_span.begin());
-      std::fill(dest_span.begin() + leftovers.size(), dest_span.end(), static_cast<std::byte>(0));
-
-      xQueueSend(dma_queue_, &dest, portMAX_DELAY);
-    }
-  }
-
-  SendOrBufferEvent(
-      std::unique_ptr<StreamEvent>(
       StreamEvent::CreateEndOfStream(input_events_)));
-
-  chunk_reader_.reset();
-  dma_size_.reset();
 }
 
 auto I2SAudioOutput::Process() -> cpp::result<void, AudioProcessingError> {
-  std::size_t spaces_available = uxQueueSpacesAvailable(dma_queue_);
+  // Note: no logging here!
-  if (spaces_available == 0) {
+  std::size_t bytes_written = dac_->WriteData(latest_chunk_);
-    // TODO: think about this more. can this just be the output event queue?
+  if (bytes_written == latest_chunk_.size_bytes()) {
-    vTaskDelay(pdMS_TO_TICKS(100));
+    latest_chunk_ = cpp::span<std::byte>();
-    return {};
+    chunk_reader_->HandleBytesLeftOver(0);
-  }
+  } else {
-
+    latest_chunk_ = latest_chunk_.subspan(bytes_written);
-  // Fill the queue as much as possible, since we need to be able to stream
-  // FAST.
-  while (latest_chunk_.size() >= *dma_size_ && spaces_available > 0) {
-    // TODO: small memory arena for this?
-    std::byte* dest = static_cast<std::byte*>(malloc(*dma_size_));
-    cpp::span dest_span(dest, *dma_size_);
-    cpp::span src_span = latest_chunk_.first(*dma_size_);
-    std::copy(src_span.begin(), src_span.end(), dest_span.begin());
-    if (!xQueueSend(dma_queue_, &dest, 0)) {
-      // TODO: calculate how often we expect this to happen.
-      free(dest);
-      break;
-    }
-    latest_chunk_ = latest_chunk_.subspan(*dma_size_);
-    ESP_LOGI(kTag, "wrote dma buffer of size %u", *dma_size_);
-  }
-  if (latest_chunk_.size() < *dma_size_) {
-    // TODO: if this is the end of the stream, then we should be sending this
-    // with zero padding. hmm. i guess we need an explicit EOF event?
-    chunk_reader_->HandleBytesLeftOver(latest_chunk_.size());
-    ESP_LOGI(kTag, "not enough samples for dma buffer");
   }
   return {};
 }
@@ -202,17 +145,4 @@ auto I2SAudioOutput::SetSoftMute(bool enabled) -> void {
   }
 }
 
-auto I2SAudioOutput::ClearDmaQueue() -> void {
-  // Ensure we don't leak any memory from events leftover in the queue.
-  while (uxQueueSpacesAvailable(dma_queue_) < kDmaQueueLength) {
-    std::byte* data = nullptr;
-    if (xQueueReceive(input_events_, &data, 0)) {
-      free(data);
-    } else {
-      break;
-    }
-  }
-  vQueueDelete(dma_queue_);
-}
-
 }  // namespace audio

src/audio/include/audio_task.hpp

@@ -1,8 +1,8 @@
 #pragma once
 
 #include <memory>
-#include <string>
 #include <optional>
+#include <string>
 
 #include "audio_element.hpp"
 #include "audio_element_handle.hpp"

src/audio/include/i2s_audio_output.hpp

@@ -38,8 +38,6 @@ class I2SAudioOutput : public IAudioElement {
   auto SetVolume(uint8_t volume) -> void;
   auto SetSoftMute(bool enabled) -> void;
 
-  auto ClearDmaQueue() -> void;
-
   drivers::GpioExpander* expander_;
   std::unique_ptr<drivers::AudioDac> dac_;
 
@@ -48,8 +46,6 @@ class I2SAudioOutput : public IAudioElement {
 
   std::optional<ChunkReader> chunk_reader_;
   cpp::span<std::byte> latest_chunk_;
-  std::optional<std::size_t> dma_size_;
-  QueueHandle_t dma_queue_;
 };
 
 }  // namespace audio

src/drivers/dac.cpp

@@ -8,9 +8,11 @@
 #include "driver/i2s_common.h"
 #include "driver/i2s_std.h"
 #include "driver/i2s_types.h"
+#include "esp_attr.h"
 #include "esp_err.h"
 #include "esp_log.h"
 #include "freertos/portmacro.h"
+#include "freertos/projdefs.h"
 #include "hal/i2c_types.h"
 
 #include "gpio_expander.hpp"
@@ -28,22 +30,13 @@ static const AudioDac::SampleRate kDefaultSampleRate =
     AudioDac::SAMPLE_RATE_44_1;
 static const AudioDac::BitsPerSample kDefaultBps = AudioDac::BPS_16;
 
-extern "C" {
-bool dma_callback(i2s_chan_handle_t handle,
-                  i2s_event_data_t* event,
-                  void* user_ctx) {
-  AudioDac* dac = static_cast<AudioDac*>(user_ctx);
-  return dac->WriteDataFromISR(static_cast<std::byte*>(event->data),
-                               event->size);
-}
-}
-
 auto AudioDac::create(GpioExpander* expander)
     -> cpp::result<std::unique_ptr<AudioDac>, Error> {
   // TODO: tune.
   i2s_chan_handle_t i2s_handle;
   i2s_chan_config_t channel_config =
       I2S_CHANNEL_DEFAULT_CONFIG(kI2SPort, I2S_ROLE_MASTER);
+
   ESP_ERROR_CHECK(i2s_new_channel(&channel_config, &i2s_handle, NULL));
   //
   // First, instantiate the instance so it can do all of its power on
@@ -108,8 +101,7 @@ AudioDac::AudioDac(GpioExpander* gpio, i2s_chan_handle_t i2s_handle)
       i2s_handle_(i2s_handle),
       clock_config_(I2S_STD_CLK_DEFAULT_CONFIG(44100)),
       slot_config_(I2S_STD_MSB_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT,
-                                                   I2S_SLOT_MODE_STEREO)),
+                                                   I2S_SLOT_MODE_STEREO)) {
-      dma_queue_(nullptr) {
   gpio_->set_pin(GpioExpander::AUDIO_POWER_ENABLE, true);
   gpio_->Write();
 }
@@ -167,9 +159,7 @@ bool AudioDac::WaitForPowerState(
   return has_matched;
 }
 
-auto AudioDac::Reconfigure(BitsPerSample bps,
+auto AudioDac::Reconfigure(BitsPerSample bps, SampleRate rate) -> void {
-                           SampleRate rate,
-                           QueueHandle_t dma_queue) -> std::size_t {
   // TODO(jacqueline): investigate how reliable the auto-clocking of the dac
   // is. We might need to explicit reconfigure the dac here as well if it's not
   // good enough.
@@ -183,44 +173,17 @@ auto AudioDac::Reconfigure(BitsPerSample bps,
       bps == BPS_24 ? I2S_MCLK_MULTIPLE_384 : I2S_MCLK_MULTIPLE_256;
   ESP_ERROR_CHECK(i2s_channel_reconfig_std_clock(i2s_handle_, &clock_config_));
 
-  dma_queue_ = dma_queue;
-
-  // TODO: less spooky action here plz.
-  // dma_buffer_size = dma_frame_num (channel config) * slot_num (always 2?) *
-  // slot_bit_width / 8
-  //size_t dma_size = 240 * 2 * slot_config_.slot_bit_width / 8;
-  size_t dma_size = 960;
-  ESP_LOGI(kTag, "new dma size: %u bytes", dma_size);
-
-  i2s_event_callbacks_t callbacks = {
-      .on_recv = NULL,
-      .on_recv_q_ovf = NULL,
-      .on_sent = &dma_callback,
-      .on_send_q_ovf = NULL,
-  };
-  ESP_ERROR_CHECK(
-      i2s_channel_register_event_callback(i2s_handle_, &callbacks, this));
-
   ESP_ERROR_CHECK(i2s_channel_enable(i2s_handle_));
-
-  return dma_size;
 }
 
-auto AudioDac::WriteDataFromISR(std::byte* data, std::size_t size) -> bool {
+auto AudioDac::WriteData(cpp::span<std::byte> data) -> std::size_t {
-  std::byte* new_data;
+  std::size_t bytes_written = 0;
-  BaseType_t high_priority_task_awoken = pdFALSE;
+  esp_err_t err = i2s_channel_write(i2s_handle_, data.data(), data.size_bytes(),
-
+                                    &bytes_written, 0);
-  if (xQueueReceiveFromISR(dma_queue_, &new_data, &high_priority_task_awoken)) {
+  if (err != ESP_ERR_TIMEOUT) {
-    // Item was received. Copy it into the DMA buffer.
+    ESP_ERROR_CHECK(err);
-    memcpy(data, new_data, size);
-    free(new_data);
-    ESP_DRAM_LOGI(kTag, "wrote dma");
-  } else {
-    // No item was received. Write empty data.
-    memset(data, 0, size);
   }
-
+  return bytes_written;
-  return high_priority_task_awoken;
 }
 
 void AudioDac::WriteRegister(Register reg, uint8_t val) {

src/drivers/include/dac.hpp

@@ -10,6 +10,7 @@
 #include "driver/i2s_std.h"
 #include "driver/i2s_types.h"
 #include "esp_err.h"
+#include "freertos/FreeRTOS.h"
 #include "freertos/portmacro.h"
 #include "result.hpp"
 #include "span.hpp"
@@ -67,10 +68,9 @@ class AudioDac {
   };
 
   // TODO(jacqueline): worth supporting channels here as well?
-  auto Reconfigure(BitsPerSample bps, SampleRate rate, QueueHandle_t dma_queue)
+  auto Reconfigure(BitsPerSample bps, SampleRate rate) -> void;
-      -> std::size_t;
 
-  auto WriteDataFromISR(std::byte* data, std::size_t size) -> bool;
+  auto WriteData(cpp::span<std::byte> data) -> std::size_t;
 
   // Not copyable or movable.
   AudioDac(const AudioDac&) = delete;
@@ -83,9 +83,6 @@ class AudioDac {
   i2s_std_clk_config_t clock_config_;
   i2s_std_slot_config_t slot_config_;
 
-  // TODO: volatile?
-  volatile QueueHandle_t dma_queue_;
-
   /*
    * Pools the power state for up to 10ms, waiting for the given predicate to
    * be true.