microWakeWord - add new ops and small improvements (#6360)

esphome/components/micro_wake_word/micro_wake_word.cpp

@@ -93,11 +93,18 @@ int MicroWakeWord::read_microphone_() {
     return 0;
   }
 
-  size_t bytes_written = this->ring_buffer_->write((void *) this->input_buffer_, bytes_read);
-  if (bytes_written != bytes_read) {
-    ESP_LOGW(TAG, "Failed to write some data to ring buffer (written=%d, expected=%d)", bytes_written, bytes_read);
+  size_t bytes_free = this->ring_buffer_->free();
+
+  if (bytes_free < bytes_read) {
+    ESP_LOGW(TAG,
+             "Not enough free bytes in ring buffer to store incoming audio data (free bytes=%d, incoming bytes=%d). "
+             "Resetting the ring buffer. Wake word detection accuracy will be reduced.",
+             bytes_free, bytes_read);
+
+    this->ring_buffer_->reset();
   }
-  return bytes_written;
+
+  return this->ring_buffer_->write((void *) this->input_buffer_, bytes_read);
 }
 
 void MicroWakeWord::loop() {
@@ -206,12 +213,6 @@ bool MicroWakeWord::initialize_models() {
     return false;
   }
 
-  this->preprocessor_stride_buffer_ = audio_samples_allocator.allocate(HISTORY_SAMPLES_TO_KEEP);
-  if (this->preprocessor_stride_buffer_ == nullptr) {
-    ESP_LOGE(TAG, "Could not allocate the audio preprocessor's stride buffer.");
-    return false;
-  }
-
   this->preprocessor_model_ = tflite::GetModel(G_AUDIO_PREPROCESSOR_INT8_TFLITE);
   if (this->preprocessor_model_->version() != TFLITE_SCHEMA_VERSION) {
     ESP_LOGE(TAG, "Wake word's audio preprocessor model's schema is not supported");
@@ -225,7 +226,7 @@ bool MicroWakeWord::initialize_models() {
   }
 
   static tflite::MicroMutableOpResolver<18> preprocessor_op_resolver;
-  static tflite::MicroMutableOpResolver<14> streaming_op_resolver;
+  static tflite::MicroMutableOpResolver<17> streaming_op_resolver;
 
   if (!this->register_preprocessor_ops_(preprocessor_op_resolver))
     return false;
@@ -329,7 +330,6 @@ bool MicroWakeWord::detect_wake_word_() {
   }
 
   // Perform inference
-  uint32_t streaming_size = micros();
   float streaming_prob = this->perform_streaming_inference_();
 
   // Add the most recent probability to the sliding window
@@ -357,6 +357,9 @@ bool MicroWakeWord::detect_wake_word_() {
     for (auto &prob : this->recent_streaming_probabilities_) {
       prob = 0;
     }
+
+    ESP_LOGD(TAG, "Wake word sliding average probability is %.3f and most recent probability is %.3f",
+             sliding_window_average, streaming_prob);
     return true;
   }
 
@@ -371,23 +374,6 @@ void MicroWakeWord::set_sliding_window_average_size(size_t size) {
 bool MicroWakeWord::slice_available_() {
   size_t available = this->ring_buffer_->available();
 
-  size_t free = this->ring_buffer_->free();
-
-  if (free < NEW_SAMPLES_TO_GET * sizeof(int16_t)) {
-    // If the ring buffer is within one audio slice of being full, then wake word detection will have issues.
-    // If this is constantly occuring, then some possibilities why are
-    //  1) there are too many other slow components configured
-    //  2) the ESP32 isn't fast enough; e.g., an ESP32 is much slower than an ESP32-S3 at inferences.
-    //  3) the model is too large
-    //  4) the model uses operations that are not optimized
-    ESP_LOGW(TAG,
-             "Audio buffer is nearly full. Wake word detection may be less accurate and have slower reponse times. "
-#if !defined(USE_ESP32_VARIANT_ESP32S3)
-             "microWakeWord is designed for the ESP32-S3. The current platform is too slow for this model."
-#endif
-    );
-  }
-
   return available > (NEW_SAMPLES_TO_GET * sizeof(int16_t));
 }
 
@@ -396,13 +382,12 @@ bool MicroWakeWord::stride_audio_samples_(int16_t **audio_samples) {
     return false;
   }
 
-  // Copy 320 bytes (160 samples over 10 ms) into preprocessor_audio_buffer_ from history in
-  // preprocessor_stride_buffer_
-  memcpy((void *) (this->preprocessor_audio_buffer_), (void *) (this->preprocessor_stride_buffer_),
+  // Copy the last 320 bytes (160 samples over 10 ms) from the audio buffer to the start of the audio buffer
+  memcpy((void *) (this->preprocessor_audio_buffer_), (void *) (this->preprocessor_audio_buffer_ + NEW_SAMPLES_TO_GET),
          HISTORY_SAMPLES_TO_KEEP * sizeof(int16_t));
 
-  // Copy 640 bytes (320 samples over 20 ms) from the ring buffer
-  // The first 320 bytes (160 samples over 10 ms) will be from history
+  // Copy 640 bytes (320 samples over 20 ms) from the ring buffer into the audio buffer offset 320 bytes (160 samples
+  // over 10 ms)
   size_t bytes_read = this->ring_buffer_->read((void *) (this->preprocessor_audio_buffer_ + HISTORY_SAMPLES_TO_KEEP),
                                                NEW_SAMPLES_TO_GET * sizeof(int16_t), pdMS_TO_TICKS(200));
 
@@ -415,11 +400,6 @@ bool MicroWakeWord::stride_audio_samples_(int16_t **audio_samples) {
     return false;
   }
 
-  // Copy the last 320 bytes (160 samples over 10 ms) from the audio buffer into history stride buffer for the next
-  // iteration
-  memcpy((void *) (this->preprocessor_stride_buffer_), (void *) (this->preprocessor_audio_buffer_ + NEW_SAMPLES_TO_GET),
-         HISTORY_SAMPLES_TO_KEEP * sizeof(int16_t));
-
   *audio_samples = this->preprocessor_audio_buffer_;
   return true;
 }
@@ -480,7 +460,7 @@ bool MicroWakeWord::register_preprocessor_ops_(tflite::MicroMutableOpResolver<18
   return true;
 }
 
-bool MicroWakeWord::register_streaming_ops_(tflite::MicroMutableOpResolver<14> &op_resolver) {
+bool MicroWakeWord::register_streaming_ops_(tflite::MicroMutableOpResolver<17> &op_resolver) {
   if (op_resolver.AddCallOnce() != kTfLiteOk)
     return false;
   if (op_resolver.AddVarHandle() != kTfLiteOk)
@@ -509,6 +489,12 @@ bool MicroWakeWord::register_streaming_ops_(tflite::MicroMutableOpResolver<14> &
     return false;
   if (op_resolver.AddQuantize() != kTfLiteOk)
     return false;
+  if (op_resolver.AddDepthwiseConv2D() != kTfLiteOk)
+    return false;
+  if (op_resolver.AddAveragePool2D() != kTfLiteOk)
+    return false;
+  if (op_resolver.AddMaxPool2D() != kTfLiteOk)
+    return false;
 
   return true;
 }

esphome/components/micro_wake_word/micro_wake_word.h

@@ -128,7 +128,6 @@ class MicroWakeWord : public Component {
 
   // Stores audio fed into feature generator preprocessor
   int16_t *preprocessor_audio_buffer_;
-  int16_t *preprocessor_stride_buffer_;
 
   bool detected_{false};
 
@@ -181,7 +180,7 @@ class MicroWakeWord : public Component {
   bool register_preprocessor_ops_(tflite::MicroMutableOpResolver<18> &op_resolver);
 
   /// @brief Returns true if successfully registered the streaming model's TensorFlow operations
-  bool register_streaming_ops_(tflite::MicroMutableOpResolver<14> &op_resolver);
+  bool register_streaming_ops_(tflite::MicroMutableOpResolver<17> &op_resolver);
 };
 
 template<typename... Ts> class StartAction : public Action<Ts...>, public Parented<MicroWakeWord> {