From 0b1b25191dea6f7a145170d8db26691b668f1326 Mon Sep 17 00:00:00 2001
From: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
Date: Tue, 8 Aug 2023 09:45:56 +1200
Subject: [PATCH] Add read interface to microphone (#5131)

---
 .../microphone/i2s_audio_microphone.cpp       | 49 +++++++++----------
 .../microphone/i2s_audio_microphone.h         |  3 +-
 esphome/components/microphone/microphone.h    |  1 +
 3 files changed, 25 insertions(+), 28 deletions(-)

diff --git a/esphome/components/i2s_audio/microphone/i2s_audio_microphone.cpp b/esphome/components/i2s_audio/microphone/i2s_audio_microphone.cpp
index 9c661c3ac2..cf0628d638 100644
--- a/esphome/components/i2s_audio/microphone/i2s_audio_microphone.cpp
+++ b/esphome/components/i2s_audio/microphone/i2s_audio_microphone.cpp
@@ -16,14 +16,6 @@ static const char *const TAG = "i2s_audio.microphone";
 
 void I2SAudioMicrophone::setup() {
   ESP_LOGCONFIG(TAG, "Setting up I2S Audio Microphone...");
-  ExternalRAMAllocator<uint8_t> allocator(ExternalRAMAllocator<uint8_t>::ALLOW_FAILURE);
-  this->buffer_ = allocator.allocate(BUFFER_SIZE);
-  if (this->buffer_ == nullptr) {
-    ESP_LOGE(TAG, "Failed to allocate buffer!");
-    this->mark_failed();
-    return;
-  }
-
 #if SOC_I2S_SUPPORTS_ADC
   if (this->adc_) {
     if (this->parent_->get_port() != I2S_NUM_0) {
@@ -110,37 +102,38 @@ void I2SAudioMicrophone::stop_() {
   this->high_freq_.stop();
 }
 
-void I2SAudioMicrophone::read_() {
+size_t I2SAudioMicrophone::read(int16_t *buf, size_t len) {
   size_t bytes_read = 0;
-  esp_err_t err =
-      i2s_read(this->parent_->get_port(), this->buffer_, BUFFER_SIZE, &bytes_read, (100 / portTICK_PERIOD_MS));
+  esp_err_t err = i2s_read(this->parent_->get_port(), buf, len, &bytes_read, (100 / portTICK_PERIOD_MS));
   if (err != ESP_OK) {
     ESP_LOGW(TAG, "Error reading from I2S microphone: %s", esp_err_to_name(err));
     this->status_set_warning();
-    return;
+    return 0;
   }
   this->status_clear_warning();
-
-  std::vector<int16_t> samples;
-  size_t samples_read = 0;
   if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_16BIT) {
-    samples_read = bytes_read / sizeof(int16_t);
-  } else if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_32BIT) {
-    samples_read = bytes_read / sizeof(int32_t);
-  } else {
-    ESP_LOGE(TAG, "Unsupported bits per sample: %d", this->bits_per_sample_);
-    return;
-  }
-  samples.resize(samples_read);
-  if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_16BIT) {
-    memcpy(samples.data(), this->buffer_, bytes_read);
+    return bytes_read;
   } else if (this->bits_per_sample_ == I2S_BITS_PER_SAMPLE_32BIT) {
+    std::vector<int16_t> samples;
+    size_t samples_read = bytes_read / sizeof(int32_t);
+    samples.resize(samples_read);
     for (size_t i = 0; i < samples_read; i++) {
-      int32_t temp = reinterpret_cast<int32_t *>(this->buffer_)[i] >> 14;
+      int32_t temp = reinterpret_cast<int32_t *>(buf)[i] >> 14;
       samples[i] = clamp<int16_t>(temp, INT16_MIN, INT16_MAX);
     }
+    memcpy(buf, samples.data(), samples_read * sizeof(int16_t));
+    return samples_read * sizeof(int16_t);
+  } else {
+    ESP_LOGE(TAG, "Unsupported bits per sample: %d", this->bits_per_sample_);
+    return 0;
   }
+}
 
+void I2SAudioMicrophone::read_() {
+  std::vector<int16_t> samples;
+  samples.resize(BUFFER_SIZE);
+  size_t bytes_read = this->read(samples.data(), BUFFER_SIZE / sizeof(int16_t));
+  samples.resize(bytes_read / sizeof(int16_t));
   this->data_callbacks_.call(samples);
 }
 
@@ -152,7 +145,9 @@ void I2SAudioMicrophone::loop() {
       this->start_();
       break;
     case microphone::STATE_RUNNING:
-      this->read_();
+      if (this->data_callbacks_.size() > 0) {
+        this->read_();
+      }
       break;
     case microphone::STATE_STOPPING:
       this->stop_();
diff --git a/esphome/components/i2s_audio/microphone/i2s_audio_microphone.h b/esphome/components/i2s_audio/microphone/i2s_audio_microphone.h
index 0cb87d42fd..dc6b70047a 100644
--- a/esphome/components/i2s_audio/microphone/i2s_audio_microphone.h
+++ b/esphome/components/i2s_audio/microphone/i2s_audio_microphone.h
@@ -21,6 +21,8 @@ class I2SAudioMicrophone : public I2SAudioIn, public microphone::Microphone, pub
   void set_din_pin(int8_t pin) { this->din_pin_ = pin; }
   void set_pdm(bool pdm) { this->pdm_ = pdm; }
 
+  size_t read(int16_t *buf, size_t len) override;
+
 #if SOC_I2S_SUPPORTS_ADC
   void set_adc_channel(adc1_channel_t channel) {
     this->adc_channel_ = channel;
@@ -42,7 +44,6 @@ class I2SAudioMicrophone : public I2SAudioIn, public microphone::Microphone, pub
   bool adc_{false};
 #endif
   bool pdm_{false};
-  uint8_t *buffer_;
   i2s_channel_fmt_t channel_;
   i2s_bits_per_sample_t bits_per_sample_;
 
diff --git a/esphome/components/microphone/microphone.h b/esphome/components/microphone/microphone.h
index ac3db3ec0f..e01a10e15c 100644
--- a/esphome/components/microphone/microphone.h
+++ b/esphome/components/microphone/microphone.h
@@ -20,6 +20,7 @@ class Microphone {
   void add_data_callback(std::function<void(const std::vector<int16_t> &)> &&data_callback) {
     this->data_callbacks_.add(std::move(data_callback));
   }
+  virtual size_t read(int16_t *buf, size_t len) = 0;
 
   bool is_running() const { return this->state_ == STATE_RUNNING; }
   bool is_stopped() const { return this->state_ == STATE_STOPPED; }