Add JPEG encoder support via new camera_encoder component (#9459)

Co-authored-by: J. Nick Koston <nick@koston.org>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>
Co-authored-by: J. Nick Koston <nick+github@koston.org>

esphome/components/camera_encoder/esp32_camera_jpeg_encoder.cpp

@@ -0,0 +1,82 @@
+#ifdef USE_ESP32_CAMERA_JPEG_ENCODER
+
+#include "esp32_camera_jpeg_encoder.h"
+
+namespace esphome::camera_encoder {
+
+static const char *const TAG = "camera_encoder";
+
+ESP32CameraJPEGEncoder::ESP32CameraJPEGEncoder(uint8_t quality, camera::EncoderBuffer *output) {
+  this->quality_ = quality;
+  this->output_ = output;
+}
+
+camera::EncoderError ESP32CameraJPEGEncoder::encode_pixels(camera::CameraImageSpec *spec, camera::Buffer *pixels) {
+  this->bytes_written_ = 0;
+  this->out_of_output_memory_ = false;
+  bool success = fmt2jpg_cb(pixels->get_data_buffer(), pixels->get_data_length(), spec->width, spec->height,
+                            to_internal_(spec->format), this->quality_, callback_, this);
+
+  if (!success)
+    return camera::ENCODER_ERROR_CONFIGURATION;
+
+  if (this->out_of_output_memory_) {
+    if (this->buffer_expand_size_ <= 0)
+      return camera::ENCODER_ERROR_SKIP_FRAME;
+
+    size_t current_size = this->output_->get_max_size();
+    size_t new_size = this->output_->get_max_size() + this->buffer_expand_size_;
+    if (!this->output_->set_buffer_size(new_size)) {
+      ESP_LOGE(TAG, "Failed to expand output buffer.");
+      this->buffer_expand_size_ = 0;
+      return camera::ENCODER_ERROR_SKIP_FRAME;
+    }
+
+    ESP_LOGD(TAG, "Output buffer expanded (%u -> %u).", current_size, this->output_->get_max_size());
+    return camera::ENCODER_ERROR_RETRY_FRAME;
+  }
+
+  this->output_->set_buffer_size(this->bytes_written_);
+  return camera::ENCODER_ERROR_SUCCESS;
+}
+
+void ESP32CameraJPEGEncoder::dump_config() {
+  ESP_LOGCONFIG(TAG,
+                "ESP32 Camera JPEG Encoder:\n"
+                "  Size: %zu\n"
+                "  Quality: %d\n"
+                "  Expand: %d\n",
+                this->output_->get_max_size(), this->quality_, this->buffer_expand_size_);
+}
+
+size_t ESP32CameraJPEGEncoder::callback_(void *arg, size_t index, const void *data, size_t len) {
+  ESP32CameraJPEGEncoder *that = reinterpret_cast<ESP32CameraJPEGEncoder *>(arg);
+  uint8_t *buffer = that->output_->get_data();
+  size_t buffer_length = that->output_->get_max_size();
+  if (index + len > buffer_length) {
+    that->out_of_output_memory_ = true;
+    return 0;
+  }
+
+  std::memcpy(&buffer[index], data, len);
+  that->bytes_written_ += len;
+  return len;
+}
+
+pixformat_t ESP32CameraJPEGEncoder::to_internal_(camera::PixelFormat format) {
+  switch (format) {
+    case camera::PIXEL_FORMAT_GRAYSCALE:
+      return PIXFORMAT_GRAYSCALE;
+    case camera::PIXEL_FORMAT_RGB565:
+      return PIXFORMAT_RGB565;
+    // Internal representation for RGB is in byte order: B, G, R
+    case camera::PIXEL_FORMAT_BGR888:
+      return PIXFORMAT_RGB888;
+  }
+
+  return PIXFORMAT_GRAYSCALE;
+}
+
+}  // namespace esphome::camera_encoder
+
+#endif