esp-iot-solution/examples/camera/README.md

Camera Examples

This directory contains a range of example esp32-camera projects.
See the README.md file in the upper level directory for more information about examples.

Camera driver workflow

The camera sensor transmits data to ESP32 device through DVP(parallel digital video port) interface. When initializing the camera, some frame_buffer will be allocated to store the data transmitted by the camera sensor. Once the camera is initialized, it starts working immediately, and the application can call esp_camera_fb_get() to get image data. After the application has applied the image data, the frame_buffer can be reused by calling esp_camera_fb_return().

Example Layout

• basic demonstrates basic usage of ESP32-camera driver.
• pic_server introduces how to control the action of taking pictures, and view the pictures immediately on the web page.
• test_framerate introduces how to evaluate the speed of the camera sensor and how to improve the speed of the camera sensor.
• video_stream_server demonstrates how to implement a video stream HTTP server on ESP32.

More

• ESP-WHO is an image processing development platform based on Espressif chips. It contains development examples that may be applied in practical applications.
• USB_camera_examples Contains some examples of using USB cameras.

API Reference

The APIs included in the esp32-camera are described below.

Header File

• esp32-camera/driver/include/esp_camera.h

Functions

• esp_err_t esp_camera_init(const camera_config_t* config)
  Initialize the camera driver.

• esp_err_t esp_camera_deinit()
  Deinitialize the camera driver.

• camera_fb_t* esp_camera_fb_get()
  Obtain pointer to a frame buffer.

• void esp_camera_fb_return(camera_fb_t * fb)
  Return the frame buffer to be reused again.

• sensor_t * esp_camera_sensor_get()
  Get a pointer to the image sensor control structure.

• esp_err_t esp_camera_save_to_nvs(const char *key)
  Save camera settings to non-volatile-storage (NVS).

• esp_err_t esp_camera_load_from_nvs(const char *key)
  Load camera settings from non-volatile-storage (NVS).

Header File

• esp32-camera/driver/include/sensor.h

Functions

• camera_sensor_info_t *esp_camera_sensor_get_info(sensor_id_t *id)
  Get the camera sensor information.

Header File

• esp32-camera/conversions/include/img_converters.h

Functions

• bool fmt2jpg_cb(uint8_t *src, size_t src_len, uint16_t width, uint16_t height, pixformat_t format, uint8_t quality, jpg_out_cb cb, void * arg)
  Convert image buffer to JPEG.

• bool frame2jpg_cb(camera_fb_t * fb, uint8_t quality, jpg_out_cb cb, void * arg)
  Convert camera frame buffer to JPEG.

• bool fmt2jpg(uint8_t *src, size_t src_len, uint16_t width, uint16_t height, pixformat_t format, uint8_t quality, uint8_t ** out, size_t * out_len)
  Convert image buffer to JPEG buffer.

• bool fmt2bmp(uint8_t *src, size_t src_len, uint16_t width, uint16_t height, pixformat_t format, uint8_t ** out, size_t * out_len)
  Convert image buffer to BMP buffer.

• bool frame2bmp(camera_fb_t * fb, uint8_t ** out, size_t * out_len)
  Convert camera frame buffer to BMP buffer.

• bool frame2bmp(camera_fb_t * fb, uint8_t ** out, size_t * out_len)
  Convert camera frame buffer to BMP buffer.

• bool fmt2rgb888(const uint8_t *src_buf, size_t src_len, pixformat_t format, uint8_t * rgb_buf)
  Convert image buffer to RGB888 buffer.

• bool jpg2rgb565(const uint8_t *src, size_t src_len, uint8_t * out, jpg_scale_t scale)
  Convert image buffer to RGB565 buffer.

Header File

• esp32-camera/conversions/include/esp_jpg_decode.h

Functions

• esp_err_t esp_jpg_decode(size_t len, jpg_scale_t scale, jpg_reader_cb reader, jpg_writer_cb writer, void * arg)
  JPEG scaling function.