import cv2 import numpy as np import queue import serial import serial.tools.list_ports import threading import time from colorama import Fore from config import EyeTrackConfig from enum import Enum WAIT_TIME = 0.1 # Serial communication protocol: # header-begin (2 bytes) # header-type (2 bytes) # packet-size (2 bytes) # packet (packet-size bytes) ETVR_HEADER = b'\xff\xa0' ETVR_HEADER_FRAME = b'\xff\xa1' ETVR_HEADER_LEN = 6 class CameraState(Enum): CONNECTING = 0 CONNECTED = 1 DISCONNECTED = 2 class Camera: def __init__( self, config: EyeTrackConfig, camera_index: int, cancellation_event: "threading.Event", capture_event: "threading.Event", camera_status_outgoing: "queue.Queue[CameraState]", camera_output_outgoing: "queue.Queue", ): self.camera_status = CameraState.CONNECTING self.config = config self.camera_index = camera_index self.camera_address = config.capture_source self.camera_status_outgoing = camera_status_outgoing self.camera_output_outgoing = camera_output_outgoing self.capture_event = capture_event self.cancellation_event = cancellation_event self.current_capture_source = config.capture_source self.wired_camera: "cv2.VideoCapture" = None self.serial_connection = None self.last_frame_time = time.time() self.frame_number = 0 self.fps = 0 self.bps = 0 self.start = True self.buffer = b'' self.error_message = f"{Fore.YELLOW}[WARN] Capture source {{}} not found, retrying...{Fore.RESET}" def __del__(self): if self.serial_connection is not None: self.serial_connection.close() def set_output_queue(self, camera_output_outgoing: "queue.Queue"): self.camera_output_outgoing = camera_output_outgoing def run(self): while True: if self.cancellation_event.is_set(): print(f"{Fore.CYAN}[INFO] Exiting Capture thread{Fore.RESET}") return should_push = True # If things aren't open, retry until they are. Don't let read requests come in any earlier # than this, otherwise we can deadlock ourselves. if ( self.config.capture_source != None and self.config.capture_source != "" ): if (self.config.capture_source[:3] == "COM"): if ( self.serial_connection is None or self.camera_status == CameraState.DISCONNECTED or self.config.capture_source != self.current_capture_source ): port = self.config.capture_source self.current_capture_source = port self.start_serial_connection(port) else: if ( self.wired_camera is None or not self.wired_camera.isOpened() or self.camera_status == CameraState.DISCONNECTED or self.config.capture_source != self.current_capture_source ): print(self.error_message.format(self.config.capture_source)) # This requires a wait, otherwise we can error and possible screw up the camera # firmware. Fickle things. if self.cancellation_event.wait(WAIT_TIME): return self.current_capture_source = self.config.capture_source self.wired_camera = cv2.VideoCapture(self.current_capture_source) should_push = False else: # We don't have a capture source to try yet, wait for one to show up in the GUI. if self.cancellation_event.wait(WAIT_TIME): self.camera_status = CameraState.DISCONNECTED return # Assuming we can access our capture source, wait for another thread to request a capture. # Cycle every so often to see if our cancellation token has fired. This basically uses a # python event as a context-less, resettable one-shot channel. if should_push and not self.capture_event.wait(timeout=0.02): continue if self.config.capture_source != None: if (self.current_capture_source[:3] == "COM"): self.get_serial_camera_picture(should_push) else: self.get_wired_camera_picture(should_push) if not should_push: # if we get all the way down here, consider ourselves connected self.camera_status = CameraState.CONNECTED def get_wired_camera_picture(self, should_push): try: ret, image = self.wired_camera.read() if not ret: self.wired_camera.set(cv2.CAP_PROP_POS_FRAMES, 0) raise RuntimeError("Problem while getting frame") frame_number = self.wired_camera.get(cv2.CAP_PROP_POS_FRAMES) self.fps = self.wired_camera.get(cv2.CAP_PROP_FPS) self.bps = image.nbytes if should_push: self.push_image_to_queue(image, frame_number, self.fps) except: print(f"{Fore.YELLOW}[WARN] Capture source problem, assuming camera disconnected, waiting for reconnect.{Fore.RESET}") self.camera_status = CameraState.DISCONNECTED pass def get_next_packet_bounds(self): beg = -1 while beg == -1: self.buffer += self.serial_connection.read(2048) beg = self.buffer.find(ETVR_HEADER + ETVR_HEADER_FRAME) # Discard any data before the frame header. if beg > 0: self.buffer = self.buffer[beg:] beg = 0 # We know exactly how long the jpeg packet is end = int.from_bytes(self.buffer[4:6], signed=False, byteorder="little") self.buffer += self.serial_connection.read(end - len(self.buffer)) return beg, end def get_next_jpeg_frame(self): beg, end = self.get_next_packet_bounds() jpeg = self.buffer[beg+ETVR_HEADER_LEN:end+ETVR_HEADER_LEN] self.buffer = self.buffer[end+ETVR_HEADER_LEN:] return jpeg def get_serial_camera_picture(self, should_push): conn = self.serial_connection if conn is None: return try: if conn.in_waiting: jpeg = self.get_next_jpeg_frame() if jpeg: # Create jpeg frame from byte string image = cv2.imdecode(np.fromstring(jpeg, dtype=np.uint8), cv2.IMREAD_UNCHANGED) if image is None: print(f"{Fore.YELLOW}[WARN] Frame drop. Corrupted JPEG.{Fore.RESET}") return # Discard the serial buffer. This is due to the fact that it # may build up some outdated frames. A bit of a workaround here tbh. if conn.in_waiting >= 32768: print(f"{Fore.CYAN}[INFO] Discarding the serial buffer ({conn.in_waiting} bytes){Fore.RESET}") conn.reset_input_buffer() self.buffer = b'' # Calculate the fps. current_frame_time = time.time() delta_time = current_frame_time - self.last_frame_time self.last_frame_time = current_frame_time if delta_time > 0: self.fps = 1 / delta_time self.bps = len(jpeg) / delta_time self.frame_number = self.frame_number + 1 if should_push: self.push_image_to_queue(image, self.frame_number, self.fps) except Exception: print(f"{Fore.YELLOW}[WARN] Serial capture source problem, assuming camera disconnected, waiting for reconnect.{Fore.RESET}") conn.close() self.camera_status = CameraState.DISCONNECTED pass def start_serial_connection(self, port): if self.serial_connection is not None and self.serial_connection.is_open: # Do nothing. The connection is already open on this port. if self.serial_connection.port == port: return # Otherwise, close the connection before trying to reopen. self.serial_connection.close() com_ports = [tuple(p) for p in list(serial.tools.list_ports.comports())] # Do not try connecting if no such port i.e. device was unplugged. if not any(p for p in com_ports if port in p): return try: conn = serial.Serial( baudrate = 3000000, port = port, xonxoff=False, dsrdtr=False, rtscts=False) # Set explicit buffer size for serial. conn.set_buffer_size(rx_size = 32768, tx_size = 32768) print(f"{Fore.CYAN}[INFO] ETVR Serial Tracker device connected on {port}{Fore.RESET}") self.serial_connection = conn self.camera_status = CameraState.CONNECTED except Exception: print(f"{Fore.CYAN}[INFO] Failed to connect on {port}{Fore.RESET}") self.camera_status = CameraState.DISCONNECTED def push_image_to_queue(self, image, frame_number, fps): # If there's backpressure, just yell. We really shouldn't have this unless we start getting # some sort of capture event conflict though. qsize = self.camera_output_outgoing.qsize() if qsize > 1: print( f"{Fore.YELLOW}[WARN] CAPTURE QUEUE BACKPRESSURE OF {qsize}. CHECK FOR CRASH OR TIMING ISSUES IN ALGORITHM.{Fore.RESET}") self.camera_output_outgoing.put((image, frame_number, fps)) self.capture_event.clear()