"""
tellotracker:
Allows manual operation of the drone and demo tracking mode.
Requires mplayer to record/save video.
Controls:
- tab to lift off
- WASD to move the drone
- space/shift to ascend/descent slowly
- Q/E to yaw slowly
- arrow keys to ascend, descend, or yaw quickly
- backspace to land, or P to palm-land
- enter to take a picture
- R to start recording video, R again to stop recording
(video and photos will be saved to a timestamped file in ~/Pictures/)
- Z to toggle camera zoom state
(zoomed-in widescreen or high FOV 4:3)
- T to toggle tracking
@author Leonie Buckley, Saksham Sinha and Jonathan Byrne
@copyright 2018 see license file for details
"""
import time
import datetime
import os
import tellopy
import numpy
import av
import cv2
from pynput import keyboard
from tracker import Tracker
def main():
""" Create a tello controller and show the video feed."""
tellotrack = TelloCV()
for packet in tellotrack.container.demux((tellotrack.vid_stream,)):
for frame in packet.decode():
image = tellotrack.process_frame(frame)
cv2.imshow('tello', image)
_ = cv2.waitKey(1) & 0xFF
class TelloCV(object):
"""
TelloTracker builds keyboard controls on top of TelloPy as well
as generating images from the video stream and enabling opencv support
"""
def __init__(self):
self.prev_flight_data = None
self.record = False
self.tracking = False
self.keydown = False
self.date_fmt = '%Y-%m-%d_%H%M%S'
self.speed = 50
self.drone = tellopy.Tello()
self.init_drone()
self.init_controls()
# container for processing the packets into frames
self.container = av.open(self.drone.get_video_stream())
self.vid_stream = self.container.streams.video[0]
self.out_file = None
self.out_stream = None
self.out_name = None
self.start_time = time.time()
# tracking a color
green_lower = (30, 50, 50)
green_upper = (80, 255, 255)
#red_lower = (0, 50, 50)
# red_upper = (20, 255, 255)
# blue_lower = (110, 50, 50)
# upper_blue = (130, 255, 255)
self.track_cmd = ""
self.tracker = Tracker(self.vid_stream.height,
self.vid_stream.width,
green_lower, green_upper)
def init_drone(self):
"""Connect, uneable streaming and subscribe to events"""
# self.drone.log.set_level(2)
self.drone.connect()
self.drone.start_video()
self.drone.subscribe(self.drone.EVENT_FLIGHT_DATA,
self.flight_data_handler)
self.drone.subscribe(self.drone.EVENT_FILE_RECEIVED,
self.handle_flight_received)
def on_press(self, keyname):
"""handler for keyboard listener"""
if self.keydown:
return
try:
self.keydown = True
keyname = str(keyname).strip('\'')
print('+' + keyname)
if keyname == 'Key.esc':
self.drone.quit()
exit(0)
if keyname in self.controls:
key_handler = self.controls[keyname]
if isinstance(key_handler, str):
getattr(self.drone, key_handler)(self.speed)
else:
key_handler(self.speed)
except AttributeError:
print('special key {0} pressed'.format(keyname))
def on_release(self, keyname):
"""Reset on key up from keyboard listener"""
self.keydown = False
keyname = str(keyname).strip('\'')
print('-' + keyname)
if keyname in self.controls:
key_handler = self.controls[keyname]
if isinstance(key_handler, str):
getattr(self.drone, key_handler)(0)
else:
key_handler(0)
def init_controls(self):
"""Define keys and add listener"""
self.controls = {
'w': 'forward',
's': 'backward',
'a': 'left',
'd': 'right',
'Key.space': 'up',
'Key.shift': 'down',
'Key.shift_r': 'down',
'q': 'counter_clockwise',
'e': 'clockwise',
'i': lambda speed: self.drone.flip_forward(),
'k': lambda speed: self.drone.flip_back(),
'j': lambda speed: self.drone.flip_left(),
'l': lambda speed: self.drone.flip_right(),
# arrow keys for fast turns and altitude adjustments
'Key.left': lambda speed: self.drone.counter_clockwise(speed),
'Key.right': lambda speed: self.drone.clockwise(speed),
'Key.up': lambda speed: self.drone.up(speed),
'Key.down': lambda speed: self.drone.down(speed),
'Key.tab': lambda speed: self.drone.takeoff(),
'Key.backspace': lambda speed: self.drone.land(),
'p': lambda speed: self.palm_land(speed),
't': lambda speed: self.toggle_tracking(speed),
'r': lambda speed: self.toggle_recording(speed),
'z': lambda speed: self.toggle_zoom(speed),
'Key.enter': lambda speed: self.take_picture(speed)
}
self.key_listener = keyboard.Listener(on_press=self.on_press,
on_release=self.on_release)
self.key_listener.start()
# self.key_listener.join()
def process_frame(self, frame):
"""convert frame to cv2 image and show"""
image = cv2.cvtColor(numpy.array(
frame.to_image()), cv2.COLOR_RGB2BGR)
image = self.write_hud(image)
if self.record:
self.record_vid(frame)
xoff, yoff = self.tracker.track(image)
image = self.tracker.draw_arrows(image)
distance = 100
cmd = ""
if self.tracking:
if xoff < -distance:
cmd = "counter_clockwise"
elif xoff > distance:
cmd = "clockwise"
elif yoff < -distance:
cmd = "down"
elif yoff > distance:
cmd = "up"
else:
if self.track_cmd is not "":
getattr(self.drone, self.track_cmd)(0)
self.track_cmd = ""
if cmd is not self.track_cmd:
if cmd is not "":
print("track command:", cmd)
getattr(self.drone, cmd)(self.speed)
self.track_cmd = cmd
return image
def write_hud(self, frame):
"""Draw drone info, tracking and record on frame"""
stats = self.prev_flight_data.split('|')
stats.append("Tracking:" + str(self.tracking))
if self.drone.zoom:
stats.append("VID")
else:
stats.append("PIC")
if self.record:
diff = int(time.time() - self.start_time)
mins, secs = divmod(diff, 60)
stats.append("REC {:02d}:{:02d}".format(mins, secs))
for idx, stat in enumerate(stats):
text = stat.lstrip()
cv2.putText(frame, text, (0, 30 + (idx * 30)),
cv2.FONT_HERSHEY_SIMPLEX,
1.0, (255, 0, 0), lineType=30)
return frame
def toggle_recording(self, speed):
"""Handle recording keypress, creates output stream and file"""
if speed == 0:
return
self.record = not self.record
if self.record:
datename = [os.getenv('HOME'), datetime.datetime.now().strftime(self.date_fmt)]
self.out_name = '{}/Pictures/tello-{}.mp4'.format(*datename)
print("Outputting video to:", self.out_name)
self.out_file = av.open(self.out_name, 'w')
self.start_time = time.time()
self.out_stream = self.out_file.add_stream(
'mpeg4', self.vid_stream.rate)
self.out_stream.pix_fmt = 'yuv420p'
self.out_stream.width = self.vid_stream.width
self.out_stream.height = self.vid_stream.height
if not self.record:
print("Video saved to ", self.out_name)
self.out_file.close()
self.out_stream = None
def record_vid(self, frame):
"""
convert frames to packets and write to file
"""
new_frame = av.VideoFrame(
width=frame.width, height=frame.height, format=frame.format.name)
for i in range(len(frame.planes)):
new_frame.planes[i].update(frame.planes[i])
pkt = None
try:
pkt = self.out_stream.encode(new_frame)
except IOError as err:
print("encoding failed: {0}".format(err))
if pkt is not None:
try:
self.out_file.mux(pkt)
except IOError:
print('mux failed: ' + str(pkt))
def take_picture(self, speed):
"""Tell drone to take picture, image sent to file handler"""
if speed == 0:
return
self.drone.take_picture()
def palm_land(self, speed):
"""Tell drone to land"""
if speed == 0:
return
self.drone.palm_land()
def toggle_tracking(self, speed):
""" Handle tracking keypress"""
if speed == 0: # handle key up event
return
self.tracking = not self.tracking
print("tracking:", self.tracking)
return
def toggle_zoom(self, speed):
"""
In "video" mode the self.drone sends 1280x720 frames.
In "photo" mode it sends 2592x1936 (952x720) frames.
The video will always be centered in the window.
In photo mode, if we keep the window at 1280x720 that gives us ~160px on
each side for status information, which is ample.
Video mode is harder because then we need to abandon the 16:9 display size
if we want to put the HUD next to the video.
"""
if speed == 0:
return
self.drone.set_video_mode(not self.drone.zoom)
def flight_data_handler(self, event, sender, data):
"""Listener to flight data from the drone."""
text = str(data)
if self.prev_flight_data != text:
self.prev_flight_data = text
def handle_flight_received(self, event, sender, data):
"""Create a file in ~/Pictures/ to receive image from the drone"""
path = '%s/Pictures/tello-%s.jpeg' % (
os.getenv('HOME'),
datetime.datetime.now().strftime(self.date_fmt))
with open(path, 'wb') as out_file:
out_file.write(data)
print('Saved photo to %s' % path)
if __name__ == '__main__':
main()
