I have a tello ryze drone, which has got a camera onboard. I am connecting to the drone in order to receive the video over wifi. My system is windows 10 and I am using python 2.7.
I am receiving a h264 bytecode and i use the libh264 decoder from tello in order to get the frames of the video, which i also display in my UI. What i need to do is to save this video as a file on my computer and i have problems with this. I am able to make a snapshot with opencv and save it as an image, this isn't a problem. But making a video isn't working for some reason. I read many posts here like this one but they dont work out for me. I am getting either an error or i get a very small video file, which doesnt open. My Frames are List of List with RGB values like:
[[255,200,100][55,200,100][25,20,100]]
Here is my code for a better understanding in order to help me
This is the UI Part(i just copy here the needed code only):
def videoLoop(self):
try:
# start the thread that get GUI image and draw skeleton
time.sleep(0.5)
self.sending_command_thread.start()
while not self.stopEvent.is_set():
system = platform.system()
# read the frame for GUI show
self.frame = self.drone.read()
if self.frame is None or self.frame.size == 0:
continue
# transfer the format from frame to image
image = Image.fromarray(self.frame)
# we found compatibility problem between Tkinter,PIL and Macos,and it will
# sometimes result the very long preriod of the "ImageTk.PhotoImage" function,
# so for Macos,we start a new thread to execute the _updateGUIImage function.
if system == "Windows" or system == "Linux":
self.refreshUI(image)
else:
thread_tmp = threading.Thread(target=self.refreshUI, args=(image,))
thread_tmp.start()
time.sleep(0.03)
except RuntimeError as e:
print("[INFO] caught a RuntimeError")
def refreshUI(self, image):
image = ImageTk.PhotoImage(image)
# if the imagePanel none ,we need to initial it
if self.imagePanel is None:
self.imagePanel = tki.Label(image=image)
self.imagePanel.image = image
self.imagePanel.pack(side="left", fill="both",
expand="yes", padx=10, pady=10)
# otherwise, simply update the imagePanel
else:
self.imagePanel.configure(image=image)
self.imagePanel.image = image
def takeSnapshot(self):
# grab the current timestamp and use it to construct the filename
ts = datetime.datetime.now()
filename = "{}.jpg".format(ts.strftime("%d-%m-%Y_%H-%M-%S"))
p = os.path.sep.join((self.screenShotPath, filename))
# save the file
cv2.imwrite(p, cv2.cvtColor(self.frame, cv2.COLOR_RGB2BGR))
print("[INFO] saved {}".format(filename))
Below you can find the Tello code (only the needed part too):
def read(self):
"""Return the last frame from camera."""
if self.is_freeze:
return self.last_frame
else:
return self.frame
def video_freeze(self, is_freeze=True):
"""Pause video output -- set is_freeze to True"""
self.is_freeze = is_freeze
if is_freeze:
self.last_frame = self.frame
def _receive_video_thread(self):
"""
Listens for video streaming (raw h264) from the Tello.
Runs as a thread, sets self.frame to the most recent frame Tello captured.
"""
packet_data = b''
while True:
try:
res_string, ip = self.socket_video.recvfrom(2048)
packet_data += res_string
# end of frame
if len(res_string) != 1460:
for frame in self._h264_decod(packet_data):
self.frame = frame
packet_data = b''
except socket.error as exc:
print(("Caught exception sock.error : %s" % exc))
def _h264_decod(self, packet_data):
"""
decode raw h264 format data from Tello
:param packet_data: raw h264 data array
:return: a list of decoded frame
"""
res_frame_list = []
frames = self.decoder.decode(packet_data)
for framedata in frames:
(frame, w, h, ls) = framedata
if frame is not None:
# print ('frame size %i bytes, w %i, h %i, linesize %i' % (len(frame), w, h, ls))
frame = np.frombuffer(frame, dtype=np.ubyte, count=len(frame))
frame = (frame.reshape((h, ls // 3, 3)))
frame = frame[:, :w, :]
res_frame_list.append(frame)
return res_frame_list
It would be very kind of you if someone could help me write a method like this pseudocode:
def saveVideo(self, frame_or_whatever_i_need_here):
out = cv2.VideoWriter('output.avi_or_other_format', -1, 20.0, (640,480))
out.write(frame_or_whatever_i_need_here)
out.release()
Edit 1: i found an option making a video out of my snapshots, this means that i coud make snapshot over a thread and later save them to a video. That would be an option. The problem is, that it would consume too much space in the disk. The workaround link is here
