Description:
I want to create a people counter using DNN. The model I'm using is MobileNetSSD. The camera I use is IPCam from Hikvision. Python communicates with IPCam using the RSTP protocol.
The program that I made is good and there are no bugs, when running the sample video the program does its job well. But when I replaced it with IPcam there was an unknown error.
Error:
Sometimes the error is:
[h264 @ 000001949f7adfc0] error while decoding MB 13 4, bytestream -6
[h264 @ 000001949f825ac0] left block unavailable for requested intra4x4 mode -1
[h264 @ 000001949f825ac0] error while decoding MB 0 17, bytestream 762
Sometimes the error does not appear and the program is killed.
Update Error
After revising the code, I caught the error. The error found is
[h264 @ 0000019289b3fa80] error while decoding MB 4 5, bytestream -25
Now I don't know what to do, because the error is not in Google.
Source Code:
Old Code
This is my very earliest code before getting suggestions from the comments field.
import time
import cv2
import numpy as np
import math
import threading
print("Load MobileNeteSSD model")
prototxt = "MobileNetSSD_deploy.prototxt"
model = "MobileNetSSD_deploy.caffemodel"
CLASSES = ["background", "aeroplane", "bicycle", "bird", "boat",
"bottle", "bus", "car", "cat", "chair", "cow", "diningtable",
"dog", "horse", "motorbike", "person", "pottedplant", "sheep",
"sofa", "train", "tvmonitor"]
net = cv2.dnn.readNetFromCaffe(prototxt, model)
pos_line = 0
offset = 50
car = 0
detected = False
check = 0
prev_frame_time = 0
def detect():
global check, car, detected
check = 0
if(detected == False):
car = 1
detected = True
def center_object(x, y, w, h):
cx = x int(w / 2)
cy = y int(h / 2)
return cx, cy
def process_frame_MobileNetSSD(next_frame):
global car, check, detected
rgb = cv2.cvtColor(next_frame, cv2.COLOR_BGR2RGB)
(H, W) = next_frame.shape[:2]
blob = cv2.dnn.blobFromImage(next_frame, size=(300, 300), ddepth=cv2.CV_8U)
net.setInput(blob, scalefactor=1.0/127.5, mean=[127.5, 127.5, 127.5])
detections = net.forward()
for i in np.arange(0, detections.shape[2]):
confidence = detections[0, 0, i, 2]
if confidence > 0.5:
idx = int(detections[0, 0, i, 1])
if CLASSES[idx] != "person":
continue
label = CLASSES[idx]
box = detections[0, 0, i, 3:7] * np.array([W, H, W, H])
(startX, startY, endX, endY) = box.astype("int")
center_ob = center_object(startX, startY, endX-startX, endY-startY)
cv2.circle(next_frame, center_ob, 4, (0, 0, 255), -1)
if center_ob[0] < (pos_line offset) and center_ob[0] > (pos_line-offset):
# car =1
detect()
else:
check = 1
if(check >= 5):
detected = False
cv2.putText(next_frame, label ' ' str(round(confidence, 2)),
(startX, startY-10), cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 0, 255), 2)
cv2.rectangle(next_frame, (startX, startY),
(endX, endY), (0, 255, 0), 3)
return next_frame
def PersonDetection_UsingMobileNetSSD():
cap = cv2.VideoCapture()
cap.open("rtsp://admin:[email protected]:554/Streaming/channels/2/")
global car,pos_line,prev_frame_time
frame_count = 0
while True:
try:
time.sleep(0.1)
new_frame_time = time.time()
fps = int(1/(new_frame_time-prev_frame_time))
prev_frame_time = new_frame_time
ret, next_frame = cap.read()
w_video = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
h_video = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
pos_line = int(h_video/2)-50
if ret == False: break
frame_count = 1
cv2.line(next_frame, (int(h_video/2), 0),
(int(h_video/2), int(h_video)), (255, 127, 0), 3)
next_frame = process_frame_MobileNetSSD(next_frame)
cv2.rectangle(next_frame, (248,22), (342,8), (0,0,0), -1)
cv2.putText(next_frame, "Counter : " str(car), (250, 20),
cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 1)
cv2.putText(next_frame, "FPS : " str(fps), (0, int(h_video)-10),
cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 1)
cv2.imshow("Video Original", next_frame)
# print(car)
except Exception as e:
print(str(e))
if cv2.waitKey(1) & 0xFF == ord('q'):
break
print("/MobileNetSSD Person Detector")
cap.release()
cv2.destroyAllWindows()
if __name__ == "__main__":
t1 = threading.Thread(PersonDetection_UsingMobileNetSSD())
t1.start()
New Code
I have revised my code and the program still stops taking frames. I just revised the PersonDetection_UsingMobileNetSSD() function. I've also removed the multithreading I was using. The code has been running for about 30 minutes but after a broken frame, the code will never re-execute the program block if ret == True.
def PersonDetection_UsingMobileNetSSD():
cap = cv2.VideoCapture()
cap.open("rtsp://admin:[email protected]:554/Streaming/channels/2/")
global car,pos_line,prev_frame_time
frame_count = 0
while True:
try:
if cap.isOpened():
ret, next_frame = cap.read()
if ret:
new_frame_time = time.time()
fps = int(1/(new_frame_time-prev_frame_time))
prev_frame_time = new_frame_time
w_video = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
h_video = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
pos_line = int(h_video/2)-50
# next_frame = cv2.resize(next_frame,(720,480),fx=0,fy=0, interpolation = cv2.INTER_CUBIC)
if ret == False: break
frame_count = 1
cv2.line(next_frame, (int(h_video/2), 0),
(int(h_video/2), int(h_video)), (255, 127, 0), 3)
next_frame = process_frame_MobileNetSSD(next_frame)
cv2.rectangle(next_frame, (248,22), (342,8), (0,0,0), -1)
cv2.putText(next_frame, "Counter : " str(car), (250, 20),
cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 1)
cv2.putText(next_frame, "FPS : " str(fps), (0, int(h_video)-10),
cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 1)
cv2.imshow("Video Original", next_frame)
# print(car)
else:
print("Crashed Frame")
else:
print("Cap is not open")
except Exception as e:
print(str(e))
if cv2.waitKey(1) & 0xFF == ord('q'):
break
print("/MobileNetSSD Person Detector")
cap.release()
cv2.destroyAllWindows()
Requirement:
Hardware : Intel i5-1035G1, RAM 8 GB, NVIDIA GeForce MX330
Software : Python 3.6.2 , OpenCV 4.5.1, Numpy 1.16.0
Question:
- What should i do for fixing this error?
- What causes this to happen?
Best Regards,
Thanks
CodePudding user response：
The main problem here is that RSTP always has some corrupted frames in it. The solution is to run video capture on thread 1 and video processing on thread 2.
As an example:
import cv2
import threading
import queue
q=queue.Queue()
def this_receive(q):
cap = cv2.VideoCapture("rtsp://admin:[email protected]:554/Streaming/channels/2/")
cap.set(cv2.CAP_PROP_FPS, 5)
ret, next_frame = cap.read()
q.put(next_frame)
while ret:
ret, next_frame = cap.read()
w_video = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
h_video = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
q.put(next_frame)
def main_program(q):
while True:
try:
if q.empty() != True:
next_frame=q.get()
except Exception as e:
print(str(e))
if cv2.waitKey(1) & 0xFF == ord('q'):
break
if __name__ == "__main__":
print("Main Program")
p2 = threading.Thread(target=this_receive,args=((q),))
p2.start()
p1 = threading.Thread(target=main_program,args=((q),))
p1.start()
This example will work according to the case you are experiencing. Damage to the frame will not affect the quality of data processing. It's just that this method can cause delays in processing. Time on video and real time have a delay of up to 10 minutes. Want to know what kind of delay? Just try it!