[Python] OpenCV & RTSP - Python errors

I’m working on a Python script that reads multiple RTSP streams using OpenCV, detects motion, and saves frames when motion is detected. Initially, I faced issues with ash-colored frames due to H.265 codec, which OpenCV doesn’t support by default. After switching the camera codecs to H.264, the ash-colored frames issue was resolved. However, I’m now encountering decoding errors and glitching frames.

System Specifications:

Processor: Intel Core i3-6100 CPU @ 3.70GHz RAM:8GB Resource Usage: CPU: 35-45% RAM: 1GB max Network Speed: 7.4 Mb/s Disk Usage: 2.3 MB/s

Here’s the Python script I’m using:

import cv2
import os
import datetime
import threading
import argparse
from cryptography.fernet import Fernet

def encrypt_text(text):
return text

class MotionDetector:
def __init__(self, base_dir="motion_frames"):
self.base_dir = base_dir
self.output_dirs = [os.path.join(self.base_dir, str(i)) for i in range(1, 4)]
for dir_path in self.output_dirs:
os.makedirs(dir_path, exist_ok=True)
self.fgbg_dict = {}

def initialize_fgbg(self, camera_name):
if camera_name not in self.fgbg_dict:
self.fgbg_dict[camera_name] = cv2.createBackgroundSubtractorMOG2(history=500, varThreshold=35, detectShadows=True)

def detect_motion(self, frame, camera_name):
self.initialize_fgbg(camera_name)
fgmask = self.fgbg_dict[camera_name].apply(frame)
thresh = cv2.threshold(fgmask, 200, 255, cv2.THRESH_BINARY)[1]
thresh = cv2.dilate(thresh, None, iterations=2)
contours, _ = cv2.findContours(thresh, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

motion_detected = any(cv2.contourArea(contour) > 500 for contour in contours)
return motion_detected

def save_frame(self, frame, camera_name, count):
folder_index = (count - 1) % 3 # This will rotate between 0, 1, and 2
output_dir = self.output_dirs[folder_index]
timestamp = datetime.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")
filename = f"{camera_name}_Entireframe_object_{count}_{timestamp}.jpg"
name = encrypt_text(filename)
pathname = os.path.join(output_dir, f'{name}.jpg')
cv2.imwrite(pathname, frame)
# print(f"Motion detected: {pathname}")

def process_camera_stream(rtsp_url, camera_name, detector, stop_event):
cap = cv2.VideoCapture(rtsp_url, cv2.CAP_FFMPEG)
print("Started Camera : ",camera_name)
count = 0

while not stop_event.is_set():
ret, frame = cap.read()
if not ret:
print(f"Connection lost: {camera_name}. Reconnecting...")
cap.release()
cap = cv2.VideoCapture(rtsp_url)
continue

if detector.detect_motion(frame, camera_name):
count += 1
detector.save_frame(frame, camera_name, count)

cap.release()

def main():
parser = argparse.ArgumentParser(description='RTSP Motion Detection')
parser.add_argument('--output', type=str, default="motion_frames", help='Output directory')
args = parser.parse_args()

rtsp_urls = {
"Camera1": "rtsp://admin:J**@884@192.168.1.103:554/cam/realmonitor?channel=1&subtype=1&protocol=TCP",
"Camera2": "rtsp://admin:J***@884@192.168.1.105:554/cam/realmonitor?channel=1&subtype=1&protocol=TCP",
"Camera3": "rtsp://admin:J***@884@192.168.1.104:554/cam/realmonitor?channel=1&subtype=1&protocol=TCP",
"Camera4": "rtsp://admin:J@884@192.168.1.101:554/cam/realmonitor?channel=1&subtype=1&protocol=TCP",

"Camera5": "rtsp://admin:admin123@192.168.1.33:554/Streaming/Channels/301&protocol=TCP",
"Camera6": "rtsp://admin:admin123@192.168.1.33:554/Streaming/Channels/401&protocol=TCP",
"Camera7": "rtsp://admin:admin123@192.168.1.33:554/Streaming/Channels/701&protocol=TCP",
}

detector = MotionDetector(base_dir=args.output)
stop_event = threading.Event()
threads = []

try:
for camera_name, url in rtsp_urls.items():
thread = threading.Thread(target=process_camera_stream, args=(url, camera_name, detector, stop_event))
thread.start()
threads.append(thread)

while True:
pass
except KeyboardInterrupt:
print("Stopping...")
stop_event.set()
for thread in threads:
thread.join()


if __name__ == "__main__":
main()



i am getting glitched some images are having glitches, i am attaching some image examples. When running the script, I’m getting the following decoding errors in the terminal:

[h264 @ 00000185da541a80] error while decoding MB 26 1, bytestream -29
[h264 @ 00000185d8fefb00] error while decoding MB 23 31, bytestream -5
[h264 @ 00000185cedcc140] error while decoding MB 36 35, bytestream -7
[h264 @ 00000185d8ae73c0] cabac decode of qscale diff failed at 40 35
[h264 @ 00000185d8ae73c0] error while decoding MB 40 35, bytestream -5
[h264 @ 00000185da541a80] error while decoding MB 32 30, bytestream -11
[h264 @ 00000185e15f8500] error while decoding MB 16 34, bytestream -11
[h264 @ 00000185e15f9700] error while decoding MB 9 33, bytestream -9
[h264 @ 00000185e15fb680] error while decoding MB 6 32, bytestream -5
[h264 @ 00000185e15f8500] error while decoding MB 23 23, bytestream -7
[h264 @ 00000185e15fb680] error while decoding MB 28 23, bytestream -5
[h264 @ 00000185e15fa000] error while decoding MB 27 19, bytestream -37
[h264 @ 00000185e15fa900] error while decoding MB 6 27, bytestream -7
[h264 @ 00000185e15f8500] error while decoding MB 14 12, bytestream -5
[h264 @ 00000185e15f9280] error while decoding MB 22 35, bytestream -7
[h264 @ 00000185d8fefb00] error while decoding MB 31 32, bytestream -7
[h264 @ 00000185e15fb680] error while decoding MB 5 24, bytestream -5
[h264 @ 00000185d8ae7b00] error while decoding MB 29 26, bytestream -7


i have ip cameras & analog cameras, the error from ip camera are too frequent compared to analog camera.

Questions:

1. What could be causing these decoding errors and glitching frames?
2. Are there any specific settings or configurations I need to adjust in OpenCV or FFMPEG to handle H.264 streams more reliably?
3. Could this be related to network latency, hardware limitations, or OpenCV’s handling of RTSP streams?
4. Are there any alternative approaches or libraries I can use to improve the stability of RTSP stream processing?

the glitches are more on person or moving objects & i have no idea if the error and glitches are rtelated

What I’ve Tried:

1. Switched camera codecs from H.265 to H.264 (resolved the ash-colored frames issue).
2. Tested the script with a single camera using a different object detection script, but the same errors occurred.

I want the frames saved without the glitches

Continue reading...