Hi,
I measure ip camera latency by Xavier and LED.
When I changed power mode by nvpmodel and jetson_clock.sh, the latency on Mode 2 was lower than on Mode 0.
Why is this? Intuitively, the latency on Mode 0 seems to be lower than Mode 2.
This event happened when using H.264. When using MJPEG, the latency was no difference between MODE 0 and MODE 2.
import numpy as np
import cv2
import argparse
import time
import RPi.GPIO as GPIO
output_pin1 = 18 # BOARD pin 12, BCM pin 18
#pixel = (1335, 335) #(x,y)
def main():
url = "rtsp://******@193.168.0.**/axis-media/media.amp?rate=0&videocodec=h264&resolution=1920x1080&fps=30&clock=0&camera=1&compression=0"
test_result = np.loadtxt("pixel_index.txt")
pixel = (int(test_result[0]), int(test_result[1]))
cap = cv2.VideoCapture()
cap.set(cv2.CAP_PROP_BUFFERSIZE,1)
cap.open(url)
GPIO.setmode(GPIO.BCM)
# set pin as an output pin with optional initial state of HIGH
GPIO.setup(output_pin1, GPIO.OUT, initial=GPIO.LOW)
start = -1000000
i = 0
j = 0
try:
while(True):
ret, frame = cap.read()
if frame[pixel[1], pixel[0]][2] > 100:
stop = time.time()
print(stop*1000 - start*1000)
GPIO.output(output_pin1, GPIO.LOW)
break
i = i+1
if i >= 100 and j == 0 :
#start = time.time()
GPIO.output(output_pin1, GPIO.HIGH)
start = time.time()
i = 0
j = 1
finally:
GPIO.cleanup()
if __name__ == '__main__':
main()