surveillance cam: ring buffer, streaming and high res pictures at same time #811

Eisbahn · 2023-10-03T15:26:29Z

Eisbahn
Oct 3, 2023

Dear all,

just switching from the old picamera to the new picamera2 interface due to whole system upgrade (lite-OS) and a new HQ camera on my (older) RPi 3b. However: I'm not a good prgrammer and have some issues with Python, or at least the latest interface...
I do want to have some kind of custom security camera, motion is detected by some radar sensor connected to GPIO. Doing motion detection vie the RPi would be nice, but isn't needed at all. Better use the CPU/GPU ressources for other tasks. However: the radar sensor kicks in quite late, therefore I do want to have some seconds before the trigger, resulting in the usage of a circular buffer. In overall the RPi should
a) record seamlingless video in highest possible solution
b) stream a Full HD video
c) if a trigger is recognized, take pictures every second in full resolution
Please see my code below, which I created for testing and having some questions:

Is there any way to have the timestamps also in the video? At the moment I so have this only in the pictures :-(
Could I take 4056 x 3040 pictures (every second) and have at same time a video recording running @1920x1080? I could only manage to go up to a max of Full HD resolution.
If I switch between ring buffer and live video recording, the brightness and saturation change is quite big, mainly in low or extrem light situations. Could it be fixed or is there any trick to take the old (internal) cam settings for the new video start (=before trigger and after trigger with same settings)?
How to offer in parallel a stream? As I switch from circular buffer to live video, I've no idea how to mange it. Also stop the server and restart it?
And is there any chance to have the circular buffer running all the time in the background? Assume a trigger is set at t=5sec lasting for 10sec until t=15sec and another trigger is set at 17sec. At the moment I would get only around ~2sec out of the ring buffer. Therefore in best case the ring buffer could run all the time and I could "split" or start some live recording anytime.
Is the very small gap in the video switching between the ring buffer and live recording somehow avoidable? (not that important, just to have it perfect)

Any help is highly appreciated. Thanks and best,

Hans

`
#!/usr/bin/python3

script could be run as daemon/service, see below for a short how-to manage it with actual systemd

is a mandatory parameter and should be Pforte_Zuweg or Eingangstuer

/usr/bin/python3 /home/pi/Tfw17_rpicamera/Tfw17_rpicamera.py

import os
import sys
from picamera2 import MappedArray, Picamera2
from picamera2.encoders import H264Encoder, Quality
from picamera2.outputs import CircularOutput, FileOutput

Transform is needed for horizontal/vertical flipping

from libcamera import Transform, controls

cv2 is needed to put some timestamps in the video and pictures

import cv2
import time
from datetime import datetime as dt
from time import sleep
import io
import logging
import socketserver
from threading import Condition
from http import server
# have a try statement to capture some basic failures
#try:
# some debug message
logging.info ('^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^')
logging.info ('^ script for the %s camera/sensor has started right now ^', location)
logging.info ('^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^')
# define a simple Webpage which is used for displaying the (mjpeg-)stream in a browser
#PAGE="""<html><title>stream from camera: """+location+"""</title>"""
# set image/video parameters used for all recordings
#cam_config_still = camera.create_still_configuration(transform=Transform(hflip=True))
#cam_config_video = camera.create_video_configuration(transform=Transform(hflip=True))
print ("test take pic")
camera_config = camera.create_still_configuration({"size":(4056, 3040)})
camera.configure(camera_config)
print ("test create pic config")
camera.pre_callback = apply_timestamp
print ("test pic config set")
camera.start(show_preview=False)
print ("test cam start")
# camera needs some waiting time after initial configuration
# web tells around 2sec is needed - I take 5sec as the RPi is doing some other CPU consuming stuff during booting phase
time.sleep(5)
print ("test take the pic")
timestamp = dt.now()
timestamp = timestamp.strftime("%Y-%m-%d-%H-%M-%S")
file_name = "pic_test_" + timestamp + ".jpg"
camera.capture_file(file_name)
camera.stop()
print ("test pic taken")

	fps=20
	camera.set_controls({"FrameRate": fps})
	duration_before = 5
	micro = int((1 / fps) * 1000000)
	camera_config = camera.create_video_configuration(main={"size": (1920, 1080)}, lores={"size": (1920,1080)}, encode="lores")
	camera_config['controls']['FrameDurationLimits'] = (micro, micro)
	camera.configure(camera_config)
	print ("test video config done")
	encoder = H264Encoder(bitrate=10000000, repeat=True, iperiod=20)
	output = CircularOutput(buffersize=int(fps * (duration_before + 0.1)), outputtofile=False)
	camera.pre_callback = apply_timestamp
	print ("test video set output done")
	camera.start_recording(encoder, output, Quality.HIGH)
	print ("test video recording")
	#wait 13 seconds, the 5.1sec circular buffer is used to capture continuously in the background
	time.sleep(13)
	print ("test trigger start")
	
	# now trigger occured, capture the video
	# in reality this is done by a radar sensor connected to a GPIO throwing an interrupt
	
	# we should have now a video from t=8sec up to t=13sec in the circular buffer (13sec diff due to time.sleep - 5sec from buffer in duration before)
	output.fileoutput = "before_trigger.h264"
	output.start()
	print ("test ring buffer stored")
	output.stop()
	camera.stop_recording()
	print ("test ring buffer stopped")
	
	#we saved the videofile from ringbuffer and need to start the video again
	camera_config = camera.create_video_configuration(main={"size": (1920, 1080)}, lores={"size": (1920,1080)}, encode="lores")
	camera.set_controls({"FrameRate": fps})
	camera.configure(camera_config)
	encoder = H264Encoder(bitrate=10000000, repeat=True, iperiod=20)
	camera.pre_callback = apply_timestamp
	print ("test new video config active, without ring buffer")
	output = "after_trigger.h264"
	camera.start_recording(encoder, output)
	print ("test video record")
	# record as long as radar sensor detects motion, here for testing 10sec
	#wait 10sec for testing and store a picture every second
	i = 1
	while i < 11:
		print ("test video screenshot #" + str(i) + " inner loop")
		request = camera.capture_request()
		timestamp = dt.now()
		timestamp = timestamp.strftime("%Y-%m-%d-%H-%M-%S")
		request.save("main", "pic_test_" + str(i) + "_" + timestamp + ".jpg")
		request.release()
		print ("test video screenshot #" + str(i) + " done")
		time.sleep(1)
		i = i+1
	# stop the recording
	# we now should have a 15sec long video from t=8sec up to t=23sec, containing the trigger at t=13sec (5sec before trigger and 10sec after)
	# and 10 pictures
	camera.stop_recording()
	print ("test video stopped")
	
	os.system('MP4Box -fps 20 -add before_trigger.h264 -fps 20 -cat after_trigger.h264 -fps 20 -new converted.mp4 -noprog -quiet -tmp ~')
	print ("test video converted")

`

Eisbahn · 2023-10-03T20:50:56Z

Eisbahn
Oct 3, 2023
Author

Hi,

I just realize picamera2 is most likely not a good lib for a security cam... Somethin like
# ...and check which one is older if triggertime > currenttime: # currenttime is older, so take the oldest time triggertime = currenttime # now do the final calculation how many seconds need to be taken/read from the circular buffer beforetime = (currenttime - triggertime).total_seconds() + secs_before # some debug message logging.info('seconds taken for camera %s from circular buffer: %s', location, beforetime) # split the recording to record the videoframes after the trigger to a file... camera.split_recording(video_path + 'after-' + triggerfile + '.h264') # ... and write the configured seconds before the trigger from circular buffer to disk as well # if mjpeg format is used, first_frame=None is mandatory needed, otherwise the file would be empty stream.copy_to((video_path + 'before-' + triggerfile + '.h264'), seconds=beforetime)
isn't possible, meaning there couldn't be one ring buffer running in the background from which you could split needed video material. Or did I miss anything?

Hans

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surveillance cam: ring buffer, streaming and high res pictures at same time #811

Eisbahn Oct 3, 2023

script could be run as daemon/service, see below for a short how-to manage it with actual systemd

is a mandatory parameter and should be Pforte_Zuweg or Eingangstuer

/usr/bin/python3 /home/pi/Tfw17_rpicamera/Tfw17_rpicamera.py

Transform is needed for horizontal/vertical flipping

cv2 is needed to put some timestamps in the video and pictures

Replies: 1 comment

Eisbahn Oct 3, 2023 Author

Eisbahn
Oct 3, 2023

Eisbahn
Oct 3, 2023
Author