cameraStreamBash1.py

#!/usr/bin/env python3
# Copyright 2016 Keith Ellis
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#
# This Python script sends picamera video output to stout,
# it is intended to be called from a bash script which pipes
# the output into ffmpeg
#
# Bash script is startPythonStream.sh

import os
import time
import picamera
import sys
from signal import pause
from time import sleep, time
from datetime import datetime
import thingspeak

sys.stdout = os.fdopen(sys.stdout.fileno(), 'wb', 0)

snapshot_frequency = 60 * 60  #frequency of snapshops in seconds
temp_frequency = 2 * 60  #frequency of temperature updates
max_images = 24 		# Maximum number of images to keep

#ThingSpeak keys
channel_id = "88282"
write_key  = "LE6B6L2ZRZ592AA8"
channel = thingspeak.Channel(id=channel_id,write_key=write_key)


def get_temp(sensor):
	if sensor == 'internal':
		field_id = 2
	else:
		field_id = 1
	temp = channel.get_field_last_text(field=field_id)
	temp = str(round(float(temp),1))
	return temp


def start_stream():
	start= time()
	last_temp = start
	last_snap = start
	snap_shot_count = 0
	ext_temp = get_temp('external')
	camera = picamera.PiCamera()
	camera.resolution = (960, 540)
	camera.framerate = 25
	camera.vflip = True
	camera.hflip = True
	camera.annotate_background = picamera.Color('black')

	camera.start_recording(sys.stdout, bitrate = 500000, format='h264')

	while True:
		if time()- last_temp > temp_frequency:
			ext_temp = get_temp('external')
			last_temp = time()
		i = datetime.now()
		now = i.strftime('%d %b %Y - %H:%M:%S')
		camera.annotate_text = (' Bird Cam - {0} - Ext temp = {1}C '
								.format(now, ext_temp))

		try:
			camera.wait_recording(0.2)

		except picamera.exc.PiCameraError:
			camera.close()
			break

		except BrokenPipeError:
			camera.close()
			break

		if time() - last_snap > snapshot_frequency:  # Take snap shot
			snap_shot('image'+str(snap_shot_count), camera)
			last_snap = time()
			if snap_shot_count >= max_images:
				snap_shot_count = 0
			else:
				snap_shot_count += 1



#Function to take a snapshop image
def snap_shot(name, camera):
	camera.capture('images/'+ name +'.jpg', use_video_port=True)


start_stream()