我正在使用Raspicam在raspberry pi上录制视频，并使用以下脚本保存视频缓冲区以及每帧的时间戳：
import io
import time
import datetime as dt
from picamera import PiCamera
from threading import Thread, Event
from queue import Queue, Empty
import sys, getopt
import argparse
WIDTH = 640
HEIGHT = 480
FRAMERATE = 30
VIDEO_STABILIZATION = True
EXPOSURE_MODE = 'night'
BRIGHTNESS = 55
CONTRAST = 50
SHARPNESS = 50
SATURATION = 30
AWB_MODE = 'off'
AWB_GAINS = 1.4
VIDEO_FILE_NAME = "cam3_output_" + str(dt.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")) + ".h264"
TIMESTAMP_FILE_NAME = "cam3_timestamp_" + str(dt.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")) + ".csv"
runningTimeHours, runningTimeMinutes, runningTimeSeconds = 0,0,0
class VideoOutput(Thread):
def __init__(self, filename):
super(VideoOutput, self).__init__()
self._output = io.open(filename, 'wb', buffering=0)
self._event = Event()
self._queue = Queue()
self.start()
def write(self, buf):
self._queue.put(buf)
return len(buf)
def run(self):
while not self._event.wait(0):
try:
buf = self._queue.get(timeout=0.1)
except Empty:
pass
else:
self._output.write(buf)
self._queue.task_done()
def flush(self):
self._queue.join()
self._output.flush()
def close(self):
self._event.set()
self.join()
self._output.close()
@property
def name(self):
return self._output.name
class TimestampOutput(object):
def __init__(self, camera, video_filename, timestamp_filename):
self.camera = camera
self._video = VideoOutput(video_filename)
self._timestampFile = timestamp_filename
self._timestamps = []
def write(self, buf):
if self.camera.frame.complete and self.camera.frame.timestamp is not None:
self._timestamps.append((
self.camera.frame.timestamp,
self.camera.dateTime,
self.camera.clockRealTime
))
return self._video.write(buf)
def flush(self):
with io.open(self._timestampFile, 'w') as f:
f.write('GPU Times, time.time(), clock_realtime\n')
for entry in self._timestamps:
f.write('%d,%f,%f\n' % entry)
def close(self):
self._video.close()
parser = argparse.ArgumentParser()
parser.add_argument("-hr", "--hours", type=int, help="number of hours to record")
parser.add_argument("-m", "--minutes", type=int, help="number of minutes to record")
parser.add_argument("-s", "--seconds", type=int, help="number of seconds to record")
args = parser.parse_args()
runningTimeHours = float(args.hours)
runningTimeMinutes = float(args.minutes)
runningTimeSeconds = float(args.seconds)
totalRunningTime = runningTimeHours*60*60 + runningTimeMinutes*60 + runningTimeSeconds
with PiCamera(resolution=(WIDTH, HEIGHT), framerate=FRAMERATE) as camera:
camera.brightness = BRIGHTNESS
camera.contrast = CONTRAST
camera.sharpness = SHARPNESS
camera.video_stabilization = VIDEO_STABILIZATION
camera.hflip = False
camera.vflip = False
#warm-up time to camera to set its initial settings
time.sleep(2)
camera.exposure_mode = EXPOSURE_MODE
camera.awb_mode = AWB_MODE
camera.awb_gains = AWB_GAINS
#time to let camera change parameters according to exposure and AWB
time.sleep(2)
#switch off the exposure since the camera has been set now
camera.exposure_mode = 'off'
output = TimestampOutput(camera, VIDEO_FILE_NAME, TIMESTAMP_FILE_NAME)
try:
camera.start_preview()
# Construct an instance of our custom output splitter with a filename and a connected socket
print('Starting Recording')
camera.start_recording(output, format='h264')
print('Started Recording')
camera.wait_recording(totalRunningTime)
camera.stop_recording()
camera.stop_preview()
print('Recording Stopped')
except KeyboardInterrupt:
print('Closing Output File')
sys.exit(2)
finally:
output.close()
print('Output File Closed')
同时进行此录制时，我正在向GPIO引脚4发送TTL脉冲。我现在想在上面的脚本中添加一个代码块，以便对于每个收到的TTL HIGH输入，我可以将相应的时间值保存在文件。
这样的事情没有相机运行脚本：
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM)
pinTTL = 4
GPIO.setup(pinTTL, GPIO.IN)
while True:
count = 0
inputState = GPIO.input(pinTTL)
if inputState == True:
print 'HIGH', time.time()
GPIO.cleanup()
针脚状态设置为HIGH的上述脚本保存了time.time（）值。
基本上我想整合上面提到的2个脚本。我尝试创建另一个线程以根据TTL输入节省time.time（）值，就像我保存视频缓冲区但无法使其工作一样。
感谢您的帮助。
答案 0 :(得分：0)
下面的脚本适合我。 add_event_callback 会自动创建一个单独的线程来处理GPIO事件更改。这允许将任何函数作为单独的线程调用，并同时记录TTL时间映射。
#import the necessary modules
import io
import time
import datetime as dt
from picamera import PiCamera
from threading import Thread, Event
from queue import Queue, Empty
import sys, getopt
import argparse
import RPi.GPIO as GPIO
#camera parameter setting
WIDTH = 640
HEIGHT = 480
FRAMERATE = 30
VIDEO_STABILIZATION = True
EXPOSURE_MODE = 'night'
BRIGHTNESS = 55
CONTRAST = 50
SHARPNESS = 50
SATURATION = 30
AWB_MODE = 'off'
AWB_GAINS = 1.4
#video, timestamps and ttl file name
VIDEO_FILE_NAME = "cam4_output_" + str(dt.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")) + ".h264"
TIMESTAMP_FILE_NAME = "cam4_timestamp_" + str(dt.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")) + ".csv"
TTL_FILE_NAME = "cam4_ttl_" + str(dt.datetime.now().strftime("%Y-%m-%d_%H-%M-%S")) + ".csv"
#running time variable intialization
runningTimeHours, runningTimeMinutes, runningTimeSeconds = 0,0,0
#set raspberry pi board layout to BCM
GPIO.setmode(GPIO.BCM)
#pin number to receive TTL input
pinTTL = 4
#set the pin as input pin
GPIO.setup(pinTTL, GPIO.IN)
#add event detection script to GPIO pin
GPIO.add_event_detect(pinTTL, GPIO.BOTH)
#video output thread to save video file
class VideoOutput(Thread):
def __init__(self, filename):
super(VideoOutput, self).__init__()
self._output = io.open(filename, 'wb', buffering=0)
self._event = Event()
self._queue = Queue()
self.start()
def write(self, buf):
self._queue.put(buf)
return len(buf)
def run(self):
while not self._event.wait(0):
try:
buf = self._queue.get(timeout=0.1)
except Empty:
pass
else:
self._output.write(buf)
self._queue.task_done()
def flush(self):
self._queue.join()
self._output.flush()
def close(self):
self._event.set()
self.join()
self._output.close()
@property
def name(self):
return self._output.name
#timestamp output object to save timestamps according to pi and TTL inputs received and write to file
class TimestampOutput(object):
def __init__(self, camera, video_filename, timestamp_filename, ttl_filename):
self.camera = camera
self._video = VideoOutput(video_filename)
self._timestampFile = timestamp_filename
self._ttlFile = ttl_filename
self._timestamps = []
self._ttlTimestamps = []
def ttlTimestampsWrite(self, input_pin):
try:
inputState = GPIO.input(input_pin)
self._ttlTimestamps.append((inputState, self.camera.frame.timestamp, self.camera.dateTime, self.camera.clockRealTime))
print(self.camera.frame.timestamp)
except Exception as e:
print(str(e))
pass
def write(self, buf):
if self.camera.frame.complete and self.camera.frame.timestamp is not None:
self._timestamps.append((
self.camera.frame.timestamp,
self.camera.dateTime,
self.camera.clockRealTime
))
return self._video.write(buf)
def flush(self):
with io.open(self._timestampFile, 'w') as f:
f.write('GPU Times, time.time(), clock_realtime\n')
for entry in self._timestamps:
f.write('%d,%f,%f\n' % entry)
with io.open(self._ttlFile, 'w') as f:
f.write('Input State, GPU Times, time.time(), clock_realtime\n')
for entry in self._ttlTimestamps:
f.write('%f,%f,%f,%f\n' % entry)
def close(self):
self._video.close()
parser = argparse.ArgumentParser()
parser.add_argument("-hr", "--hours", type=int, help="number of hours to record")
parser.add_argument("-m", "--minutes", type=int, help="number of minutes to record")
parser.add_argument("-s", "--seconds", type=int, help="number of seconds to record")
args = parser.parse_args()
runningTimeHours = float(args.hours)
runningTimeMinutes = float(args.minutes)
runningTimeSeconds = float(args.seconds)
totalRunningTime = runningTimeHours*60*60 + runningTimeMinutes*60 + runningTimeSeconds
with PiCamera(resolution=(WIDTH, HEIGHT), framerate=FRAMERATE) as camera:
camera.brightness = BRIGHTNESS
camera.contrast = CONTRAST
camera.sharpness = SHARPNESS
camera.video_stabilization = VIDEO_STABILIZATION
camera.hflip = False
camera.vflip = False
#warm-up time to camera to set its initial settings
time.sleep(2)
camera.exposure_mode = EXPOSURE_MODE
camera.awb_mode = AWB_MODE
camera.awb_gains = AWB_GAINS
#time to let camera change parameters according to exposure and AWB
time.sleep(2)
#switch off the exposure since the camera has been set now
camera.exposure_mode = 'off'
output = TimestampOutput(camera, VIDEO_FILE_NAME, TIMESTAMP_FILE_NAME, TTL_FILE_NAME)
GPIO.add_event_callback(pinTTL, output.ttlTimestampsWrite)
try:
camera.start_preview()
# Construct an instance of our custom output splitter with a filename and a connected socket
print('Starting Recording')
camera.start_recording(output, format='h264')
print('Started Recording')
camera.wait_recording(totalRunningTime)
camera.stop_recording()
camera.stop_preview()
print('Recording Stopped')
except KeyboardInterrupt:
print('Closing Output File')
sys.exit(2)
except:
output.close()
print('exception! output file closed')
finally:
output.close()
print('Output File Closed')