my_Cameo.py文件
import cv2
import numpy
import time
class CaptureManager(object):
def __init__(self, capture, previewWindowManger=None, shouldMirrorPreview=False):
self.previewWindowManager = previewWindowManger
self.shouldMirrorPreview = shouldMirrorPreview
self._capture = capture
self._channel = 0
self._enteredFrame = False
self._frame = None
self._imageFilename = None
self._videoFilename = None
self._videoEncoding = None
self._videoWriter = None
self._startTime = None
self._framesElapsed = int(0)
self._fpsEstimate = None
@property
def channel(self):
return self._channel
@channel.setter
def chanel(self, value):
if self._channel != value:
self._channel = value
self._frame = None
@property
def frame(self):
if self._enteredFrame and self._frame is None:
_, self._frame = self._capture.retrieve()
return self._frame
@property
def isWritingImage(self):
return self._imageFilename is not None
@property
def isWritingVideo(self):
return self._videoFilename is not None
def writeImage(self, filename):
"""Write the next exited frame to an image file."""
self._imageFilename = filename
def startWritingVideo(self, filename, encoding= \
cv2.VideoWriter_fourcc('I', '4', '2', '0')):
"""Start writing exited frames to a video file."""
self._videoFilename = filename
self._videoEncoding = encoding
def stopWritingVideo(self):
"""Stop writing exited frames to a video file."""
self._videoFilename = None
self._videoEncoding = None
self._videoWriter = None
def _writeVideoFrame(self):
if not self.isWritingVideo:
return
if self._videoWriter is None:
fps = self._capture.get(cv2.CAP_PROP_FPS)
if fps == 0:
# The capture's FPS is unknown so use an estimate.
if self._framesElapsed < 20:
# Wait until more farmes elapse so that the estimate is more stable.
return
else:
fps = self._fpsEstimate
size = (int(self._capture.get(cv2.CAP_PROP_FRAME_WIDTH)),
int(self._capture.get(cv2.CAP_PROP_FRAME_HEIGHT)))
self._videoWriter = cv2.VideoWriter(self._videoFilename,
self._videoEncoding,
fps,
size)
self._videoWriter.write(self._frame)
def enterFrame(self):
"""Capture the next frame, if any"""
# But first, check that any previous frame was exited.
assert not self._enteredFrame, 'previous enterFrame() had no matching exitFrame()'
if self._capture is not None:
self._enteredFrame = self._capture.grab()
def exitFrame(self):
"""Draw to the window. Write to files. Release the frame"""
# Check whether any grabbed frame is retrievable.
# The getter may retrieve and cache the frame.
if self.frame is None:
self._enteredFrame = False
return
# Update the FPS estimate and related variables.
if self._framesElapsed == 0:
self._startTime = time.time()
else:
timeElapsed = time.time() - self._startTime
self._fpsEstimate = self._framesElapsed / timeElapsed
self._framesElapsed += 1
# Draw to the window, if any.
if self.previewWindowManager is not None:
if self.shouldMirrorPreview:
mirroredFrame = numpy.fliplr(self._frame).copy()
self.previewWindowManager.show(mirroredFrame)
else:
self.previewWindowManager.show(self._frame)
# Write to the image file, if any.
if self.isWritingImage:
cv2.imwrite(self._imageFilename, self._frame)
self._imageFilename = None
# Write to the video file, if any.
self._writeVideoFrame()
# Release the frame.
self._frame = None
self._enteredFrame = False
class WindowManager(object):
def __init__(self, windowName, keypressCallback=None):
self.keypressCallback = keypressCallback
self._windowName = windowName
self._isWindowCreated = False
@property
def isWindowCreated(self):
return self._isWindowCreated
def createWindow(self):
cv2.namedWindow(self._windowName)
self._isWindowCreated = True
def show(self, frame):
cv2.imshow(self._windowName, frame)
def destroyWindow(self):
cv2.destroyWindow(self._windowName)
self._isWindowCreated = False
def processEvents(self):
keycode = cv2.waitKey(1)
if self.keypressCallback is not None and keycode != -1:
# Discard any non-ASCII info encoded by GTK.
keycode &= 0xFF
self.keypressCallback(keycode)
程序运行文件：
mport cv2
from my_Cameo import WindowManager, CaptureManager
class Cameo(object):
def __init__(self):
self._windowManager = WindowManager('Cameo', self.onKeypress)
self._captureManager = CaptureManager(cv2.VideoCapture(0 + cv2.CAP_DSHOW),
self._windowManager, True)
def run(self):
"""Run the main loop."""
self._windowManager.createWindow()
while self._windowManager.isWindowCreated:
self._captureManager.enterFrame()
frame = self._captureManager.frame
# TODO:Filter the frame (Chapter 3).
self._captureManager.exitFrame()
self._windowManager.processEvents()
def onKeypress(self, keycode):
"""Handle a keypress."""
if keycode == 32: # space
self._captureManager.writeImage('screenshot.png')
elif keycode == 9: # tab
if not self._captureManager.isWritingVideo:
self._captureManager.startWritingVideo('screencast.avi')
else:
self._captureManager.stopWritingVideo()
elif keycode == 27: # escape
self._windowManager.destroyWindow()
if __name__ == "__main__":
Cameo().run()
想问一下是代码的问题还是我摄像头硬件的问题？
