问题
I'm using OpenCV 4.0 and Python 3.7 to create a timelapse video.
When constructing a VideoWriter object, the documentation says the Size argument should be a tuple.
When I give it a tuple it rejects it. When I try to replace it with something else, it won't accept it because it says the argument isn't a tuple.
When Size not a tuple:
out = cv2.VideoWriter('project.avi', 1482049860, 30, height, width)
SystemError: new style getargs format but argument is not a tuple
When I changed Size to a tuple:
out = cv2.VideoWriter('project.avi', 1482049860, 30, (height, width))
TypeError: must be real number, not tuple
I just want to create a simple cv2.VideoWriter object.
回答1:
I was trying to take the height and width from an uploaded video using:
width = cap.get(cv2.CAP_PROP_FRAME_WIDTH)
height = cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
I changed it to:
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
Now I don't get that error. It doesn't work yet as a whole, but that particular error isn't there anymore.
回答2:
I encountered the same situation, here is my solution:
It seems like cv2.VideoWriter() tend to "drop" the argument that has the wrong type. In my case I used pathlib.Path for the first output file name argument,like:
p=Path('project.avi')
out = cv2.VideoWriter(p, 1482049860, 30, frameSize=(height, width))
But cv2.VideoWriter() only accepts str, so it "dropped" the p, and it received:
out = cv2.VideoWriter(1482049860, 30, frameSize=(height, width))
Then (height, width) is actually at the fps position, it requires real but gets tuple
So I suggest you check every argument to make sure they have the right type.
回答3:
Try updating to opencv v4.1.0. Not seeing that issue there.
Else try:
out = cv2.VideoWriter('project.avi', 1482049860, 30, frameSize=(height, width))
来源：https://stackoverflow.com/questions/56370802/cv2-videowriter-asks-for-a-tuple-as-size-argument-then-rejects-it