为什么我的OpenCV视频拒绝写入磁盘？

So I am starting to get very confused by the openCV libraries ability to write out video to disk, because even the openCV documentation is not terribly clear as to how the video actually gets written in this case. The code I have below seems to collect the data just fine but the video file it tries to write has no data in it. All I want to do is take a video that I know I can, change the data within it to a ramp between 0 and 255, and then write that data back out to disk. However, the final I/O step is not cooperating for reasons I don't understand. Can anyone help? Find the code below:So I am starting to get very confused by the op