I have some videos with the extra lines and bars on the top/bottom or the left/right sides. Had these been photos, I would have easily cropped them but I had very limited choice since these were video files.
I came across a free tool called Avidemux, using which you can crop videos easily and remove black bars/lines at the edges of the video. All you have to do is, download and install the tool which is supported on Windows, Linux and Mac.
After you have installed the files, load the video file using the Open menu. Go to Video tab, load the codec so that your file becomes readable like MPEG-4 XVID. Click on the Filters button after that as this is where you will find the Crop button available.
Now you can provide the pixels in the top, bottom, left and right fields to have the video cropped. This won’t be difficult as you would be able to see the preview of the crop being done right below so that you can make proper adjustments. Click OK to save the changes.
After your video has been cropped, you can save the final image by selecting the save as option and selecting the proper output format.