Yes, they are. You can read more about it here:
vk.com/wall-2158488_458564 (for now only available in Russian).
Please note that videos start getting processed immediately after upload. A video’s resolution on the website increases gradually, so at first, the video will be available in low quality, but will increase in quality as time goes on. After uploading the video, you’ll have to wait about 10 to 15 minutes as processing can take a long time if the video is large.