Use video Proofing to add comments at specific times and locations on a video.
Video Proofing works like image/doc/weblinks Proofing:
Attach a video to a task, folder, or project. Click the Attach files icon above the description field and upload a video from your computer or from YouTube. For YouTube videos, you'll just need a video URL.
Click the attachment and begin playing the video.
Click anywhere on the video to add a comment.
To comment on specific points on the video:
Advance frame by frame: Use the arrow buttons under the video to move forward or backward by a single frame.
Jump to a specific point: Click the current time field, enter the time you want to jump to, and press Enter.
Some videos can't be played outside of YouTube. To view such a video, open it in Proofing, right-click the video, and select what you want to do: either open it in a new tab or copy the link to the video.
Use the left and right arrow buttons on your keyboard to move forward or backward by five seconds. Press Shift + arrow to move by 10 seconds.