Creating a video from a set of frames

I'm trying to create a video (say a .mp4 file) from the set of frames that I'll collect during gameplay. This is not as same as Video recording, i.e, I don't want each frame in the video but maybe every 10th frame or every 100th frame or every nth frame I don't know the value of n here. I want to collect some frames captured at regular interval and make a video file using these frames. Is this possible yet in Unity ? If yes, how ? If no, any pointers on where should I be looking at to write a plugin to achieve this ? Thanks in advance !