I have searched through out the forum for ffmpeg hardcoded watermark.
I couldn't find or i'm unable to find.

All i found was this:

If you use ffmpeg for converting you can use the vhook feature ( http://ffmpeg.mplayerhq.hu/hooks.html#SEC7 ) to add image watermarks to your videos.

You will have to read the docs and work it out yourself though....post a guide if you use this way as i dont have time to look into it.
The above link in the qoute is not valid now.

If you have successfully used ffmpeg hardcoded watermark,
Pl post a step by step tutorial here.

Thank you.