Ok so if you want your FLV files to have a watermark hardcoded onto them then this guide should help you. You might want this feature if you offer FLV files for download ( http://forums.buyscripts.in/viewtopic.php?t=1438 ) and want to keep your site URL on the video or if you want to make sure no one is removing the watermark from the embeded code.
You have 2 choices depending on what you use to convert you videos. I use mencoder as it seems to have better quaility results and is default converter on vshare, however if you use ffmpeg you have a better option.
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.
If you use mencoder for converting it has a feature that is supposed to add image watermarks called bmov, however from my research it doesn't work great and no one knows how to use it. So for mencoder i just used the subtitler feature which lets me have a text watermark pop up with my site URL when i want and for how long i want.
Here is how to do it, first of all you need to create your watermark text file (subs file).
just open up a text editor and paste this into it.
the code above will after 5 seconds of watching the video display "mysite.com" on the video for 15 seconds and then disapear. Edit it to display how you want, more info can be found here http://en.wikipedia.org/wiki/.srt
00:00:05,000 --> 00:00:20,000
save the text file as watermark.srt and upload it to your include/settings/ directory.
Then open up include/settings/video_conversion.php with a text editor.
change the mencoder line so it looks like this
Remember to change the /home/USER/public_html to your path to vshare.
$cmd_mencoder = "$config[mencoder] '$video_src' -o $video_flv -of lavf -oac mp3lame -lameopts abr:br=56 -ovc lavc -lavcopts vcodec=flv:vbitrate=500:mbd=2:mv0:trell:v4mv:cbp:last_pred=3 -srate 22050 -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames -sub /home/USER/public_html/include/settings/watermark.srt -subpos 98";
The -subpos 98 bit puts the watermark 98% down from the top of the video....so it would be right at the bottom....you could change it to -subpos 2 if you wanted the watermark at the top of the video.
And thats it....when your video is converted you should have a hardcoded text watermark on your video
You should also be able to change the font, size, colour, width position etc but i have not had time to look into that yet.