[Libav-user] Performance Optimization: 200 different Watermarks in 200 different Frames

[Marc Waesche]

Hello!

I want to let build and deliver individual encoded video clips on the 
fly from my server. There is a source video clip in which an actor is 
moving a piece of paper from the left to the right in front of the cam. 
On this piece of paper there is an image visible. And this image is 
individual. That means: A user can upload an image file to my server per 
POST and on the next website he can watch the source video clip in which 
his uploaded image is inserted in a perfect visual manner so that it 
looks like that this image is indeed printed on that white piece of paper.
Yeah, I know, this sounds to be something for Adobe After Effects or 
kind of that but there is no chance to handle such a video editing tool 
on server side and let it produce and deliver the result FAST. :-) So I 
decided to do it in kind of a primitive way. I plan to build 200 
different images on the fly and overlay 200 frames of the source video 
file. (sounds terrible I know but I found no other solution).

My question is: Is there a way to let ffmpeg set watermarks to the video 
file with dynamical changing watermark source file names depending on 
the single frames? Or is it better to build a second video clip out of 
the 200 images and merge this 2 video clips together?
Also every other new idea (for me) how my challenge could be come to a 
happy end is very welcome! :-)

Best regards from Germany
Marc