Uniquely watermarking video for attendees

Would it be possible to uniquely watermark the video sent to each attendee? The idea is that if a user shares the incoming video stream, it can be detected and traced to a given user.

Would it be possible in Video Bridge when it has the streams decrypted? This might turn into paid work.


I’m not a jitsi expert here, so I could be wrong… but:

The Jitsi server does not do any processing of the video stream. For 2 people (1-1 communications), they send streams directly to each other. For 3+ people, the server is nothing more than a relay – it receives and forwards streams, but doesn’t do any alterations.

Watermarking the live stream would require a change to the video stream that goes to each client. As the client decodes and renders each video, it would be uniquely watermarked.

Locally saved videos are a different (and easier) problem. If you have this enabled, then you effectively store a video file on your local server; this video is available after the conference ends. After the conference is over, you can post-process that however you want, including re-encoding it with a unique per-user watermark. FFmpeg makes this pretty ease (see http://ksloan.net/watermarking-videos-from-the-command-line-using-ffmpeg-filters/).

Hi @Neal, thanks for the links to ffmpeg which looks useful for watermarking whole videos.

I am a total noob with Jitsi having only come across it yesterday as a result of a request from a video production company to protect the stream that gets sent to the clients. So, the watermark needs to be added during the relaying. They reckon this is a common use case - and a requirement for them to detect not only a copy but which client has copied it. They would pay for it, I believe.