On 26/05/2024 14.18, Bart Westenenk wrote:
Hello all,

I want to alter the motion vectors of B and P frames in a H.264 video. The point of doing this is watermarking / steganography, the goal is to change the motion vectors' width / height based on the watermark.

Motion vectors don't work like you're visualizing, Bart. Motion vectors move macroblocks measuring 16x16 pixels from a reference picture to the current picture, then apply individual pixel corrections to finish the destination picture's macroblock. It's more complex than that because the destination macroblock will not be on macroblock boundaries, so the moved macroblock needs to be merged into the destination's macroblock geometry.

Your plan to somehow use motion vectors to watermark is not feasible.

_______________________________________________
ffmpeg-user mailing list
[email protected]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user

To unsubscribe, visit link above, or email
[email protected] with subject "unsubscribe".

Reply via email to