At Google I/O, DeepMind extends SynthID — its imperceptible watermark for AI-generated content — into video, embedding a signal across every frame of Veo output that downstream tools can detect even after editing, compression, or re-uploads. Where C2PA attaches signed metadata as a label, SynthID hides the signal inside the pixels themselves. Together they sketch the two-track provenance future every AI-filmmaking tool will eventually have to support.