Synthesia AI uses deep learning algorithms to analyze and synthesize different types of data, such as audio, video, and text, in order to create realistic digital models of people and objects. Specifically, the technology works by breaking down the original data into smaller components, or "features," which can be analyzed and manipulated by the AI algorithm.

In the case of Synthesia AI, the algorithm analyzes the visual and audio features of a person's face and body movements, as well as their voice or speech patterns. These features are then used to create a digital model of the person, which can be manipulated to say or do different things.

To create a realistic deepfake video, for example, the algorithm can take an existing video of a person and map their facial movements and speech patterns onto a different video, creating the illusion that the person is saying or doing something they did not actually do. Similarly, to create a dubbed video in a different language, the algorithm can use the original video as a reference and generate a new audio track that matches the person's lip movements.

Overall, Synthesia AI works by leveraging the power of deep learning to analyze and synthesize different types of data, creating realistic digital models that can be manipulated to produce new and interesting content. However, it is important to be aware of the potential risks and ethical concerns associated with this technology, and to develop safeguards to prevent its misuse.

To know more about how Synthesia AI works, you can view their research blog.