Method to trace video content processed by a decoder

A method for fingerprinting a data object A having a nominal stream format F, to provide a fingerprinted data object B, comprising a pre-fingerprinting and forensic luring process, wherein

• the pre-fingerprinting process comprises:
• determining a first set of elements of the original data object (A) each having an original value and a position,
• replacing each original value by an alternate value to create a modified data object (C) that remains syntactically correct according to the stream format F, but semantically different according to the perceptive information carried by the original data object (A), regardless which alternate value (AV) was replaced, and
• extending the modified data object (C) with at least one supplementary object (Ss) to provide a fingerprinting-ready data object (D) having the same nominal stream format F, comprising, for each element, its position and at least a first replacement value and a second replacement value;
• and
• the forensic luring process comprises:
• extracting the supplementary object from the fingerprinting-ready data object (D),
• obtaining an identifier to be associated with the fingerprinted data object (B), and
• modifying the alternate values at positions in the first set of elements, and for each element, selecting one of the replacement values based on all or part of the identifier to create the fingerprinted data object (B).