Media decoder and a decoding method allowing for the media decoder to be traced

摘要

The present invention aims to overcome drawbacks of conventional content tracing methods requiring re-processing the content before its broadcast with a significant side channel transmission i.e. extra processing, storage and/or bandwidth at the distribution side, or alternately a complex signal processing implementation at the receiver side that has to be protected against hackers attacks. An efficient system and method consists of tracing and uniquely identifying decoders of a video stream wherein the decoders implement at least one variant of a standard image decompression algorithm and wherein the resulting decompressed image approximation varies according to the decoders' identifier.

主权项

1. A decoder for decoding video compressed according to a first image compression algorithm to yield a video reconstruction output; the decoder comprising:
a decompression module configured to decompress the compressed video; wherein the decompression module is configured to apply a first image decompression algorithm which matches, the first image compression algorithm or a second image decompression algorithm which does not match the first image compression algorithm, and to selectively switch between the first and second image decompression algorithms depending on a unique identifier with which the decoder is associated; the video reconstruction output thereby exhibiting the selective switching between the first and second image decompression algorithms in dependence on the unique identifier, which allows for the decoder associated with the unique identifier to be traced.