Systems and Methods for Protecting Elementary Bitstreams Incorporating Independently Encoded Tiles
AssigneeDivx, LLC
InventorsJason A. Braness, William David Amidei, Mayur Srinivasan
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Abstract
Systems and methods for partial frame encryption in accordance with embodiments of the invention are disclosed. In one embodiment, the method receives a video bitstream that includes several frames, each frame including several independently encoded compression units within the frame, encrypts a portion of each of several compression units in several frames, and generates an output bitstream that includes the several independently encoded compression units including the encrypted portions of the compression units.
Claims13
A method for decrypting and decoding encrypted video, the method comprising:
- receiving at least a portion of a container file that contains encrypted video comprising a plurality of encoded frames of video and encryption-related metadata, where:
- each of the plurality of encoded frames of video comprises a plurality of tiles that partition the encoded frame of video into rectangular regions and are independently encoded;
- and
- the plurality of encoded frames of video comprises a partially encrypted frame of video that is encrypted using partial frame encryption such that each of the plurality of tiles within the partially encrypted frame of video includes at least one portion that is protected using encryption and at least one portion that is not encrypted;
- locating encryption-related metadata from the container file, where the located encryption-related metadata identifies portions of the partially encrypted frame for decryption prior to decoding the plurality of tiles within the partially encrypted frame;
- decrypting the portions of the partially encrypted frame identified by the located encryption-related metadata to obtain a decrypted frame;
- and
- decoding the decrypted frame using information from a header associated with the frame to determine the locations of the plurality of tiles.
A method for decrypting and decoding encrypted video, the method comprising:
- receiving at least a portion of a container file that contains encrypted video comprising a plurality of encoded frames of video and encryption-related metadata, where:
- each of the plurality of encoded frames of video comprises a plurality of tiles that partition the encoded frame of video into rectangular regions and are independently encoded;
- and
- the plurality of encoded frames of video comprises a partially encrypted frame of video that is encrypted using partial frame encryption such that each of the plurality of tiles within the partially encrypted frame of video includes at least one portion that is protected using encryption and at least one portion that is not encrypted, where the locations of the plurality of tiles are determined using information from a header associated with the frame;
- locating encryption-related metadata from the container file, where the located encryption-related metadata are contained in a separate DRM track at least a portion of which is located within the at least one portion of the container file, and identifies portions of the partially encrypted frame for decryption prior to decoding the plurality of tiles within the partially encrypted frame;
- decrypting the portions of the partially encrypted frame identified by the located encryption-related metadata to obtain a decrypted frame, where decrypting the portions of the partially encrypted frame comprises decrypting each of the at least one portion that is protected using encryption within each of the plurality of tiles within the partially encrypted frame of video using an AES cipher;
- decoding the decrypted frame using information from the header associated with the frame;
- and
- displaying the decoded frame.
Dependencies are inferred from the claim text.