Patent ID: 11943274
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. Apparatus for recovering a video stream from a set of bit streams and an extractor, the set of bitstreams having encoded thereinto different portions of a video picture area, the apparatus comprising a processor implemented system configured to
compile, using the extractor (20), a compiled bitstream out of the set of bitstreams by extracting, from each of the set of bitstreams, a picture portion relating to a current picture frame by parsing the respective bitstream and forming the compiled bitstream out of the extracted picture portions so that the compiled bitstream comprises a sub-picture portion for the picture portion of each of the set of bitstreams the compiled bitstream is formed of; and, decrypt a coding payload section of each subpicture portion of a subset of one or more of the subpicture portions of the compiled bitstream by using block-wise decryption by use of sequential variation of a plaintext mask and/or block-decryption key by reinitializing the sequential variation for each subpicture portion to be decrypted and finding a border of the coding payload section of each subpicture portion to be decrypted by, parsing the coding payload section of the respective subpicture portion up to a currently decrypted position and/or, deriving a length of the coding payload section of the respective subpicture portion from a header within the respective subpicture portion, and/or
using a bitstream length or pointer indication signaled within the bitstream from which the picture portion is extracted which the respective subpicture portion belongs to.