GE Video Compression, LLC

Embodiments are described which exploit a finding, according to which a higher compression rate or better rate/distortion ratio may be achieved by adopting or predicting second coding parameters used for encoding a second view of the multi-view signal from first coding parameters used in encoding a first view of the multi-view signal. In other words, the inventors found out that the redundancies between views of a multi-view signal are not restricted to the views themselves, such as the video information thereof, but that the coding parameters in parallelly encoding these views show similarities which may be exploited in order to further improve the coding rate.

Scalable coding concepts are described. One aspect improves parallel decoding of inter-dependent layers of a multi-layer video data stream by introducing a long-term syntax element structure for guaranteeing that during a predetermined time period the pictures of the dependent layer are subdivided so that borders of the spatial segments of the pictures of the second layer and the spatial segments of the first layer overlay. Another aspect concerns upsampling from base layer to enhancement layer. Another aspect introduces a long-term syntax element structure allowing the decoder to determine the inter-layer offset for a predetermined time period. Another aspect introduces a type indicator field changing a way a layer indicator field within the NAL unit headers is to be interpreted. Another aspect allows different codecs/standards to be used for the different layers. Another aspect concerns a syntax element structure which indicates the inter-layer offset in units of the base layer blocks.

A decoder for decoding a data stream into which media data is coded has a mode switch configured to activate a low-complexity mode or a high-efficiency mode depending on the data stream, an entropy decoding engine configured to retrieve each symbol of a sequence of symbols by entropy decoding using a selected one of a plurality of entropy decoding schemes, a desymbolizer configured to desymbolize the sequence of symbols to obtain a sequence of syntax elements, a reconstructor configured to reconstruct the media data based on the sequence of syntax elements, selection depending on the activated low-complexity mode or the high-efficiency mode. In another aspect, a desymbolizer is configured to perform desymbolization such that the control parameter varies in accordance with the data stream at a first rate in case of the high-efficiency mode being activated and the control parameter is constant irrespective of the data stream or changes depending on the data stream, but at a second lower rate in case of the low-complexity mode being activated.

A better compromise between encoding complexity and achievable rate distortion ratio, and/or to achieve a better rate distortion ratio is achieved by using multitree sub-divisioning not only in order to subdivide a continuous area, namely the sample array, into leaf regions, but using the intermediate regions also to share coding parameters among the corresponding collocated leaf blocks. By this measure, coding procedures performed in tiles—leaf regions—locally, may be associated with coding parameters individually without having to, however, explicitly transmit the whole coding parameters for each leaf region separately. Rather, similarities may effectively exploited by using the multitree subdivision.

The coding efficiency of a multi-component picture or video coding concept is improved by reconstructing a third component signal relating to a third component of the multi-component video using inter-component prediction from both a reconstructed first component signal and a reconstructed second component signal.

A favorable merging or grouping of simply connected regions into which the array of information samples is sub-divided, is coded with a reduced amount of data. To this end, a predetermined relative locational relationship is defined enabling an identifying, for a predetermined simply connected region, of simply connected regions within the plurality of simply connected regions which have the predetermined relative locational relationship to the predetermined simply connected region. Namely, if the number is zero, a merge indicator for the predetermined simply connected region may be absent within the data stream. In other embodiments, spatial sub-division is performed depending on a first subset of syntax elements, followed by combining spatially neighboring simply connected regions depending on a second subset of syntax elements, to obtain an intermediate sub-division.

Wedgelet separation lines of neighboring blocks are predicted from each other by aligning the wedgelet separation lines of such neighboring blocks to each other, thereby reducing the side information coding rate that may be used.

An apparatus ( 200 ) for receiving an input video data stream according to an embodiment is provided. The input video data stream has a video encoded thereinto. The apparatus ( 200 ) is configured to generate an output video data stream from the input video data stream.

A better rate distortion ratio is achieved by making interrelationships between coding parameters of different planes available for exploitation for the aim of redundancy reduction despite the additional overhead resulting from the need to signal the inter-plane prediction information to the decoder. In particular, the decision to use inter plane prediction or not may be performed for a plurality of planes individually. Additionally or alternatively, the decision may be done on a block basis considering one secondary plane.

An interleaved multi-layered video data stream with interleaved decoding units of different layers is provided with further timing control information in addition to the timing control information reflecting the interleaved decoding unit arrangement. The additional timing control information pertains to either a fallback position according to which all decoding units of an access unit are treated at the decoded buffer access unit-wise, or a fallback position according to which an intermediate procedure is used: the interleaving of the DUs of different layers is reversed according to the additionally sent timing control information, thereby enabling a DU-wise treatment at the decoder's buffer, however, with no interleaving of decoding units relating to different layers. Both fallback positions may be present concurrently. Various advantageous embodiments and alternatives are the subject of the various claims attached herewith.