摘要:
Adaptive variable length coding techniques may be used for entropy coding of residual block coefficients produced by predictive video coding. The techniques may be applied to schemes that code positions of nonzero transform coefficients using zero runs. Coding parameters such as end of block (EOB) shift and VLC codebook selection tables may be maintained as internal states, instead of sending them with coded video slice data. Table entries may be periodically updated based on statistics collected during a coding pass. A special EOB shift table may adapt the position of a special EOB symbol in a symbol set to probability of significant coefficients with magnitude greater than one for a coding condition, such as a coding cycle. Chroma blocks may be coded independently of luma blocks using separate EOB shift, special EOB shift, and VLC codebook selection tables.
摘要:
The disclosure is directed to video coding techniques that support spatial scalability using a generalized fine granularity scalability (FGS) approach. Various degrees of spatial scalability can be achieved by sending spatially scalable enhancement layers in a generalized FGS format. Spatially scalable enhancement bitstreams can be arbitrarily truncated to conform to network conditions, channel conditions and/or decoder capabilities. Coding coefficients and syntax elements for spatial scalability can be embedded in a generalized FGS format. For good network or channel conditions, and/or enhanced decoder capabilities, additional bits received via one or more enhancement layers permit encoded video to be reconstructed with increased spatial resolution and continuously improved video quality across different spatial resolutions. The techniques permit spatial scalability layers to be coded as FGS layers, rather than discrete layers, permitting arbitrary scalability. The techniques may include features to curb error propagation that may otherwise arise due to partial decoding.
摘要:
Adaptive variable length coding techniques may be used for entropy coding of residual block coefficients produced by predictive video coding. The techniques may be applied to schemes that code positions of nonzero transform coefficients using zero runs. Coding parameters such as end of block (EOB) shift and VLC codebook selection tables may be maintained as internal states, instead of sending them with coded video slice data. Table entries may be periodically updated based on statistics collected during a coding pass. A special EOB shift table may adapt the position of a special EOB symbol in a symbol set to probability of significant coefficients with magnitude greater than one for a coding condition, such as a coding cycle. Chroma blocks may be coded independently of luma blocks using separate EOB shift, special EOB shift, and VLC codebook selection tables.
摘要:
The disclosure describes FGS video coding techniques that use cycle-aligned fragments (CAFs). The techniques may perform cycle-based coding of FGS video data block coefficients and syntax elements, and encapsulate cycles in fragments for transmission. The fragments may be cycle-aligned such that a start of a payload of each of the fragments substantially coincides with a start of one of the cycles. In this manner, cycles can be readily accessed via individual fragments. Some cycles may be controlled with a vector mode to scan to a predefined position within a block before moving to another block. In this manner, the number of cycles can be reduced, reducing the number of fragments and associated overhead. The CAFs may be entropy coded independently of one another so that each fragment may be readily accessed and decoded without waiting for decoding of other fragments. Independent entropy coding may permit parallel decoding and simultaneous processing of fragments.
摘要:
This disclosure describes techniques for coding information in a scalable video coding (SVC) scheme that supports spatial scalability. In one example, a method for coding video data with spatial scalability comprises upsampling base layer residual video data to a spatial resolution of enhancement layer residual video data, and coding the enhancement layer residual video data based on the upsampled base layer residual video data. In accordance with this disclosure, upsampling base layer residual video data includes interpolating values for one or more pixel locations of the upsampled base layer residual video data that correspond to locations between different base layer residual video data blocks.
摘要:
A method for decoding significance coefficients in an encoded video sequence is described. An encoded video bitstream is received. Codebook table information is retrieved from the bitstream. Significance symbols are decoded using the retrieved codebook table information. Significance coefficients are decoded using the significance symbols. A plurality of transform coefficients is dequantized. An inverse transform is applied to a residual signal. A video sequence is constructed. A method for coding significance coefficients in a video sequence is also described.
摘要:
This disclosure describes techniques for coding information in a scalable video coding (SVC) scheme that supports spatial scalability. In one example, a method for coding video data with spatial scalability comprises upsampling base layer residual video data to a spatial resolution of enhancement layer residual video data, and coding the enhancement layer residual video data based on the upsampled base layer residual video data. In accordance with this disclosure, upsampling base layer residual video data includes interpolating values for one or more pixel locations of the upsampled base layer residual video data that correspond to locations between different base layer residual video data blocks.
摘要:
A method for decoding significance coefficients in an encoded video sequence is described. An encoded video bitstream is received. Codebook table information is retrieved from the bitstream. Significance symbols are decoded using the retrieved codebook table information. Significance coefficients are decoded using the significance symbols. A plurality of transform coefficients is dequantized. An inverse transform is applied to a residual signal. A video sequence is constructed. A method for coding significance coefficients in a video sequence is also described.
摘要:
This disclosure is directed to video coding techniques that support normal single layer video coding, or scalable video coding with features such as signal-to-noise ratio (SNR) scalability and spatial scalability. A video coding device may implement these techniques in a video decoder that includes a motion compensation module and a filter. The motion compensation module decodes a prediction frame from a digital video signal, wherein the motion compensation module determines each block of the inter-coded frame from motion vectors encoded in the digital video signal. The filter adaptively filters one or more of the inter-coded blocks based on a signal either encoded or inferred from the digital video signal. In some instances, the video decoder may adaptively apply different filter functions, one in the horizontal and another in the vertical direction, based on the signal. By implementing these techniques, the video decoder may increase the visual quality of the resulting decoded digital video signal while reducing complexity.
摘要:
A method for decoding significance coefficients in an encoded video sequence is described. An encoded video bitstream is received. Codebook table information is retrieved from the bitstream. Significance symbols are decoded using the retrieved codebook table information. Significance coefficients are decoded using the significance symbols. A plurality of transform coefficients is dequantized. An inverse transform is applied to a residual signal. A video sequence is constructed. A method for coding significance coefficients in a video sequence is also described.