Abstract: There are provided methods and apparatus for video usability information (VUI) for scalable video coding (SVC). An apparatus includes an encoder (100) for encoding video signal data into a bitstream. The encoder specifies video user information, excluding hypothetical reference decoder parameters, in the bitstream using a high level syntax element. The video user information corresponds to a set of interoperability points in the bitstream relating to scalable video coding (340, 355).

Abstract: Syntax structures that indicate the completion of coded regions of pictures are described. For example, a syntax structure in an elementary bitstream indicates the completion of a coded region of a picture. The syntax structure can be a type of network abstraction layer unit, a type of supplemental enhancement information message or another syntax structure. For example, a media processing tool such as an encoder can detect completion of a coded region of a picture, then output, in a predefined order in an elementary bitstream, syntax structure(s) that contain the coded region as well as a different syntax structure that indicates the completion of the coded region. Another media processing tool such as a decoder can receive, in a predefined order in an elementary bitstream, syntax structure(s) that contain a coded region of a picture as well as a different syntax structure that indicates the completion of the coded region.

Abstract: Innovations in video decoding and rendering operations for inter-coded blocks in a graphics pipeline, in which at least some of the operations are performed using a graphics processing unit (“GPU”), are described. For example, a video playback tool receives encoded data for a current picture and performs operations to decode the encoded data and reconstruct the current picture. For a given inter-coded block of the current picture, a graphics primitive represents texture values as a point for processing by the GPU. The graphics primitive can have one or more attributes, including a motion vector, a block size, a display index value (indicating a location in a display buffer), and/or a residual index value (indicating a location of residual values). The operations performed by the video playback tool can include interpolation of sample values at fractional-sample offsets and motion compensation performed for inter-coded blocks in multiple passes for different block sizes.

Abstract: Innovations in encoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, according to a set of decision rules, high chroma resolution details are selectively encoded on a region-by-region basis such that increases in bit rate (due to encoding of sample values for the high chroma resolution details) happen when and where corresponding increases in chroma resolution are likely to improve quality in noticeable ways. In this way, available encoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: There are provided methods and apparatus for video usability information (VUI) for scalable video coding (SVC). An apparatus includes an encoder for encoding video signal data into a bitstream. The encoder specifies video user information, excluding hypothetical reference decoder parameters, in the bitstream using a high level syntax element. The video user information corresponds to a set of interoperability points in the bitstream relating to scalable video coding.

Abstract: Syntax structures that indicate the completion of coded regions of pictures are described. For example, a syntax structure in an elementary bitstream indicates the completion of a coded region of a picture. The syntax structure can be a type of network abstraction layer unit, a type of supplemental enhancement information message or another syntax structure. For example, a media processing tool such as an encoder can detect completion of a coded region of a picture, then output, in a predefined order in an elementary bitstream, syntax structure(s) that contain the coded region as well as a different syntax structure that indicates the completion of the coded region. Another media processing tool such as a decoder can receive, in a predefined order in an elementary bitstream, syntax structure(s) that contain a coded region of a picture as well as a different syntax structure that indicates the completion of the coded region.

Abstract: Non-limiting examples of the present disclosure describe detection of gross motion of a region of content. Gross motion of a region of content may be detected. A determination may be made as to a current quality level of the region. Based on detection of the gross motion, residual values may be generated for a progressive update of the region. The residual values are generated using the current quality level of the region as a base to determine a quantization update for a progressive update of the region at a higher quality level as compared with the current quality level of the region. Frame data for the progressive update of the region may be encoded. The frame data may comprise the residual values and motion vectors for progressive update of the region. The frame data may be transmitted for decoding. Other examples are also described.

Abstract: Innovations in video decoding and rendering operations in a graphics pipeline, in which at least some of the operations are performed using a graphics processing unit (“GPU”), are described. For example, a video playback tool aggregates texture values for intra-coded blocks of a picture in central processing unit (“CPU”) memory, then transfers the texture values for the intra-coded blocks from the CPU memory to GPU memory. The video playback tool performs operations to decode the encoded data and reconstruct the picture. For a given block (e.g., of a macroblock, coding unit) of the picture, a graphics primitive represents texture values for the given block as a point for processing by the GPU. The video playback tool uses one or more shader routines, executable by the GPU, to transfer texture values to a display buffer. In some cases, the video playback tool also performs decoding operations with the shader routines.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: A GPU loads point sprites that represent coded blocks of transform coefficients of one or more frames encoded in a bitstream and loads a transform kernel as a transform kernel texture. The GPU constructs an output frame using an inverse transform on the coded blocks of transform coefficients by transforming the point sprites with the transform kernel texture and by optionally dequantizing the point sprites. A single render pass may be used in which the rasterization formula performs the inverse transform and optionally dequantization. To preserve bandwidth, a CPU may refrain from sending the GPU at least some zero valued transform coefficients for the point sprites. Also, to reduce processing, the transform coefficients can remain in a zig-zag arrangement. The transform kernel texture used in the decoding can correspond to a modified version of the basis matrices used to encode the frame, which compensates for the zig-zag arrangement.

Abstract: Innovations are provided for encoding and/or decoding video and/or image content using transform coefficient level gradual updating. Transform coefficient level gradual updating can be applied by encoding (or decoding) different subsets of the transform coefficients for the blocks, macroblocks, or other coding unit for each of a sequence of pictures. For example, a first subset of the transform coefficients of the blocks of a first picture can be encoded with the first picture, a second subset of the transform coefficients of the blocks of a second picture can be encoded with the second picture, and so on. A decoder can reconstruct pictures with increasing quality by receiving additional subsets of the transform coefficients.

Abstract: Innovations in syntax and semantics of coded picture buffer removal delay (“CPBRD”) values potentially simplify splicing operations. For example, a video encoder sets a CPBRD value for a current picture that indicates an increment value relative to a nominal coded picture buffer removal time of a preceding picture in decoding order, regardless of whether the preceding picture has a buffering period SEI message. The encoder can signal the CPBRD value according to a single-value approach in which a flag indicates how to interpret the CPBRD value, according to a two-value approach in which another CPBRD value (having a different interpretation) is also signaled, or according to a two-value approach that uses a flag and a delta value. A corresponding video decoder receives and parses the CPBRD value for the current picture. A splicing tool can perform simple concatenation operations to splice bitstreams using the CPBRD value for the current picture.

Abstract: Innovations in encoding and decoding of video pictures in a high-resolution chroma sampling format (such as YUV 4:4:4) using a video encoder and decoder operating on coded pictures in a low-resolution chroma sampling format (such as YUV 4:2:0) are presented. For example, high chroma resolution details are selectively encoded on a region-by-region basis. Or, as another example, coded pictures that contain sample values for low chroma resolution versions of input pictures and coded pictures that contain sample values for high chroma resolution details of the input pictures are encoded as separate sub-sequences of a single sequence of coded pictures, which can facilitate effective motion compensation. In this way, available encoders and decoders operating on coded pictures in the low-resolution chroma sampling format can be effectively used to provide high chroma resolution details.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Innovations in syntax and semantics of coded picture buffer removal delay (“CPBRD”) values potentially simplify splicing operations. For example, a video encoder sets a CPBRD value for a current picture that indicates an increment value relative to a nominal coded picture buffer removal time of a preceding picture in decoding order, regardless of whether the preceding picture has a buffering period SEI message. The encoder can signal the CPBRD value according to a single-value approach in which a flag indicates how to interpret the CPBRD value, according to a two-value approach in which another CPBRD value (having a different interpretation) is also signaled, or according to a two-value approach that uses a flag and a delta value. A corresponding video decoder receives and parses the CPBRD value for the current picture. A splicing tool can perform simple concatenation operations to splice bitstreams using the CPBRD value for the current picture.

Abstract: An invention is disclosed for conducting a remote presentation session with a client that uses a web browser to conduct the session. The client previously received browser-native program code that executes within a runtime environment of the web browser. The browser-native program code instantiates a remote presentation client executing within a runtime environment of the web browser. The server generates graphics encoded according to a remote presentation protocol and sends them to the remote presentation client for display in the web browser. The client captures user input at the web browser and sends it to the remote presentation client, which encodes it with the remote presentation protocol and sends it to the server to be processed.

Abstract: Innovations in the area of prediction of block vector (“BV”) values improve encoding or decoding of blocks using intra block copy (“BC”) prediction. For example, some of the innovations relate to use of a default BV predictor with a non-zero value. Other innovations relate to use of a selected one of multiple BV predictor candidates for a current block. Still other innovations relate to use of a skip mode in which a current intra-BC-predicted block uses a predicted BV value.

Abstract: Techniques are described for performing multi-stage image classification. For example, multi-stage image classification can comprise a first classification stage and a second classification stage. The first classification stage can determine an overall classification for an input image (e.g., based on a relative entropy result calculated for the input image). The second classification stage can be performed by dividing the image into a plurality of blocks and classifying individual blocks, or groups of blocks, based on a classification model that is specific to the overall classification of the image determined in the first classification stage.

Abstract: Innovations in the area of filtering in and around high chroma resolution regions of output pictures are presented. For example, a video processing tool applies a recovery filter in a high chroma resolution region of an output picture, which compensates for anti-aliasing filtering previously performed during chroma sub-sampling, but skips application of the recovery filter in a low chroma resolution region of the output picture. Or, a video processing tool applies a deblocking filter to chroma sample values at a boundary between a low chroma resolution region and high chroma resolution region in the output picture, which can mitigate perceptible distortion at the boundary. Or, a video processing tool selectively applies a deringing filter to chroma sample values in a high chroma resolution region of the output picture, which can mitigate perceptible distortion due to low quality coding of high chroma resolution details.