Abstract: Methods and Systems disclosed to counteract spatial distortions introduced by imaging processes of multi-directional video frames, where objects may be projected to spherical or equirectangular representations. Techniques provided to invert the spatial distortions in video frames used as reference picture data in predictive coding, by spatially transforming the image content of the reference picture data before this image content is being used for the prediction of input video data in prediction-based coders and decoders.

Abstract: Techniques are disclosed for overcoming communication lag between interactive operations among devices in a streaming session. According to the techniques, a first device streaming video content to a second device and an annotation is entered to a first frame being displayed at the second device, which is communicated back to the first device. Responsive to a communication that identifies the annotation, a first device may identify an element of video content from the first frame to which the annotation applies and determine whether the identified element is present in a second frame of video content currently displayed at the first terminal. If so, the first device may display the annotation with the second frame in a location where the identified element is present. If not, the first device may display the annotation via an alternate technique.

Abstract: Techniques presented herein provide an improved relay user experience and improved management of scarce computing and network resources as the number of relay endpoints increases. A sourcing endpoint device may generate a media feed, such as video and/or audio feed, representing contribution from a conference participant. The sourcing endpoint device may generate a priority value for the media feed, and the priority value may be transmitted to other members of the relay along with the input feed. Priority values of the different relay participants may be used by other devices, for example, intermediate servers or receiving endpoint devices, to manage aspects of the relay. For example, a relay server may prune streams from select endpoint devices based on relative priority values received from those devices. Alternatively, receiving endpoint devices may alter presentation of received feeds based on their associated priority values.

Abstract: Techniques are presented for managing for visual prominence of participants in a video conference, including conferences where participants communicate visually, such as with sign language. According to these techniques, a visual prominence indication of a participant in a video conference may be estimated, a video stream of the participant may be encoded, and the encoded video stream may be transmitted along with an indication of the estimated visual prominence to a receiving device in the video conference.

Abstract: Techniques are disclosed for coding video data predictively based on predictions made from spherical-domain projections of input pictures to be coded and reference pictures that are prediction candidates. Spherical projection of an input picture and the candidate reference pictures may be generated. Thereafter, a search may be conducted for a match between the spherical-domain representation of a pixel block to be coded and a spherical-domain representation of the reference picture. On a match, an offset may be determined between the spherical-domain representation of the pixel block to a matching portion of the of the reference picture in the spherical-domain representation. The spherical-domain offset may be transformed to a motion vector in a source-domain representation of the input picture, and the pixel block may be coded predictively with reference to a source-domain representation of the matching portion of the reference picture.

Abstract: Systems and methods for coding a video to be overlaid by annotations are devised. A motion compensated predictive coding is employed, wherein coding parameters of video pixel blocks are determined based on the pixel blocks' relation to the annotations. A decoder decodes the video and annotates it based on metadata, obtained from the coder or other sources, describing the annotations' appearance and rendering mode.

Abstract: Chroma deblock filtering of reconstructed video samples may be performed to remove blockiness artifacts and reduce color artifacts without over-smoothing. In a first method, chroma deblocking may be performed for boundary samples of a smallest transform size, regardless of partitions and coding modes. In a second method, chroma deblocking may be performed when a boundary strength is greater than 0. In a third method, chroma deblocking may be performed regardless of boundary strengths. In a fourth method, the type of chroma deblocking to be performed may be signaled in a slice header by a flag. Furthermore, luma deblock filtering techniques may be applied to chroma deblock filtering.

Abstract: Techniques are disclosed for managing display of content from multi-view video data. According to these techniques, an object may be identified from content of the multi-view video. The object's location may be tracked across a sequence of multi-view video. The technique may extract a sub-set of video that is contained within a view window that is shifted in an image space of the multi-view video in correspondence to the tracked object's location. These techniques may be implemented either in an image source device or an image sink device.

Abstract: Aspects of the present disclosure provide techniques for reducing latency and improving image quality of a viewport extracted from multi-directional video communications. According to such techniques, first streams of coded video data are received from a source. The first streams include coded data for each of a plurality of tiles representing a multi-directional video, where each tile corresponding to a predetermined spatial region of the multi-directional video, and at least one tile of the plurality of tiles in the first streams contains a current viewport location at a receiver. The techniques include decoding the first streams and displaying the tile containing the current viewport location. When the viewport location at the receiver changes to include a new tile of the plurality of tiles, retrieving and decoding first streams for the new tile, displaying the decoded content for the changed viewport location, and transmitting the changed viewport location to the source.

Abstract: In communication applications, aggregate source image data at a transmitter exceeds the data that is needed to display a rendering of a viewport at a receiver. Improved streaming techniques that include estimating a location of a viewport at a future time. According to such techniques, the viewport may represent a portion of an image from a multi-directional video to be displayed at the future time, and tile(s) of the image may be identified in which the viewport is estimated to be located. In these techniques, the image data of tile(s) in which the viewport is estimated to be located may be requested at a first service tier, and the other tile in which the viewport is not estimated to be located may be requested at a second service tier, lower than the first service tier.

Abstract: Techniques are disclosed for managing memory allocations when coding video data according to multiple codec configurations. According to these techniques, devices may negotiate parameters of a coding session that include parameters of a plurality of different codec configurations that may be used during the coding session. A device may estimate sizes of decoded picture buffers for each of the negotiated codec configurations and allocate in its memory a portion of memory sized according to a largest size of the estimated decoded picture buffers. Thereafter, the devices may exchange coded video data. The exchange may involve decoding coded data of reference pictures and storing the decoded reference pictures in the allocated memory. During the coding session, the devices may toggle among the different negotiated codec configurations. As they do, reallocations of memory may be avoided.

Abstract: A device implementing the subject technology may include at least one processor configured to receive an indication of a task being performed at an other device. The at least one processor is further configured to perform, in response to receipt of the indication, one or more preliminary operations in anticipation of receiving a handoff of the task. The at least one processor is further configured to receive, after performing the one or more preliminary operations, a notification that the task is being handed off. The at least one processor is further configured to receive the handoff of the task from the other device. The at least one processor is further configured to continue to perform the task based at least in part on the one or more preliminary operations that were performed prior to receiving the notification that the task is being handed off.

Abstract: Techniques are disclosed for coding video data predictively based on predictions made from spherical-domain projections of input pictures to be coded and reference pictures that are prediction candidates. Spherical projection of an input picture and the candidate reference pictures may be generated. Thereafter, a search may be conducted for a match between the spherical-domain representation of a pixel block to be coded and a spherical-domain representation of the reference picture. On a match, an offset may be determined between the spherical-domain representation of the pixel block to a matching portion of the of the reference picture in the spherical-domain representation. The spherical-domain offset may be transformed to a motion vector in a source-domain representation of the input picture, and the pixel block may be coded predictively with reference to a source-domain representation of the matching portion of the reference picture.

Abstract: Aspects of the present disclosure provide techniques for reducing latency and improving image quality of a viewport extracted from multi-directional video communications. According to such techniques, first streams of coded video data are received from a source. The first streams include coded data for each of a plurality of tiles representing a multi-directional video, where each tile corresponding to a predetermined spatial region of the multi-directional video, and at least one tile of the plurality of tiles in the first streams contains a current viewport location at a receiver. The techniques include decoding the first streams and displaying the tile containing the current viewport location. When the viewport location at the receiver changes to include a new tile of the plurality of tiles, retrieving and decoding first streams for the new tile, displaying the decoded content for the changed viewport location, and transmitting the changed viewport location to the source.

Abstract: Frame packing techniques are disclosed for multi-directional images and video. According to an embodiment, a multi-directional source image is reformatted into a format in which image data from opposing fields of view are represented in respective regions of the packed image as flat image content. Image data from a multi-directional field of view of the source image between the opposing fields of view are represented in another region of the packed image as equirectangular image content. It is expected that use of the formatted frame will lead to coding efficiencies when the formatted image is processed by predictive video coding techniques and the like.

Abstract: In communication applications, aggregate source image data at a transmitter exceeds the data that is needed to display a rendering of a viewport at a receiver. Improved streaming techniques that include estimating a location of a viewport at a future time. According to such techniques, the viewport may represent a portion of an image from a multi-directional video to be displayed at the future time, and tile(s) of the image may be identified in which the viewport is estimated to be located. In these techniques, the image data of tile(s) in which the viewport is estimated to be located may be requested at a first service tier, and the other tile in which the viewport is not estimated to be located may be requested at a second service tier, lower than the first service tier.

Abstract: A device implementing a system for audio-video conferencing using multiple stream identifiers includes a processor configured to receive, from a sending device, indication of a first content stream and a first stream identifier, and indication of a second content stream and a second stream identifier associated. The first content stream and the second content stream correspond to different bit rates of streaming content. The processor is configured to receive, from a receiving device, a request to subscribe to the second content stream, the request including the second stream identifier, and receive, from the sending device, an indication that the second stream identifier has been associated with the first content stream. The processor is configured to forward, to the receiving device, the first content stream based on the request to subscribe to the second content stream and on the indication that the second stream identifier has been associated with the first content stream.

Abstract: Techniques are disclosed for coding and decoding video captured as cube map images. According to these techniques, padded reference images are generated for use during predicting input data. A reference image is stored in a cube map format. A padded reference image is generated from the reference image in which image data of a first view contained in reference image is replicated and placed adjacent to a second view contained in the cube map image. When coding a pixel block of an input image, a prediction search may be performed between the input pixel block and content of the padded reference image. When the prediction search identifies a match, the pixel block may be coded with respect to matching data from the padded reference image. Presence of replicated data in the padded reference image is expected to increase the likelihood that adequate prediction matches will be identified for input pixel block data, which will increase overall efficiency of the video coding.

Abstract: A device implementing the subject technology may include at least one processor configured to receive a plurality of buffer reports from a plurality of other devices, each of the plurality of buffer reports indicating a current target buffer level for a respective one of the plurality of other devices. The at least one processor may be further configured to determine a group target buffer level based at least in part on the current target buffer levels of the plurality of other devices and a current target buffer level of the at least one buffer. The at least one processor may be further configured to transmit the group target buffer level to the plurality of other devices. The at least one processor may be further configured to manage an occupancy of the at least one buffer based at least in part on the group target buffer level.

Abstract: Techniques are disclosed for coding high dynamic range (HDR) data. According to such techniques, HDR data may be converted to a domain of uniform luminance data. The uniform domain data may be coded by motion compensated predictive coding. The HDR data also may be coded by motion compensated predictive coding, using a coding parameter that is derived from a counterpart coding parameter of the coding of the uniform domain data. In another technique, HDR data may be coded using coding parameters that are derived from HDR domain processing but distortion measurements may be performed in a uniform domain.