Microsoft Technology Licensing, LLC

You Zhou

Chih-Lung Lin

Ming-Chieh Lee

Gary Joseph Sullivan

Sergey Sablin

Sergey Silkin

Feng Wu

Jian Li

Binlong Li

Jizheng Xu

Ming Chieh Lee

Mei-Hsuan Lu

A format for use in encoding moving image data, comprising: a sequence of frames including plurality of the frames in which at least a region is encoded using motion estimation; a respective set of motion vector values representing motion vectors of the motion estimation for each respective one of these frames or each respective one of one or more regions within each of such frames; and at least one respective indicator associated with each of the respective frames or regions, indicating whether the respective motion vector values of the respective frame or region are encoded at a first resolution or a second resolution.

Representing motion vectors in an encoded bitstream

Approaches to selection of motion vector ('MV') precision during video encoding are presented. These approaches can facilitate compression that is effective in terms of rate-distortion performance and/or computational efficiency. For example, a video encoder determines an MV precision for a unit of video from among multiple MV precisions, which include one or more fractional-sample MV precisions and integer-sample MV precision. The video encoder can identify a set of MV values having a fractional-sample MV precision, then select the MV precision for the unit based at least in part on prevalence of MV values (within the set) having a fractional part of zero. Or, the video encoder can perform rate-distortion analysis, where the rate-distortion analysis is biased towards the integer-sample MV precision. Or, the video encoder can collect information about the video and select the MV precision for the unit based at least in part on the collected information.

Selection of motion vector precision

When encoding/decoding a current block of a current picture using intra block copy ('BC') prediction, the location of a reference block is constrained so that it can be entirely within an inner search area of the current picture or entirely within an outer search area of the current picture, but cannot overlap both the inner search area and the outer search area. In some hardware-based implementations, on-chip memory buffers sample values of the inner search area, and off-chip memory buffers sample values of the outer search area. By enforcing this constraint on the location of the reference block, an encoder/decoder can avoid memory access operations that are split between on-chip memory and off-chip memory when retrieving the sample values of the reference block. At the same time, a reference block close to the current block may be used for intra BC prediction, helping compression efficiency.

Constraints on locations of reference blocks for intra block copy prediction

Disclosed herein are exemplary embodiments of innovations in the area of encoding pictures or portions of pictures (e.g., slices, coding tree units, or coding units) and determining whether and how certain filtering operation should be performed and flagged for performance by the decoder in the bitstream. In particular examples, various implementations for setting the sample adaptive offset (SAO) syntax elements in the H.265/HEVC standard are disclosed. Although these examples concern the H.265/HEVC standard and its SAO filter, the disclosed technology is more widely applicable to other video codecs that involve filtering operations (particularly multi-stage filtering operations) as part of their encoding and decoding processes.

Encoder-side decisions for sample adaptive offset filtering

Various embodiments of the present technology generally relate to encoding techniques. More specifically, some embodiments relate to encoding techniques for screen data. Intra block copy (IntraBC) using motion compensation within a frame (not between frames) is very useful for encoding data captured from screen. Unfortunately, this tool is not included in most of video coding standards, including the base version of HEVC (i.e., H.265). Various embodiments of the present technology utilize encoding techniques to simulate IntraBC with compliant syntax. For example, embodiments divide a high-resolution frame into smaller areas and then encode these areas independently as if these smaller areas were independent frames.

Effective intra encoding for screen data

Techniques for recording video from a bitstream are described. In at least some implementations, video data generated as part of a communication session is recorded. According to various implementations, techniques described herein enable portions of an encoded bitstream of video data to be directly recorded as encoded frames and without requiring re-encoding of decoded frames.

Recording video from a bitstream

Disclosed herein are exemplary embodiments of innovations in the area of encoding pictures or portions of pictures and determining whether and how certain encoding operations should be performed and flagged for performance by the decoder in the bitstream. In particular examples, various implementations for selectively encoding picture portions (e.g., blocks) in a skip mode (e.g., as in the skip mode of the H.265/HEVC standard) are disclosed. Embodiments of the disclosed techniques can be used to improve encoder efficiency, decrease overall encoder resource usage, and/or improve encoder speed. Such embodiments can be used in encoder modes in which efficient, fast encoder performance is desired (e.g., during encoding of live events, such as video conferencing).

Growing community of inventors

Sammamish, WA, United States of America

You Zhou