Indication of use of wavefront parallel processing in video coding

摘要

A video encoder generates a bitstream that includes a syntax element that indicates whether a picture is encoded according either a first coding mode or a second coding mode. In the first coding mode, the picture is entirely encoded using wavefront parallel processing (WPP). In the second coding mode, each tile of the picture is encoded without using WPP and the picture may have one or more tiles. A video decoder may parse the syntax element from the bitstream. In response to determining that the syntax element has a particular value, the video decoder decodes the picture entirely using WPP. In response to determining that the syntax element does not have the particular value, the video decoder decodes each tile of the picture without using WPP.

主权项

1. A method for decoding video data, the method comprising:
parsing a syntax element from a bitstream, the bitstream including a coded slice Network Abstraction Layer (NAL) unit for a slice of a picture of the video data that is partitioned into coding tree blocks (CTBs), each of the CTBs being associated with a different equally sized block of pixels within the picture, the coded slice NAL unit including a plurality of sub-streams, the syntax element having a particular value indicating each respective row of CTBs of the picture forms a respective tile of the picture, wherein each respective sub-stream of the plurality of sub-streams contains all encoded bits of a respective tile of the picture, a number of ending encoded bits of the respective tile, or starting encoded bits of the respective tile, and none of the sub-streams contains encoded bits of more than one tile of the picture; determining, based on the syntax element, whether the sub-streams include padding bits that ensure byte alignment of the sub-streams; and in response to determining that the syntax element has the particular value, decoding each tile of the picture using wavefront parallel processing (WPP), wherein the syntax element not having the particular value indicates each tile of the picture is decoded without using WPP.