A method of encoding a video stream in a video encoder is provided that includes computing an offset into a transform matrix based on a transform block size, wherein a size of the transform matrix is larger than the transform block size, and wherein the transform matrix is one selected from a group consisting of a DCT transform matrix and an IDCT transform matrix, and transforming a residual block to generate a DCT coefficient block, wherein the offset is used to select elements of rows and columns of a DCT submatrix of the transform block size from the transform matrix.

A method of encoding a video stream in a video encoder is provided that includes computing an offset into a transform matrix based on a transform block size, wherein a size of the transform matrix is larger than the transform block size, and wherein the transform matrix is one selected from a group consisting of a DCT transform matrix and an IDCT transform matrix, and transforming a residual block to generate a DCT coefficient block, wherein the offset is used to select elements of rows and columns of a DCT submatrix of the transform block size from the transform matrix.

A transmission device according to an embodiment includes one or more processors. The processors divide a plurality of pieces of transmission data to be transmitted into first data and second data. The processors transmit the first data to a server device configured to distribute the transmission data to a reception device. The processors store the second data in storage. The processors receive, from the reception device or the server device, a request for transmission of the second data. The processors transmit the second data to the server device in accordance with the request for transmission.

Provided is a method of coding blocks of video data representing an image using an encoder, the method including identifying, by the encoder, a first region of the image and a second region of the image, a sum of a first number of pixels in the first region and a second number of pixels in the second region being equal to a total number of pixels of the image, and allocating, by the encoder, a first number of bits including base bits for encoding the first region, and a second number of bits including base bits and enhancement bits for encoding the second region, a sum of the first number of bits and the second number of bits being equal to a total number of bits for encoding all of the pixels, wherein the second region is encoded with a greater number of bits per pixel than the first region.

Provided is a method of coding blocks of video data representing an image using an encoder, the method including identifying, by the encoder, a first region of the image and a second region of the image, a sum of a first number of pixels in the first region and a second number of pixels in the second region being equal to a total number of pixels of the image, and allocating, by the encoder, a first number of bits including base bits for encoding the first region, and a second number of bits including base bits and enhancement bits for encoding the second region, a sum of the first number of bits and the second number of bits being equal to a total number of bits for encoding all of the pixels, wherein the second region is encoded with a greater number of bits per pixel than the first region.

A method by which a decoding device decodes an image, according to the present document, comprises the steps of: acquiring image information including decoded picture buffer (DPB) parameter information and an output layer set (OLS) DPB parameter index for a target OLS; deriving the DPB parameter information about the target OLS on the basis of the OLS DPB parameter index; updating a DPB on the basis of the DPB parameter information about the target OLS; and decoding the current picture on the basis of the updated DPB.

A method by which a decoding device decodes an image, according to the present document, comprises the steps of: acquiring image information including decoded picture buffer (DPB) parameter information and an output layer set (OLS) DPB parameter index for a target OLS; deriving the DPB parameter information about the target OLS on the basis of the OLS DPB parameter index; updating a DPB on the basis of the DPB parameter information about the target OLS; and decoding the current picture on the basis of the updated DPB.

Described herein are video streaming techniques for applications and workloads executed in the cloud. In one example, the cloud server device encodes display frames using low-delay encoding techniques for transmission to a client device. The cloud server device receives an overlay bitstream from a client device, combines the overlay data with the display frames, and encodes the frames for the viewers using statistics from the display frames encoded for the client device and/or from the overlay data. The cloud server device can then transmit the bitstream to a third device for viewing (e.g., to a viewer device or a streaming server device).

Methods and devices for decoding a video stream are provided, a method includes storing previously decoded pictures of the video stream in a decoded picture buffer, including a plurality of first pictures of a same temporal sub-layer, the plurality of first pictures including at least one sub-layer reference picture for predicting a current picture of the video stream; identifying a network abstract layer (NAL) unit type of a picture of the plurality of first pictures; removing, based on the NAL unit type of the picture identified, the picture from the decoded picture buffer; and decoding the current picture using the decoded picture buffer. The decoding includes predicting the current picture using one or more of the at least one sub-layer reference picture that is stored within the decoded picture buffer, after removing the picture from the decoded picture buffer.

Methods and devices for decoding a video stream are provided, a method includes storing previously decoded pictures of the video stream in a decoded picture buffer, including a plurality of first pictures of a same temporal sub-layer, the plurality of first pictures including at least one sub-layer reference picture for predicting a current picture of the video stream; identifying a network abstract layer (NAL) unit type of a picture of the plurality of first pictures; removing, based on the NAL unit type of the picture identified, the picture from the decoded picture buffer; and decoding the current picture using the decoded picture buffer. The decoding includes predicting the current picture using one or more of the at least one sub-layer reference picture that is stored within the decoded picture buffer, after removing the picture from the decoded picture buffer.