Abstract:
A block of a video frame may be predicted and decoded using a local affine motion prediction scheme. At least three points within the video frame are selected, each point being adjacent to a respective corner of the current block to be encoded. For each point, a motion search is performed for a template block centered about the point within a reference frame to find a template reference block. The template reference block has a center point that forms an anchor point pair with the corresponding point adjacent to the current block. Using coordinates of the anchor point pairs, affine coefficients for an affine transformation are generated. Using the affine transformation, a prediction block for the current block is generated and used to encode the current block within a bitstream. Providing the local affine motion prediction scheme can improve the prediction of certain blocks with complex motion, increasing compression.
Abstract:
Video data streams can be encoded and decoded using inter or intra prediction. The blocks of a frame can be processed based on depth, from the lowest level sub-blocks to the highest level large blocks, and divided into groups of blocks to be inter predicted, blocks having sub-blocks that are to be inter predicted and sub-blocks that are to be intra predicted, and blocks to be intra predicted, and the blocks to be inter predicted are encoded first, the blocks having sub-blocks to be inter predicted and intra predicted encoded second, and the blocks to be intra predicted encoded last. The availability of data from the inter predicted blocks can improve the performance of intra prediction over processing the blocks in the scan order since more pixel data is available for intra prediction of some blocks.
Abstract:
A system includes an encoder and a decoder. The encoder selects a first matched template for un-encoded pixels of a video frame using an algorithm for measuring a similarity between image blocks of the video frame, the algorithm being based on a weighted scheme of reconstructed adjacent pixels, generates at least one residual for the un-encoded pixels of the video frame based on the matched template, and encodes residuals as compressed bits using an asymmetric discrete sine transform (ADST). The decoder decodes the compressed video bits as residuals using the ADST, selects a second matched template using an algorithm for measuring a similarity between image blocks of a video frame associated with the compressed video bits, the algorithm being based on a weighted scheme of reconstructed adjacent pixels, and generates reconstructed pixels of the video frame based on the matched template and the decoded compressed video bits.
Abstract:
Adaptive composite intra-prediction may include in response to a determination that a first prediction pixel from a first block immediately adjacent to a first edge of a current block is available for predicting a current pixel of the current block, determining whether a second prediction pixel from a second block immediately adjacent to a second edge of the current block is available for predicting the current pixel, wherein the second edge is opposite the first edge, and, in response to a determination that the second prediction pixel is available, generating a prediction value for the current pixel based on at least one of the first prediction pixel or the second prediction pixel. Adaptive composite intra-prediction may include generating a reconstructed pixel corresponding to the current pixel based on the prediction value, including the reconstructed pixel in the decoded current block, and outputting or storing the decoded current block.
Abstract:
A block of a video frame may be predicted and encoded using a local affine motion prediction scheme. At least three points within the video frame are selected, each point being adjacent to a respective corner of the current block to be encoded. For each point, a motion search is performed for a template block centered about the point within a reference frame to find a template reference block. The template reference block has a center point that forms an anchor point pair with the corresponding point adjacent to the current block. Using coordinates of the anchor point pairs, affine coefficients for an affine transformation are generated. Using the affine transformation, a prediction block for the current block is generated and used to encode the current block within a bitstream. Providing the local affine motion prediction scheme can improve the prediction of certain blocks with complex motion, increasing compression.
Abstract:
Using directional intra prediction modes for encoding and decoding a video stream is described. A method includes identifying, peripheral to a current block of a frame of the video stream, a set of previously coded pixels in the frame, identifying a candidate set of directional intra prediction modes from a plurality of directional intra prediction modes based on a size of the current block, and selecting, for the current block, an optimal intra prediction mode from the candidate set of directional intra prediction modes. The optimal intra prediction mode is used to predict the current block based on the set of previously coded pixels.