Hulu, LLC

Juncheng Ma

Wenhao Zhang

Chen Liu

Deliang Fu

Min Gao

In some embodiments, a method maintains a list that is configured to store motion vectors from one or more blocks that have been previously processed in a frame. When a current block is in a first set of positions in the frame, the method resets the list by storing a motion vector with a horizontal component and a vertical component equal to zero in the list. The motion vector with the horizontal component and the vertical component equal to zero from the list is used to transcode the current block. When the current block is not in the first set of positions, the method uses a motion vector from the list to transcode the current block.

Reset of historical motion vector prediction

A method includes transcoding a first block from a spatial region. The first block is associated with a first block tree pattern defining a structure of splitting a block into smaller blocks. A bit string of bits for the first block tree pattern is included in an encoded bitstream. The method determines a location of the first block in the spatial region when the first block tree pattern of the first block can be reused for a second block tree pattern of a second block. The spatial region includes blocks and the location is based on the first block being in the spatial region. Information for the second block is included in the encoded bitstream that indicates the location of the first block in the spatial region. The location allows the bit string for the first block tree pattern to be retrieved for use to decode the second block.

Reuse of block tree pattern in video compression

In some embodiments, a method performs a first calculation to select an anchor point based on a first reference block in a first reference frame and a second reference block in a second reference frame. The first reference frame is selected as the anchor point. A third reference block in the second reference frame is selected based on the first reference frame being selected as the anchor point. The method performs a second calculation to select the anchor point based on the first reference block in the first reference frame and the third reference block in the second reference frame and determines whether to use the first reference block and the third reference block as a prediction for a current block based on the second calculation.

Template refined bi-prediction for video coding using anchor point

In some embodiments, a method maintains a first list that stores motion vectors from one or more blocks that have been previously processed in a frame. When a current block is in the first set of positions in the frame, the method resets and uses a motion vector from a second list to transcode the current block due to the resetting of the first list. When the current block is not in the first set of positions, the method uses a motion vector from the first list to transcode the current block.

A method includes transcoding a first block of a video. The first block is associated with a first block tree pattern defining a structure of splitting a block into smaller blocks. A bit string of bits for the first block tree pattern is included in an encoded bitstream for the video. The method determines that the first block tree pattern of the first block can be reused for a second block tree pattern of a second block and includes information in the encoded bitstream that indicates that the first block tree pattern is to be used to decode the second block from the encoded bitstream.

In some embodiments, a method analyzing a first set of values for a first bin plane in a plurality of bin planes. The plurality of bin planes are used to determine a context model for entropy coding of a current block in a video. The method determines whether to use a second set of values from a second bin plane based on the analyzing. When it is determined to use the second set of values, information is calculated for the context model using the first set of values and the second set of values. When it is determined to not use the second set of values, information is calculated for the context model using the first set of values.

Coefficient context modeling in video coding

In some embodiments, a method determines a plurality of classes of bins that are used to determine a context model for entropy coding of a current block in a video. The method calculates a first value for a first class of bins in the plurality of classes of bins and calculates a second value for a second class of bins in the plurality of classes of bins. The first value for the first class of bins is weighted by a first weight to generate a weighted first value and the second value for the second class of bins is weighted by a second weight to generate a weighted second value. The method then selects a context model based on the first weighted value and the second weighted value.

In some embodiments, a method selects a current block in a frame and determines whether the current block is in a first set of positions in the frame. When the current block is in the first set of positions: the method loads a first set of motion vectors from a first list as historical motion vector predictors, wherein the one or more motion vectors are from one or more blocks in the first set of positions in the frame; and uses the first set of motion vectors to transcode the current block. When the current block is not in the first set of positions, the method uses a second set of motion vectors from a second list.

Historical motion vector prediction with reset list

In one embodiment, a method selects a first reference block in a first reference frame and a second reference block in a second reference frame. The first reference block and the second reference block are used to predict a current block. The first reference block is selected as an anchor point. Then, the method searches in the second reference frame for a third reference block and determines whether the third reference block is a better reference block than the second reference block for predicting the current block.

Template refined bi-prediction for video coding

In one embodiment, a method selects a first reference block in a first reference frame and a second reference block in a second reference frame. The first reference block and the second reference block are used to predict a current block in a current frame. A first region is selected based on the first reference block, a second region is selected based the second reference block, and a third region is selected based on the current block. The method compares a characteristic of the first region to a characteristic of the third region and compares a characteristic of the second region to the characteristic of the third region to adaptively determine a first weight for the first reference block and a second weight for the second reference block. Then, a prediction block is calculated for the current block using the first weight and the second weight.

Template based adaptive weighted bi-prediction for video coding

In one embodiment, a method receives a first chunk in a plurality of chunks from a video. The plurality of chunks are sent to a plurality of transcoding units for transcoding in parallel. The method transcodes the first chunk at a first transcoding unit to generate a first transcoded sub-bitstream. Then, first statistical information is received from one or more second chunks being transcoded by other transcoding units. The first statistical information from the one or more second chunks is compared to second statistical information from the first chunk and it is determined whether to perform a second transcoding process based on the comparing. When the second transcoding process is to be performed, the method performs the second transcoding process with the first chunk to generate a second transcoded bitstream and outputs the second transcoded bitstream. When the second transcoding process is not to be performed, the method outputs the first transcoded sub-bitstream.

Two pass chunk parallel transcoding process

In one embodiment, a method determines if a first flag for using a most probable mode (MPM) set for intra prediction is set. When the first flag indicates the MPM set is used, the method decodes a first index for the MPM, the first index indicating a first intra prediction mode in the MPM set. When the first flag does not indicate the MPM set is being used, the method determines if a second flag for using a near-MPM set is set. When the second flag indicates the near-MPM set is being used, the method decodes a second index for the near-MPM, the second index indicating a second intra prediction mode in the near-MPM set. When the second flag does not indicate the near-MPM is being used, the method decodes a third index for a non-MPM, the third index indicating a third intra prediction mode in the non-MPM set.

Intra prediction mode signaling for video coding

In one embodiment, a method generates chunk boundaries that are used to form a plurality of chunks from a video. The chunks are transcoded by transcoding units in parallel. The method selects at least one of a first number of frames before a first boundary of a chunk and a second number of frames after a second boundary of the chunk. A chunk is generated that includes the at least one of the first number of frames and the second number of frames, and a third number of frames between the first boundary and the second boundary. Then, the chunk is transcoded to generate a transcoded chunk using a first transcoding unit. The chunk is sent to a chunk assembler where the chunk assembler removes the at least one of the first number of frames and the second number of frames from the chunk and adds the chunk to a transcoded bitstream.

Growing community of inventors

Beijing, China

Juncheng Ma