Transmitting Apparatus and Method Thereof for Video Processing

Abstract

The present invention relates to a method and a transmitting apparatus for encoding a bitstream representing a sequence of pictures of a video stream comprising a processor and memory, said memory containing instructions executable by said processor whereby said transmitting apparatus is operative to: send a syntax element, wherein a value of the syntax element is indicative of restrictions that are enforced on the bitstream in a way that guarantees a certain level of parallelism for decoding the bitstream.

What is claimed is: 
     
         1 . A method of encoding a bitstream representing a sequence of pictures of a video stream, the method comprising:
 determining an encoding constraint corresponding to a known or assumed per-core processing capability of a multi-core decoder, the encoding constraint being a spatial segmentation constraint that constrains a spatial size needed to be handled by a single core of the multi-core decoder during parallel, multi-core decoding at the multi-core decoder;   encoding the bitstream subject to the constraint and thereby obtaining an encoded bitstream wherein a processing capability needed for decoding separately decodable portions of the encoded bitstream does not exceed the known or assumed per-core processing capability;   generating a Sequence Parameter Set (SPS) for use in decoding the encoded bitstream, and including a syntax element in the SPS that indicates the encoding constraint; and   transmitting the encoded bitstream for decoding, including transmitting the SPS, for use by a multi-core decoder in determining whether its individual cores have sufficient processing capability for decoding the separately decodable portions of the encoded bitstream.   
     
     
         2 . The method of  claim 1 , wherein the constraint is a limit on the number of luma samples per picture slice, said limit being dependent on a picture size associated with the sequence of pictures. 
     
     
         3 . The method of  claim 1 , wherein encoding the bitstream subject to the constraint comprises dividing treeblocks of the pictures in the bitstream into slices such that each division consists of consecutive treeblocks in raster scan order and such that each division does not contain more luma samples than a maximum number representing said constraint. 
     
     
         4 . The method of  claim 1 , wherein the constraint is slice based, tile based, or wavefront based, and wherein the constraint defines a maximum number of bytes or bits per slice, per tile, or per wavefront 
     
     
         5 . The method of  claim 1 , wherein the separately decodable portions of the encoded bitstream correspond to decoding threads and wherein the encoding constraint ensures that the decoding threads can be performed in parallel for a multi-core decoder having available processing cores that provide or exceed the known or assumed per-core processing capability. 
     
     
         6 . The method of  claim 1 , wherein encoding the bitstream subject to the constraint comprises encoding the bitstream to obtain separately decodable portions equal in number to a known or assumed number of processing cores at the multi-core decoder, such that any multi-core decoder having that number of available individual processing cores can decode the separately decodable portions in parallel, assuming that each available individual processing core has at least the known or assume processing capability. 
     
     
         7 . The method of  claim 1 , wherein the method includes receiving a report from a decoder that indicates decoding capabilities of the decoder and wherein the known or assumed per-core processing capability is determined from the report. 
     
     
         8 . An encoding apparatus configured to encode a bitstream representing a sequence of pictures of a video stream, the encoding apparatus comprising:
 processing circuitry configured to:
 determine an encoding constraint corresponding to a known or assumed per-core processing capability of a multi-core decoder, the encoding constraint being a spatial segmentation constraint that constrains a spatial size needed to be handled by a single core of the multi-core decoder during parallel, multi-core decoding at the multi-core decoder; 
 encode the bitstream subject to the constraint and thereby obtaining an encoded bitstream wherein a processing capability needed for decoding separately decodable portions of the encoded bitstream does not exceed the known or assumed per-core processing capability; 
 generate a Sequence Parameter Set (SPS) for use in decoding the encoded bitstream, and including a syntax element in the SPS that indicates the encoding constraint; and 
   input/output circuitry configured to transmit the encoded bitstream for decoding, including transmitting the SPS, for use by a multi-core decoder in determining whether its individual cores have sufficient processing capability for decoding the separately decodable portions of the encoded bitstream.   
     
     
         9 . The encoding apparatus of  claim 8 , wherein the constraint is a limit on the number of luma samples per picture slice, said limit being dependent on a picture size associated with the sequence of pictures. 
     
     
         10 . The encoding apparatus of  claim 8 , wherein the processing circuitry is configured to encode the bitstream subject to the constraint by dividing treeblocks of the pictures in the bitstream into slices such that each division consists of consecutive treeblocks in raster scan order and such that each division does not contain more luma samples than a maximum number representing said constraint. 
     
     
         11 . The encoding apparatus of  claim 8 , wherein the constraint is slice based, tile based, or wavefront based, and wherein the constraint defines a maximum number of bytes or bits per slice, per tile, or per wavefront. 
     
     
         12 . The encoding apparatus of  claim 8 , wherein the separately decodable portions of the encoded bitstream correspond to decoding threads and wherein the encoding constraint ensures that the decoding threads can be performed in parallel for a multi-core decoder having available processing cores that provide or exceed the known or assumed per-core processing capability. 
     
     
         13 . The encoding apparatus of  claim 8 , wherein the processing circuitry is configured to encode the bitstream subject to the constraint by encoding the bitstream to obtain separately decodable portions equal in number to a known or assumed number of processing cores at the multi-core decoder, such that any multi-core decoder having that number of available individual processing cores can decode the separately decodable portions in parallel, assuming that each available individual processing core has at least the known or assume processing capability. 
     
     
         14 . The encoding apparatus of  claim 8 , wherein the processing circuitry is configured to receive, via the input/output circuitry, a report from a decoder that indicates decoding capabilities of the decoder and wherein the processing circuitry is configured to determine the known or assumed per-core processing capability from the report.