Motion analysis based buffer regulation scheme

A video encoding system comprising:

• a transform device that is configured to transform video data blocks of a video frame into transform blocks of transform coefficients,
• each transform block of the transform blocks corresponding to a respective video data block of the video data blocks,
• the video frame being one of:
• a first type, and a second type having an associated frame of motion vectors,
• a quantizer, operably coupled to the transform device, that is configured to quantize the transform coefficients of each transform block to create a corresponding quantized block frame,
• each quantized coefficient of the quantized frames having a quantized value that is based on a quantization factor associated with each video data block,
• a variable length encoder, operably coupled to the quantizer, that encodes the quantized block frame into an encoded frame for communication to a receiving buffer via a communications channel, and
• a buffer regulator, operably coupled to the variable length encoder and the quantizer, that provides buffer control commands to the quantizer to effect a modification of the quantization factor based on a fullness measure of the receiving buffer,
• wherein
• the quantizer is further configured to modify the quantization factor associated with each video data block based on a motion map corresponding to the video data frame, and
• the motion map is initialized to a first predetermined value at a start of the video data frame when the video data frame is of the first type,
• the motion map is modified based on motion vectors associated with the video data blocks of the video data frame when the video data frame is of the second type, and
• the quantization step is clipped to ensure that the quantization step stays between a predetermined minimum bound and a predetermined maximum bound.

A method of processing video data, the method comprising:

• encoding of the video data in blocks of an image for communication to a receiving buffer via a communications channel, the encoding comprising:
• transforming the video data by subjecting the blocks of video data to a frequency domain coding;
• determining a quantization step based on a motion activity map corresponding to respective motion vectors for respective ones of the blocks of video data,
• clipping the quantization step to ensure that the quantization step stays between a predetermined minimum bound and a predetermined maximum bound, and
• quantizing the transformed blocks using the quantization step;
• wherein the motion activity map is
• initialized to a nominal value for each block, and
• subsequently modified in dependence upon subsequent motion vectors associated with each block, so that:
• the quantization step has a first value lower than a prior value for a first block of the transformed blocks if the first block has an associated value in the map that corresponds to relatively small motion vectors, and
• the quantization step has a second value higher than a prior value for a second block of the transformed blocks if the second block has an associated value in the map that corresponds to relatively large motion vectors.