Method and apparatus for adaptively scaling motion vector information in an information stream decoder

A method for adapting motion vector information to a scaling factor associated with scaled pixel block reference information, comprising the steps of:

• identifying an encoding mode of a predicted pixel block;
• scaling, using said scaling factor, a horizontal displacement parameter of each motion vector associated with said predicted pixel block;
• and
• in the case of a field prediction encoding mode including an interfield motion vector prediction:
• imparting to a vertical displacement parameter of said motion vector associated with said predicted pixel block, a first offset;
• scaling, using said scaling factor, said offset vertical displacement parameter;
• and
• imparting, to said scaled offset vertical displacement parameter, a second offset;
• and
• truncating, to a predetermined level of accuracy, said scaled vertical and horizontal displacement parameters.

A method comprising the steps of:

• scaling, by a first factor, a pixel block;
• scaling, by said first factor, a horizontal displacement parameter of a motion vector associated with said pixel block;
• and
• in the case of a said pixel block being encoded using a field prediction encoding mode including an inter-field motion vector prediction:
• imparting, to a vertical displacement parameter of said motion vector associated with said predicted pixel block, a first offset;
• scaling, using said scaling factor, said offset vertical displacement parameter;
• and
• imparting, to said scaled offset vertical displacement parameter, a second offset;
• in the case of a said pixel block not being encoded using a field prediction encoding mode including an inter-field motion vector prediction,
• scaling, using said scaling factor, said offset vertical displacement parameter, wherein:
• if said inter-field motion vector prediction comprises a top field prediction into a bottom field, said first offset comprises a positive offset;
• and
• if said inter-field motion vector prediction comprises a bottom field prediction into a top field, said first offset comprises a negative offset.

A method comprising the steps of:

• scaling, by a first factor, a pixel block;
• scaling, by said first factor, a horizontal displacement parameter of a motion vector associated with said pixel block;
• and
• in the case of a said pixel block being encoded using a field prediction encoding mode including an inter-field motion vector prediction:
• imparting, to a vertical displacement parameter of said motion vector associated with said predicted pixel block, a first offset;
• scaling, using said scaling factor, said offset vertical displacement parameter;
• and
• imparting, to said scaled offset vertical displacement parameter, a second offset;
• in the case of a said pixel block not being encoded using a field prediction encoding mode including an inter-field motion vector prediction, scaling, using said scaling factor, said offset vertical displacement parameter;
• and
• truncating, to a predetermined level of accuracy, said scaled vertical and horizontal displacement parameters.

An apparatus comprising:

• a pixel processor, for receiving decoded reference pixel blocks and producing therefrom scaled reference pixel blocks according to a scaling factor;
• and
• a motion vector processor, for receiving motion vector information associated with a predicted pixel block and producing therefrom a scaled motion vector according to said scaling factor;
• wherein
• said motion vector processor, in the case of a said pixel blocks being encoded using a field prediction encoding mode including an inter-field motion vector prediction, scaling said motion vector information associated with said predicted pixel block by imparting a first offset to a vertical displacement parameter of said motion vector, scaling said vertical displacement parameter and a horizontal displacement parameter of said motion vector according to said scaling factor, and imparting, to said scaled offset vertical displacement parameter, a second offset, wherein:
• if said inter-field motion vector prediction comprises a top field prediction into a bottom field, said first offset comprises a positive offset;
• and
• if said inter-field motion vector prediction comprises a bottom field prediction into a top field, said first offset comprises a negative offset.

An apparatus comprising:

• a pixel processor, for receiving decoded reference pixel blocks and producing therefrom scaled reference pixel blocks according to a scaling factor;
• and
• a motion vector processor, for receiving motion vector information associated with a predicted pixel block and producing therefrom a scaled motion vector according to said scaling factor;
• wherein
• said motion vector processor, in the case of a said pixel blocks being encoded using a field prediction encoding mode including an inter-field motion vector prediction, scaling said motion vector information associated with said predicted pixel block by imparting a first offset to a vertical displacement parameter of said motion vector, scaling said vertical displacement parameter and a horizontal displacement parameter of said motion vector according to said scaling factor, and imparting, to said scaled offset vertical displacement parameter, a second offset,
• wherein:
• said motion vector processor, in the case of a said pixel blocks not being encoded using a field prediction encoding mode including an inter-field motion vector prediction, scaling said motion vector information associated with said predicted pixel block by scaling said vertical displacement parameter of said motion vector and said horizontal displacement parameter of said motion vector according to said scaling factor.