Stmicroelectronics Asia Pacific Pte Limited

Hong Lye Oh

Yau Wai Lucas Hui

Jean-Michel Bard

A method and apparatus of encoding digital video according to the ISO/IEC MPEG standards (ISO/IEC 11172-2 MPEG-1 and ISO/IEC 13818-2 MPEG-2) using an adaptive motion estimator. A plurality of global motion vectors are derived from the motion vectors of a previous picture in a sequence, and the global motion vectors are analyzed to determine motion characteristics. The video encoding is arranged to enable switching among different types of local motion estimators based on the motion characteristics of the moving pictures sequence. This gives rise to a motion estimation algorithm that can adaptively change its search range, search area and block matching scheme to suit different types of moving sequences.

Adaptive motion estimator

A method and apparatus control bit rates used in a moving pictures encoder, such as an MPEG standard encoder. A sequence of moving pictures is divided into segments each of which comprises one or more groups of pictures. A constant overall bit rate is specified for the sequence of pictures, but variable bit rate encoding used within each segment. A difference between the number of bits allocated for encoding the segment and the actual bits used for encoding is determined, and the difference distributed over one or more subsequent segments.

Moving pictures encoding with constant overall bit-rate

A method and apparatus control bit rates used in a moving pictures encoder, such as an MPEG standard encoder. A sequence of moving pictures is divided into segments each of which comprises one or more groups of pictures. A constant overall bit rate is specified for the sequence of pictures, but variable bit rate encoding is used within each segment. A difference between the number of bits allocated for encoding the segment and the actual bits used for encoding is determined, and the difference is distributed over one or more subsequent segments.

Moving pictures encoding with constant overall bit rate

A method and apparatus of encoding digital video, for example according to the ISO/IEC MPEG standards (ISO/IEC 11172-2 MPEG-1 and ISO/IEC 13818-2 MPEG-2), which employs a local motion estimator for determining respective local motion vectors for groups of adjacent macroblocks in a picture. A local motion vector is determined for each row of macroblocks in a picture from the motion vectors of the macroblocks in that row. Then, for macroblocks in the corresponding row of a subsequently coded picture, the local motion vector can be used to select the search window used for determining the motion vectors. The local motion estimator improves search range and accuracy of macroblock motion vector detection without increasing the search window accessing bandwidth and caching requirement, and computation lode of searching.

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Singapore, Singapore

Hong Lye Oh