Abstract: Pixel information of a current block is correlated with pixel information of a reference frame indicated by a first motion vector of a block proximate to the current block, pixel information of the reference frame indicated by a second motion vector of a block of the reference frame spatially coincident with the current block, and pixel information of predetermined regions of the reference frame. At least one of the first, second, and third motion vectors having the lowest cost function is selected as a candidate motion vector. Pixel information of the current block is correlated with pixel information of regions offset from the regions indicated by the candidate motion vectors to determine refined candidate motion vectors and corresponding refined cost functions. The refined candidate motion vector having the lowest refined cost function is selected as the motion vector of the current block.

Abstract: A block matching motion estimation method for obtaining a motion vector between a macro block in a current frame and a best match block in a reference frame is provided. The block matching motion estimation method includes steps of dividing a search window of the reference frame into a first area, a second area and a third area, wherein the first area is located between the second area and the third area, and searching initially from the first area for the motion vector.

Abstract: A method provides a predetermined sequence of video frames, the predetermined sequence beginning with an I-frame, ending with a P-frame, and having intermediate B-frames. The method encodes blocks of each frame according to the order of the frame in the sequence and the frame type, determines a number of intra picture coded blocks in an encoded P-frame, and determines that a scene change occurs when the number of intra-picture encoded blocks is greater than a predetermined number. The method redefines the P-frame detected as having a scene change as an I-frame, redefines all B-frames of the sequence as P-frames, and re-encodes redefined frames while detecting for the scene change in the newly defined P-frames.

Abstract: Pixel information of a current block is correlated with pixel information of a reference frame indicated by a first motion vector of a block proximate to the current block, pixel information of the reference frame indicated by a second motion vector of a block of the reference frame spatially coincident with the current block, and pixel information of predetermined regions of the reference frame. At least one of the first, second, and third motion vectors having the lowest cost function is selectedas a candidate motion vector. Pixel information of the current block is correlated with pixel information of regions offset from the regions indicated by the candidate motion vectors to determine refined candidate motion vectors and corresponding refined cost functions. The refined candidate motion vector having the lowest refined cost function is selected as the motion vector of the current block.