Abstract: According to the present invention, methods and apparatus for filtering transform coefficients are provided. Transform coefficients associated with an input bit sequence can be zeroed to provide modified transform coefficients associated with an output bit sequence. The transform coefficients may represent information in a portion of data such as a video frame, a picture, or an audio stream. In one example, the transform coefficients are DCT coefficients of an MPEG-2 video sequence. The transform coefficients are filtered to provide modified transform coefficients associated with an output bit sequence. The output bit sequence is a rescaled version of the input bit sequence.

Abstract: A method and apparatus for clock recovery for constant bit rate MPEG-2 compliant single program transport stream and multiple program transport stream delivered over UDP/IP is disclosed. Clock recovery utilizes a dejittering filter to remove arrival time jitter from received packets and a phase lock loop is used to recover a PCR clock rate up to a range allowed by the MPEG-2 System specification. An MPEG-2 compliant output stream is produced, even when the input PCR does not meet the timing requirement specified by the MPEG-2 System specification.