Harmonic, Inc.

Divicom Inc.

Michael P Lenihan

Brian W Johnson

Christopher Mills

Mark Magee

Thomas R Ayers

Sean C Hart

A method and apparatus for recording and playback of transport stream packets including multiplexed audio, video and other data streams. The transport streams may be generated in accordance with an MPEG-2 standard. In a record mode, an arrival timestamp is generated for each input transport packet to be recorded in a peripheral storage device. A given arrival timestamp indicates the arrival time of the corresponding transport packet in the recording system. Each of the transport packets are then stored with their corresponding arrival timestamps. The record mode may utilize a packet identifier (PID) decoder to perform packet filtering such that only incoming transport packets with selected PIDs are stored. In a playback mode, transport packets and corresponding arrival timestamps are retrieved from the storage device and the arrival timestamps are utilized to direct synchronous delivery of the transport packets to, for example, a decoder or a transport stream broadcast system. The playback mode may detect a timestamp discontinuity code in one or more of the arrival timestamps, and adjust the playback system time clock accordingly. The playback mode may also provide null packet interleaving in which a selectable number of null packets are inserted between each valid transport packet to thereby provide a selectable fixed-rate transport packet output. The recording and playback features may be implemented using a spooler card and a storage controller card incorporated into an otherwise conventional personal computer.

Recording and playback of audio-video transport streams

A method and apparatus for differential video data encoding which utilizes a reduced number of bits per pixel to encode chroma and luma components of a video data stream. A 4-bit absolute code is determined for a given 8-bit luma or chroma component in the data stream. The determined absolute code is indicative of a particular one of a plurality of ranges into which the given component falls. The given component is encoded using the determined absolute code if the absolute code produces a lower encoding error than a 4-bit delta code which encodes the component as a difference relative to a previously-encoded component. If the delta code produces a lower encoding error than the determined absolute code, the given component is encoded using the delta code. In a situation in which the given component is the first component of its type on a line of video, an absolute code may be used regardless of whether or not the absolute code produces a higher encoding error than the delta code.

Processing system with delta-based video data encoding

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Sunnyvale, CA, United States of America

Michael P Lenihan