Patent ID: 7778173
Filing Date: 2010-08-17
Classification: H04L,H04N

Abstract:
1. In an MPEG-2 compliant network over which a stream of packets is delivered over UDP/IP, a method for performing clock recovery comprising: applying a dejittering filter to incoming packets in the stream to form dejittered packets with reduced IP packetization; adjusting program clock references in the dejittered packets by applying a phase lock loop to the dejittered packets that have program clock references, where applying the phase lock loop to the dejittered packets comprises using an infinite impulse response low pass filter to produce a time-averaged time base error, and converting the time-averaged time base error into a clock frequency difference by a loop gain multiplier, and where the frequency difference is clamped to maintain a clock slew rate in compliance with an MPEG-2 System specification; performing delivery time calculations on the incoming packets; and assembling the dejittered packets into an MPEG-2 compliant output stream.