SYSTEM FOR PRESENTATION TIME STAMP RECOVERY FROM A TRANSCODER

A method for transcoding a digital video stream that includes transcoding using a transcoder a video stream that includes presentation time stamps for the video stream together with an audio stream that includes presentation time stamps for the audio stream in a manner that modifies the presentation time stamps for the video stream in a manner such that a plurality of first values for presentation time stamps for a first set of video frames of the video stream are modified to a plurality of second values for presentation time stamps for the second set of video frames. The audio stream includes embedded first values for presentation time stamps in a first location. The method includes determining an offset of the second values of the second set of presentation time stamps of the transcoded video stream based upon the first values of the set of presentation time stamps embedded in the audio stream from the transcoder. The method includes combining the transcoded video stream and an associated audio stream based upon the offset. Preferably, the transcoder also modifies the audio time stamps. Preferably, the audio stream includes the embedded first values. Preferably, the offset is determined by taking the diff between the audio PTS in the PES and the embedded PTS in the audio packet (private data or embedded in the audio frame).