When a MPEG Transport Stream file is indexed (to produce an index (.tsx) file), our code skips over PES headers, so that the resulting index file points *only* to MPEG Elementary Stream video data, not PES headers (or any other non-MPEG-video data). The 'trick play' code uses this indexed video data to generate new video data that represents the new (fast-forward or reverse-play) stream.

This new video stream is then converted back into a MPEG Transport Stream file. As part of doing this, our code inserts a new PES header in front of the video data, before packaging it as MPEG Tranport Stream packets. This new PES header is not an 'extra' header; it is simply replacing the PES header that we skipped over when we indexed the original file. I don't believe there is anything wrong with this PES header; on the contrary, it is necessary in order to make the resulting Transport Stream file (for the 'trick play' stream) legal.

In summary: I believe that the Transport Stream data that our 'trick play' code produces is legal; there are no 'extra' PES headers. If, however, your decoder is not properly handling this 'trick play' Transport Stream data because of something illegal that we are doing, then please let us know (with specific details).
--

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/
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