Patent ID: 6792047
Filing Date: 2004-09-14
Classification: H04N

Abstract:
A method of real-time seamless splicing of a first transport stream to a second transport stream to produce a spliced transport stream, the first transport stream including video access units encoding video presentation units representing video frames, the video access units of the first transport stream encoding the video presentation units using a data compression technique and containing a variable amount of compressed video data, the second transport stream including video access units encoding video presentation units representing video frames, the video access units of the second transport stream encoding the video presentation units using a data compression technique and containing a variable amount of compressed video data, the first transport stream having a last video frame to be included in the spliced transport stream, and the second transport stream having a first video frame to be included in the spliced transport stream, each of the video access units having a time at which each video access unit is to be received in a video decoder buffer and a time at which said each video access unit is to be removed from the video decoder buffer, said method comprising:(a) setting the time at which the video access unit for the first video frame of the second transport stream is to be removed from the video decoder buffer to a time following in a decoding sequence next after the time at which the last video access unit for the last frame of the first transport stream is to be removed from the video decoder buffer; (b) accessing pre-computed metadata for the second transport stream including metadata about a decode time stamp (DTSF2) at which the beginning of the video access unit for the first video frame of the second transport stream is removed from the video decoder buffer and an extrapolated program clock reference (PCRe2) time at which the beginning of the video access unit for the first video frame of the second transport stream will be received in the video decoder buffer, and using the pre-computed metadata to adjust content of the first transport stream so that the beginning of the video access unit for the first video frame of the second transport stream will be received in the video decoder buffer immediately after the end of the video access unit for the last video frame of the first transport stream is received in the video decoder buffer while maintaining the difference (DTSF2âˆ’PCRe2) in the spliced transport stream; and (c) concatenating a portion of the first transport stream up to and including the last video frame to a portion of the second transport stream including and subsequent to the first video frame.