Non-seamless splicing of audio-video transport streams
First Claim
1. A method of splicing a plurality of transport streams, the method comprising the steps of:
- inserting a black frame in a first transport stream, wherein the black frame is the final first transport stream frame to be displayed before display of a second transport stream to be spliced with the first transport stream at a splice point, wherein the inserted black frame ensures continuity between the first and second streams to avoid visual flickering;
storing said first transport stream in a buffer;
outputting transport packets of a third transport stream, said transport packets being null packets and having a predetermined packet characteristic in place of transport packets of the first stream for a period of time after the splice point to inhibit decoder underflow and overflow, wherein the period of time is greater than the splice decoding delay associated with the splice point;
emptying said buffer during said period of time; and
outputting transport packets of the second transport stream and storing the outputted second transport stream into the emptied buffer, such that timing errors will be eliminated since frames of the second transport stream do not enter said buffer until all frames of the first transport stream emptied, which further inhibits decoder underflow and overflow.
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Accused Products
Abstract
A method and apparatus for non-seamless splicing of audio-video transport streams configured in accordance with MPEG-2 or other suitable techniques. A first transport stream is to be spliced with a second transport stream at a splice point. The first stream is configured such that the final first stream frame to be displayed will be a black frame or will have another suitable characteristic. Null packets are then delivered in place of the first stream transport packets for a predetermined period of time after the splice point. The predetermined time is generally greater than the sum of the splice decoding delay associated with the splice point and the maximum frame duration in the first stream. The transport packets of the second stream are then delivered. Null packets may be again delivered for a period of time sufficient to allow the final frame of the second stream to be displayed. The final first stream frame can be guaranteed to be a black frame by directing a digital stream insertion device to insert a black I-frame followed by an end-of-sequence code into the first stream. Alternatively, the final first stream frame could be forced to black during an encoding operation, and an end-of-sequence code could then be inserted at the splice point.
299 Citations
22 Claims
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1. A method of splicing a plurality of transport streams, the method comprising the steps of:
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inserting a black frame in a first transport stream, wherein the black frame is the final first transport stream frame to be displayed before display of a second transport stream to be spliced with the first transport stream at a splice point, wherein the inserted black frame ensures continuity between the first and second streams to avoid visual flickering; storing said first transport stream in a buffer; outputting transport packets of a third transport stream, said transport packets being null packets and having a predetermined packet characteristic in place of transport packets of the first stream for a period of time after the splice point to inhibit decoder underflow and overflow, wherein the period of time is greater than the splice decoding delay associated with the splice point; emptying said buffer during said period of time; and outputting transport packets of the second transport stream and storing the outputted second transport stream into the emptied buffer, such that timing errors will be eliminated since frames of the second transport stream do not enter said buffer until all frames of the first transport stream emptied, which further inhibits decoder underflow and overflow. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for splicing a plurality of transport streams, the apparatus comprising:
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a packet filter having a first input corresponding to a first transport stream and a first output corresponding to splice point data associated with the first input stream; and a controller connected to the first output of the packet filter and operative to direct a digital stream insertion device to insert a black frame in a first transport stream, wherein the black frame is the final first transport stream frame to be displayed before display of a second transport stream to be spliced with the first transport stream at a splice point, wherein the inserted black frame ensures continuity between the first and second streams to avoid visual flickering; and a buffer for storing said first transport stream, wherein said controller being further operative to output transport packets of a third transport stream, said transport packets being null packets and having a predetermined packet characteristic in place of transport packets of the first steam for a period of time after the splice point to inhibit decoder underflow and overflow, wherein the period of time is greater than the splice decoding delay associated with the splice point, being further operative to empty all frames of the first transport steam from said buffer, and being further operative to output transport packets of the second transport stream, where the outputted second transport stream are stored in the emptied buffer, such that timing errors will be eliminated since frames of the second transport stream do not enter said buffer until all frames of the first transport steam are emptied, which further inhibits decoder underflow and overflow. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification