Method and apparatus for information stream frame synchronization
AssigneeSarnoff Corporation
InventorsPaul Wallace Lyons, John Prickett Beltz, Alfonse Anthony Acampora
Life of this patent
Estimating the term…
Abstract
A timing synchronization method and apparatus for processing a compressed information stream comprising a plurality of information segments representative of a sequence of information frames. Information segments representative of information frames are deleted in response to an indicium of buffer overutilization.
Claims18
Apparatus for processing a compressed information stream to produce an output information stream, said compressed information stream representing a sequence of compressed information frames that have been encoded according to a first timing reference, said apparatus comprising:
- an input buffer, coupled to a controller, for receiving said compressed information stream and providing a buffered information stream;
- and
- a frame sequence adjuster, coupled to said controller, for selectively adding and deleting information frames from said buffered information stream to produce said output information stream;
- said controller, in response to an indicia of input buffer utilization exceeding a first threshold level, causing said input buffer to delete at least one information frame from said output information stream;
- said controller, in response to a calculated utilization level of a buffer suitable for receiving said output stream exceeding a second threshold level, causing said frame sequence adjuster to delete at least one information frame from said output information stream;
- said controller, in response to said calculated utilization level of a buffer suitable for receiving said output stream being below a third threshold level, causing said frame sequence adjuster to add at least one information frame to said output information stream.
A method of processing at least one compressed image stream to produce a compressed output information stream, each compressed information stream representing a respective sequence of compressed image frames, said output information stream being processed in a manner tending to avoid decoder buffer underflow and overflow conditions, said method comprising the steps of:
- receiving, via an input buffer, a first compressed information stream and providing a buffered information stream therefrom, said buffered information stream being further processed by a frame sequence adjuster to form a processed information stream;
- deleting, from said input buffer, at least one information frame in response to an input buffer utilization level exceeding a first threshold level;
- calculating a utilization level of a decoder buffer receiving said buffered information stream to provide a first calculated utilization level;
- deleting, using said frame sequence adjuster, at least one information frame from said buffered information stream in response to said calculated utilization level exceeding a second threshold level;
- and
- adding, using said frame sequence adjuster, at least one information frame to said buffered information stream in response to said calculated utilization level being below a third threshold level.
Dependencies are inferred from the claim text.