Intel Corporation

Lucent Technologies Inc.

Imove, Inc.

Thomson Licensing S.a.

Other

Sarnoff Corporation

Technology Inc. 64

Infinite Pictures

Stuart J Golin

Michael J Keith

Brian Astle

Allen H Simon

John M Keith

Rohan G Coelho

Brian R Nickerson

Scott Gilbert

Thomas Baker

Adnan M Alattar

Rohit Agarwal

Jungwoo Lee

Dinei Afonso Ferreira Florencio

Joseph N Romriell

Agesino Primatic, Jr

Jonathan A Eggert

Suz H Wan

Possible overflow of a video buffer verifier (VBV) buffer employed in MPEG-like video encoders is prevented by controlling bits being drained from a video encoder buffer (eBuff). Specifically, a number of bits in the encoder buffer is determined when a last prior picture (pic n&#x2212;1) ends, or when it should end. This number of bits (maxBits) is the maximum number of bits to be read from the encoder buffer and written to the remote decoder before a prescribed time T(n). When maxBits has been read from the encoder buffer and written to the decoder, the writing of bits to the remote decoder is stopped until the process is reset. If the prior picture ends early, maxBits is defined as being the number of bits in the encoder buffer at an expected time (Texp) that the picture should have ended less the number of bits written into the encoder buffer between the time the prior picture actually ended and the expected time for it to end, i.e., Texp. If the prior picture is late, i.e., ends after the expected time for it to end, maxBits is defined as being the number of bits in the encoder buffer at the actual time the prior picture ended. During the interval from the expected time the prior picture should have ended, i.e., Texp, and the actual time that it ended, the maxBits mechanism is essentially disabled. That is, bits are allowed to be read out of the encoder buffer and written to the decoder.

Controlling a video-buffer-verifier buffer using an MPEG-like encoder

In encoding high-definition video signals, the method includes overlapping panels with a single row in the overlap, selecting the better-encoded one of the rows in the overlap, removing the unselected row, and merging bit streams from the panels. In deciding which one of the rows in the overlap is better encoded, a heuristic approach may be used, for example, a panel with the fewer bits, or with fewer errors or the panel as suggested by the motion vectors. Optionally, panels may be synchronized by copying the selected row in the overlap in place of the unselected row in the overlap.

Encoding high-definition video using overlapping panels

A method and apparatus for generating views of an environment with proper perspective and parallax. This invention captures panoramic views at many points in the environment, preferably by using fisheye lenses with subhemispherical fields of views to yield overlapping fisheye images that are seemed together, and stores them as planar polygons, which have been extended to include imagery occluded at their viewing position but visible at nearby points. Three-dimensional information on the environmental source of these polygons is determined and stored, enabling the playback system to simulate parallax as well as to produce stereographic images. Given a location and orientation in the environment, the playback system finds a nearby capture point and translates the polygons at that point to the specified location, producing an image. It then rotates that image to the desired orientation which it then displays.

Seaming polygonal projections from subhemispherical imagery

Ensuring integrity of a video buffer verifier (VBV) employed in MPEG-like video encoders is realized by controllably adjusting the bits being drained from a video encoder buffer (eBuff). The number of bits being drained from eBuff is adjusted through feedback to minimize the difference in the bit content of a buffer (mBuff) maintained in a bit-rate controller in the video encoder that models the buffer of a hypothetical decoder, and the bit content of that hypothetical buffer (vBuff). Specifically, this is realized by controllably inhibiting transmission of bits from eBuff during intervals that the value of a prescribed relationship is greater than a predetermined value. In one example, the prescribed relationship is dependent on an instantaneous video encoding rate, an end-to-end delay, the bit content of mBuff and the bit content of eBuff.

Ensuring video buffer verifer integrity in MPEG-like encoding

A transcoding method for inserting a visual element into an encoded bit stream with minimal decoding of the encoded bit stream. The transcoding method includes the steps of receiving an encoded bit stream containing a picture, partially decoding a copy of the bit stream, determining if a segment of the picture in the bit stream is affected by the insertion of the visual element, re-encoding the segment if the segment is affected by the insertion of the visual element, and outputting the re-encoded bit stream. The encoded and re-encoded bit streams may be MPEG-encoded bit streams. The re-encoded bit stream may be output using a bit rate control process that randomly selects an initial processing point within the re-encoded bit stream, requantizes the re-encoded bit stream using a modified quantization table, and/or utilizes a slice-level stopping criteria for selectively starting or ending bit rate control.

Method for inserting a visual element into an MPEG bit stream

Method and apparatus for simulating movement in multidimensional space with polygonal projections from subhemispherical imagery

A transcoding method is performed by receiving a first bitstream of compressed image data having identifiable coding parameters. These parameters may relate to the GOP structure of pictures represented in the first bitstream, the size of the pictures represented in the first bitstream, whether the pictures represented in the first bitstream are field or frame pictures, and/or whether the pictures represented in the first bitstream define a progressive or interlaced sequence. First motion information is obtained from the first bitstream, and is used to extrapolate second motion information for a second bitstream of compressed image data. The second bitstream, which has one or more parameters different from the parameters of the first bitstream, is provided as a transcoded output.

Motion vector extrapolation for transcoding video sequences

Method and apparatus for simulating movement in multidimensional space

Frame dissimilarity measure (FDM) values are generated for pairs of frames in a video sequence that are separated by a specified timing window size, where each FDM value is the ratio of a net dissimilarity measure and a cumulative dissimilarity measure. In one embodiment, a first threshold condition is applied to identify peaks in the FDM data that could correspond to transitions between shots in a video sequence. A second threshold condition is applied to the FDM data adjacent to the detected peaks to identify frames at the start and end of the transition. The first threshold condition determines whether the FDM values exceed a first specified threshold level, while the second threshold condition determines whether the FDM values fall below a second specified threshold level. The net and cumulative dissimilarity measures may be based on histograms for the two frames. The present invention is effective in detecting gradual transitions between shots, such as wipes, dissolves, and fades, as well as abrupt transitions, such as cuts.

Detection of transitions in video sequences

The efficiency of variable-length (VL) encoding data using a defined VL encoding table is characterized and one or more changes to one or more entries of the defined VL encoding table are determined that increase the efficiency of encoding the data. An updated VL encoding table is generated from the defined VL encoding table based on the changes. VL codes for the data are generated using the updated VL encoding table, and an encoded bitstream is generated from VL codes, wherein the encoded bitstream explicitly identifies the changes. For decoding, the changes are extracted from the encoded bitstream and an updated VL decoding table is generated from a defined VL decoding table corresponding to the defined VL encoding table, based on the changes. The VL codes in the encoded bitstream are decoded using the updated VL decoding table to generate a set of decoded data.

Variable-length encoding using code swapping

A computer-implemented method for encoding symbols of a current message with a variable-length code. According to a preferred embodiment, the statistics of the current message, are analyzed, wherein the symbols of the current message constitute a symbol set. Dominant symbols of the symbol set which are out of order are determined. Selected symbols of the dominant symbols are reordered in the variable-length code to reduce the size of code words of the variable-length code which represent the selected symbols.

Ordering corrector for variable length codes

Information for forming a predicted image having at least two blocks sharing a common border is evaluated to determine whether a discontinuity exists at the common border. If it is determined that a discontinuity exists at the border, the predicted image is filtered in the vicinity of the border.

Method and apparatus for minimizing blockiness in reconstructed images

An apparatus and computer-implemented method for decoding code words of an encoded bitstream associated with a variable-length code. According to a preferred embodiment, a processor forms a byte having BS bits in accordance with bits of the encoded bitstream and in accordance with any unused bits remaining after decoding a previous code word. The byte is applied to a table, and if the byte comprises at least one complete code word, then the table means produces at least one decoded symbol corresponding to the at least one complete code word, and a plurality of unused bits comprised of bits of the byte not within the at least one complete code word is determined.

Table-driven statistical decoder

A method and apparatus for generating views of an environment with proper perspective and parallax. This invention captures panoramic views at many points in the environment and stores them as planar polygons, which have been extended to include imagery occluded at their viewing position but visible at nearby points. Three-dimensional information on the environmental source of these polygons is determined and stored, enabling the playback system to simulate parallax as well as to produce stereographic images. Given a location and orientation in the environment, the playback system finds a nearby capture point and translates the polygons at that point to the specified location, producing an image. It then rotates that image to the desired orientation which it then displays.

A computer-implemented method for processing signals. According to a preferred embodiment, at least one dominant symbol of a set S comprising a plurality of symbols is determined and a dominant set comprising the at least one dominant symbol is formed. A next symbol for encoding is received. It is determined whether the next symbol is in the dominant set. The next symbol is encoded by either entropy encoding or variable-length encoding in accordance with this determination.

Growing community of inventors

East Windsor, NJ, United States of America

Stuart J Golin