Ravi Krishnamurthy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: The algorithm assumes a constant bit rate over a timing window of specified duration (e.g., a specified number of consecutive frames), where the current frame to be encoded lies in the interior of the timing window. A target bit rate for the current frame is initially selected by calculating the number of bits already used to encode other frames within the window and then assuming that the remaining available bits allocated to the timing window will be evenly distributed to the remaining unencoded frames in the timing window. The target bit rate may then be optionally adjusted based on scene content, encoder state, and buffer considerations. Through a combination of target bit allocation and frame skipping, spatial and temporal resolutions are maintained within acceptable ranges while meeting buffer delay constraints. The algorithm has also been extended to include PB frames in addition to P-only coders.
November 20, 1998
Date of Patent:
October 31, 2000
Sarnoff Corporation, LG Electronics, Inc.
Abstract: After performing integer-pel motion estimation to select the best integer-pel location, half-pel (or other fractional-pel) motion estimation is performed by estimating the distortion values for all of the surrounding half-pel locations by linearly interpolating using the distortion value for the best integer-pel location and the distortion values available from the integer-pel motion estimation analysis corresponding to the surrounding integer-pel locations. A subset of those half-pel locations is then selected as candidate half-pel locations (e.g., based on lowest estimated distortion values) and true distortion values are then generated for those candidate locations. The best half-pel location is then selected based on the distortion values for the candidate half-pel locations and the best integer-pel location. This best half-pel location may then be used to perform the motion-compensated inter-frame differencing step of a video coding scheme.
Abstract: A programmable machine system and method for managing electronic data access among multiple different relational databases in a network distributed database environment. The machine is programmed so that it can construct cost-effective access strategies for any of the participating databases absent any DBMS-specific cost models. The system provides query optimization across different database management systems in a network distributed database environment based on a calibrating database relying only on typical relational database statistics and cost data is developed by running queries in the various databases against the calibrating database. A logical cost model is constructed using the resulting cost data and is used to estimate the cost of a given query based on logical characteristics of the DBMS, the relations, and the query itself. The cost of a complex query is estimated using primitive queries.
August 20, 1992
Date of Patent:
May 2, 1995
Weimin Du, Ravi Krishnamurthy, Ming-Chien Shan