Intervideo, Inc.

Corel Corporation

Corel Software LLC

8324450 Delaware LLC

Ioannis Katsavounidis

Chang-su Kim

Lifeng Zhao

Chung-Tao Chu

Te-Chien Chen

Yu-Nien Chien

Chun-Huan Chuang

Kuo-Wei Hsu

Jong Hyuk Kim

Jongwon Kim

Jin-Gyeong Kim

A method and an apparatus for performing multi-threaded video decoding are disclosed. The method takes use of a multi-threaded scheme to process an encoded picture stream on a picture by picture basis. In the method, multiple threads are used for performing video decoding at the same time, such as one thread for the operation of parsing input bits into syntax elements of one picture implemented by the first thread, another thread for the operation of decoding the parsed syntax elements of another picture into pixel values implemented by the second thread, and the other threads for the operations of the non-reference picture, such as bidirectional predictive picture, including parsing input bits into syntax elements and the subsequent operation of decoding the parsed syntax elements into pixel values. Therefore, the decoding speed is substantially increased, and the decoding efficiency is enhanced.

Method and apparatus for multi-threaded video decoding

The invention is related to methods and apparatus that decode robustly encoded video bitstreams. One embodiment of a decoder can advantageously reconstruct a predictive-coded video object plane (P-VOP) from a standard motion vector and the previous frame; from a redundant motion vector and a frame prior to the previous frame; or from both. Advantageously, this permits the decoder to display a frame based on a reconstructed VOP in the presence of unfavorable environmental conditions, such as interference, delays, and the like, which could otherwise corrupt a previous frame that is used as a reference by a standard decoder, such as a standard MPEG-4 decoder. One embodiment is advantageously backwards compatible with standard MPEG-4 compliant bitstreams and retrieves redundant motion vector information from user data video packets. One embodiment includes at least one extra frame buffer or memory, which stores a reference frame corresponding to a redundant motion vector.

Systems and methods for decoding redundant motion vectors in compressed video bitstreams

The invention is related to methods and apparatus that advantageously improve picture quality in a video encoder, such as an MPEG video encoder. The picture quality of a video encoder can be compromised by bit stuffing. Bit stuffing is a technique that is commonly used when encoding to resolve buffer underrun problems. However, bit stuffing can introduce instabilities in the encoding process. Embodiments of the invention advantageously stabilize the encoding process due to bit stuffing, and thereby improve picture quality.

Systems and methods for improving bit rate control of video encoding by correcting for the effects of scene changes and bit stuffing in a video buffer verifier (VBV) buffer model

The invention is related to methods and apparatus that can advantageously be used in a video encoder to improve picture quality, to improve the speed of encoding, and the like. One embodiment of the invention advantageously computes activity measures using an efficient L1-norm, which can advantageously be relatively quickly computed by selected microprocessors. Another embodiment of the invention advantageously allocates bits to macroblocks of a picture based at least in part on the motion activities of the macroblocks.

Systems and methods for allocating bits to macroblocks within a picture depending on the motion activity of macroblocks as calculated by an L1 norm of the residual signals of the macroblocks

Methods and apparatus are provided to advantageously improve bit rate control in a video encoder, such as an MPEG video encoder. The targeted bit allocation for a picture to be encoded is advantageously varied based on an occupancy level of a buffer model, such as a video buffer verifier (VBV) buffer model.

Systems and methods for adjusting targeted bit allocation based on an occupancy level of a VBV buffer model

The invention is related to methods and apparatus that recover usable video data from partially corrupted data. Embodiments inspect corrupted data packets and identify the location or locations of an error, whether the corrupted data packet contains data expected to be error-free, and whether the error-free data should be used. Decoding of a packet in both the forward direction and the backward direction can be used to locate a position of an error. Intra-coded macroblocks can also be recovered. A decoder can elect to use or to drop an intra-coded macroblock recovered from a corrupted data packet according to further criteria that is applied to the recovered intra-coded macroblock. One embodiment inspects video bitstream data that has been encoded with an optional data partitioning feature enabled, and retrieves specified data in areas of a corrupted packet that are expected to be free from error.

Systems and methods for decoding of partially corrupted reversible variable length code (RVLC) intra-coded macroblocks and partial block decoding of corrupted macroblocks in a video decoder

The invention is related to methods and apparatus that encode redundant motion vectors for predictive-coded visual object planes (P-VOPs) to increase the robustness of transmitted video signals. One embodiment provides the redundant motion vectors in a user data video packet of an MPEG-4 compliant bitstream, which thereby allows the enhanced bitstream to remain compliant with MPEG-4 syntax and backwards compatible with MPEG-4 decoders. The enhanced bitstreams allow a video decoder to display a video with a better picture and relatively less error and error propagation when portions of the bitstream are disturbed or corrupted by interference, delays, and the like.

Systems and methods for encoding redundant motion vectors in compressed video bitstreams

The present invention is related to video encoding. In an embodiment, a bit budget is calculated for a first scene. In addition, bit budgets for corresponding frames, including at least a first frame, within the first scene are determined. Optionally, bit budgets corresponding to macroblocks within the first frame are also determined.

Systems and methods for performing bit rate allocation for a video data stream

The invention is related to methods and apparatus that advantageously improve picture quality in a video encoder, such as an MPEG video encoder. Scene changes typically occur relatively frequently in picture sequences, such as movies. One embodiment of the invention detects a scene change within a group of pictures and allocates bits within the group of pictures in response to the detected scene change without changing a predetermined structure for the group of pictures.

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Pasadena, CA, United States of America

Ioannis Katsavounidis