Abstract: 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.

Abstract: 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.

Abstract: 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.