463 results about "Error concealment" patented technology

An insertion-based error concealment method and apparatus are provided whereby, instead of directly inserting white noise, a filter is created to shape the white noise. The filtered white noise is then used to replace lost data. The method of the present invention is implemented by first estimating the power spectrum of the previous frame; then designing a filter with transfer function H(f), where |H(f)|²=the estimated power spectrum; and finally generating the replacement packet using noise which has been spectrally modified by the filter. The resulting filtered noise has the same power spectrum as the previous packet but is not highly correlated with it.

An information processing apparatus and method for reducing an unnecessary waiting time in a depacketizing process and enabling processing to be easily performed at high speeds applicable to, for example, an encoding apparatus. An analysis unit compares input image data with image data of one previous picture read out from a storage unit. On the basis of the analysis result, a concealment header generation unit generates a concealment header that is referred to by a receiving apparatus at the time of an error concealment process. On the basis of the concealment header, a loss analysis unit performs error concealment for the occurrence of a transmission error by suitably using encoded data stored in a storage unit.

A method and apparatus to process erroneous bi-directionally predicted multimedia data is described. The method includes determining temporal prediction data for the erroneous multimedia data, and estimating the erroneous multimedia data based on the determined temporal prediction data. The temporal prediction data includes data that was used to predict a forward reference section and/or a backward reference section. In some aspects, the temporal prediction data comprises motion vector data of the reference frames which is scaled to correspond to a frame containing the erroneous data.

Concealment of errors in a coded image occurs by first selecting an inter-prediction mode in accordance with the coding of the image. The selected intra-prediction mode, while ordinarily used to specify the direction for obtaining a coding prediction value, also serves to specify the direction for obtaining estimated values for error concealment. An interpolation filter defines the manner of obtaining estimated pixel values along the direction specified by the intra-prediction mode. Like the intra-prediction mode, the interpolation filter is derived in accordance with the coding of the image. Concealment of the image is achieved using the estimated values obtained in the manner prescribed by the interpolation filter.

A system and method for partitioning XML-based content into fragments, where transport packets are generated for encapsulating the fragments and streaming the encapsulated fragments to a receiver, such as a mobile device. Fragmentation of the XML-based content can be performed either with or without regard for any underlying XML syntax or structure. In either case, certain relevant fragmentation information is encapsulated with the fragmented XML-based content in the transport packets that allow for various reconstruction, error concealment, and retransmission schemes for presenting the streamed XML-based content on/to the receiver.

Video encoding and decoding methods and apparatuses are provided which are effective for error correction and error concealment in an error-prone environment. The video encoding method includes determining an encoding operation to encode raw video among a frame encoding operation, a top/bottom field encoding operation, and a left/right field encoding operation based on at least one characteristic of the raw video; and generating a bit stream by adaptively performing the encoding operation that is determined to encode the raw video. Further, video may be divided into frame pictures, top/bottom field pictures and left/right field pictures, and encoded accordingly. Therefore, a compression rate can be increased, and error correction and concealment can be effectively performed on a lost field by using a normally received field.

An MPEG-4 system with error concealment is provided for video service under the network with packet loss. The MPEG-4 system includes an encoder and a decoder. The encoder uses an intra-refreshment technique is used to make coded bitstream more robust against noise in order to stop error propagation. The rate-distortion optimization criterion is also introduced to adaptively update in synchronization with intra-coded blocks adaptively based on the true network condition with minimal overhead. The Lagrange multiplier is modified to achieve the best rate-distortion balance. In addition, a decoder loop is used in the encoder and is synchronized with the true decoder to achieve the best performance and avoid mismatch with the decoder used in the MPEG-4 system. The decoder is able to achieve resilient decoding from any kind of noise and enhance the reconstructed image quality with spatial and temporal hybrid concealment method. The result shows that a 3.65-9.71 dB further improvement on peak-signal-to-noise-ratio (PSNR) can be achieved in comparison with the existing methods that adopt spatial copy and zero motion concealment in decoding.

Disclosed herein is a system and method for reconstruction video information lost as a result of transmission errors. The system and method have four aspects, including: (1) changing the bit and/or packet rate; (2) inserting redundant information into the video bitstream; (3) providing automatic refresh of certain regions of the video on a periodic basis; and (4) interleaving coded macroblocks into diversity groups for transmission to spatially spread the effect of lost packets. The image reconstruction may then take advantage of these three aspects to provide an enhanced result in the presence of transmission losses.

Efficient techniques are provided to detect and correct channel errors found in an encoded video signal. In one example embodiment, header information in a video frame is analyzed to detect channel errors in the video frame. The video frame is then corrected for detected channel errors by isolating the detected channel errors to a few macroblocks in the video frame to reduce data loss and improve video quality.

The present invention provides an apparatus and a method for error concealment. The control core receives an input signal and identifies an error macro-block in a column of slice of a frame and a frame type of the frame. The parameter computation module receives a plurality of DCT coefficients and temporal data to derive at least a coefficient for the weighting in an adaptive computation for the frame. The temporal compensation module computes the temporal data to obtain a result of the temporal compensation. The spatial processing module computes spatial data to obtain a result of the spatial processing. The adaptive processing module proceeds the adaptive computation with the coefficient for the weighting derived by the parameter computation module, the result of the temporal compensation and the result of the spatial processing, and generates a result of the adaptive processing. The spatial processing may be a bilinear interpolation or a spatial interpolation.

A frame error concealment method and apparatus and a decoding method and apparatus using the same. The frame error concealment method includes setting a concealment method to conceal an error based on one or more signal characteristics of an error frame having the error and concealing the error using the set concealment method.

Errors in coded macroblocks are concealed during decoding by way of an error concealment stage present in a decoder. Error-concealed macroblocks produced by the error concealment stage undergo deblocking filtering by a deblocking filter before being output by the decoder to avoid the spread of erroneous pixel values. The error concealment stage controls the deblocking filter in accordance with the error concealment technique to vary the strength of the deblocking filter to force maximum strength on transitions artificially created by the recovery of lost macroblocks.

Error concealment is used to hide the effects of errors detected within digital video information. A complex error concealment mode decision is disclosed to determine whether spatial error concealment (SEC) or temporal error concealment (TEC) should be used. The error concealment mode decision system uses different methods depending on whether the damaged frame is an intra-frame or an inter-frame. If the video frame is an intra-frame then a similarity metric is used to determine if the intra-frame represents a scene-change or not. If the video frame is an intra-frame, a complex multi-termed equation is used to determine whether SEC or TEC should be used. A novel spatial error concealment technique is disclosed for use when the error concealment mode decision determines that spatial error concealment should be used for reconstruction. The novel spatial error concealment technique divides a corrupt macroblock into four different regions, a corner region, a row adjacent to the corner region, a column adjacent to the corner region, and a remainder main region. Those regions are then reconstructed in that order and information from earlier reconstructed regions may be used in later reconstructed regions. Finally, a macroblock refreshment technique is disclosed for preventing error propagation from harming non-corrupt inter-blocks. Specifically, an inter-macroblock may be ‘refreshed’ using spatial error concealment if there has been significant error caused damage that may cause the inter-block to propagate the errors.

Spatial concealment of errors in an intra picture comprised of a stream of macroblocks is achieved by predicting the missing data in a macroblock based on an intra prediction mode specified in neighboring block. In practice, when macroblocks within a stream are coded by a block based coding technique, such as coding technique specified in the H.264 ISO/ITU standard, a macroblock can be predicted for coding purpose based on neighboring intra prediction modes specified by the coding technique.

Error concealment for video with a scene change detection based on inter-coded macroblock energy, spatial concealment for scene changes, and temporal concealment with predicted motion vectors as the global motion vector of the prior frame when half of the current frame macroblocks are corrupted.

An error concealment method and device for recovering lost data in the AAC bitstream in the compressed domain. The bitstream are partitioned into frames each having a plurality of data parts including the header/global gain, scale factors and QMDCT coefficients. The data parts are stored in a plurality of buffers, so that if one or more data parts of a current frame is corrupted or lost, the corresponding data part in the neighboring frames is used to conceal the errors in the current frame.

In video coding, prediction of P- and B-frames is based on reference frames, which are indicated by reference picture lists. Scalable video coding (SVC) requires this for both, base-layer and enhancement-layer. The invention describes a decoding process for reference picture list construction for spatial enhancement layer. With just one flag of syntax modification, it provides simpler and direct reference lists construction process. By using this, complicated RPLR and other syntaxes can be skipped, and the RPLR process for spatial enhancement layer can also be avoided. The process also can be used as for error concealment when the spatial enhancement layer slice is lost.

A method for performing spatial error concealment is provided. The method includes the following steps: detecting a damaged macroblock; obtaining coding information of neighboring macroblocks of the damaged macroblock; determining edge feature of the damaged macroblock based on the coding information; and according to the edge feature, selecting a bilinear interpolation algorithm or a directional interpolation algorithm to conceal errors within the damaged macroblock.

Provided are a method and apparatus for detecting an error during video decoding and handling of the error. An error is detected in a received video stream having a predetermined format, error information is recorded at a predetermined location of the video stream, and the type of the error is determined using the recorded error information. The video decoder includes a broadcast signal receiver that extracts a broadcast stream from a broadcast signal being transmitted via a transmission medium, a demultiplexing and error detection unit that demultiplexes the broadcast stream of a predetermined format extracted by the broadcast signal receiver for extraction of a video stream, detects errors in packets making up the extracted video stream, and records error information at a predetermined location of the video stream, and a video decoding unit that interprets the error information, determines the type of the errors using a predetermined method, and decodes the video stream according to the result of determination. The type and position of an error may be determined during video decoding. The video decoder is able to improve video quality by performing proper error concealment according to the type of error determined.