Abstract: This invention provides a method for creating/writing defect management information of an information recording medium and an apparatus and optical disc based on the method. In the present invention, it depends on the type of data to be reproduced whether or not defective sectors which are detected during reproduction operation are replaced with non-defective sectors. If read-out errors are detected in reproducing non-audio/video data, linear replacement algorithm is applied to the corresponding defective sectors. On the other hand, in case of audio/video data, location information of the corresponding defective sectors is just kept without any sector replacement. Therefore, this invention enables to reproduce audio/video data in real-time regardless of the presence of defective sectors and to avoid writing data to the defective sectors when new data is overwritten to the information recording medium.

Abstract: An error concealment method of a motion video decompression system is disclosed. The present invention uses motion vector estimation to recover video signals, with errors generated by a transmission state, nearly to the original video. Particularly, the present method includes estimating motion information of a lost video, and restoring the lost video from a video adjacent to the lost video by using the estimated motion information.

Abstract: Data which is transmitted over the internet or other transmission networks is first divided up into individual information packets, transmitted and then reassembled into useful data after reception. Parity packets are included in with the information packets in the transmission of data in order to enable the regeneration of any information packets which were lost or damaged during transmission. The grouping of information packets and parity packets derived therefrom is termed a chunk. Chunk arrangements to recover from all cases of single and double lost packets are disclosed. Bursts of lost packets are recovered by interleaving the transmission of packets from different chunks. If the recovery is not successful then retransmission occurs in a manner similar to TCP.

Abstract: In a method for concealing errors in an audio data stream the occurrence of an error is detected in the audio data stream, audio data prior to the occurrence of the fault being intact audio data. Thereafter a spectral energy of a subgroup of the intact audio data is calculated. After forming a pattern for substitute data on the basis of the spectral energy calculated for the subgroup of the intact audio data, substitute data for erroneous or missing audio data which correspond to the subgroup are created on the basis of the pattern.

Abstract: A video decoder is provided with robust error handling and concealment. In one embodiment, the video decoder detects syntactic, semantic, and coding errors in encoded slices of macroblocks. An error handler determines the number of remaining un-decoded macroblocks in the corrupted slice and replaces these corrupted macroblocks using substitute DCT coefficient matrices and motion vectors. The zero-frequency DCT coefficient of each substitute matrix is set equal to the zero-frequency DCT coefficient of the last uncorrupted macroblock, while the higher frequency DCT coefficients are set equal to zero. The substitute motion vectors are provided from a concealment vector memory which buffers the motion vectors of the previous macroblock row. In this way, intelligent approximations are made for the missing macroblocks, effectively masking the video bitstream error.

Abstract: Cable TV providers have an infrastructure which is well suited for providing additional services such as telephone and data connections to their subscribers. Techniques are disclosed for improving the error detection, masking, and avoidance capabilities of such a system. Because the system can distinguish telephony from data traffic, alternate error masking techniques can be employed for each type of traffic. An erroneous telephony packet, for example, can be replaced by silence, because the ear is relatively insensitive to short voids. Additionally, the links to the data or telephony provider can be maintained by the cable provider during interim noise periods. Because the network is structured as a multiple access network, and the likelihood of simultaneous upstream messages from all subscribers is low, error monitoring can be implemented on underutilized equipment to effect error avoidance, both as a preventive measure as well as a corrective measure.

Abstract: The system and method of the present invention provides an innovative technique and efficient hardware structure for recovering lost or damaged (lost/damaged) compression constants in the encoded domain. In one embodiment, a lost/damaged compression constant is recovered by estimating a compression constant of the block using encoded data of at least one neighboring block of data and other recoverable compression constants of the block.

Abstract: A method and apparatus for generating blocks of data for an image is described. An image is divided into a localized area. For each localized area, pixels are assigned to blocks following a complementary pattern. The complementary pattern is designed such that most pixels are adjacent to pixels arising from other blocks. The neighboring pixels provide information that is useful for reconstructing data that is lost due to burst error. In one embodiment, this is used in the transmission of video signals over a potentially lossy communications channel.

Abstract: An image processing apparatus comprises a receiving device for receiving encoded image data which is encoded by using orthogonal transform in a predetermined block unit, an error detecting device for detecting a transmission error of the encoded image data, a correcting device for correcting the transmission error in the predetermined block unit, and a decoding device for decoding the encoded image data and outputting image data for reproducing an image. The image processing apparatus satisfactorily controls the amount of compressed data and prevents a deterioration of image quality even if any error occurs on a transmission path, thereby reproducing good image quality.

Abstract: Method and apparatus for preventing unauthorized replication of a digital data file. A plurality of second data set samples are substituted for a plurality of user data samples in a user data sequence to generate a combined data set. Error correction codes are calculated to correct errors in the combined data set. Uncorrectable errors are then intentionally written to the error correction codes corresponding to the second data set samples so that, during playback, the readback system conceals the corresponding second data set samples. An unauthorized copy of the digital data file will not include the uncorrectable errors; thus, the same readback system will output both the user data samples and the second data set samples, with the second data set samples interfering with the integrity of the user data samples.

Abstract: An approach for error flow control in a communications system involves receiving a plurality of frames of data; determining in said plurality of frames of data, two or more contiguous defective frames of data, the two or more contiguous defective frames of data being followed by at least one frame of data in said plurality of frames that is not defective; forming a group reject message indicative of a range of the two or more contiguous defective frames; transmitting the group reject message; and receiving replacement frames, the replacement frames corresponding to the two or more contiguous defective frames, wherein said at least one frame that is not defective is not received again in response to the group reject message.

Abstract: A remote convenience system (10) includes a portable transmitter unit (14) and a receiver unit (18), and by a method, permits remote control of performance of a function, via a signal (16). Preferably, the system (10) is a remote convenience system for a vehicle (12). The transmitter unit (14) has a microcomputer (90) that provides a message that contains a function request. First and second signals are transmitted from the transmitter unit (14). Each signal is provided by a transmitter portion (70) at a different frequency and conveys the complete message. The receiver unit (18) has a detector (e.g., 190) tuned to receive the signal (16) for both the first and second frequencies, and can discern the complete message provided via both frequencies or either frequency. Thus, if the transmitter unit (14) is in a frequency dependent “dead spot”, communication is not prevented.

Abstract: A frame error detection method includes the steps of determining a plurality of comparison values which include a given comparison value depending on a frame energy of a given speech frame or a change in frame energy between the given speech frame and a preceding speech frame. The given speech frame is identified as a bad speech frame if a logical combination of a plurality of criteria is met. One of the criteria is based on a comparison of a threshold value with the given comparison value depending on the frame energy or the change in frame energy. A device for frame error detection and a receiver including the device for frame error detection are also provided.

Abstract: First and second instances of a message are received over a wireless connection. It is determined whether the first and second instances of the message contain an error. If both instances contain an error, an error free instance of the message is reconstructed from the two erroneous instances by merging portions of the first and second instances.

Abstract: A system and method for conducting secure fault tolerant transactions, such as financial transaction, remotely is disclosed. The transactions are conducted utilizing a portable processor device which is initialized and authorized according to the present invention. Thereafter, the portable processor operates to conduct transactions involving information exchange through unsecured communication paths according to a predetermined protocol. The protocol includes the use of atomic transactions within the portable processor device.

Abstract: Disclosed is a peripheral device for reliably detecting synchronization patterns in CD-ROM media. The peripheral device has an internal circuitry for controlling and processing data that is read from a medium of the peripheral device is disclosed. The peripheral device comprises a digital signal processor, a decoder circuit, and a state machine. The digital signal processor is configured to receive the data that is being read from the medium of the peripheral device. The decoder circuit is coupled to the digital signal processor and forms a part of the internal circuitry. Further, the decoder circuit includes an internal RAM that is configured to store a sector of the data including a current sync pattern and a next sync pattern. The state machine resides in the decoder for analyzing the current sync pattern and the next sync pattern of the sector of the data. In the analysis mode, the state code is configured to determine whether a fatal error is present in the data.

Abstract: A system and method for recovering lost/damaged attribute data in a bitstream of encoded data comprising attribute data and encoded sample data is disclosed. The decoded neighboring data is retrieved and lost/damaged attribute data is estimated using the encoded sample data, the decoded neighboring data, and available attribute data. In one embodiment, this is used in the transmission of video signals over a potentially lossy communications channel.

Abstract: In order to improve the transmission quality of block-coded audio signals in audio communications systems, for example in DECT cordless telephones, when transmission errors occur, in such a manner that the requirement for computation power and thus the costs are minimal and no additional delay occurs to the audio signal to be transmitted, pauses in the audio signal which are caused by transmission errors are replaced by a pause-specific substitution signal which is generated in advance. In the simplest case, the substitution signal is generated by the signal section which immediately precedes a given signal section of the audio signal being buffer-stored and, if the given signal section is disturbed, being inserted into the gap which is produced by the disturbance.

Abstract: The renew characters (R1/R2 or, respectively, R1'/R2') that are entered into a transmission frame by the subscriber equipment (MS) or by the network equipment (IWF) upon setup or resetting of the information protection connection indicate a frame number of a frame that has not yet been sent or, respectively, of a frame that is guaranteed to have been received. The first numbered transmission frame (NFR) to be sent in the information transmission phase after the setup or resetting receives the frame number. As a result of the renew character, the same static starting value is not always employed for the numbering of the frames to be sent after the setup or resetting of the information protection connection. It can thus be reliably recognized whether the frame was sent before or after the setup or, respectively, resetting of the information protection connection.

Abstract: A system and method are provided for improving speech quality for signals divided into a frame structure. Speech information in a signal is detected, and a lost or corrupted transmitted frame is detected. The lost or corrupted frame is replaced by a suitable frame if a number of frames represented e.g., by a counter value, exceeds a predetermined value. The counter value may be changed, depending on whether the system is in a comfort noise generation state or in a muting period. The frame may be replaced by a frame representing mainly background noise, generated at the transmitting end during speech pauses or at the receiving end, or such a frame and a correctly received frame. The predetermined value may be the length of a muting period or may be the number of lost or corrupted frames preceding a speech frame. A first of the correctly received speech frames that follows a number of lost or corrupted frames may also be replaced. The output frames gradually approach pure speech frames.

Abstract: Bit streams are divided on a block-by-block basis based on information of bit numbers and a parity bit added to each bit stream is checked to generate a switching signal. Either each bit stream or a proximate bit stream for each bit stream is selected as an optimum bit stream based on the switching signal, wherein the proximate bit stream is generated based on degrees of proximity for reference bit streams spatially adjacent to each bit stream, and the optimum bit stream is decoded to generate decoded data on a block-by-block basis.

Abstract: A receiver of block coded speech signals receives signals transmitted by means of discontinuous transmission and estimates the acceptable or unacceptable nature of the blocks received. A volume control device commands reduction of the volume in the case of reception of unacceptable blocks. A detector, on the basis of the results of the estimate, determines if the signals received are signals transmitted using discontinuous transmission. The volume is restored in the case of such detection.

Abstract: Desired audio information intermittently present in a first audio signal is communicated over a communications medium by generating a first communications signal in the communications medium when the desired audio information is present in the first audio signal, the first communications signal representing the first audio signal encoded as blocks of communications data according to a predetermined code. A second communications signal is received from the communications medium. The received second communications signal is processed to produce processed blocks of communications data. A metric representing the validity of a plurality of the processed blocks of communications data is then determined, and a second audio signal is generated from the plurality of processed blocks of communications data when the metric is within a predetermined range.

Abstract: Bit streams transmitted from a coding system through a transmission channel are divided on a block-by-block basis based on bit numbers thereof and a parity bit added to each bit stream is checked to decide whether or not each bit stream is error bit stream having one or more error bits therein. Based on the check result, either each bit stream or a proximate bit stream for each bit stream is selected as an optimum bit stream, wherein the proximate bit stream is generated based on degrees of proximity between masked transform coefficients for each candidate bit stream and masked transform coefficients for each of reference bit streams spatially adjacent to each bit stream.

Abstract: Transmission and reception nodes are connected to a communication network to be controlled with respect to time according to bus time as time information shared therebetween. The transmission node periodically transmits data while keeping a predetermined free period of time. The reception node decides normality of data received. At detection of abnormality in reception, the reception node transmits during the free period of time a re-transmission request signal to the transmission node with specification of information identifying the bus time of the abnormal data reception. On receiving the re-transmission request signal, the transmission node obtains the data transmitted at the bus time identified by the information specified by the re-transmission request signal and then re-transmits the data during the free period of time to the reception node.