Showing papers on "Encoder published in 1995"

Turbo codes for PCS applications

Abstract: Turbo codes are the most exciting and potentially important development in coding theory in many years. They were introduced in 1993 by Berrou, Glavieux and Thitimajshima, and claimed to achieve near Shannon-limit error correction performance with relatively simple component codes and large interleavers. A required E/sub b//N/sub o/ of 0.7 dB was reported for BER of 10/sup -5/ and code rate of 1/2. However, some important details that are necessary to reproduce these results were omitted. This paper confirms the accuracy of these claims, and presents a complete description of an encoder/decoder pair that could be suitable for PCS applications. We describe a new simple method for trellis termination, we analyze the effect of interleaver choice on the weight distribution of the code, and we introduce the use of unequal rate component codes which yields better performance. Turbo codes are extended to encoders with multiple codes and a suitable decoder structure is developed, which is substantially different from the decoder for two-code based encoders.

Multiple resolution, multi-stream video system using a single standard decoder

Abstract: A video system is disclosed in which a single generic MPEG standard encoder (107) is used to simultaneously code and compress plural different resolution video signals from a single input video signal; and in which a single generic MPEG standard decoder (402) is used to simultaneously decode plural coded and compressed video signals of different resolutions and form a single composite video signal. The coder converts each frame of pixel data of the input video signal into plural frames having different resolutions, which are then combined into a common frame (106) for input to the generic MPEG encoder. The MPEG encoder produces a single coded and compressed output bitstream in slices of macroblocks of pixel data, which output bitstream is demultiplexed (108) into separate resolution bitstreams using Slice Start Code identifiers associated with each slice and Macroblock Address Increments associated with the first macroblock in each slice, to properly route each slice to the appropriate output. The decoder processes (405) the slices within the coded and compressed bitstreams of different resolutions received from plural sources using the Slice Start Codes and Macroblock Address Increments of each slice to produce a single composite bitstream of successive slices. By merging the slices from the plural sources into the composite bitstream in a predetermined manner, the generic MPEG decoder produces a digital output video signal that is a composite of the different resolution input video signals.

Miniature combination valve and pressure transducer and system

Abstract: A valve/transducer and system for pressure measuring: which has a valve/transducer (24) comprised of an appropriately dimensioned tapered barrel (30) of rigid material with a gasket (40) near the barrel's larger diameter proximal end. The valve/transducer has an opening closable by valve cup (32) which is operated by a pin (34) extending from the barrel. The valve/transducer has within the barrel an integrated silicon circuit (44) and flex circuit electrical interface (76). The integrated circuit provides a pressure transducer (58) and an integrated processor/encoder (68). The system includes wireless transmitter/receiver paired circuits consisting of a transponder (26) and a transmit/receive channel circuit (164). The system includes a control/display processor (162) and an indicator (182) with novel displays of useful tire inflation and maintenance parameters.

An adaptive congestion control scheme for real time packet video transport

Abstract: We show that modulating the source rate of a video encoder based on congestion signals from the network has two major benefits: the quality of the video transmission degrades gracefully when the network is congested and the transmission capacity is used efficiently. Source rate modulation techniques have been used in the past in designing fixed rate video encoders used over telephone networks. In such constant bit rate encoders, the source rate modulation is done using feedback information about the occupancy of a local buffer. Thus, the feedback information is available instantaneously to the encoder. In the scheme proposed, the feedback may be delayed by several frames because it comes from an intermediate switching node of a packet switched network. The paper shows the proposed scheme performs quite well despite this delay in feedback. We believe the use of such schemes will simplify the architecture used for supporting real time video services in future nationwide gigabit networks.

Byte-parallel system for implementing reed-solomon error-correcting codes

Abstract: A high-speed byte-parallel pipelined error-correcting system for Reed-Solomon codes includes a parallelized and pipelined encoder and decoder and a feedback failure location system. Encoding is accomplished in a parallel fashion by multiplying message words by a generator matrix. Decoding is accomplished with or without byte failure location information by multiplying the received word by an error detection matrix, solving the key equation and generating the most-likely error word and code word in a parallel and pipelined fashion. Parallelizing and pipelining allows inputs to be received at very high (fiber optic) rates and outputs to be delivered at correspondingly high rates with minimum delay. The error-correcting system can be used with any type of parallel data storage or transmission media to create an arbitrary level of fault-tolerance and allows previously considered unreliable media to be effectively used in highly reliable memory or communications systems.

MPEG transport encoding/decoding system for recording transport streams

Abstract: A system records a single program from a multi-program transport stream that is encoded according to the MPEG-2 standard. The system demultiplexes transport packets from the multi-program transport stream and records the demultiplexed packets on a digital video cassette recorder (DVCR). The system includes circuitry in the encoder which emulates a buffer in the digital recorder that is used to hold the packets to convert the bursty packet data into constant rate data for recording. This emulated buffer controls the overall rate at which packets of the selected program are inserted into the multi-program transport stream by the encoder. As each packet is recorded, a time stamp value, representing when the packet was demultiplexed and a clock count value, representing a number of pulses of a high-frequency system clock signal that occurred during a predetermined number of bytes of the demultiplexed packet are recorded with the demultiplexed packet. These values are used to regenerate timing signals for a single program transport stream when the recorded packet data is replayed from the tape.

Method and apparatus for encoding and decoding data

Abstract: A method and apparatus for decompressing and compressing data is described. The present invention provides an encoder for use in a compression system having a decoder for decoding information generated by the encoder. The encoder of the present invention includes a coder for producing codeword information in response to data. The encoder also includes a reorder unit that generates a coded data stream in response to the codeword information from the coder. The reorder unit comprises a run count reorder unit for arranging codewords into a decoding order and a bit pack unit to combine variable length codewords into fixed length interleaved words and to output the fixed length interleaved words in an order required by the decoder.

Method and apparatus for compressing images

Abstract: A system and method is disclosed that compresses and decompresses images The compression system and method (126, 128, 130, 132) includes an encoder (130) which compresses images and stores such compressed images in a unique file format, and a decoder (110) which decompresses images The encoder (130) optimizes the encoding process to accommodate different image types with fuzzy logic methods (152) that automatically analyze and decompose a source image, classify its components, select the optimal compression method for each component, and determine the optimal parameters of the selected compression methods The encoding methods inlcude: a Reed Spline Filter (138), a discrete cosine transform (136), a differential pulse code modulator (140), and enhancement analyzer (144), an adaptive vector quantizer (134) and a channel encoder (132) to generate a plurality of data segments that contain the compressed image The plurality of data segments are layered in the compressed file (104) to optimize the decoding process The first layer allows the decoder (110) to display the compressed image as a miniature or a coarse quality full sized image, the decoder (110) then adds additional detail and sharpness to the displayed image as each new layer is received The decoder (110) uses optimal decompression methods to expand the compressed image file

An encoder buffer having an effective size which varies automatically with the channel bit-rate

Abstract: The effective (or logical) size of the encoder buffer in a video transmission system is varied with the transmission bit-rate. Also, a minimum fill level is maintained in the encoder buffer whenever the transmission rate is too high to assure otherwise that the decoder buffer will not overflow or underflow. The encoding rate is varied so as to maintain a fill level in the encoder buffer within limits. In the preferred embodiment, the logical encoder buffer has a size which is maintained at RΔT(1-m1)-M, where R is the average transmission bit-rate, which may vary, ΔT is the fixed delay between the encoding and decoding processes for a transmitted video signal, R(1-m1) is the minimum instantaneous transmission rate that the communication system achieves at average rate R, and M is the maximum total buffer storage in the communication system. When the decoder buffer has a size less than RΔT(1+m2), where R(1+m2) is the maximum instantaneous transmission rate at average rate R, the encoder buffer fill level is maintained above a minimum level that is equal to the amount by which the decoder buffer is less than RΔT(1+m2).

Rate compatible turbo codes

Abstract: Turbo codes can easily be used when two error protection levels are needed. The same encoder and decoder is used to achieve this unequal error protection. This will allow turbo codes to be used for channels where some information bits are more sensitive to errors than others, and at the same time where powerful codes are required (e.g. a mobile satellite channel).

Multimedia television receiver and method of booting the same

Abstract: An NTSC tuner, an ISDB tuner, a CATV tuner, and a CATV modulator are connected to an analog switch box. Demodulation sections, an A/D, clock-reproducing section, and a modulation section are connected between the analog switch box a bus. MPEG2 video decoder sections, an MPEG2 audio decoder sections, an NTSC/EDTV horizontal decoder section, an EDTV vertical decoder section, an MPEG2 video encoder section, and an MPEG2 audio encoder section are connected between the bus and a bus. An audio amplifier, a graphics controller, and A/D conversion sections are connected the bus. The switch box and the buses are connected to a bus controller, which is connected to a CPU, a memory, and a remote-control I/F. These modules are selectively used to receive and process digital broadcasting signals, digital CATV signals or NTSC broadcasting signals. Even while the CPU is performing bootstrap processing immediately after the power switch of the television receiver is turned on, a DMA device is initialized, causing a monitor to display an image being received, no matter whether an operating system has been activated or not.

Portable video-on-demand in wireless communication

Abstract: Our present ability to work with video has been confined to a wired environment, requiring both the video encoder and decoder to be physically connected to a power supply and a wired communication link. This paper describes an integrated approach to the design of a portable video-on-demand system capable of delivering high-quality image and video data in a wireless communication environment. The discussion will focus on both the algorithm and circuit design techniques developed for implementing a low-power video compression/decompression system at power levels that are two orders of magnitude below existing solutions. This low-power video compression system not only provides a compression efficiency similar to industry standards, but also maintains a high degree of error tolerance to guard against transmission errors often encountered in wireless communication. The required power reduction can best be attained through reformulating compression algorithms for energy conservation. We developed an intra-frame compression algorithm that requires minimal computation energy in its hardware implementations. >

Method and apparatus for a region-based approach to coding a sequence of video images

Abstract: An encoder segments frames in a sequence of digital images into multiple regions of arbitrary shape each of which has a corresponding motion vector relative to a previous decoded frame. A hierarchical multi-resolution motion estimation and segmentation technique, which segments the frame into multiple blocks and which assigns a best motion vector to each block is used. Blocks having the same or similar motion vector are then merged to form the arbitrarily-shaped regions. The shape of each region is coded, and a decision is made to code additional image data of each region in one of three modes. In a first inter-frame mode, a motion vector associated with a region is encoded. In a second inter-frame mode, a prediction error for the region is also encoded. In an intra-frame mode, the intensity of each picture element in the region is encoded. A region interior coder with frequency domain region-zeroing and space domain region-enforcing operations is employed for effectively coding the interior image data of the arbitrarily-shaped regions. The region interior coder uses an iterative technique based on the theory of successive projection onto convex sets (POCS) to find the best values for a group of selected transform coefficients. The coded information, including the shape of the region, the choice of the mode, and the motion vector and/or the region's interior image data, may then be transmitted to a decoder where the image can be reconstructed.

Fitness feedback system for weight stack machines

Abstract: An apparatus for providing feedback to a user of a weight stack machine having weights for lifting has an enclosure adapted for attachment to the weight stack machine. Means for sensing weight for determining the number of weights lifted is provided as well as encoder means for detecting the motion of the weights during a lift. Electronic detection means are operatively coupled to the weight sensors means and the encoder means for computing data describing the number of weights lifted. Interface means for transmitting the computed data from the electronic detection means to a central storage means and the display is provided. The interface means also receives information from the central storage means and displays it on the display.

Digital encoding process

Abstract: A digital encoding process for transmitting and/or storing acoustical sigs and, in particular, music signals, in which scanned values of the acoustical signal are transformed by means of a transformation or a filter bank into a sequence of second scanned values, which reproduce the spectral composition of the acoustical signal, and the sequence of second scanned values is quantized in accordance with the requirements with varying precision and is partially or entirely encoded by an optimum encoder, and in which a corresponding decoding and inverse transformation takes place during the reproduction. An encoder is utilized in a manner in which the occurrence probability of the quantized spectral coefficient is correlated to the length of the code in such a way that the more frequently the spectral coefficient occurs, the shorter the code word. A code word and, if needed, a supplementary code is allocated to several elements of the sequence or to a value range in order to reduce the size of the table of the encoder. A portion of the code words of variable length are arranged in a raster, and the remaining code words are distributed in the gaps still left so that the beginning of a code word can be more easily found without completely decoding or in the event of faulty transmission.

Lossless compression/decompression of digital audio data

Abstract: An audio signal compression and decompression method and apparatus that provide lossless, realtime performance. The compression/decompression method and apparatus are based on an entropy encoding technique using multiple Huffman code tables. Uncompressed audio data samples are first processed by a prediction filter which generates prediction error samples. An optimum coding table is then selected from a number of different preselected tables which have been tailored to different probability density functions of the prediction error. For each frame of prediction error samples, an entropy encoder selects the one Huffman code table which will yield the shortest encoded representation of the frame of prediction error samples. The frame of prediction error samples is then encoded using the selected Huffman code table. A block structure for the compressed data and a decoder for reconstructing the original audio signal from the compressed data are also disclosed.

Constrained and general dynamic rate shaping of compressed digital video

Abstract: We introduce the concept of dynamic rate shaping, a technique to adapt the rate of compressed video bitstreams (MPEG-1, MPEG-2, H.261, as well as JPEG) to dynamically varying bit rate constraints. The approach provides an interface (or filter) between the encoder and the network, with which the encoder's output can be perfectly matched to the network's quality of service characteristics. Since the presented algorithms do not require interaction with the encoder, they are fully applicable to precoded, stored video (e.g., video-on-demand systems). By decoupling the encoder and the network, universal interoperability can be achieved. In essence, DRS bridges the gap between CBR and VBR video, allowing a continuum of possibilities between the two. A set of low-complexity algorithms for so-called unconstrained dynamic rate shaping are presented, and both optimal and extremely fast designs are discussed. Experimental results are provided using actual MPEG-2 bitstreams.

Remote control unit for video apparatus

Abstract: A remote control unit for an external video apparatus such as a video camera and a VTR includes an infrared signal receiving section for receiving a video signal as a infrared signal from the video apparatus. A video image depending upon the video signal is displayed on a LCD display together with display information necessary for a remote control in a LCD display. An operator can easily carry out the necessary remote control operation through a key matrix, confirming the result of the operation upon reviewing the video image in the LCD display. The operator's key matrix operation is put into a microcomputer which, in turn, produces a control information for the video apparatus and transmits it to the video apparatus through an encoder and an infrared signal transmitting section. The above-mentioned display information is produced by the microcomputer and input through a character generator to the LCD display. Employing the LCD display increases the amount of information to be displayed, thereby making the remote control unit multi-functional.

Secure self learning system

Abstract: A method and system for the remote control of devices having a secure self learn capability. The system includes an encoder and a decoder, the encoder encoding variable information including a user key using a non-linear algorithm to produce an encoded value transmitted to the decoder, the decoder decoding the value using the same algorithm. In a learning mode a new encoder is to be added to the system. The new encoder produces an encoded value using a key generation seed. The decoder, upon receiving the encoded key generation seed, produces a decoding key based upon the decoded key generation seed. The decoding key is stored in the decoder memory allowing valid recognition of the new encoder in a secure manner.

JAGUAR: a fully pipelined VLSI architecture for JPEG image compression standard

Abstract: In this paper, we describe a fully pipelined single chip VLSI architecture for implementing the JPEG baseline image compression standard. The architecture exploits the principles of pipelining and parallelism to the maximum extent in order to obtain high speed and throughput. The architecture for discrete cosine transform and the entropy encoder are based on efficient algorithms designed for high speed VLSI implementation. The entire architecture can be implemented on a single VLSI chip to yield a clock rate of about 100 MHz which would allow an input rate of 30 frames per second for 1024/spl times/1024 color images. >

Check processing equipment

Abstract: A check processing equipment having an optical amount character recognizing function for a proof machine used at a bank. A received amount can be corrected on an image screen, and it enables the efficient processing for certifying operation. A document capturing unit converts the data on the document into an image data and transfers the image data to a frame memory of recognizing unit. A recognizing unit compresses the image data through a recognizing/determining section and also carries out CAR with the attribute on an E13B code line data. A work station stores the compressed image data, the code line data, and the CAR result in a hard disk and it also displays an extended image and implements the proof of a whole batch through key-in operation for handling unrecognizable data and exceptional error data. An encoder unit performs encode printing and endorse printing on proved documents while verifying the code lines thereof.

Parallel implementation of an MPEG-1 encoder: faster than real time

Abstract: In this paper we present an implementation of an MPEG1 encoder on the Intel Touchstone Delta and Intel Paragon parallel computers. We describe the unique aspects of mapping the algorithm onto the parallel machines and present several versions of the algorithms. We will show that I/O contention can be a bottleneck relative to performance. We will also describe how the Touchstone Delta and Paragon can be used to compress video sequences faster than real-time.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Field frame macroblock encoding decision

Abstract: A rate control algorithm for an MPEG-2 compliant encoder is described. The rate control algorithm has embodiments useful for constant bit rate and variable bit rate encoding. In particular, the invention relates to a field frame macroblock encoding decision.

An error concealment algorithm for images subject to channel errors

Abstract: We present an algorithm to conceal bit errors in still images and image sequences that are coded using the discrete cosine transform (DCT) and variable length codes (VLCs). No modification is necessary to an existing encoder, and no additional bit rate is required. The concealment algorithm is kept simple so that real-time decoding and concealment is possible. A single bit error in these images can cause a block to split into several blocks or several blocks to merge into one. This causes the DCT coefficients of all subsequent blocks to be correctly decoded but stored in the wrong location in the image. Furthermore, the DC coefficient of all subsequent blocks may be incorrect. The error concealment algorithm uses transform domain information to identify the location of the affected blocks and to correct errors. The image quality after error concealment is shown to be significantly improved. >

Storage optimizing encoder and method

Abstract: An encoder and method, such as for use in CD-ROM pre-mastering software, optimizes storage on a computer readable recording medium by eliminating redundant storage of identical data streams for duplicate files. The encoder and method detect whether two files have equivalent data streams, and encodes such duplicate files as a single data stream referenced by the respective directory entries of the files. In the illustrated embodiment, the encoder and method detect duplicate files based on file size and a cyclic redundancy check calculated on the file's data stream or portion thereof.

Meeting Arbitrary QoS Constraints Using Dynamic Rate Shaping of Coded Digital Video

Abstract: We introduce the concept of Dynamic Rate Shaping, a technique to adapt the rate of compressed video bitstreams (MPEG-1, MPEG-2, H.261, as well as JPEG) to dynamically varying rate (and delay) constraints. The approach provides an interface (or filter) between the encoder and the network, with which the encoder's output can be perfectly matched to the network's quality of service characteristics. Since the presented algorithms do not require interaction with the encoder, they are fully applicable to precoded, stored video (as in, for example, video-on-demand systems). By providing decoupling of the encoder and the network, universal interoperability can be achieved. A set of lowcomplexity algorithms for dynamic rate shaping is presented, and both optimal and extremely fast designs are discussed. The latter are simple enough to allow software-based implementation. Experimental results are provided using actual MPEG-2 bitstreams.

High efficiency encoding and decoding of picture signals and recording medium containing same

Abstract: An encoder considers a frame representing a picture as comprised of areas. For each area, the encoder decides which of frame-based or field-based orthogonal transformation will be most efficient at reducing spatial redundancy in that area. For each area, the encoder decides which of frame-based or field-based predictive encoding will be most efficient at reducing temporal redundancy in that area. The encoder encodes each area of the picture frame using the most efficient orthogonal transformation technique and using the most efficient predictive encoding technique to produce an encoded signal. A decoder decodes the encoded signal. The encoded signal is recorded on a recording medium, transmitted over a transmission channel, or broadcast.

Video indexing protocol

Abstract: At least one client application (510) creates a message to be transmitted to a receiver (240). The client application transmits the message to an encoder which receives the message and other messages from other client applications. The encoder transforms the composite messages into packets and multiplexes them into a bitstream to be encoded with a video programming signal. The multiplexing is performed according to priorities assigned to the at least one client application and the other applications. The encoder transmits the bitstream to a video encoder to transmit the bitstream with the programming signal to be received by a decoder. The decoder can then decode the information from the video signal and transmit the information to at least one decoder client application. The client applications may include a status application which transmits a status information (e.g. time references) at regular intervals; a program application which transmits descriptive information of the video programming synchronized with the video signal (e.g. program markers and/or program text, such as closed-captions and/or subtitles); and a non-program application.

Dual mode code division multiple access communication system and method

Abstract: A CDMA communication system capable of operating at higher data rates with less bit errors and reduced cochannel interference facilitates coherent detection without the use of a pilot tracking signal. A transmitter in the communication system includes a coherence interval channel encoder, an orthogonal function encoder, such as a Walsh encoder, as well as a pseudo noise (PN) channel modulator. The channel encoder processes data sequences into sufficiently short encoded data blocks to minimize any phase shifts at a receiver in a high mobility environment due to a Doppler frequency shift. Depending on the application, several transmitters may be synchronized such that the corresponding transmitted information signals are orthogonal to one another. A receiver of the communication system includes a channel demodulator, matched filters and coherent decoder that generates weighted decoded signals, one of which is determined to be a proper coherent synchronous reading of the received information signals without the use of a pilot tracking signal. The communication system may be used as a forward and/or reverse communications link in a cellular telephone system.

ISO-IEC MPEG-2 software video codec

Abstract: Part 5 of the International Standard ISO/IEC 13818 `Generic Coding of Moving Pictures and Associated Audio' (MPEG-2) is a Technical Report, a sample software implementation of the procedures in parts 1, 2 and 3 of the standard (systems, video, and audio). This paper focuses on the video software, which gives an example of a fully compliant implementation of the standard and of a good video quality encoder, and serves as a tool for compliance testing. The implementation and some of the development aspects of the codec are described. The encoder is based on Test Model 5 (TM5), one of the best, published, non-proprietary coding models, which was used during MPEG-2 collaborative stage to evaluate proposed algorithms and to verify the syntax. The most important part of the Test Model is controlling the quantization parameter based on the image content and bit rate constraints under both signal-to-noise and psycho-optical aspects. The decoder has been successfully tested for compliance with the MPEG-2 standard, using the ISO/IEC MPEG verification and compliance bitstream test suites as stimuli.