A system of distributing video and/or audio information employs digital signal processing to achieve high rates of data compression. The compressed and encoded audio and/or video information is sent over standard telephone, cable or satellite broadcast channels to a receiver specified by a subscriber of the service, preferably in less than real time, for later playback and optional recording on standard audio and/or video tape.

Audio and video transmission and receiving system

A digital video compression system and an apparatus implementing this system are disclosed. Specifically, matrices of pixels in the RGB signal format are converted into YUV representation, including a step of selectively sampling the chrominance components. The signals are then subjected to a discrete cosine transform (DCT). A circuitry implementing the DCT in a pipelined architecture is provided. A quantization step eliminates DCT coefficients having amplitude below a set of preset thresholds. The video signal is further compressed by coding the elements of the quantized matrices in a zig-zag manner. This representation is further compressed by Huffman codes. Decompression of the signal is substantially the reverse of compression steps. The inverse discrete cosine transform (IDCT) may be implemented by the DCT circuit. Circuits for implementing RGB to YUV conversion, DCT, quantization, coding and their decompression counterparts are disclosed. The circuits may be implemented in the form an integrated circuit chip.

System for compression and decompression of video data using discrete cosine transform and coding techniques

A low bit-rate (192 kBits per second) transform encoder/decoder system (44.1 kHz or 48 kHz sampling rate) for high-quality music applications employs short time-domain sample blocks (128 samples/block) so that the system signal propagation delay is short enough for real-time aural feedback to a human operator. Carefully designed pairs of analysis/synthesis windows are used to achieve sufficient transform frequency selectivity despite the use of short sample blocks. A synthesis window in the decoder has characteristics such that the product of its response and that of an analysis window in the encoder produces a composite response which sums to unity for two adjacent overlapped sample blocks. Adjacent time-domain signal samples blocks are overlapped and added to cancel the effects of the analysis and synthesis windows. A technique is provided for deriving suitable analysis/synthesis window pairs. In the encoder, a discrete transform having a function equivalent to the alternate application of a modified Discrete Cosine Transform and a modified Discrete Sine Transform according to the Time Domain Aliasing Cancellation technique or, alternatively, a Discrete Fourier Transform is used to generate frequency-domain transform coefficients. The transform coefficients are nonuniformly quantized by assigning a fixed number of bits and a variable number of bits determined adaptively based on psychoacoustic masking. A technique is described for assigning the fixed bit and adaptive bit allocations. The transmission of side information regarding adaptively allocated bits is not required. Error codes and protected data may be scattered throughout formatted frame outputs from the encoder in order to reduce sensitivity to noise bursts.

Low bit rate transform coder, decoder and encoder/decoder for high-quality audio

A pipeline video decoder and decompression system handles a plurality of separately encoded bit streams arranged as a single serial bit stream of digital bits and having separately encoded pairs of control codes and corresponding data carried in the serial bit stream. The pipeline system employs a plurality of interconnected stages to decode and decompress the single bit stream, including a start code detector. When in a search mode, the start code detector searches for a specific start code corresponding to one of multiple compression standards. The start code detector responding to the single serial bit stream generates control tokens and data tokens. A respective one of the tokens includes a plurality of data words. Each data word has an extension bit which indicates a presence of additional words therein. The data words are thereby unlimited in number. A token decode circuit positioned in certain of the stages recognizes certain of the tokens as control tokens pertinent to that stage and passes unrecognized control tokens to a succeeding stage. A reconfigurable decode and parser processing means positioned in certain of the stages is responsive to a recognized control token and reconfigures a particular stage to handle an identified data token. Methods relating to the decoder and decompression system include processing steps relating thereto.

Multistandard video decoder and decompression system for processing encoded bit streams including a video formatter and methods relating thereto

A pipeline video decoder and decompression system handles a plurality of separately encoded bit streams arranged as a single serial bit stream of digital bits and having separately encoded pairs of control codes and corresponding data carried in the serial bit stream. The pipeline system employs a plurality of interconnected stages to decode and decompress the single bit stream, including a start code detector. When in a search mode, the start code detector searches for a specific start code corresponding to one of multiple compression standards. The start code detector responding to the single serial bit stream generates control tokens and data tokens. A respective one of the tokens includes a plurality of data words. Each data word has an extension bit which indicates a presence of additional words therein. The data words are thereby unlimited in number. A token decode circuit positioned in certain of the stages recognizes certain of the tokens as control tokens pertinent to that stage and passes unrecognized control tokens to a succeeding stage. A reconfigurable decode and parser processing means positioned in certain of the stages is responsive to a recognized control token and reconfigures a particular stage to handle an identified data token. Methods relating to the decoder and decompression system include processing steps relating thereto

Data pipeline system and data encoding method

A moving image signal encoding apparatus includes: a frame decimating circuit for extracting . .encoded.!. frames from an input moving image signal at specified intervals; a frame interpolating circuit for obtaining an interpolated frame between the . .encoded.!. .Iadd.extracted .Iaddend.frames, and a circuit for obtaining an error formed by frame interpolation. A moving image signal decoding apparatus includes: a receiving circuit for extracting a frame code from an inputted signal; a frame decoding circuit for decoding the frame code to obtain a reproduced frame, and a frame interpolating circuit for obtaining an interpolated frame between the reproduced frames. By transmitting an error of the interpolated frame from the encoding apparatus to the decoding apparatus and correcting the error of the interpolated frame with the decoding apparatus, the error of the interpolated frame is eliminated. Alternatively, depending on the value of the error of the interpolated frame obtained with the encoding apparatus, a circuit determines the operation mode as to whether the frame interpolating circuit of the decoder carries out frame interpolation or preceding value holding and sends a flag to show the operation mode to the decoder, so that improvement occurs when the error of the interpolated frame is large.

Moving image signal encoding apparatus and decoding apparatus

A hierarchical coding apparatus comprising first and second compressive coding units for subjecting high- and low-resolution digital image signals to hierarchical coding to generate high- and low-resolution coded data, and a resolution conversion circuit for subjecting a portion of low-resolution decoded image signal obtained by decoding the low-resolution coded data to resolution conversion, wherein only the resolution converted image signal is used as a reference signal for a low resolution side in coding the high-resolution digital image signal, thereby making the reduction of compression efficiency of image data, which is transmitted or stored, less, and simplifying the configuration of the hierarchical coding apparatus.

Hierarchical image decoding apparatus and multiplexing method

A method of encoding and decoding image and/or audio signals includes an encoding step comprising previously preparing a quantization table which has pairs of a sam­pling interval and a quantized difference value, cal­culating a difference value between a given initial value and a sampling point succeeding to the initial value, comparing the calculated difference value with the quantization table, and searching the most matching quan­tization level. The search is started from the sampling point immediately succeeding to the initial value and then stopped upon finding of the matching quantization level. The index of that matching quantization level is transmitted. The decoding step comprises preparing the same quantization table as used in the encoding step, determining the sampling interval and the quantized difference value based on the index received, and adding the quantized difference value to the initial value to obtain a decoded value. In case there are present two or more sampling intervals, the corresponding samples are interporated. As a result, the sampling interval is prolonged in the flat parts of signal and shortened in the steeply changing parts, thereby providing compression fit for human visual and auditory characteristics.

Signal encoding and decoding method and device

For mode selection in motion compensated coding of digital video signals, reference is mode to the original pictures instead of decompressed pictures. Minimum errors produced during motion estimation, corresponding to optimum motion vectors, are used for mode selection. A motion detector detects a optimum motion vector of a current block, for each possible reference picture in the past and future, and outputs the optimum motion vectors and corresponding minimum errors. In a mode selector, an activity of the current block is estimated, an interpolated prediction obtained by averaging predictions from the past and future is evaluated, and an optimum mode is determined which gives a smallest value among all the minimum errors, the activity of the current block and the evaluation of the interpolated prediction.

Apparatus for motion compensation coding of digital video signal

PROBLEM TO BE SOLVED: To provide an information setting device for a music reproducing device which sets the reproduction timing of guide speech so as to allow a player to sing easily. SOLUTION: The information setting device includes a block compartmentalizing means 46 which compartmentalizes performance music to a plurality of blocks consisting of blank portions not having lyrics and performance portions having the lyrics and a speech reproduction timing setting means 48 for setting the reproduction timing of the guide speech by each of the blocks in such a manner that the reproduction of the guide speech showing the lyrics of the performance portions ends before the prescribed time t sp when the reproduction of the performance section starts and therefore the reproduction start timing of the performance portion corresponding to the guide speech from the reproduction end timing of the guide speech is made to be recognized. Namely, the information setting device for a karaoke device 10 which sets the reproduction timing of the guide speech so as to allow the player to sing easily can be provided. COPYRIGHT: (C)2005,JPO&NCIPI

Kenichi Takahashi

Papers

Moving image signal encoding apparatus and decoding apparatus

Hierarchical image decoding apparatus and multiplexing method

Signal encoding and decoding method and device

Apparatus for motion compensation coding of digital video signal

Information setting device and method for music reproducing device