摘要:
A method and apparatus for decoding a bitstream. The method may include generating an indication of a number of coefficients and a number of trailing ones in a portion of a bitstream using either a first lookup table (LUT) indexed by a number of leading zeros to return a number of remaining bits in a code and a second LUT indexed by both the number of leading zeros and the remaining code bits to return the number of coefficients and the number of trailing ones or bit parsing processing when the leading zeros value equals a predetermined value, generating an indication of a number of total zeros, including using either a third LUT indexed by the number of coefficients and bits of the bitstream when the number of coefficients is in a first range or bit level processing when the number of coefficients is outside the first range, generating an indication of one or more run before values using either a fourth LUT indexed by the number of coefficients and bits of the bitstream when a zeros left value is in a second range or bit parsing processing when the zeros left is not in the second range, and generating coefficients in block positions in response to the generation of the trailing ones value, the number of coefficients value, the total zeros value and run before values.
摘要:
Known systems use two probability signals for coding an input signal into an output signal and for decoding said output signal into the input signal. In a first memory field two probability signals are stored, and in a second memory field two other probability signals are stored, and in response to a further received symbol processor means adapt the probability signals. Such a system needs a giant memory capacity, which can be reduced by combining probability signals into a first combination signal to be stored in the first memory field and by combining further probability signals into a second combination signal to be stored in the second memory field, and by converting a third combination signal into at least one probability signal just before (de)coding takes place.
摘要:
In an encoding method which utilizes plural codebooks, certain bits of a user data input sequence are considered as branch selection bit(s) which determine (1) how the remainder of the input sequence is to be divided into plural subsequences and (2) which codebooks are addressed using the plural subsequences in order to generate corresponding plural output sequences. The plural output sequences are then concatentated together to form a codeword. The method reduces the size of the codebooks that otherwise would be employed for the particular code involved in the encoding method. The encoding of the present invention is particularly suitable for a Quadbit Modulo 2 (QM2) code.
摘要:
A variable-length coding device includes: a code presence/absence determination table storing information concerning whether a code is allocated or not correspondingly to a prescribed region in a region represented by a combination of run data and level data; a first region determination circuit and a second region determination circuit determining whether a pair of run data and level data is contained in the prescribed region; and a run.level pair conversion circuit, a first code table, and a second code table that perform coding, referring to the code presence/absence determination table, if the first region determination circuit and the second region determination circuit determine that the pair of run data and level data is contained in the prescribed region, and that perform coding without referring to the code presence/absence determination table if the first region determination circuit and the second region determination circuit determine that the pair of run data and level data is not contained in the prescribed region.
摘要:
Apparatus and method for compressing Huffman encoded data. The compression apparatus includes a string detector and a record generator. The compression apparatus operates to receive the Huffman encoded data and the length of the codewords used to generate the Huffman encoded data. The string detector then operates to detect each set of repeating strings and each non-repeating string in the encoded data. Each set of repeating strings is replaced with a record that indicates the length of the repeating string, the number of repeats and an instantiation of the repeating string. In addition, each non-repeating string is replaced with a record that indicates the length of the non-repeating string and the non-repeating string. The resulting compressed Huffman data can then be transmitted to a printer.
摘要:
An alpha-map encoding apparatus includes a first down-sampling circuit for down-sampling an alpha-map signal which represents the shape of an object and the position in the frame of the object at a down-sampling ratio based on size conversion ratio information, an up-sampling circuit for up-sampling the alpha-map signal at an up-sampling ratio based on size conversion ratio information given to restore the down-sampled alpha-map signal to an original size, and outputting a local decoded alpha-map signal, a motion estimation/compensation circuit for generating a motion estimation/compensation signal on the basis of the previous decoded video signal and a motion vector signal, a second down-sampling circuit for down-sampling the motion estimation/compensation signal at the down-sampling ratio, a binary image encoder for encoding the alpha-map signal down-sampled by the first down-sampling circuit to a binary image in accordance with the motion estimation/compensation signal down-sampled by the second down-sampling circuit, and outputting an encoded binary image signal, and a multiplexer for multiplexing and outputting the encoded binary image signal and the up-sampling ratio information.
摘要:
A data compression apparatus for data compressing a digital information signal obtained from a digital audio signal. The digital information signal includes p-bit samples, where p is an integer larger than 1. The apparatus has an input (16) for receiving the digital information signal, and a lossless compression unit (18) for carrying out a substantially lossless compression step on the digital information signal so as to obtain a data compressed digital information signal. The lossless compression unit includes a Rice encoder, which is distinguishable by a code parameter m. Further, an output terminal (22) is available for supplying the data compressed digital information signal. The Rice encoder has a generator unit (30) for generating the code parameter m from N samples of the digital information signal, in accordance with a formula which optimizes the value of m for each frame of N samples.
摘要:
One embodiment of the present invention provides a method and an apparatus for decoding a variable length code using lookup tables. This embodiment improves lookup performing by allowing multiple symbols to be retrieved in a single lookup, and allowing lookups into different tables to proceed in parallel. Another embodiment of the present invention provides for multiple secondary lookup tables to be selected based upon a prefix value decoded by a primary lookup table. Thus, one embodiment of the present invention can be characterized as an apparatus for decoding a variable length code. This apparatus includes an input from an encoded bitstream, the input including a first set of bits and a second set of bits. This apparatus also includes a first table indexed by the first set of bits, which includes entries containing decoded symbols corresponding to variable length codewords in the first set of bits. At least one entry contains multiple symbols for the case where the first set of bits contains multiple codewords. Another embodiment includes a second table indexed by the second set of bits. This second table includes entries containing decoded symbols corresponding to variable length codewords spanning the first set of bits and the second set of bits. In yet another embodiment, the first table and the second table are configured to allow a lookup from the first table to proceed in parallel with a lookup from the second table. In another embodiment, the first table and the second table are configured so that a lookup in the first table precedes a lookup in the second table.
摘要:
An MPEG video decompression method and apparatus utilizing a plurality of stages interconnected by a two-wire interface arranged as a pipeline processing machine. Control tokens and DATA Tokens pass over the single two-wire interface for carrying both control and in token format. A token decode circuit is positioned in certain of the stages for recognizing certain of the tokens as control tokens pertinent to that stage and for passing unrecognized control tokens along the pipeline. Reconfiguration processing circuits are positioned in select stages and are responsive to a recognized control token for reconfiguring such stages to handle an identified DATA Token. A wide variety of unique supporting subsystems circuitry and processing techniques are disclosed for implementing the system, including memory addressing, transforming data using a common processing block, time synchronization, asynchronous swing buffering, storing of video information, a parallel Huffman decoder, and the like.
摘要:
A noise codebook selects a code most suitable to the characteristics of an input speech vector from an inside quantification table. Furthermore, a codebook renewal circuit determines a correlative value between a noise code selected by the noise codebook and the input speech vector, subsequently calculates a multiplication value for each of noise codes to generate a renewal code by using the multiplication value with respect to the code selected most frequently by the coding processing at the time of voice. Renewal processing is preformed by replacing a desired code of the codebook with the renewal code. Furthermore, the renewal code is sent to a multiplexing circuit together with a renewal flag value to be sent to a decoding device by using the superfluous bit portion of an unvoice frame.