KR950013086A

KR950013086A - Quantizer of Subband Encoder

Info

Publication number: KR950013086A
Application number: KR1019930021342A
Authority: KR
Inventors: 황성배
Original assignee: 이헌조; 주식회사 금성사
Priority date: 1993-10-14
Filing date: 1993-10-14
Publication date: 1995-05-17

Abstract

본 발명은 서브밴드 엔코더의 양자화장치에 관한 것으로, 종래는 조인트 스테레오 코딩(Joint stereo coding)에서는 비트를 절약할 수 있는 좋은 방법을 제안하고 있지만 이것은 신호의 대체적인 크기만이 복원되기 때문에 고주파영역에서 노이즈가 커지는 단점이 있고, 이 방식에서는 라이트(RIGHT)와 레프트(LEFT) 채널중 한 채널만 코딩해도 되는 경우 비트를 줄여주지 못하는 단점 및 양 채널의 신호가 다를경우 (음성 다중방송과 같은 경우) 에는 사용할 수 없는 문제점이 있었다.The present invention relates to a quantization apparatus of a subband encoder, and conventionally proposes a good method for saving bits in joint stereo coding. There is a disadvantage in that the noise is large. In this method, it is not possible to reduce the bit when only one of the RIGHT and LEFT channels is coded, and when the signals of both channels are different (such as voice multicasting). There was a problem that can not be used.

따라서 종래의 문재점운 해결하기 위하여 본 발명은 비트를 할당한후 그 할당된 비트를 조정하여 양자화하도록 하여 비트수를 절약함과 아울러 DPCM모드에서 몇개의 신호들중 1개 또는 수개의 신호는 균일양자화기로 양자화하여 전송함으로써 예측에 의한 에러가 계속 누적되지 않도록 한다.Therefore, in order to solve the conventional problem, the present invention saves the number of bits by allocating bits and adjusting the allocated bits, and in the DPCM mode, one or several signals among the signals are uniformly quantized. By quantizing and transmitting the result, the error due to the prediction is not accumulated continuously.

Description

Quantizer of Subband Encoder

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is an open matter, no full text was included.

제2도는 본 발명 서브밴드 엔코더의 양자화장치 구성도,2 is a configuration diagram of a quantization device of a subband encoder of the present invention;

제3도는 제2도에 있어서, 신양자화기의 상세도,3 is a detailed view of the new quantizer in FIG.

제4도는 제3도에 있어서, 디피씨엠기의 상세도,4 is a detailed view of the PDMC in FIG.

제5도는 제3도에 있어서, 디피씨엠기가 1차 K비트양자화기인 경우의 상세도.FIG. 5 is a detailed view of the case where the PDMC group is the primary K-bit quantizer in FIG.

Claims

A filter bank (1) for passing the input digital audio input through N band pass filters into N subband signals, and a maximum of the signals filtered through the filter bank (1) in several signal units. A new quantizer for quantizing the absolute value and quantizing the value to be equal to the probability of the subband signal inputted through the scale factor calculator 2; 3 ') and a Psycorecortic model unit (4) for calculating SMR in each subband using a fast furier transform (FFT) transform and a scale factor of the scale factor calculator 2 for the input digital audio input. ), An optimal bit allocator (5) for allocating bits according to the SMR calculated by the psychocortic model unit (4) and a bitrate by the user, and the optimal bit allocator (5). Seconds if exceeded bit A bit allocation adjusting unit (7) for converting several subbands into DPCM (Differential Pulse Code Modulation) quantization mode according to the allocated amount and outputting them to the new quantizer (3 ') and input from the new quantizer (3'). And a bitstream formatter (6) for formatting encoded bits and outputting the encoded bits.

The new quantizer 3 'receives the subband sample value and the scale factor value output from the scale factor calculator 2 and normalizes the subband sample value to the scale factor value. The normalized section 3'-1, the value inputted from the normalized section 3'-1, and the uniform quantized value fed back are input values according to a control signal inputted from the bit allocation adjusting section 7. Selector 3'-2 for selecting and outputting the data, and inputting the selected data through the selector 3'-2 to perform uniform quantization and outputting the same; Input to the selection unit 3'-2 without passing through the uniform quantizer 3'-3 and the data input through the uniform quantizer 3'3 or the uniform quantizer 3'-3. The uniform quantum in accordance with the control signal of the DPCM unit 3'-4 for receiving and outputting the DPCM data and outputting the DPCM. Group (3'-3) or dipissi emgi quantization apparatus subband encoder characterized in that it consists of a multiplexer (3'-5) for selecting and outputting the output of the (3'-4).

The DPCM 3'-4 includes a linear predictor 3'-41 for predicting a next value by a signal input from the selector 3'-2, and the linear predictor 3 '. A first adder (3'-42) for inputting the output of -41) to the inverting input terminal (-) and the output of the bit allocation adjusting unit (7) to the non-inverting input terminal (+) and adding two values; Output values of the DPCM quantizers 3'-43 and the DPCM quantizers 3'-43 that quantize data input from the first adders 3'-42 according to the control signal CTL. And a second adder (3'-44) for adding the output values of the linear predictor (3'-41) to the linear predictor (3'-41).

※ Note: The disclosure is based on the initial application.