摘要:
A bit allocating method is provided that includes determining the allocated number of bits in decimal point units based on each frequency band so that a Signal-to-Noise Ratio (SNR) of a spectrum existing in a predetermined frequency band is maximized within a range of the allowable number of bits for a given frame; and adjusting the allocated number of bits based on each frequency band.
摘要:
Provided is an audio encoding method. The audio encoding method includes: acquiring envelopes based on a predetermined sub-band for an audio spectrum; quantizing the envelopes based on the predetermined sub-band; and obtaining a difference value between quantized envelopes for adjacent sub-bands and lossless encoding a difference value of a current sub-band by using a difference value of a previous sub-band as a context. Accordingly, the number of bits required to encode envelope information of an audio spectrum may be reduced in a limited bit range, thereby increasing the number of bits required to encode an actual spectral component.
摘要:
A method and apparatus to quantize and dequantize an input signal, and a method and apparatus to encode and decode an input signal. The method of quantizing an input signal includes determining a quantization scale type according to a distribution feature of the input signal, and quantizing the input signal according to the determined quantization scale type. Accordingly, when a number of assigned bits is small in an encoding process, signal distortion can be minimized without an increase in complexity or having to use large sized additional information in order to determine an optimum scale. In addition, the input signal can be encoded by considering a trade-off of a distortion rate corresponding to the number of assigned bits of the input signal.
摘要:
A low-bitrate encoding system includes: a time-frequency transform unit transforming an input time-domain audio signal into a frequency-domain audio signal; a frequency component processor unit decimating frequency components in the frequency-domain audio signal; a psychoacoustic model unit modeling the received time-domain audio signal on the basis of human auditory characteristics, and calculating encoding bit allocation information; a quantizer unit quantizing the frequency-domain audio signal input from the frequency component processor unit to have a bitrate based on the encoding bit allocation information input from the psychoacoustic model unit; and a lossless encoder unit encoding the quantized audio signal losslessly, and outputting the encoded audio signal in a bitstream format. Using the low-bitrate encoding system, it is possible to effectively compress data at a low bitrate, and thus to provide a high quality audio signal.
摘要:
A method and apparatus to quantize and dequantize an input signal, and a method and apparatus to encode and decode an input signal. The method of quantizing an input signal includes determining a quantization scale type according to a distribution feature of the input signal, and quantizing the input signal according to the determined quantization scale type. Accordingly, when a number of assigned bits is small in an encoding process, signal distortion can be minimized without an increase in complexity or having to use large sized additional information in order to determine an optimum scale. In addition, the input signal can be encoded by considering a trade-off of a distortion rate corresponding to the number of assigned bits of the input signal.