Up: MPEG Audio Compression
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- Use convolution
filters to divide the audio signal (e.g., 48 kHz sound) into frequency
subbands that approximate the 32 critical bands -> sub-band
- Determine amount of masking for each band caused by nearby band using the
results shown above (this is called the psychoacoustic model).
- If the power in a band is below the masking threshold, don't encode it.
- Otherwise, determine number of bits needed to represent the
coefficient such that noise introduced by quantization is below the
masking effect (Recall that 1 bit of quantization introduces
about 6 dB of noise).
- Format bitstream