AAC | ADPCM | Convolution | DAFx | FFT | IIR | Mixer | MP3 | MPEG | MPEG-4

Hi all,

I am Mynampati Kuldeep Kumar. I am working on MPEG-2 AAC Low Delay Filter Bank. In this it has
an algorithmic delay of 20 ms. The reason is as follows

A forward and Inverse MDCT with N Frequency bands introduces a delay of 2*N-1 samples. By
decomposing the MDCT into Windowing /TDAC and DCT (Type-4) it can be observed that DCT-4
generates N-1 Sample delay and Windowing/TDAC generates additional N samples delay.

To reduce the delay, dependency in the analysis filter bank only in Forward direction that is
previous block does not depend on current block then there is chance to have low delay .So, it
requires a New Windowing 
method or modification of existing Sine window that should satisfy Time Domain Aliasing and
Perfect Reconstruction and Samples depend only on Current block

Any suggestion or web sites/literature regarding this is highly appreciated and would be a
great help.
	Thanking you..

Mynampati Kuldeep Kumar
	

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