the standard specfified a medium complexity implementation for the synthesis filter bank. The specification is shown below


now, I want to seperate the 32 subbands out, and I will check the frequency component of every subband.
but i have no idea how the proposed flow chart come from.


So, can anybody show me any tips?


Best Regards

Ok, then, what's the problem?


Does it matter where it came from?


Try rephrasing your question.

Cheers,
SG

I am sorry, my question is:
in the alogrithms of synthesis filter bank, the synthesised result should be the sum of 32 subbands: result=sb0+sb1+....+sb31;

but in the proposed implementation, i can't find the 32 subbands.

In fact, I want to calculate the spectrum of each subband, e.g. the spectrum of sb0, sb1....sb31. But I can not find the signal of each subband in the proposed algorithms of ISO-11172.

is it clear?

They come from the exact same PQMF filter as Layer II.

Don't you want to look at the analysis filterbank if you want to create the subbands?

I still fail to see what you're asking for. Didn't you already check the effect of zeroing some subbands prior synthesis?

You might want to tell us what your goal is. I'm guessing here that you're trying to exploit the filterbank to do cheap lowpass filtering -- either at the encoder side (like LAME does) or at the decoder side (for whatever reason).

Cheers,
SG