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Topic: WHERE is the implementation for synthesis filter bank of ISO-11172 com (Read 5645 times) previous topic - next topic
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WHERE is the implementation for synthesis filter bank of ISO-11172 com

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

WHERE is the implementation for synthesis filter bank of ISO-11172 com

Reply #1 –
Quote from: ieangel on
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.

Ok, then, what's the problem?

Quote from: ieangel on
but i have no idea how the proposed flow chart come from.

Does it matter where it came from?

Quote from: ieangel on
So, can anybody show me any tips?

Try rephrasing your question.

Cheers,
SG

WHERE is the implementation for synthesis filter bank of ISO-11172 com

Reply #2 –
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?

WHERE is the implementation for synthesis filter bank of ISO-11172 com

Reply #3 –
They come from the exact same PQMF filter as Layer II.

WHERE is the implementation for synthesis filter bank of ISO-11172 com

Reply #4 –
Don't you want to look at the analysis filterbank if you want to create the subbands?
 

WHERE is the implementation for synthesis filter bank of ISO-11172 com

Reply #5 –
Quote from: ieangel on
[...] But I can not find the signal of each subband in the proposed algorithms of ISO-11172.

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