Re: Re[2]: III_requantize question

On Monday, October 20, 2003, at 04:24  AM, Grigory Abuladze wrote:
>>> 2.
>>>       Xr = is^(4/3) * 2^(exp)       (sign not discussed)
>>>
>>>       What value exp can be and what step?
>>>       -88.5 <= exp <= 11.5, 0 <= is[i] <= 8207
>>>       are this equation true?
>>
>> I calculate -81.5 <= exp <= 11.25 based on the theoretical limits of 
>> the requantization formula variables.
>>
>> Also 0 <= is[i] <= 8206, although there is some debate over whether 
>> ISO/IEC 11172-3 actually permits values greater than 8191.
>
> Thanks for answer!
>
> and one more
> Does it true    |Xr|<1     ?
> and is[i] & exp managed so above statement is always correct?

In general, no, you cannot assume this is true although it usually is. 
When |Xr|>1 it is usually not much greater than 1, but there are no 
technical boundaries. The end goal is to have the PCM after synthesis 
also |s|<1, but this too is not guaranteed, and leads to the need for 
clipping or other reduction mechanisms outside the decoder.

-- 
Rob Leslie
[email protected]