Can anybody tell me if there is a limit to max value of 'global gain'. I know its a 8 bit field so in theory its max value can be 255. but that means that the max value of xr(requntized value) = 8192 * 2^1/4(255-210), putting subblock gain = 0 and scalefac_s = 0.
=8191*2352.534
=19269607.88
which looks like a non realistic value.
Can anybody explain?
Kr,
Avi

You forgot the power law of the non-uniform quantizer.
--> 8192^(4/3) * 2^(0.25*(...))

:-)

yeah, the dynamic headroom is quite large.


SebastianG

I want to know the maximum value of all parameters in mp3 decoder process.

a.is value
b. requantization value
c. ms stereo
d intensity stereo
e alias reduction
f IMDCT
g overlap

I am not sure what these max value are?
a. max is => 8191 + 15 = 8206 ??? (need 14 bits)
b. max xr => (8026)^(4/3) * 2^(255-210)=403196976 (need 29bits)
c. max (M + S) / 1.414 = (403196976 + 403196976) /1.414 =570292752
d. L= L * is_ratio/(1 + is_ration) =?? R= L * 1/(1 +is_ratio) =?
e. xar=xr[18*sb + i]*Cs + xr[18*sb -1 -i]*Ca==???
f. IMDCT = ??

Is any one know if we need so large number bits to implemented mp3 decoder?
Since I want to evaluate the hardware cost for implementing mp3 decoder.

I hope that some one can help me ..
Thanks

Naughty, naughty... double posting (see here).
I also don't know the answer.