Hi prakash , i believe the 48 is added for rounding the final prod. But like to have more clarifications in depth. vikram -------Original Message------- From: Bhanu Prakash Date: Tuesday, April 30, 2002 21:18:30 To: Subject: [speechcoding] Re: Query on fmult in G.726 Hi all, I have a doubt in "FMULT" operation in G.726. The "fmult" is used to compute multiplication of fixed point number and a floating point number.In this function, the fixed point is first converted to floating point and the sign,magnitude and mantissas of both the floating point numbers are extracted. The resultant is computed as follows. WAnS == SRnS ** AnS ; signs of float1 float2 WAnEXP == SRnEXP + AnEXP ; exponents of float1 float2 WAnMANT == ((SRnMANT * AnMANT) + 48) >> 4 Mantissas of the two operands (Q6 format) are multiplied to form the product mantissa (Q12), which is then truncated in Q8 format.Thats why, we are right shifting the result by 4. But i dont understand why 48 is added to the product of mantissas. please clarify my doubt. Best regards, Prakash ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Stock for $4 and no minimums. FREE Money 2002. http://us.click.yahoo.com/k6cvND/n97DAA/ySSFAA/GP4qlB/TM ---------------------------------~-> _____________________________________ Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. You need to do a "reply all" if you want your answer to be distributed to the entire group. _____________________________________ About this discussion group: To Join: To Post: To Leave: Archives: http://www.yahoogroups.com/group/speechcoding Other DSP-Related Groups: http://www.dsprelated.com ">http://docs.yahoo.com/info/terms/ . | |||
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