Re: Hdot264-devel digest, Vol 1 #29 - 2 msgs
"yulejun" <[email protected]> Thu, 17 Apr 2003 21:57:10 +0000
| Newsgroups | gmane.comp.video.h264.devel |
|---|---|
| Message-ID | <[email protected]> |
In jvt-b038.doc, qbits = 17 + QP/6. And In the JM5.0c, ABT_N=17 (see abt_const.c). I noted that 12 is subtracted from QP. Set qp = QP -17 so qbit = 17 + qp/6 = 15 + QP/6 But I do not know how the a^2 ab/2 b^2/4 are counted in JM6 [email protected] : > Send Hdot264-devel mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.sourceforge.net/lists/listinfo/hdot264-devel > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Hdot264-devel digest..." > > > Today's Topics: > > 1. confusions about qbits and quant coef matrix (Eric Miao) > 2. Re: confusions about qbits and quant coef matrix (Aitor Garay) > > --__--__-- > > Message: 1 > Date: Tue, 15 Apr 2003 06:18:23 -0700 (PDT) > From: Eric Miao <[email protected]> > To: [email protected] > Subject: [Hdot264-devel] confusions about qbits and quant coef matrix > > --0-305635399-1050412703=:68618 > Content-Type: text/plain; charset=us-ascii > Content-Id: > Content-Disposition: inline > > Hi, > > In jvt-b038.doc, qbits = 17 + QP/6. > But I also noted that in some articles and jm6 ref > software, qbits = 15 + QP/6. > What is right? > > And I also calculated quant coef matrix according to > equation: MF/qbits = PF/qstep. > My result is > a^2 (b^2)/4 (ab)/2 > 13107 5243 8290 > 11916 4766 7536 > 10082 4033 6377 > 9362 3745 5921 > 8192 3277 5181 > 7282 2913 4605 > But it is different from the one used in jm61 > software, > mainly column 2 and column 3. > The following is used in jm61: > a^2 (b^2)/4 (ab)/2 > 13107 5243 8066 > 11916 4660 7490 > 10082 4194 6554 > 9362 3647 5825 > 8192 3355 5243 > 7282 2893 4559 > > Attached is a c file I used to calculate the matrix. > Can anyone point out any wrong in my implem? > > > > __________________________________________________ > Do you Yahoo!? > The New Yahoo! Search - Faster. Easier. Bingo > http://search.yahoo.com > --0-305635399-1050412703=:68618 > Content-Type: text/plain; name="calc_mf.c" > Content-Description: calc_mf.c > Content-Disposition: inline; filename="calc_mf.c" > > #include <stdio.h> > #include <math.h> > > static double quantStep[6] = > { > 0.625, > 0.6875, > 0.8125, > 0.875, > 1.0, > 1.125 > }; > > static double postScalingFactor[3]; > > int > main() > { > double a, b; > int i; > > a = 0.5; > b = sqrt(0.4); > > postScalingFactor[0] = a * a; > postScalingFactor[1] = (b * b) / 4; > postScalingFactor[2] = (a * b) /2; > > for(i = 0; i < 6; i++) > { > printf("%8d %8d %8d\n", > (int)((postScalingFactor[0] * 32768) / quantStep[i] + 0.5), > (int)((postScalingFactor[1] * 32768) / quantStep[i] + 0.5), > (int)((postScalingFactor[2] * 32768) / quantStep[i] + 0.5)); > } > > return 0; > } > > --0-305635399-1050412703=:68618-- > > > --__--__-- > > Message: 2 > From: "Aitor Garay" <[email protected]> > To: "Eric Miao" <[email protected]>, > <[email protected]> > Subject: Re: [Hdot264-devel] confusions about qbits and quant coef matrix > Date: Tue, 15 Apr 2003 16:16:58 +0200 > > In the reference software the positions with factors (b^2)/4 and ab/2 have > been modified, but i ignore the rationale they followed to do so. It's OK to > modify the forward quantizer since it is not standarised, only the rescaling > process is binded to the standard. > > /AITOR > > ----- Original Message ----- > From: "Eric Miao" <[email protected]> > To: <[email protected]> > Sent: Tuesday, April 15, 2003 3:18 PM > Subject: [Hdot264-devel] confusions about qbits and quant coef matrix > > >> Hi, >> >> In jvt-b038.doc, qbits = 17 + QP/6. >> But I also noted that in some articles and jm6 ref >> software, qbits = 15 + QP/6. >> What is right? >> >> And I also calculated quant coef matrix according to >> equation: MF/qbits = PF/qstep. >> My result is >> a^2 (b^2)/4 (ab)/2 >> 13107 5243 8290 >> 11916 4766 7536 >> 10082 4033 6377 >> 9362 3745 5921 >> 8192 3277 5181 >> 7282 2913 4605 >> But it is different from the one used in jm61 >> software, >> mainly column 2 and column 3. >> The following is used in jm61: >> a^2 (b^2)/4 (ab)/2 >> 13107 5243 8066 >> 11916 4660 7490 >> 10082 4194 6554 >> 9362 3647 5825 >> 8192 3355 5243 >> 7282 2893 4559 >> >> Attached is a c file I used to calculate the matrix. >> Can anyone point out any wrong in my implem? >> >> >> >> __________________________________________________ >> Do you Yahoo!? >> The New Yahoo! Search - Faster. Easier. Bingo >> http://search.yahoo.com > > > -------------------------------------------------------------------------------- > > >> #include <stdio.h> >> #include <math.h> >> >> static double quantStep[6] = >> { >> 0.625, >> 0.6875, >> 0.8125, >> 0.875, >> 1.0, >> 1.125 >> }; >> >> static double postScalingFactor[3]; >> >> int >> main() >> { >> double a, b; >> int i; >> >> a = 0.5; >> b = sqrt(0.4); >> >> postScalingFactor[0] = a * a; >> postScalingFactor[1] = (b * b) / 4; >> postScalingFactor[2] = (a * b) /2; >> >> for(i = 0; i < 6; i++) >> { >> printf("%8d %8d %8d\n", >> (int)((postScalingFactor[0] * 32768) / quantStep[i] + 0.5), >> (int)((postScalingFactor[1] * 32768) / quantStep[i] + 0.5), >> (int)((postScalingFactor[2] * 32768) / quantStep[i] + 0.5)); >> } >> >> return 0; >> } >> > > > > > --__--__-- > > _______________________________________________ > Hdot264-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/hdot264-devel > > > End of Hdot264-devel Digest ---------------------------------------------------------------- FESCOmail.net ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf