4. real-time implementation of melp vocoder.doc

8/10/2019 4. REAL-TIME IMPLEMENTATION OF MELP VOCODER.doc

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Nghin cu khoa hc cng ngh (Tn chuyn mc do Ban bin tpquyt nh

REAL-TIME IMPLEMENTATION OF MELP VOCODER

ON TI FIXED-POINT TMS320C55X DSPPhm Vn Hu*, inh Vn Ngc*, Nguyn Anh c**, Thi Trung Kin*

Abstract: This paper presents a real-time full-duplex implementation of the 2400 bit persecond (bps) Mixed Excitation Linear Prediction (MELP) vocoder on TM!20"##x$i%ital i%nal Processors ($P)& 't briefl revies the MELP al%orithm and procedure toreali*e and evaluate the implementation on the selected hardare platforms& peech+ualit of the developed MELP is evaluated ith both En%lish and ,ietnamese voice

samples usin% direct listenin% assessment and the 'T P&./2 PE ob1ective method& 'tcomes to a conclusion that this reali*ation not onl full meets re+uirements specified bthe MELP standard (M'L-T$-!00#) but also can provide %ood performance bein%

comparable ith some commercial MELP vocoder products available on the mar3et&

Keywords:peech codin% vocoder Melp speech +ualit evaluation real-time $P

1. INTRODUCTION

Mixe !xci"#"i$n %ine#r Preic"i$n &M!%P' ($c$er i) $ne $ "he m$)" rec$gni+e#n ie-y u)e ).eech c$ing me"h$) ue "$ i") ).eech /u#-i"y, c$m.re))i$nr#"e, #n r$0u)"ne)) "$ #(er)e $r1ing c$ni"i$n) )uch #) #m0ien" n$i)e) $rim.erec" "r#n)mi))i$n ch#nne-)2 # e)ire re/uiremen" $r mi-i"#ry #..-ic#"i$n)34" h#) # r#nge $ #..-ic#"i$n) )uch #) igi"#- ($ice in high re/uency &H5'"r#n)cei(er) #n in )ecure ($ice #..-ic#"i$n)3 M!%P #) )"#n#ri+e 0y "he 67

8e.#r"men" $ 8een)e in 9::; 1n$n #) M4%? @93 Thi) ($c$er h#)0een im.r$(e #n re


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Tn chuyn ng3nh do t4c gi5 quyt nh (6" d+ 7i8u khi9n % T*:ng h;a

Thi) 87P #mi-y i) #-)$ rich in .eri.her#-) #n h#) # -#rge .$r"i$n $ $n>> e(ice) #re #

.erec" i" $r # (#rie"y $ -$ .$er #n c$)">> Ihi. 7u..$r" %i0r#ry &I7%' #nnumer$u) he-.u- #..-ic#"i$n) re.$r")35r$m "he )"r$ng em#n $ -$: #n I??9>, #ng#ine )$me )igniic#n" re)u-") "h#" i-- 0e .re)en"e in "hi) .#.er3 The )"ruc"ure $"hi) .#.er i) #) $--$)3 7ec"i$n 9 .re)en") "he im.$r"#nce $ M!%P $r mi-i"#ry#..-ic#"i$n) #n # /uic1 in"r$uc"i$n "$ -$>>)y)"em) u)e "$ e(e-$. ).eech c$er M!%P, 7ec"i$n E )h$) e(#-u#"i$n $ "he)y)"em i"h e"#i-e ex.erimen"#- re)u-"), #n in#--y )ec"i$n ? gi(e) c$nc-u)i$n)#n e#"ure $r1)3

2. MELP VOCODER ALGORITHM DESCRIPTION

M!%P c#n 0e c-#))iie in "he gr$u. $ ($c$er) u)ing %ine#r Preic"i$n I$ing&%PI' m$e-3 4n "hi) gr$u. "here h#(e 0een e--> 0i") .er )ec$n I!%P c$er &5eer#- 7"#n#r 9>9' #"# -$er 0i" r#"e @E3 ener#--y, M!%P #) e(e-$.e 0#)e $n %PI &579?,7TANA E9:B' i"h i(e m#Q$r ch#nge)3 They #re mixe


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The ##."i(e ).ec"r#- enh#ncemen" i-"er i) u)e "$ enh#nce "he $rm#n" )"ruc"urein "he )yn"he"ic ).eech i" i) c$n)"ruc"e 0#)e $n "he .$-e) $ "he %PI ($c#- "r#c"i-"er3 Thi) i-"er im.r$(e) "he m#"ch 0e"een )yn"he"ic #n n#"ur#- 0#n.#))#(e$rm), #n in"r$uce) # m$re n#"ur#- /u#-i"y "$ "he ).eech $u".u" @93 e)ie"he rem#r1#0-e #-re#y men"i$ne im.r$(emen"), #n$"her e#"ure )h$u- 0e .#i#""en"i$n i) "he 5$urier m#gni"ue) hich #re u)e "$ 0e""er m$e- "he ).eech

.r$uc"i$n .r$ce)) "h#n %PI m$e-) i"h # m$re #ccur#"e exci"#"i$n )$urce @93

-$c1 i#gr#m) $ M!%P ($c$er i"h c$ing n#-y)i)' #n ec$ing&)yn"he)i)' .r$ce))e) "#1en r$m @9 #re .re)en"e in 5igure 9 #n C in "h#" $rer34n "he #n#-y)i) .r$ce)), $ne he#(y #n im.$r"#n" .r$ceure i) u)e re.e#"e-y #nin"en)i(e-y i) "he .i"ch e"ermin#"i$n, hich inc-ue) in"eger .i"ch )e#rch #nr#c"i$n#- .i"ch reinemen" @9, )ec"i$n A?3C3E #n @?3 T$ge"her i"h .i"che"ermin#"i$n, "he /u#n"i+#"i$n $ %PI c$eicien"),c$n)i)"ing $ "he c$n(er)i$n $%PI c$eicien") "$ "he %ine 7.ec"rum 5re/uency &%75' $rm @9, ; #n Mu-"i>> e(ice), I??>: &u-- n#me TM7=C>VI??>:A' #n I??9> &u-- n#meTM7=C>VI??9>A' #re $ "he m$)" high>>3 7$me 1eyh#r#re e#"ure) #reD # c$m.-ex in"ern#- 0u) )"ruc"ure c$m.$)e $ $ne .r$gr#m

0u), "hree #"# re# 0u)e), "$ #"# ri"e 0u)e), #n #i"i$n#- 0u)e) eic#"e "$.eri.her#- #n 8MA #c"i(i"y hich .r$(ie "he #0i-i"y "$ .er$rm u. "$ "hree #"#re#) #n "$ #"# ri"e) in # )ing-e cyc-e, "$ mu-"i.-y: #n

I??9> h#(e # )e" $ (#-u#0-e .eri.her#-) )uch #) Timer &C', Mc7P &=', 8MA&',Pr$gr#mm#0-e Ph#)e>:A i) richeri"h 67 939, 4CI in"er#ce), I??9> i) i"h m$re $n: #n I??9>3 The c$m.-e"e h#r#re .-#"$rm "$ 0e u)e #)I??>: #n I??9> 87P 7"#r"er Ki" &87K' hich #re .r$(ie ei"her irec"-y 0y T4$r $ne $ i") c-$)e .#r"ner) 7.ec"rum 8igi"#- &h"".DFF3).ec"rumigi"#-3c$m'3The)e 87K) h#(e n$" $n-y # I??>: $r # I??9> 87P #) "he he#r" $ "he )y)"em, 0u"#-)$.r$(ie )e(er#- he-.u- .eri.her#-) #r$un, )uch #) c$ec &T%V=C>A4IC='i"h $ur =3? mm3 #ui$ Q#c1) &micr$.h$ne, -ine


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Figure 5.;eneral dia%ram of a tpical measure&

A-"h$ugh )u0Qec"i(e #))e))men" me"h$) #re .erh#.) "he m$)" re-i#0-eh$e(er, "hey #re "ime3 H$e(er, "$ 0e #0-e "$c$m.#re "he .er$rm#nce $ "he I??x M!%P i"h )$me $"her M!%P .r$uc") )$-$n m#r1e" @9=, 9E, )$me !ng-i)h c$r.u)e) ere "#1en irec"-y r$m "he)e

.r$uc")L e0)i"e) inc-uing $rigin#- c-e#n #n "he .r$ce))e ).eeche)3 4ne"#i-), )en"ence) #" )#m.-ing r#"e B>>> )#m.-e)


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C !ng53#( @9= !ng-i)h 5em#-e

= VnM3#( Vie"n#me)e M#-eE Vn53#( Vie"n#me)e 5em#-e? V$(93#( Vie"n#me)e 5em#-e reerenceE.>13#( @9E !ng-i)h $"h

The P!7S )c$re) $0"#ine 0y u)ing "he I??x M!%P im.-emen"#"i$n inc$m.#ri)$n i"h c$mmerci#- .r$uc") #re )h$n in T#0-e E3

Table 4.PE scores of "##x MELP implementation

Or&r F$)'am C55 MELPC#mmr%$a)

r#&/%!"

9 !ngM3#( C3E9 C3 @9=C !ng53#( C3=BE C3EE? @9== VnM3#( C3=9 6n#(#i-#0-eE Vn53#( C3C; 6n#(#i-#0-e? V$(93#( C3;9= 6n#(#i-#0-e reerenceE.>13#( =39> C3:;> &*'

&*'D 7c$re i"h "he 4T6 P3BC "$$- @99

5igure) #n ; )h$ "he $rigin#- #n I??x M!%P .r$ce))e ).eeche) $

VnM3#( #n Vn53#( i"h "he re).ec"i(e .h#)e) Wo s?n s>n% ch@a cAc

thanh niBnX #n WvC sD %ii thFch cGa hH l> cI lJX3

0 5000 10000 15000-0.4

-0.2

0

0.2

0.4Vn_M original speech

0 5000 10000 15000

-0.4

-0.2

0

0.2

0.4MELP processed Vn_M speech

Figure 6.6ri%inal and "##x MELP processed ,ietnamese male spo3en

Ko s?n s>n% ch@a cAc thanh niBn

T!p ch" Nghin cu #$%&N 'un )*+ ,- + 0. 1 .02


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0 0.5 1 1.5 2

x 104

-0.4

-0.2

0

0.2

0.4Vn_F original speech

0 0.5 1 1.5 2

x 104

-0.4

-0.2

0

0.2

0.4MELP processed Vn_F speech

Figure 7.6ri%inal and "##x MELP processed ,ietnamese male spo3en

KvC sD %ii thFch cGa hH l> cI lJ

Thr$ugh "he ex.erimen"#- re)u-"), i" #) $0)er(e "h#" "he I??x M!%P .er$rmem$re $r -e)) "he )#me #) )$me M!%P .r$uc") curren"-y )$- $n "he m#r1e" i"h"he gi(en in.u" ).eeche)3 7.eciic#--y, I??x M!%P i 0e""er Q$0 "h#n V$c#- 0u"$r)e "h#n 7ign#-$gic, 0u" "he ierence) #re m#rgin#-, #" $n-y #r$un >39 P!7S)c$re3 M$re in"en)i(e "e)") i"h $"her ).eech c$r.u) c$nirme "he /u#-i"y $ "heim.-emen"e I??x M!%P 0#)e $n "he P!7S )c$re) e-- #n 0y irec" -i)"ening#))e))men")3 Oi"h $n-ine re#-> 0.), 0u" #-)$ 9C>>

0.) #n >> 0.)' #n 0e""er ).eech /u#-i"y )h$u- 0e # g$$ irec"i$n $r "hee(e-$.men" $ "hi) $r13

T!p ch" Nghin cu #$%&N 'un )*+ ,- ./+ 0. 1 .02/ 15


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AC8NO9LEDGES

Thi) $r1 i) )u..$r"e 0y .r$Qec" 99BFC>9=FH 2 NT &C>9=9E', une 0yMini)"ry $ )cience #n "echn$-$gy $ Vie"n#m3

REFERENCES

@9 63 73 8$8, WM4%?,X $epartment of $efense Telecommunicationsstems tandard, 9:::3@C A3 V3 McIree #n T3 P3 #rne-- 444, WA mixe exci"#"i$n %PI ($c$er m$e-$r -$ 0i" r#"e ).eech c$ing,X peech and udio Processin% 'EEE Transactionson, ($-3 =, n$3 E, ..3 CEC2C?>, 9::?3

@= %3 M3 7u..-ee, J3 P3 I$hn, R3 73 I$--ur#, #n A3 V3 McIree, WM!%PD "he neeer#- )"#n#r #" CE>> 0.),X incoustics peech and i%nal Processin% 899N&'"P-9N& 899N 'EEE 'nternational "onference on, 9::;, ($-3 C, ..3 9?:929?:E3@E M3 K$h-er, WA c$m.#ri)$n $ "he ne CE>> 0.) M!%P eer#- )"#n#r i"h$"her )"#n#r c$er),X in coustics peech and i%nal Processin% 899N&

'"P-9N& 899N 'EEE 'nternational "onference on, 9::;, ($-3 C, ..3 9?B;29?:>3@? Y3 Me#n, !3 Y#ir, #n 83 Ih#+#n, W7u.er re)$-u"i$n .i"ch e"ermin#"i$n $).eech )ign#-),X i%nal Processin% 'EEE Transactions on, ($-3 =:, n$3 9, ..3 E>2EB, 9::93@ O3 P3 %e-#nc, 3 h#""#ch#ry#, 73 A3 M#hm$u, #n V3 Iu.erm#n, W!icien")e#rch #n e)ign .r$ceure) $r r$0u)" mu-"i>, TM7=C>VI??9>#, TM7=C>VI??>:#, #n II7=3=@9> Technic#- ).eciic#"i$n) $ T#ir#n H5>>>, rin"e1 TJCE>>, I$#nL)

NT 7Jx

@99 4T6 P3BC, WPerce."u#- e(#-u#"i$n $ ).eech /u#-i"y &P!7S', #n $0Qec"i(eme"h$ $r en>;3@9= M!%P c$mmerci#-.r$uc" .r$(ie 0y 7ign#-$gich"".DFF3)ign#-$gic3c$mFinex3.-Z.#gec$ec)#m.-e)@9E M!%P c$mmerci#-.r$uc" .r$(ie 0y V$c#-h"".DFF3($c#-3c$mF#ui$


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Qa chRO * Vi[n I\ng ngh[ "h\ng "in F Vi[n KH]INS7

** Trung "^m I\ng ngh[ c#$ F _ "` -[nh "h\ng "in

T!p ch" Nghin cu #$%&N 'un )*+ ,- ./+ 0. 1 .02/ 17

4. real-time implementation of melp vocoder.doc

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