[vorbis-dev] Multichannel Encoding

Tue Jan 23 15:52:06 PST 2001

Ahhhh, there's my "welcome to the list" message... ;-)

The quick answer is "yes, but not as much as I'd like" - which is a large 
part of why I'm here. I don't actually know too much about MP3 - I've read 
a few books but never got my hands dirty. As I understand it, less 
directional information is stored in frequency bands in which direction 
perception is weakest. I'm not quite clear about that and have less of a 
clue about what happens for upper frequencies. Please would you explain?

I do have some ideas that I find quite exciting about ways to combine the 
MDCT with Ambisonics, but I've not done the maths formally enough to know 
that they will work - but now you know where I'm coming from! Do you know 
if this kind of approach has been investigated?

Thanks,

--Richard

-----Original Message-----
From:	Marshall Eubanks [SMTP:tme at 21rst-century.com]
Sent:	Tuesday, January 23, 2001 9:50 PM
To:	vorbis-dev at xiph.org
Subject:	Re: [vorbis-dev] Multichannel Encoding

[...]

Dear Richard;

Have you given consideration as to the difference in channel correlation 
and human audio phase / amplitude sensitivity as a function
of frequency ? This is, of course, the basis of normal stereo in MP3...
[...]

begin 600 WINMAIL.DAT
M>)\^(@@7`0:0" `$```````!``$``0>0!@`(````Y 0```````#H``$(@ <`
M& ```$E032Y-:6-R;W-O9G0 at 36%I;"Y.;W1E`#$(`0V ! `"`````@`"``$$
MD 8`I ,```(````1`````P``, T````+``\.`0````(!_P\!````20``````
M``"!*Q^DOJ,0&9UN`-T!#U0"```!`'1M94 R,7)S="UC96YT=7)Y+F-O;0!3
M3510`'1M94 R,7)S="UC96YT=7)Y+F-O;0`````>``(P`0````4```!33510
M`````!X``S !````%@```'1M94 R,7)S="UC96YT=7)Y+F-O;0````,`%0P!
M`````@'Y#P$```!)`````````($K'Z2^HQ 9G6X`W0$/5 (```$`=&UE0#(Q
M<G-T+6-E;G1U<GDN8V]M`%--5% `=&UE0#(Q<G-T+6-E;G1U<GDN8V]M````
M``,`_@\&````'@`!, $````8````)W1M94 R,7)S="UC96YT=7)Y+F-O;2<`
M`@$+, $````;````4TU44#I4345 ,C%24U0M0T5.5%5262Y#3TT```,``#D`
M````"P! .@`````>`/9?`0```!8```!T;65 ,C%R<W0M8V5N='5R>2YC;VT`
M```"`?=?`0```$D`````````@2L?I+ZC$!F=;@#=`0]4`@```0!T;65 ,C%R
M<W0M8V5N='5R>2YC;VT`4TU44 !T;65 ,C%R<W0M8V5N='5R>2YC;VT`````
M`P#]7P$````#`/]?``````(!]@\!````! ````````T0`````P``, X````+
M``\.``````(!_P\!````10````````"!*Q^DOJ,0&9UN`-T!#U0"`````'9O
M<F)I<RUD979 >&EP:"YO<F<`4TU44 !V;W)B:7,M9&5V0'AI<&@N;W)G````
M`!X``C !````!0```%--5% `````'@`#, $````4````=F]R8FES+61E=D!X
M:7!H+F]R9P`#`!4,`@````,`_@\&````'@`!, $````6````)W9O<F)I<RUD
M979 >&EP:"YO<F<G`````@$+, $````9````4TU44#I63U)"25,M1$560%A)
M4$@N3U)'``````,``#D`````"P! .@$````>`/9?`0```!0```!V;W)B:7,M
M9&5V0'AI<&@N;W)G``(!]U\!````10````````"!*Q^DOJ,0&9UN`-T!#U0"
M`````'9O<F)I<RUD979 >&EP:"YO<F<`4TU44 !V;W)B:7,M9&5V0'AI<&@N
M;W)G``````,`_5\!`````P#_7P`````"`?8/`0````0````````.4<<!!( !
M`"<```!213H at 6W9O<F)I<RUD979=($UU;'1I8VAA;FYE;"!%;F-O9&EN9P#U
M#0$%@ ,`#@```-$'`0`7`!<`- `&``(`0P$!(( #``X```#1!P$`%P`7`#0`
M!@`"`$,!`0F `0`A````04$P-$4R.3$X1C at U0S Q,3A$1$,X,D5%1D,V.$$P
M13(`70<!`Y &`, (```B````"P`"``$````+`",``0````,`)@``````"P`I
M``$````#`"X```````(!,0`!````\ ```%!#1$9%0C Y``$``@!,````````
M`#BANQ %Y1 :H;L(`"LJ5L(``$U34%-4+D1,3 ``````3DE40?F_N $`J@`W
MV6X```!#.EQ724Y$3U=37&UA:6QB;W at N<'-T`!@`````````>IMT\UF=T!&U
M,T1%4U0``** ```8`````````'J;=/-9G= 1M3-$15-4``!$ABT`& ``````
M``!ZFW3S69W0$;4S1$535 ``PH ``! ```"J!.*1CX7 $8W<@N[\:*#B)P``
M`%)%.B!;=F]R8FES+61E=ET at 375L=&EC:&%N;F5L($5N8V]D:6YG``,`-@``
M````0 `Y`*#O$GZ7A< !'@!P``$````G````4D4Z(%MV;W)B:7,M9&5V72!-
M=6QT:6-H86YN96P at 16YC;V1I;F<```(!<0`!````%@````' A99^X<^#!B/Q
M at A'4M33%(8 ]<Z0``!X`'@P!````!0```%--5% `````'@`?# $````9````
M<FEC:&%R9$!M=7-E+F1E;6]N+F-O+G5K``````,`!A!:SJ at I`P`'$, #```>
M``@0`0```&4```!!2$A(2"Q42$5215--62)714Q#3TU%5$]42$5,25-4(DU%
M4U-!1T4[+2E42$5154E#2T%.4U=%4DE3(EE%4RQ"551.3U1!4TU50TA!4TE$
M3$E+12(M5TA)0TA)4T%,05)'15!!``````(!"1 !````E 0``) $``"5!@``
M3%I&=3#TQGX#``H`<F-P9S$R-78R`/0!]R "I /C`@!C at F@*P'-E=# @!Q.'
M`H,`4 ^V<')Q,A"V9GT*@ C((#L);PXP-;,"@ J!=6,`4 L#8P!!Q0M@;@X0
M,#,S"Z80L$)H%S$L('1H!)!E`B<$(&UY(")W92YL!: '@!> ;Q>"(&P9! !T
M(A@`!Y!S86?,92X:$!.0+2D*H at J$)0J 5!D1<74-X&L at WP!Q&% %P 0`&#!Y
M!Y 7<*1B=05 ;F\%0&$7\4450&@=4DDG9!DQ:\)E&8 M('=H#> =P-T<46$9
M, K &? @"K$%0)QO9A[!&" >$&T@%Z)1&C!)(&0"("<=06/4='4'0&P8(&L=
M( ?@'QC0&. =E ;@'/%-4#/;'J$>$'88L EP81XP'V!F9@?1!N!O:P0@'.-E
M.R00!<!G'3$8$1! ;F2I!"!D:0`@>1HP01WQ?"!U)H $D!E@)G$<0'2=%W!L
M&;$FL at 60=&D"(.L'0!Q ;@(0<@# *1(<0O\98 6P"8 I<22@"7 ;@ GP^F,8
M(&(F<RKA'M0HQQ_0N0208V4%,"H%&%!A'G!?&6 A(2"Q'2(;@708L&/_*' *
MP2,T%Y IX!O1'C 00/\D$2AS(#$?8"^0"E C)1[0^S!Q$$!P+4 &,2FA)W R
M\=<%P"L6")!S&C!0+Z$0<"L>P A@;!XP>0A@(&6Z> M3/QJ*(4(PU',8DMYI
M`0`=83!3(4!F"X >,#\O-#70-& I$!8P,A9A>7<X01C@&(%B"X 8L1D13;A$
M0U0>P"@P'<!!.Q'[-[ #`&,<M2/S'2(A83M4?2G1:#,S`, B$@GP"&!G_QW 
M&-$B5#!B%Y$8( /P(A#]-2%R&\ >L!SD!^ UDB)3/Q[0%[$@DQB!.=(#4B$@
MOD08X$(W!I 7 at 1Q1:SCB_S&",O #8 #0'< 00"4Q">'G*7$D$!E@:6<IX F 
M-DL7&T `<"4 at +!J*+2U2_Q[Q"Q,:J!7!`4!&$2]@(=!9$40Q-AZ at 3')/!1!G
M^PN *5%-&;1,<QJ&2X1+48,+$TN&:2TQ-#0!0(\90% 3#-!0$V(@1 at -AZCH,
M at V(0H$T041! 01$,174KL24A6U--5(A0.G0'@$ R,2?!OBTM< (P"' G`!B!
M71J%+U% !F ",%&G5 I0<V0[.H 7<$H`<"'P5) @, at 8S%W !T# Q(#DZDC40
MH%!-50=4;U&G%G8%L#QQ+0$`=D!X:04@:"X%L&=5"%+0:F,H\5&G4F4Z4S!9
MN%WO!= U4"D0$#%N)9!2H2MP/P1P.=%.'T\J%A(!T#4W_PNG2M8585]54S :
M$53V2SJ]&I-$+[))]1.@&IE(,/+_-9),\"00`Z %H "!!($IY/\X,ACD)L !
M(!>Q*W WX6<1OUWE!:$)< M at 9\0PLG4#@KQA=2; &.!:@#3R+QO0?FT+4"@P
M:X WD3,1.;%V_R at P&" =8221)X I`QJ$(#']*Q at _5E!%, at 0`%W @,06 at _PAP
M$' 7<RNA`) Q8QT@/O+_*F$7L1C@*N$CD1H18:]BMPMCKQ+!`'9 `P`0$ ``
M```#`!$0" ````,`@!#_____0 `', "U/[21A< !0 `(,*#O$GZ7A< !"P``
M@ @@!@``````P ```````$8``````X4````````#``* "" &``````# ````
M````1@`````0A0````````,`!8 (( 8``````, ```````!&`````%*%``"W
M#0``'@`E@ @@!@``````P ```````$8`````5(4```$````$````."XP``,`
M)H (( 8``````, ```````!&``````&%````````"P`O@ @@!@``````P ``
M`````$8`````#H4````````#`#" "" &``````# ````````1@`````1A0``
M``````,`,H (( 8``````, ```````!&`````!B%````````'@!!@ @@!@``
M````P ```````$8`````-H4```$````!`````````!X`0H (( 8``````, `
M``````!&`````#>%```!`````0`````````>`$. "" &``````# ````````
M1@`````XA0```0````$`````````'@`]``$````%````4D4Z( `````#``TT
&_3<``(HV
`
end

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-dev-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.