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HI I want to know the difference between the voiced and unvoiced frame in context of the MELP 2.4 kbps codec, (and other codecs as well). What encoder does in case of a voiced or an unvoiced frame..?. Regards Khubaib |
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Difference between voiced and unvoiced frame.?
Started by ●February 27, 2004
Reply by ●March 1, 20042004-03-01
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hi for finding out voiced or unvoiced, there is some threshold limit, if it is above some value, it is voiced and if it is less then it is unvoiced.i think while finding out pitch we will find out this. atpresent iam involved in g.722.2 speech coder. evry speechcoder will have some standards regarding how to code every part of the coder. it is specified by ITU-T. they will provide some rules and regulations regarding gsm series speech coder. --- Khubaib <> wrote: > HI > I want to know the difference between the voiced and > unvoiced frame > in context of the MELP 2.4 kbps codec, (and other > codecs as well). > What encoder does in case of a voiced or an unvoiced > frame..?. Regards > Khubaib > __________________________________ |
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Reply by ●March 3, 20042004-03-03
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Hi,
Regarding voiced and unvoiced distinction, one method is using
autocorrelation to check on pitch frequency. If you use threshold method coupled
with pitch it should be a good bet for distinguising between the two.
Pitch varies between males, females and children. We have not reached the
point of analyzing extra terrestrials yet but this may be in the higher
regions:)
Max frequency for pitch is around 250 Hz and thus if you a BPF or LPF with
higher cutoff at 500 Hz and then check for pitch you should be there.
Based on this you should be able to distinguish between voiced and
unvoiced.
cheers
vijay bharathi <v...@yahoo.com> wrote:
Shree Jaisimha
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Reply by ●March 4, 20042004-03-04
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hi yes thats good idea. generally we will find out the correlation beteween weighted speech and weighted speech delayed by some pitch lag. maximum autocorrelation for one such delay is chosen as pitch lag. then from this we will find out gain using some formulae. using gain, we will find out voiced or unvoiced using some threshold limit. this is standard method for finding voiced or unvoiced in g.7xx series speech coders --- Shree Jaisimha <> wrote: > Hi, > > Regarding voiced and unvoiced distinction, one > method is using autocorrelation to check on pitch > frequency. If you use threshold method coupled with > pitch it should be a good bet for distinguising > between the two. > > Pitch varies between males, females and children. We > have not reached the point of analyzing extra > terrestrials yet but this may be in the higher > regions:) > > Max frequency for pitch is around 250 Hz and thus if > you a BPF or LPF with higher cutoff at 500 Hz and > then check for pitch you should be there. > > Based on this you should be able to distinguish > between voiced and unvoiced. > > cheers > > vijay bharathi <> wrote: > hi > > for finding out voiced or unvoiced, there is > some > threshold limit, if it is above some value, it is > voiced and if it is less then it is unvoiced.i think > while finding out pitch we will find out this. > > atpresent iam involved in g.722.2 speech > coder. evry > speechcoder will have some standards regarding how > to > code every part of the coder. it is specified by > ITU-T. they will provide some rules and regulations > regarding gsm series speech coder. > > > --- Khubaib <> wrote: > > HI > > I want to know the difference between the voiced > and > > unvoiced frame > > in context of the MELP 2.4 kbps codec, (and other > > codecs as well). > > What encoder does in case of a voiced or an > unvoiced > > frame..?. Regards > > Khubaib > > > > > > __________________________________ > > _____________________________________ > 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 > > > --------------------------------- > Yahoo! Groups Links > > To > > Shree Jaisimha > > --------------------------------- > __________________________________ |
