ETSI has a AMR reference code. 3GPP also has AMR reference code for both fix-point and floating point. What's the difference between them? Which version is preferred? |
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AMR codec (ETSI version v.s. 3GPP version)
Started by ●January 9, 2004
Reply by ●January 30, 20042004-01-30
Hi Murphy, There is no algorithmic difference btw ETSI AMR and 3GPP AMR. 3GPP AMR support packing of coded bits and unpacking of bits before decoding. This packing and unpaking is done as per RFC3267. There is difference between these two versions of AMR for DTX mode. In ETSI amr for DTX ON, 245th word in coded bit stream is alway value of mode i.e. from 0 to 8, where 8 for DTX mode. In 3GPP AMR for DTX ON, 245th word is value of mode for non DTX frame but it is equal to -1, if DTX frame is found. Hence for NON DTX test streams there is no diff. in ETSI and unpacked bit stream. But for DTX bit stream only 245th word of DTX frame is different. Snehal --- Murphy Chen <> wrote: > ETSI has a AMR reference code. > 3GPP also has AMR reference code for both fix-point > and floating > point. > > What's the difference between them? > Which version is preferred? > __________________________________ |
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Reply by ●January 31, 20042004-01-31
Hi all can anyone of you tell me where I can get codes for LPC-10 algorithm written in Matlab,C,C++ or the compact algorithm for this. Please send me the links and if u have LPC-10 codes written in any language send me. Thanks Regards Devi Lal Sharma ===== Devi Lal Sharma #143,Ganga Hostel 3/5 Dual Degree IIT Chennai-36,India Stream:Communication Ph: +91-44-22579073,8917 Deptt.:Electrical Engg. IIT MADRAS (INDIA) email:, __________________________________ |
Reply by ●February 1, 20042004-02-01
Another diffrence.. In ETSI one flag called NSYNC is used as input from the n/w. Where as in 3GPP this is not used. The NSYNC is used in mobile communication when switching from one Base station to next base station. This alter the VAD operation. When ever NSYNC is set, the mode will not be NODTX. Regards --- Shivanand Hiremath ---- On Thu, 29 Jan 2004, snehal joshi wrote: > Hi Murphy, > There is no algorithmic difference btw ETSI AMR and > 3GPP AMR. 3GPP AMR support packing of coded bits and > unpacking of bits before decoding. This packing and > unpaking is done as per RFC3267. > There is difference between these two versions of AMR > for DTX mode. > In ETSI amr for DTX ON, 245th word in coded bit stream > is alway value of mode i.e. from 0 to 8, where 8 for > DTX mode. > In 3GPP AMR for DTX ON, 245th word is value of mode > for non DTX frame but it is equal to -1, if DTX frame > is found. > Hence for NON DTX test streams there is no diff. in > ETSI and unpacked bit stream. But for DTX bit stream > only 245th word of DTX frame is different. > Snehal > --- Murphy Chen <> wrote: > > ETSI has a AMR reference code. > > 3GPP also has AMR reference code for both fix-point > > and floating > > point. > > > > What's the difference between them? > > Which version is preferred? > > > > > > __________________________________ > _____________________________________ > 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 |
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