|
Hello all, I am on the lookout for a low bitrate speech coder which works at 2 - 8 kbps and has a good quality. also i am on the look out for the code for the GSM half rate speech coder. Can any one of u plz help me out in my search. Thanks in advance, |
|
|
GSM half rate coder
Started by ●September 16, 2002
Reply by ●September 16, 20022002-09-16
|
B V Harsha- Try searching Google for "MELP". Surprisingly good MOS scores from 1200 bps through 4000 bps. Jeff Brower DSP sw/hw engineer Signalogic b_v_harsha wrote: > > Hello all, > I am on the lookout for a low bitrate speech coder which > works at 2 - 8 kbps and has a good quality. > > also i am on the look out for the code for the GSM half rate speech > coder. Can any one of u plz help me out in my search. > > Thanks in advance, |
|
|
Reply by ●September 17, 20022002-09-17
|
Hi Jeff But MELP quality below 1800 bit/sec is not acceptable with changing the input frame width. Do you know any other way to decreasing the total bit rate from 2400 bit/sec to 1200 bit/sec ? Shahram DSP hw/sw Eng BBS --- Jeff Brower <> wrote: > B V Harsha- > > Try searching Google for "MELP". Surprisingly good > MOS scores from 1200 bps through > 4000 bps. > > Jeff Brower > DSP sw/hw engineer > Signalogic > b_v_harsha wrote: > > > > Hello all, > > I am on the lookout for a low bitrate > speech coder which > > works at 2 - 8 kbps and has a good quality. > > > > also i am on the look out for the code for the GSM > half rate speech > > coder. Can any one of u plz help me out in my > search. > > > > Thanks in advance, __________________________________________________ |
Reply by ●September 17, 20022002-09-17
|
Shahram- > But MELP quality below 1800 bit/sec is not acceptable > with changing the input frame width. Do you know any > other way to decreasing the total bit rate from 2400 > bit/sec to 1200 bit/sec ? By "changing" I assume you mean "increasing". What is your maximum allowable framesize, in msec? Jeff Brower DSP sw/hw engineer Signalogic > --- Jeff Brower <> wrote: > > B V Harsha- > > > > Try searching Google for "MELP". Surprisingly good > > MOS scores from 1200 bps through > > 4000 bps. > > > > Jeff Brower > > DSP sw/hw engineer > > Signalogic > > > > > > b_v_harsha wrote: > > > > > > Hello all, > > > I am on the lookout for a low bitrate > > speech coder which > > > works at 2 - 8 kbps and has a good quality. > > > > > > also i am on the look out for the code for the GSM > > half rate speech > > > coder. Can any one of u plz help me out in my > > search. > > > > > > Thanks in advance, |
|
|
Reply by ●September 17, 20022002-09-17
|
Hi Jeff For myself there is not any limitiation in this issue to increase frame size. I mean your sloution to decrease the total bit rate to 1200bit/sec, is to increasing the fame size , two times, or you have any other idea. Thanks in advance. Regards Shahram R&D DSP Hw/Sw Engineer BBS --- Jeff Brower <> wrote: > Shahram- > > > But MELP quality below 1800 bit/sec is not > acceptable > > with changing the input frame width. Do you know > any > > other way to decreasing the total bit rate from > 2400 > > bit/sec to 1200 bit/sec ? > > By "changing" I assume you mean "increasing". What > is your maximum allowable > framesize, in msec? > > Jeff Brower > DSP sw/hw engineer > Signalogic > > --- Jeff Brower <> wrote: > > > B V Harsha- > > > > > > Try searching Google for "MELP". Surprisingly > good > > > MOS scores from 1200 bps through > > > 4000 bps. > > > > > > Jeff Brower > > > DSP sw/hw engineer > > > Signalogic > > > > > > > > > b_v_harsha wrote: > > > > > > > > Hello all, > > > > I am on the lookout for a low > bitrate > > > speech coder which > > > > works at 2 - 8 kbps and has a good quality. > > > > > > > > also i am on the look out for the code for the > GSM > > > half rate speech > > > > coder. Can any one of u plz help me out in my > > > search. > > > > > > > > Thanks in advance, __________________________________________________ |
Reply by ●September 17, 20022002-09-17
|
Shahram- > For myself there is not any limitiation in this issue > to increase frame size. I mean your sloution to > decrease the total bit rate to 1200bit/sec, is to > increasing the fame size , two times, or you have any > other idea. Thanks in advance. I believe the way the default 1200 bps MELP algorithm works is to process (3) 22.5 msec frames, and produce an 81-bit packet. At least part of that is because the algorithm has an option to use the AT&T noise pre-processor, which requires 3x frames. It might be possible to skip the NPP and go with 27-bit packets, but I don't know; I'll have to ask our engineers. The 2000-2700 bps MELP algorithm works differently, and processes only 1 frame. We've tested that at frames from 17.5 msec to 22.5 msec. It also supports an NPP option. Jeff Brower DSP sw/hw engineer Signalogic > --- Jeff Brower <> wrote: > > Shahram- > > > > > But MELP quality below 1800 bit/sec is not > > acceptable > > > with changing the input frame width. Do you know > > any > > > other way to decreasing the total bit rate from > > 2400 > > > bit/sec to 1200 bit/sec ? > > > > By "changing" I assume you mean "increasing". What > > is your maximum allowable > > framesize, in msec? > > > > Jeff Brower > > DSP sw/hw engineer > > Signalogic > > > > > > > --- Jeff Brower <> wrote: > > > > B V Harsha- > > > > > > > > Try searching Google for "MELP". Surprisingly > > good > > > > MOS scores from 1200 bps through > > > > 4000 bps. > > > > > > > > Jeff Brower > > > > DSP sw/hw engineer > > > > Signalogic > > > > > > > > > > > > b_v_harsha wrote: > > > > > > > > > > Hello all, > > > > > I am on the lookout for a low > > bitrate > > > > speech coder which > > > > > works at 2 - 8 kbps and has a good quality. > > > > > > > > > > also i am on the look out for the code for the > > GSM > > > > half rate speech > > > > > coder. Can any one of u plz help me out in my > > > > search. > > > > > > > > > > Thanks in advance, |
