Dear all,

I have to do some GSM codec related analysis of audio and I've been using
the GSM library available from http://kbs.cs.tu-berlin.de/~jutta/toast.html.
I have managed to compile the basic core API (without the toast client) in
WindowsXP. I am using the gsm_explode function to extract the information
for each frame as I process the audio. By reading through the source code
for the gsm_explode function, I have gotten some idea of what each of the 76
members of the info array mean but I would appreciate if someone could
provide some detail from the perspective of the GSM standard.

LARc 0-7 (8), which I guess represents the long-term predictor
coefficients.
Nc (1), bc(1), Mc(1), xmaxc(1) and xmc (13) (17 in total) are repeated for 4
times and (I guess) represent the short-term predictor coefficient.

I would especially appreciate it if someone could tell me what Nc, bc, Mc
and xmaxc represent.

Any help would be greatly appreciated,

Many Thanks,

RG

rg wrote:

Dear all,

I have to do some GSM codec related analysis of audio and I've been using
the GSM library available from http://kbs.cs.tu-berlin.de/~jutta/toast.html.
I have managed to compile the basic core API (without the toast client) in
WindowsXP. I am using the gsm_explode function to extract the information
for each frame as I process the audio. By reading through the source code
for the gsm_explode function, I have gotten some idea of what each of the 76
members of the info array mean but I would appreciate if someone could
provide some detail from the perspective of the GSM standard.

LARc 0-7 (8), which I guess represents the long-term predictor
coefficients.
Nc (1), bc(1), Mc(1), xmaxc(1) and xmc (13) (17 in total) are repeated for 4
times and (I guess) represent the short-term predictor coefficient.

I would especially appreciate it if someone could tell me what Nc, bc, Mc
and xmaxc represent.

Look in the file "private.h" to find these answers.

Any help would be greatly appreciated,

Many Thanks,

RG

--
Phil Frisbie, Jr.
Hawk Software
http://www.hawksoft.com