X-Git-Url: https://scm.cri.ensmp.fr/git/Faustine.git/blobdiff_plain/1059e1cc0c2ecfa237406949aa26155b6a5b9154..66f23d4fabf89ad09adbd4dfc15ac6b5b2b7da83:/interpreter/lib/src/libsndfile-1.0.25/src/GSM610/code.c diff --git a/interpreter/lib/src/libsndfile-1.0.25/src/GSM610/code.c b/interpreter/lib/src/libsndfile-1.0.25/src/GSM610/code.c new file mode 100644 index 0000000..78cb853 --- /dev/null +++ b/interpreter/lib/src/libsndfile-1.0.25/src/GSM610/code.c @@ -0,0 +1,87 @@ +/* + * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische + * Universitaet Berlin. See the accompanying file "COPYRIGHT" for + * details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE. + */ + + +#include +#include + +#include "gsm610_priv.h" + +/* + * 4.2 FIXED POINT IMPLEMENTATION OF THE RPE-LTP CODER + */ + +void Gsm_Coder ( + + struct gsm_state * State, + + word * s, /* [0..159] samples IN */ + +/* + * The RPE-LTD coder works on a frame by frame basis. The length of + * the frame is equal to 160 samples. Some computations are done + * once per frame to produce at the output of the coder the + * LARc[1..8] parameters which are the coded LAR coefficients and + * also to realize the inverse filtering operation for the entire + * frame (160 samples of signal d[0..159]). These parts produce at + * the output of the coder: + */ + + word * LARc, /* [0..7] LAR coefficients OUT */ + +/* + * Procedure 4.2.11 to 4.2.18 are to be executed four times per + * frame. That means once for each sub-segment RPE-LTP analysis of + * 40 samples. These parts produce at the output of the coder: + */ + + word * Nc, /* [0..3] LTP lag OUT */ + word * bc, /* [0..3] coded LTP gain OUT */ + word * Mc, /* [0..3] RPE grid selection OUT */ + word * xmaxc,/* [0..3] Coded maximum amplitude OUT */ + word * xMc /* [13*4] normalized RPE samples OUT */ +) +{ + int k; + word * dp = State->dp0 + 120; /* [ -120...-1 ] */ + word * dpp = dp; /* [ 0...39 ] */ + + word so[160]; + + Gsm_Preprocess (State, s, so); + Gsm_LPC_Analysis (State, so, LARc); + Gsm_Short_Term_Analysis_Filter (State, LARc, so); + + for (k = 0; k <= 3; k++, xMc += 13) { + + Gsm_Long_Term_Predictor ( State, + so+k*40, /* d [0..39] IN */ + dp, /* dp [-120..-1] IN */ + State->e + 5, /* e [0..39] OUT */ + dpp, /* dpp [0..39] OUT */ + Nc++, + bc++); + + Gsm_RPE_Encoding ( /*-S,-*/ + State->e + 5, /* e ][0..39][ IN/OUT */ + xmaxc++, Mc++, xMc ); + /* + * Gsm_Update_of_reconstructed_short_time_residual_signal + * ( dpp, State->e + 5, dp ); + */ + + { register int i; + for (i = 0; i <= 39; i++) + dp[ i ] = GSM_ADD( State->e[5 + i], dpp[i] ); + } + dp += 40; + dpp += 40; + + } + (void)memcpy( (char *)State->dp0, (char *)(State->dp0 + 160), + 120 * sizeof(*State->dp0) ); +} +