git-svn-id: http://svn.miranda-ng.org/main/trunk@1123 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c

1 files changed, 183 insertions, 0 deletions

diff --git a/!NotAdopted/Tlen/codec/gsm_long.c b/!NotAdopted/Tlen/codec/gsm_long.c
new file mode 100644
index 0000000000..7d9148061c
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+++ b/!NotAdopted/Tlen/codec/gsm_long.c
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+/*

+

+Tlen Protocol Plugin for Miranda IM

+Copyright (C) 2004-2007  Piotr Piastucki

+

+This program is based on GSM 06.10 source code developed by 

+Jutta Degener and Carsten Bormann,

+Copyright 1992, 1993, 1994 by Jutta Degener and Carsten Bormann,

+Technische Universitaet Berlin 

+  

+This program is free software; you can redistribute it and/or

+modify it under the terms of the GNU General Public License

+as published by the Free Software Foundation; either version 2

+of the License, or (at your option) any later version.

+

+This program is distributed in the hope that it will be useful,

+but WITHOUT ANY WARRANTY; without even the implied warranty of

+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+GNU General Public License for more details.

+

+You should have received a copy of the GNU General Public License

+along with this program; if not, write to the Free Software

+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

+

+*/

+#include "gsm.h"

+#include <stdio.h>

+#include <math.h>

+#include <stdlib.h>

+

+/* Decision levels */

+const static int gsm_DLB[4] = {  6554,    16384,   26214,      32767   };

+/* Quantization levels */

+const static int gsm_QLB[4] = {  3277,    11469,   21299,      32767   };

+

+/*

+ * Long term parameters calculation - lag (Nc) and gain (bc).

+ */

+static void longTermLTPCalculation(gsm_state *state, short *in, short *in_1)

+{

+	int  	k, lambda;

+   	int	   	Nc, bc;

+   	float   in_1_float_base[120], * in_1_float = in_1_float_base + 120;

+   	float   in_float[40];

+ 	float   L_result, L_max, L_power;

+

+	for (k = -120; k < 0; k++) in_1_float[k] = (float)in_1[k];

+	for (k =    0; k < 40; k++) in_float[k] =  (float)in[k];

+

+	/* Search for the maximum cross-correlation and coding of the LTP lag */

+

+	L_max = 0;

+	Nc    = 40;   /* index for the maximum cross-correlation */

+

+	for (lambda = 40; lambda < 121; lambda++) {

+		for (L_result = 0, L_power = 0, k = 0; k < 40; k++) {

+			L_result += in_float[k] * in_1_float[k - lambda];

+//			L_power += in_1_float[k - lambda] * in_1_float[k - lambda];

+		}

+//		L_result = L_result / L_power;

+		if (L_result > L_max) {

+			Nc    = lambda;

+			L_max = L_result;

+		}

+	}

+	state->Nc[state->subframe] = Nc;

+	if (L_max <= 0.)  {

+		state->bc[state->subframe] = 0;

+		return;

+	}

+	/*  Compute the power of the reconstructed short term residual signal dp[..] */

+	in_1_float -= Nc;

+	L_power = 0;

+	for (k = 0; k < 40; k++) {

+		float f = in_1_float[k];

+		L_power += f * f;

+	}

+	if (L_max >= L_power) { //1.0

+		state->bc[state->subframe] = 3;

+		return;

+	}

+   /*  Coding of the LTP gain

+    *  Table gsm_DLB must be used to obtain the level DLB[i] for the

+    *  quantization of the LTP gain b to get the coded version bc.

+    */

+//	lambda = L_max * 32768.;

+	lambda = (int)(L_max * 32768. / L_power);

+	for (bc = 0; bc <= 2; ++bc) if (lambda <= gsm_DLB[bc]) break;

+	state->bc[state->subframe] = bc;

+}

+

+/*

+ *  Here we decode the bc parameter and compute samples of the estimate out[0..39].

+ *  The decoding of bc needs the gsm_QLB table.

+ *  The long term residual signal e[0..39] is then calculated to be fed to the

+ *  RPE encoding section.

+ */

+static void longTermAnalysisFilter(int Nc, int bc, short *in, short *in_1, short *out, int *e)

+{

+	int	gain, k, l;

+	gain = gsm_QLB[bc];

+	for (k = 0; k < 40; k++) {

+		l = (gain * (int)in_1[k - Nc] + 16384) >> 15;

+		if (l < -32768) l = -32768;

+		else if (l > 32767) l = 32767;

+		out[k]  = l;

+		e[k]   = in[k] - l;

+	}

+}

+

+/*

+ *  This procedure uses the bcr and Ncr parameter to realize the

+ *  long term synthesis filtering.  The decoding of bcr needs table gsm_QLB.

+ */

+static void longTermSynthesisFilter(gsm_state * state, int Ncr, int bcr, int *e, short *out)

+{

+	int 	k;

+	int 	brp, Nr;

+

+	/*  Check the limits of Nr. */

+	Nr = Ncr < 40 || Ncr > 120 ? state->nrp : Ncr;

+	state->nrp = Nr;

+	/*  Decoding of the LTP gain bcr */

+	brp = gsm_QLB[ bcr ];

+

+   /*  Computation of the reconstructed short term residual

+    *  signal drp[0..39]

+    */

+	for (k = 0; k < 40; k++) {

+		int temp = (brp * (int)out[ k-Nr ] + 16384) >> 15;

+		out[k] = e[k] + temp;

+   }

+}

+

+/*

+ *  This procedure performs long term analysis.

+ */

+void longTermAnalysis(gsm_state *state, short *in)

+{

+	short *in_1 = state->dp0 + 120 + state->subframe * 40;

+	short *out = state->dp0 + 120 + state->subframe * 40;

+	int *e = state->e + state->subframe * 40;

+/*

+

+	int   i;

+	printf("Long-term in: \n");

+	for (i=0;i<40;i++) {

+		printf("%7d ", in[i]);

+	}

+	printf("\n");

+	*/

+	longTermLTPCalculation(state, in, in_1);

+	/* printf("Nc: %d, bc: %d \n", state->Nc[state->subframe], state->bc[state->subframe]);

+	*/

+	longTermAnalysisFilter(state->Nc[state->subframe], state->bc[state->subframe], in, in_1, out, e);

+/*

+	printf("Long-term out: \n");

+	for (i=0;i<40;i++) {

+		printf("%7d ", out[i]);

+	}

+	printf("\n");

+	*/

+}

+

+/*

+ *  This procedure performs long term synthesis.

+ */

+void longTermSynthesis(gsm_state *state)

+{

+	int Nc = state->Nc[state->subframe];

+	int bc = state->bc[state->subframe];

+	int *e = state->e + state->subframe * 40;

+	short *out = state->dp0 + 120 + state->subframe * 40;

+	//int i;

+	longTermSynthesisFilter(state, Nc, bc, e, out);

+	/*

+	printf("Long-term reconstructed: \n");

+	for (i=0;i<160;i++) {

+		printf("%7d ", state->dp0[i]);

+	}

+	printf("\n");

+	*/

+}