First submission of audio effect library from NXP software.

This CL contains the first open sourceable version of the audio effect library from NXP software.
The effects implemented are:
- Bass boost
- Virtualizer (stereo widening)
- Equalizer
- Spectrum analyzer

Source file for the effect engines are located under libeffects/lvm/lib
The wrapper implementing the interface with the audio effect framework in under libeffects/lvm/wrapper

The code of other effect libraries has also been reorganized fo clarity:
- the effect factory is now under libeffects/factory
- the test equalizer and reverb effects are under libeffect/testlibs
- the visualizer is under libeffects/virtualizer

Change-Id: I8d91e2181f81b89f8fc0c1e1e6bf552c5809b2eb

1 files changed, 109 insertions, 0 deletions

diff --git a/media/libeffects/lvm/lib/Common/src/dB_to_Lin32.c b/media/libeffects/lvm/lib/Common/src/dB_to_Lin32.c
new file mode 100755
index 0000000..ac0343f
--- /dev/null
+++ b/media/libeffects/lvm/lib/Common/src/dB_to_Lin32.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2004-2010 NXP Software
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/************************************************************************/
+/*                                                                      */
+/*     %created_by:    sra % (CM/S)*/
+/*     %name:          dB_to_Lin32.c % (CM/S)*/
+/*     %version:       2 % (CM/S)*/
+/*     %date_created:  Wed Jun 18 11:27:46 2008 % (CM/S)*/
+/*                                                                      */
+/************************************************************************/
+
+/*######################################################################################*/
+/*  Include files                                                                       */
+/*######################################################################################*/
+
+#include "ScalarArithmetic.h"
+
+
+/****************************************************************************************
+ *  Name        : dB_to_Lin32()
+ *  Input       : Signed 16-bit integer
+ *                  MSB (16) = sign bit
+ *                  (15->05) = integer part
+ *                  (04->01) = decimal part
+ *  Output      : Signed 32-bit integer
+ *                  MSB (32) = sign bit
+ *                  (31->16) = integer part
+ *                  (15->01) = decimal part
+ *  Returns     : Lin value format 1.16.15
+ *  Description :
+ *  Remarks     :  Makes an approximation to the conversion by counting the number
+ *                 of 6dB steps for use as shifts and then interpolates with a remainder
+ *                 with the equation:
+ *
+ *                 Correction = (Remainder / 1.5029) - (Remainder^2 / 6)
+ *
+ *                 The two coefficients are scaled from 0x40000000 in 96 steps and calculated
+ *                 as follows:
+ *
+ *                 FIRST_COEF  = 0x80000000 / (96 * 1.5029)
+ *                 SECOND_COEF = 0x80000000 / (96^2 * 6)
+ *
+ ****************************************************************************************/
+
+#define FOUR_OVER_SIX    21846                  /* (4 / 6) * 2^15 */
+#define SIX_DB           96                     /* 6 * 16 or 6dB in Q11.4 format */
+#define FIRST_COEF_NEG   14884305
+#define FIRST_COEF_POS   7442152                /* FIRST_COEF_NEG / 2 */
+#define SECOND_COEF      38836
+#define MAX_VALUE        1536                   /* 96 * 16 */
+
+LVM_INT32   dB_to_Lin32(LVM_INT16    db_fix)
+{
+    LVM_INT32 Lin_val_32;
+    LVM_INT16 Shift;
+    LVM_INT32 Remain;
+
+
+    /*
+     * Check sign of the input
+     */
+    if (db_fix<0)
+    {
+        if (db_fix > -MAX_VALUE)
+        {
+            Shift  = (LVM_INT16)((((LVM_UINT32)(-db_fix) >> 4) * FOUR_OVER_SIX) >> 17);        /* Number of 6dB steps in Q11.4 format */
+            Remain = -db_fix - (Shift * SIX_DB);
+            Remain = (0x7FFFFFFF - (Remain * FIRST_COEF_NEG)) + (Remain * Remain * SECOND_COEF);
+            Lin_val_32 = (LVM_INT32)((LVM_UINT32)Remain >> (16 + Shift));
+        }
+        else
+        {
+            Lin_val_32 = 0;
+        }
+    }
+    else
+    {
+        if (db_fix < MAX_VALUE)
+        {
+            Shift  = (LVM_INT16)((((LVM_UINT32)db_fix >> 4) * FOUR_OVER_SIX) >> 17);        /* Number of 6dB steps in Q11.4 format */
+            Remain = db_fix - (Shift * SIX_DB);
+            Remain = 0x3FFFFFFF + (Remain * FIRST_COEF_POS) + (Remain * Remain * SECOND_COEF);
+            Lin_val_32 = (LVM_INT32)((LVM_UINT32)Remain >> (15 - Shift));
+        }
+        else
+        {
+            Lin_val_32 = 0x7FFFFFFF;
+        }
+    }
+
+
+    return Lin_val_32;  /* format 1.16.15 */
+}
+