From 2c8e5cab3faa6d360e222b7a6c40a80083d021ac Mon Sep 17 00:00:00 2001
From: Eric Laurent <elaurent@google.com>
Date: Fri, 9 Jul 2010 12:28:50 -0700
Subject: 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
---
 .../libeffects/testlibs/AudioCoefInterpolator.cpp  | 84 ++++++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 media/libeffects/testlibs/AudioCoefInterpolator.cpp

(limited to 'media/libeffects/testlibs/AudioCoefInterpolator.cpp')

diff --git a/media/libeffects/testlibs/AudioCoefInterpolator.cpp b/media/libeffects/testlibs/AudioCoefInterpolator.cpp
new file mode 100644
index 0000000..039ab9f
--- /dev/null
+++ b/media/libeffects/testlibs/AudioCoefInterpolator.cpp
@@ -0,0 +1,84 @@
+/* //device/servers/AudioFlinger/AudioCoefInterpolator.cpp
+ **
+ ** Copyright 2008, 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.
+ */
+
+#include <string.h>
+#include "AudioCoefInterpolator.h"
+
+#define LIKELY( exp )       (__builtin_expect( (exp) != 0, true  ))
+#define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))
+
+namespace android {
+
+AudioCoefInterpolator::AudioCoefInterpolator(size_t nInDims,
+                                             const size_t inDims[],
+                                             size_t nOutDims,
+                                             const audio_coef_t * table) {
+    mNumInDims = nInDims;
+    memcpy(mInDims, inDims, nInDims * sizeof(size_t));
+    mNumOutDims = nOutDims;
+    mTable = table;
+    // Initialize offsets array
+    size_t dim = nInDims - 1;
+    mInDimOffsets[nInDims - 1] = nOutDims;
+    while (dim-- > 0) {
+        mInDimOffsets[dim] = mInDimOffsets[dim + 1] * mInDims[dim + 1];
+    }
+}
+
+void AudioCoefInterpolator::getCoef(const int intCoord[], uint32_t fracCoord[],
+                                    audio_coef_t out[]) {
+    size_t index = 0;
+    size_t dim = mNumInDims;
+    while (dim-- > 0) {
+        if (UNLIKELY(intCoord[dim] < 0)) {
+            fracCoord[dim] = 0;
+        } else if (UNLIKELY(intCoord[dim] >= (int)mInDims[dim] - 1)) {
+            fracCoord[dim] = 0;
+            index += mInDimOffsets[dim] * (mInDims[dim] - 1);
+        } else {
+            index += mInDimOffsets[dim] * intCoord[dim];
+        }
+    }
+    getCoefRecurse(index, fracCoord, out, 0);
+}
+
+void AudioCoefInterpolator::getCoefRecurse(size_t index,
+                                           const uint32_t fracCoord[],
+                                           audio_coef_t out[], size_t dim) {
+    if (dim == mNumInDims) {
+        memcpy(out, mTable + index, mNumOutDims * sizeof(audio_coef_t));
+    } else {
+        getCoefRecurse(index, fracCoord, out, dim + 1);
+        if (LIKELY(fracCoord != 0)) {
+           audio_coef_t tempCoef[MAX_OUT_DIMS];
+           getCoefRecurse(index + mInDimOffsets[dim], fracCoord, tempCoef,
+                           dim + 1);
+            size_t d = mNumOutDims;
+            while (d-- > 0) {
+                out[d] = interp(out[d], tempCoef[d], fracCoord[dim]);
+            }
+        }
+    }
+}
+
+audio_coef_t AudioCoefInterpolator::interp(audio_coef_t lo, audio_coef_t hi,
+                                           uint32_t frac) {
+    int64_t delta = static_cast<int64_t>(hi-lo) * frac;
+    return lo + static_cast<audio_coef_t> (delta >> 32);
+}
+
+}
-- 
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