1 files changed, 136 insertions, 0 deletions
diff --git a/webrtc/modules/audio_processing/agc/circular_buffer.cc b/webrtc/modules/audio_processing/agc/circular_buffer.cc
new file mode 100644
index 0000000000..8ecb76008f
--- /dev/null
+++ b/webrtc/modules/audio_processing/agc/circular_buffer.cc
@@ -0,0 +1,136 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/modules/audio_processing/agc/circular_buffer.h"
+
+#include <assert.h>
+#include <stdlib.h>
+
+namespace webrtc {
+
+AgcCircularBuffer::AgcCircularBuffer(int buffer_size)
+    : buffer_(new double[buffer_size]),
+      is_full_(false),
+      index_(0),
+      buffer_size_(buffer_size),
+      sum_(0) {}
+
+AgcCircularBuffer::~AgcCircularBuffer() {}
+
+void AgcCircularBuffer::Reset() {
+  is_full_ = false;
+  index_ = 0;
+  sum_ = 0;
+}
+
+AgcCircularBuffer* AgcCircularBuffer::Create(int buffer_size) {
+  if (buffer_size <= 0)
+    return NULL;
+  return new AgcCircularBuffer(buffer_size);
+}
+
+double AgcCircularBuffer::Oldest() const {
+  if (!is_full_)
+    return buffer_[0];
+  else
+    return buffer_[index_];
+}
+
+double AgcCircularBuffer::Mean() {
+  double m;
+  if (is_full_) {
+    m = sum_ / buffer_size_;
+  } else {
+    if (index_ > 0)
+      m = sum_ / index_;
+    else
+      m = 0;
+  }
+  return m;
+}
+
+void AgcCircularBuffer::Insert(double value) {
+  if (is_full_) {
+    sum_ -= buffer_[index_];
+  }
+  sum_ += value;
+  buffer_[index_] = value;
+  index_++;
+  if (index_ >= buffer_size_) {
+    is_full_ = true;
+    index_ = 0;
+  }
+}
+int AgcCircularBuffer::BufferLevel() {
+  if (is_full_)
+    return buffer_size_;
+  return index_;
+}
+
+int AgcCircularBuffer::Get(int index, double* value) const {
+  int err = ConvertToLinearIndex(&index);
+  if (err < 0)
+    return -1;
+  *value = buffer_[index];
+  return 0;
+}
+
+int AgcCircularBuffer::Set(int index, double value) {
+  int err = ConvertToLinearIndex(&index);
+  if (err < 0)
+    return -1;
+
+  sum_ -= buffer_[index];
+  buffer_[index] = value;
+  sum_ += value;
+  return 0;
+}
+
+int AgcCircularBuffer::ConvertToLinearIndex(int* index) const {
+  if (*index < 0 || *index >= buffer_size_)
+    return -1;
+
+  if (!is_full_ && *index >= index_)
+    return -1;
+
+  *index = index_ - 1 - *index;
+  if (*index < 0)
+    *index += buffer_size_;
+  return 0;
+}
+
+int AgcCircularBuffer::RemoveTransient(int width_threshold,
+                                       double val_threshold) {
+  if (!is_full_ && index_ < width_threshold + 2)
+    return 0;
+
+  int index_1 = 0;
+  int index_2 = width_threshold + 1;
+  double v = 0;
+  if (Get(index_1, &v) < 0)
+    return -1;
+  if (v < val_threshold) {
+    Set(index_1, 0);
+    int index;
+    for (index = index_2; index > index_1; index--) {
+      if (Get(index, &v) < 0)
+        return -1;
+      if (v < val_threshold)
+        break;
+    }
+    for (; index > index_1; index--) {
+      if (Set(index, 0.0) < 0)
+        return -1;
+    }
+  }
+  return 0;
+}
+
+}  // namespace webrtc