Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 107 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/audio_processing/vad/pole_zero_filter.cc b/third_party/libwebrtc/modules/audio_processing/vad/pole_zero_filter.cc
new file mode 100644
index 0000000000..e7a611309c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/vad/pole_zero_filter.cc
@@ -0,0 +1,107 @@
+/*
+ *  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 "modules/audio_processing/vad/pole_zero_filter.h"
+
+#include <string.h>
+
+#include <algorithm>
+
+namespace webrtc {
+
+PoleZeroFilter* PoleZeroFilter::Create(const float* numerator_coefficients,
+                                       size_t order_numerator,
+                                       const float* denominator_coefficients,
+                                       size_t order_denominator) {
+  if (order_numerator > kMaxFilterOrder ||
+      order_denominator > kMaxFilterOrder || denominator_coefficients[0] == 0 ||
+      numerator_coefficients == NULL || denominator_coefficients == NULL)
+    return NULL;
+  return new PoleZeroFilter(numerator_coefficients, order_numerator,
+                            denominator_coefficients, order_denominator);
+}
+
+PoleZeroFilter::PoleZeroFilter(const float* numerator_coefficients,
+                               size_t order_numerator,
+                               const float* denominator_coefficients,
+                               size_t order_denominator)
+    : past_input_(),
+      past_output_(),
+      numerator_coefficients_(),
+      denominator_coefficients_(),
+      order_numerator_(order_numerator),
+      order_denominator_(order_denominator),
+      highest_order_(std::max(order_denominator, order_numerator)) {
+  memcpy(numerator_coefficients_, numerator_coefficients,
+         sizeof(numerator_coefficients_[0]) * (order_numerator_ + 1));
+  memcpy(denominator_coefficients_, denominator_coefficients,
+         sizeof(denominator_coefficients_[0]) * (order_denominator_ + 1));
+
+  if (denominator_coefficients_[0] != 1) {
+    for (size_t n = 0; n <= order_numerator_; n++)
+      numerator_coefficients_[n] /= denominator_coefficients_[0];
+    for (size_t n = 0; n <= order_denominator_; n++)
+      denominator_coefficients_[n] /= denominator_coefficients_[0];
+  }
+}
+
+template <typename T>
+static float FilterArPast(const T* past,
+                          size_t order,
+                          const float* coefficients) {
+  float sum = 0.0f;
+  size_t past_index = order - 1;
+  for (size_t k = 1; k <= order; k++, past_index--)
+    sum += coefficients[k] * past[past_index];
+  return sum;
+}
+
+int PoleZeroFilter::Filter(const int16_t* in,
+                           size_t num_input_samples,
+                           float* output) {
+  if (in == NULL || output == NULL)
+    return -1;
+  // This is the typical case, just a memcpy.
+  const size_t k = std::min(num_input_samples, highest_order_);
+  size_t n;
+  for (n = 0; n < k; n++) {
+    output[n] = in[n] * numerator_coefficients_[0];
+    output[n] += FilterArPast(&past_input_[n], order_numerator_,
+                              numerator_coefficients_);
+    output[n] -= FilterArPast(&past_output_[n], order_denominator_,
+                              denominator_coefficients_);
+
+    past_input_[n + order_numerator_] = in[n];
+    past_output_[n + order_denominator_] = output[n];
+  }
+  if (highest_order_ < num_input_samples) {
+    for (size_t m = 0; n < num_input_samples; n++, m++) {
+      output[n] = in[n] * numerator_coefficients_[0];
+      output[n] +=
+          FilterArPast(&in[m], order_numerator_, numerator_coefficients_);
+      output[n] -= FilterArPast(&output[m], order_denominator_,
+                                denominator_coefficients_);
+    }
+    // Record into the past signal.
+    memcpy(past_input_, &in[num_input_samples - order_numerator_],
+           sizeof(in[0]) * order_numerator_);
+    memcpy(past_output_, &output[num_input_samples - order_denominator_],
+           sizeof(output[0]) * order_denominator_);
+  } else {
+    // Odd case that the length of the input is shorter that filter order.
+    memmove(past_input_, &past_input_[num_input_samples],
+            order_numerator_ * sizeof(past_input_[0]));
+    memmove(past_output_, &past_output_[num_input_samples],
+            order_denominator_ * sizeof(past_output_[0]));
+  }
+  return 0;
+}
+
+}  // namespace webrtc