Index: webrtc/modules/audio_coding/neteq/cross_correlation.cc |
diff --git a/webrtc/modules/audio_coding/neteq/cross_correlation.cc b/webrtc/modules/audio_coding/neteq/cross_correlation.cc |
deleted file mode 100644 |
index ad89ab8a139eafadafb27632de5e9bc3ddbc5376..0000000000000000000000000000000000000000 |
--- a/webrtc/modules/audio_coding/neteq/cross_correlation.cc |
+++ /dev/null |
@@ -1,62 +0,0 @@ |
-/* |
- * Copyright (c) 2016 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_coding/neteq/cross_correlation.h" |
- |
-#include <cstdlib> |
-#include <limits> |
- |
-#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" |
- |
-namespace webrtc { |
- |
-// This function decides the overflow-protecting scaling and calls |
-// WebRtcSpl_CrossCorrelation. |
-int CrossCorrelationWithAutoShift(const int16_t* sequence_1, |
- const int16_t* sequence_2, |
- size_t sequence_1_length, |
- size_t cross_correlation_length, |
- int cross_correlation_step, |
- int32_t* cross_correlation) { |
- // Find the maximum absolute value of sequence_1 and 2. |
- const int16_t max_1 = WebRtcSpl_MaxAbsValueW16(sequence_1, sequence_1_length); |
- const int sequence_2_shift = |
- cross_correlation_step * (static_cast<int>(cross_correlation_length) - 1); |
- const int16_t* sequence_2_start = |
- sequence_2_shift >= 0 ? sequence_2 : sequence_2 + sequence_2_shift; |
- const size_t sequence_2_length = |
- sequence_1_length + std::abs(sequence_2_shift); |
- const int16_t max_2 = |
- WebRtcSpl_MaxAbsValueW16(sequence_2_start, sequence_2_length); |
- |
- // In order to avoid overflow when computing the sum we should scale the |
- // samples so that (in_vector_length * max_1 * max_2) will not overflow. |
- // Expected scaling fulfills |
- // 1) sufficient: |
- // sequence_1_length * (max_1 * max_2 >> scaling) <= 0x7fffffff; |
- // 2) necessary: |
- // if (scaling > 0) |
- // sequence_1_length * (max_1 * max_2 >> (scaling - 1)) > 0x7fffffff; |
- // The following calculation fulfills 1) and almost fulfills 2). |
- // There are some corner cases that 2) is not satisfied, e.g., |
- // max_1 = 17, max_2 = 30848, sequence_1_length = 4095, in such case, |
- // optimal scaling is 0, while the following calculation results in 1. |
- const int32_t factor = (max_1 * max_2) / (std::numeric_limits<int32_t>::max() |
- / static_cast<int32_t>(sequence_1_length)); |
- const int scaling = factor == 0 ? 0 : 31 - WebRtcSpl_NormW32(factor); |
- |
- WebRtcSpl_CrossCorrelation(cross_correlation, sequence_1, sequence_2, |
- sequence_1_length, cross_correlation_length, |
- scaling, cross_correlation_step); |
- |
- return scaling; |
-} |
- |
-} // namespace webrtc |