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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
tree | f435a8308119effd964b339f76abb83a57c29483 /third_party/libwebrtc/modules/audio_coding/neteq/cross_correlation.cc | |
parent | Initial commit. (diff) | |
download | firefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz firefox-26a029d407be480d791972afb5975cf62c9360a6.zip |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | third_party/libwebrtc/modules/audio_coding/neteq/cross_correlation.cc | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/neteq/cross_correlation.cc b/third_party/libwebrtc/modules/audio_coding/neteq/cross_correlation.cc new file mode 100644 index 0000000000..37ed9374f0 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_coding/neteq/cross_correlation.cc @@ -0,0 +1,55 @@ +/* + * 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 "modules/audio_coding/neteq/cross_correlation.h" + +#include <cstdlib> +#include <limits> + +#include "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 element that has the maximum absolute value of sequence_1 and 2. + // Note that these values may be negative. + const int16_t max_1 = + WebRtcSpl_MaxAbsElementW16(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_MaxAbsElementW16(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. + const int64_t max_value = + abs(max_1 * max_2) * static_cast<int64_t>(sequence_1_length); + const int32_t factor = max_value >> 31; + 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 |