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/*
* Copyright (c) 2017 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/aec3/aec3_common.h"
#include <stdint.h>
#include "rtc_base/checks.h"
#include "rtc_base/system/arch.h"
#include "system_wrappers/include/cpu_features_wrapper.h"
namespace webrtc {
Aec3Optimization DetectOptimization() {
#if defined(WEBRTC_ARCH_X86_FAMILY)
if (GetCPUInfo(kAVX2) != 0) {
return Aec3Optimization::kAvx2;
} else if (GetCPUInfo(kSSE2) != 0) {
return Aec3Optimization::kSse2;
}
#endif
#if defined(WEBRTC_HAS_NEON)
return Aec3Optimization::kNeon;
#else
return Aec3Optimization::kNone;
#endif
}
float FastApproxLog2f(const float in) {
RTC_DCHECK_GT(in, .0f);
// Read and interpret float as uint32_t and then cast to float.
// This is done to extract the exponent (bits 30 - 23).
// "Right shift" of the exponent is then performed by multiplying
// with the constant (1/2^23). Finally, we subtract a constant to
// remove the bias (https://en.wikipedia.org/wiki/Exponent_bias).
union {
float dummy;
uint32_t a;
} x = {in};
float out = x.a;
out *= 1.1920929e-7f; // 1/2^23
out -= 126.942695f; // Remove bias.
return out;
}
float Log2TodB(const float in_log2) {
return 3.0102999566398121 * in_log2;
}
} // namespace webrtc
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