1 /* 2 * Copyright (c) 2016 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "modules/audio_mixer/default_output_rate_calculator.h" 12 13 #include <algorithm> 14 #include <iterator> 15 16 #include "modules/audio_processing/include/audio_processing.h" 17 #include "rtc_base/checks.h" 18 19 namespace webrtc { 20 CalculateOutputRateFromRange(rtc::ArrayView<const int> preferred_sample_rates)21int DefaultOutputRateCalculator::CalculateOutputRateFromRange( 22 rtc::ArrayView<const int> preferred_sample_rates) { 23 if (preferred_sample_rates.empty()) { 24 return DefaultOutputRateCalculator::kDefaultFrequency; 25 } 26 using NativeRate = AudioProcessing::NativeRate; 27 const int maximal_frequency = *std::max_element( 28 preferred_sample_rates.cbegin(), preferred_sample_rates.cend()); 29 30 RTC_DCHECK_LE(NativeRate::kSampleRate8kHz, maximal_frequency); 31 RTC_DCHECK_GE(NativeRate::kSampleRate48kHz, maximal_frequency); 32 33 static constexpr NativeRate native_rates[] = { 34 NativeRate::kSampleRate8kHz, NativeRate::kSampleRate16kHz, 35 NativeRate::kSampleRate32kHz, NativeRate::kSampleRate48kHz}; 36 const auto* rounded_up_index = std::lower_bound( 37 std::begin(native_rates), std::end(native_rates), maximal_frequency); 38 RTC_DCHECK(rounded_up_index != std::end(native_rates)); 39 return *rounded_up_index; 40 } 41 } // namespace webrtc 42