120 lines
4.5 KiB
C++
120 lines
4.5 KiB
C++
/************************************************************************************
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*
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* D++, A Lightweight C++ library for Discord
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*
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* Copyright 2021 Craig Edwards and D++ contributors
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* (https://github.com/brainboxdotcc/DPP/graphs/contributors)
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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************************************************************************************/
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#pragma once
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#if defined _MSC_VER || defined __GNUC__ || defined __clang__
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#include <arm_neon.h>
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#include <numeric>
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#include <cstdint>
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#include <limits>
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namespace dpp {
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using neon_float = float32x4_t;
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/**
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* @brief A class for audio mixing operations using ARM NEON instructions.
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*/
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class audio_mixer {
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public:
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/**
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* @brief The number of 32-bit values per CPU register.
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*/
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inline static constexpr int32_t byte_blocks_per_register{ 4 };
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/**
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* @brief Collect a single register worth of data from data_in, apply gain and increment, and store the result in data_out.
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* This version uses ARM NEON instructions.
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*
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* @param data_in Pointer to the input array of int32_t values.
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* @param data_out Pointer to the output array of int16_t values.
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* @param current_gain The gain to be applied to the elements.
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* @param increment The increment value to be added to each element.
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*/
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inline void collect_single_register(int32_t* data_in, int16_t* data_out, float current_gain, float increment) {
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neon_float gathered_values = gather_values(data_in);
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neon_float gain_vector = vdupq_n_f32(current_gain);
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static constexpr float data[4] = { 0.0f, 1.0f, 2.0f, 3.0f };
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neon_float floats = vld1q_f32(data);
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neon_float increment_vector = vmulq_f32(vdupq_n_f32(increment), floats);
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neon_float current_samples_new = vmulq_f32(gathered_values, vaddq_f32(gain_vector, increment_vector));
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// Clamping the values between int16_t min and max
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neon_float min_val = vdupq_n_f32(static_cast<float>(std::numeric_limits<int16_t>::min()));
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neon_float max_val = vdupq_n_f32(static_cast<float>(std::numeric_limits<int16_t>::max()));
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current_samples_new = vmaxq_f32(current_samples_new, min_val);
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current_samples_new = vminq_f32(current_samples_new, max_val);
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store_values(current_samples_new, data_out);
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}
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/**
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* @brief Combine a register worth of elements from decoded_data and store the result in up_sampled_vector.
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* This version uses ARM NEON instructions.
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*
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* @param up_sampled_vector Pointer to the array of int32_t values.
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* @param decoded_data Pointer to the array of int16_t values.
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*/
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inline void combine_samples(int32_t* up_sampled_vector, const int16_t* decoded_data) {
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neon_float up_sampled = gather_values(up_sampled_vector);
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neon_float decoded = gather_values(decoded_data);
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neon_float newValues = vaddq_f32(up_sampled, decoded);
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store_values(newValues, up_sampled_vector);
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}
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protected:
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/**
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* @brief Array for storing the values to be loaded/stored.
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*/
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alignas(16) float values[byte_blocks_per_register]{};
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/**
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* @brief Stores values from a 128-bit NEON vector to a storage location.
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* @tparam value_type The target value type for storage.
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* @param values_to_store The 128-bit NEON vector containing values to store.
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* @param storage_location Pointer to the storage location.
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*/
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template<typename value_type> inline void store_values(const neon_float& values_to_store, value_type* storage_location) {
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vst1q_f32(values, values_to_store);
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for (int64_t x = 0; x < byte_blocks_per_register; ++x) {
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storage_location[x] = static_cast<value_type>(values[x]);
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}
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}
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/**
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* @brief Specialization for gathering non-float values into a NEON register.
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* @tparam value_type The type of values being gathered.
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* @return A NEON register containing gathered values.
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*/
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template<typename value_type> inline neon_float gather_values(value_type* values_new) {
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for (uint64_t x = 0; x < byte_blocks_per_register; ++x) {
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values[x] = static_cast<float>(values_new[x]);
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}
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return vld1q_f32(values);
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}
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};
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} // namespace dpp
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#endif |