MLECO-2354 MLECO-2355 MLECO-2356: Moving noise reduction to public repository

* Use RNNoise model from PMZ
* Add Noise reduction use-case

Signed-off-by: Richard burton <richard.burton@arm.com>
Change-Id: Ia8cc7ef102e22a5ff8bfbd3833594a4905a66057
diff --git a/source/use_case/noise_reduction/include/RNNoiseModel.hpp b/source/use_case/noise_reduction/include/RNNoiseModel.hpp
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+++ b/source/use_case/noise_reduction/include/RNNoiseModel.hpp
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+/*
+ * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef RNNOISE_MODEL_HPP
+#define RNNOISE_MODEL_HPP
+
+#include "Model.hpp"
+
+extern const uint32_t g_NumInputFeatures;
+extern const uint32_t g_FrameLength;
+extern const uint32_t g_FrameStride;
+
+namespace arm {
+namespace app {
+
+    class RNNoiseModel : public Model {
+    public:
+        /**
+         * @brief Runs inference for RNNoise model.
+         *
+         * Call CopyGruStates so GRU state outputs are copied to GRU state inputs before the inference run.
+         * Run ResetGruState() method to set states to zero before starting processing logically related data.
+         * @return True if inference succeeded, False - otherwise
+         */
+        bool RunInference() override;
+
+        /**
+         * @brief Sets GRU input states to zeros.
+         * Call this method before starting processing the new sequence of logically related data.
+         */
+        void ResetGruState();
+
+        /**
+        * @brief Copy current GRU output states to input states.
+        * Call this method before starting processing the next sequence of logically related data.
+         */
+        bool CopyGruStates();
+
+        /* Which index of model outputs does the main output (gains) come from. */
+        const size_t m_indexForModelOutput = 1;
+
+    protected:
+        /** @brief   Gets the reference to op resolver interface class. */
+        const tflite::MicroOpResolver& GetOpResolver() override;
+
+        /** @brief   Adds operations to the op resolver instance. */
+        bool EnlistOperations() override;
+
+        const uint8_t* ModelPointer() override;
+
+        size_t ModelSize() override;
+
+        /*
+        Each inference after the first needs to copy 3 GRU states from a output index to input index (model dependent):
+        0 -> 3, 2 -> 2, 3 -> 1
+        */
+        const std::vector<std::pair<size_t, size_t>> m_gruStateMap = {{0,3}, {2, 2}, {3, 1}};
+    private:
+        /* Maximum number of individual operations that can be enlisted. */
+        static constexpr int ms_maxOpCnt = 15;
+
+        /* A mutable op resolver instance. */
+        tflite::MicroMutableOpResolver<ms_maxOpCnt> m_opResolver;
+    };
+
+} /* namespace app */
+} /* namespace arm */
+
+#endif /* RNNOISE_MODEL_HPP */
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