| /* |
| * Copyright (c) 2014 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. |
| */ |
| |
| #ifndef WEBRTC_COMMON_AUDIO_FIR_FILTER_H_ |
| #define WEBRTC_COMMON_AUDIO_FIR_FILTER_H_ |
| |
| #include <string.h> |
| |
| namespace webrtc { |
| |
| // Finite Impulse Response filter using floating-point arithmetic. |
| class FIRFilter { |
| public: |
| // Creates a filter with the given coefficients. All initial state values will |
| // be zeros. |
| // The length of the chunks fed to the filter should never be greater than |
| // |max_input_length|. This is needed because, when vectorizing it is |
| // necessary to concatenate the input after the state, and resizing this array |
| // dynamically is expensive. |
| static FIRFilter* Create(const float* coefficients, |
| size_t coefficients_length, |
| size_t max_input_length); |
| |
| virtual ~FIRFilter() {} |
| |
| // Filters the |in| data supplied. |
| // |out| must be previously allocated and it must be at least of |length|. |
| virtual void Filter(const float* in, size_t length, float* out) = 0; |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // WEBRTC_COMMON_AUDIO_FIR_FILTER_H_ |