1 /* 2 * Copyright (c) 2011 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 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_MAIN_SOURCE_SPLITTING_FILTER_H_ 12 #define WEBRTC_MODULES_AUDIO_PROCESSING_MAIN_SOURCE_SPLITTING_FILTER_H_ 13 14 #include "typedefs.h" 15 #include "signal_processing_library.h" 16 17 namespace webrtc { 18 /* 19 * SplittingFilterbank_analysisQMF(...) 20 * 21 * Splits a super-wb signal into two subbands: 0-8 kHz and 8-16 kHz. 22 * 23 * Input: 24 * - in_data : super-wb audio signal 25 * 26 * Input & Output: 27 * - filt_state1: Filter state for first all-pass filter 28 * - filt_state2: Filter state for second all-pass filter 29 * 30 * Output: 31 * - low_band : The signal from the 0-4 kHz band 32 * - high_band : The signal from the 4-8 kHz band 33 */ 34 void SplittingFilterAnalysis(const WebRtc_Word16* in_data, 35 WebRtc_Word16* low_band, 36 WebRtc_Word16* high_band, 37 WebRtc_Word32* filt_state1, 38 WebRtc_Word32* filt_state2); 39 40 /* 41 * SplittingFilterbank_synthesisQMF(...) 42 * 43 * Combines the two subbands (0-8 and 8-16 kHz) into a super-wb signal. 44 * 45 * Input: 46 * - low_band : The signal with the 0-8 kHz band 47 * - high_band : The signal with the 8-16 kHz band 48 * 49 * Input & Output: 50 * - filt_state1: Filter state for first all-pass filter 51 * - filt_state2: Filter state for second all-pass filter 52 * 53 * Output: 54 * - out_data : super-wb speech signal 55 */ 56 void SplittingFilterSynthesis(const WebRtc_Word16* low_band, 57 const WebRtc_Word16* high_band, 58 WebRtc_Word16* out_data, 59 WebRtc_Word32* filt_state1, 60 WebRtc_Word32* filt_state2); 61 } // namespace webrtc 62 63 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_MAIN_SOURCE_SPLITTING_FILTER_H_ 64