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 12 /* 13 * This file contains the function WebRtcSpl_FilterMAFastQ12(). 14 * The description header can be found in signal_processing_library.h 15 * 16 */ 17 18 #include "signal_processing_library.h" 19 20 void WebRtcSpl_FilterMAFastQ12(WebRtc_Word16* in_ptr, 21 WebRtc_Word16* out_ptr, 22 WebRtc_Word16* B, 23 WebRtc_Word16 B_length, 24 WebRtc_Word16 length) 25 { 26 WebRtc_Word32 o; 27 int i, j; 28 for (i = 0; i < length; i++) 29 { 30 G_CONST WebRtc_Word16* b_ptr = &B[0]; 31 G_CONST WebRtc_Word16* x_ptr = &in_ptr[i]; 32 33 o = (WebRtc_Word32)0; 34 35 for (j = 0; j < B_length; j++) 36 { 37 o += WEBRTC_SPL_MUL_16_16(*b_ptr++, *x_ptr--); 38 } 39 40 // If output is higher than 32768, saturate it. Same with negative side 41 // 2^27 = 134217728, which corresponds to 32768 in Q12 42 43 // Saturate the output 44 o = WEBRTC_SPL_SAT((WebRtc_Word32)134215679, o, (WebRtc_Word32)-134217728); 45 46 *out_ptr++ = (WebRtc_Word16)((o + (WebRtc_Word32)2048) >> 12); 47 } 48 return; 49 } 50
