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
WebRtcSpl_FilterMAFastQ12(WebRtc_Word16 * in_ptr,WebRtc_Word16 * out_ptr,WebRtc_Word16 * B,WebRtc_Word16 B_length,WebRtc_Word16 length)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