andrew@webrtc.org | a7b57da | 2012-10-22 18:19:23 +0000 | [diff] [blame] | 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_GetScalingSquare(). |
| 14 | * The description header can be found in signal_processing_library.h |
| 15 | * |
| 16 | */ |
| 17 | |
pbos@webrtc.org | abf0cd8 | 2013-05-27 09:49:58 +0000 | [diff] [blame] | 18 | #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" |
andrew@webrtc.org | a7b57da | 2012-10-22 18:19:23 +0000 | [diff] [blame] | 19 | |
pbos@webrtc.org | 1727dc7 | 2013-04-09 16:40:28 +0000 | [diff] [blame] | 20 | int WebRtcSpl_GetScalingSquare(int16_t *in_vector, int in_vector_length, int times) |
andrew@webrtc.org | a7b57da | 2012-10-22 18:19:23 +0000 | [diff] [blame] | 21 | { |
| 22 | int nbits = WebRtcSpl_GetSizeInBits(times); |
| 23 | int i; |
pbos@webrtc.org | 1727dc7 | 2013-04-09 16:40:28 +0000 | [diff] [blame] | 24 | int16_t smax = -1; |
| 25 | int16_t sabs; |
| 26 | int16_t *sptr = in_vector; |
andrew@webrtc.org | a7b57da | 2012-10-22 18:19:23 +0000 | [diff] [blame] | 27 | int t; |
| 28 | int looptimes = in_vector_length; |
| 29 | |
| 30 | for (i = looptimes; i > 0; i--) |
| 31 | { |
| 32 | sabs = (*sptr > 0 ? *sptr++ : -*sptr++); |
| 33 | smax = (sabs > smax ? sabs : smax); |
| 34 | } |
| 35 | t = WebRtcSpl_NormW32(WEBRTC_SPL_MUL(smax, smax)); |
| 36 | |
| 37 | if (smax == 0) |
| 38 | { |
| 39 | return 0; // Since norm(0) returns 0 |
| 40 | } else |
| 41 | { |
| 42 | return (t > nbits) ? 0 : nbits - t; |
| 43 | } |
| 44 | } |