1 /*
2  *  Copyright (c) 2012 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  * This file contains the implementation of functions
13  * WebRtcSpl_MaxAbsValueW16C()
14  * WebRtcSpl_MaxAbsValueW32C()
15  * WebRtcSpl_MaxValueW16C()
16  * WebRtcSpl_MaxValueW32C()
17  * WebRtcSpl_MinValueW16C()
18  * WebRtcSpl_MinValueW32C()
19  * WebRtcSpl_MaxAbsIndexW16()
20  * WebRtcSpl_MaxIndexW16()
21  * WebRtcSpl_MaxIndexW32()
22  * WebRtcSpl_MinIndexW16()
23  * WebRtcSpl_MinIndexW32()
24  *
25  */
26 
27 #include <assert.h>
28 #include <stdlib.h>
29 
30 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
31 
32 // TODO(bjorn/kma): Consolidate function pairs (e.g. combine
33 //   WebRtcSpl_MaxAbsValueW16C and WebRtcSpl_MaxAbsIndexW16 into a single one.)
34 // TODO(kma): Move the next six functions into min_max_operations_c.c.
35 
36 // Maximum absolute value of word16 vector. C version for generic platforms.
WebRtcSpl_MaxAbsValueW16C(const int16_t * vector,size_t length)37 int16_t WebRtcSpl_MaxAbsValueW16C(const int16_t* vector, size_t length) {
38   size_t i = 0;
39   int absolute = 0, maximum = 0;
40 
41   assert(length > 0);
42 
43   for (i = 0; i < length; i++) {
44     absolute = abs((int)vector[i]);
45 
46     if (absolute > maximum) {
47       maximum = absolute;
48     }
49   }
50 
51   // Guard the case for abs(-32768).
52   if (maximum > WEBRTC_SPL_WORD16_MAX) {
53     maximum = WEBRTC_SPL_WORD16_MAX;
54   }
55 
56   return (int16_t)maximum;
57 }
58 
59 // Maximum absolute value of word32 vector. C version for generic platforms.
WebRtcSpl_MaxAbsValueW32C(const int32_t * vector,size_t length)60 int32_t WebRtcSpl_MaxAbsValueW32C(const int32_t* vector, size_t length) {
61   // Use uint32_t for the local variables, to accommodate the return value
62   // of abs(0x80000000), which is 0x80000000.
63 
64   uint32_t absolute = 0, maximum = 0;
65   size_t i = 0;
66 
67   assert(length > 0);
68 
69   for (i = 0; i < length; i++) {
70     absolute = abs((int)vector[i]);
71     if (absolute > maximum) {
72       maximum = absolute;
73     }
74   }
75 
76   maximum = WEBRTC_SPL_MIN(maximum, WEBRTC_SPL_WORD32_MAX);
77 
78   return (int32_t)maximum;
79 }
80 
81 // Maximum value of word16 vector. C version for generic platforms.
WebRtcSpl_MaxValueW16C(const int16_t * vector,size_t length)82 int16_t WebRtcSpl_MaxValueW16C(const int16_t* vector, size_t length) {
83   int16_t maximum = WEBRTC_SPL_WORD16_MIN;
84   size_t i = 0;
85 
86   assert(length > 0);
87 
88   for (i = 0; i < length; i++) {
89     if (vector[i] > maximum)
90       maximum = vector[i];
91   }
92   return maximum;
93 }
94 
95 // Maximum value of word32 vector. C version for generic platforms.
WebRtcSpl_MaxValueW32C(const int32_t * vector,size_t length)96 int32_t WebRtcSpl_MaxValueW32C(const int32_t* vector, size_t length) {
97   int32_t maximum = WEBRTC_SPL_WORD32_MIN;
98   size_t i = 0;
99 
100   assert(length > 0);
101 
102   for (i = 0; i < length; i++) {
103     if (vector[i] > maximum)
104       maximum = vector[i];
105   }
106   return maximum;
107 }
108 
109 // Minimum value of word16 vector. C version for generic platforms.
WebRtcSpl_MinValueW16C(const int16_t * vector,size_t length)110 int16_t WebRtcSpl_MinValueW16C(const int16_t* vector, size_t length) {
111   int16_t minimum = WEBRTC_SPL_WORD16_MAX;
112   size_t i = 0;
113 
114   assert(length > 0);
115 
116   for (i = 0; i < length; i++) {
117     if (vector[i] < minimum)
118       minimum = vector[i];
119   }
120   return minimum;
121 }
122 
123 // Minimum value of word32 vector. C version for generic platforms.
WebRtcSpl_MinValueW32C(const int32_t * vector,size_t length)124 int32_t WebRtcSpl_MinValueW32C(const int32_t* vector, size_t length) {
125   int32_t minimum = WEBRTC_SPL_WORD32_MAX;
126   size_t i = 0;
127 
128   assert(length > 0);
129 
130   for (i = 0; i < length; i++) {
131     if (vector[i] < minimum)
132       minimum = vector[i];
133   }
134   return minimum;
135 }
136 
137 // Index of maximum absolute value in a word16 vector.
WebRtcSpl_MaxAbsIndexW16(const int16_t * vector,size_t length)138 size_t WebRtcSpl_MaxAbsIndexW16(const int16_t* vector, size_t length) {
139   // Use type int for local variables, to accomodate the value of abs(-32768).
140 
141   size_t i = 0, index = 0;
142   int absolute = 0, maximum = 0;
143 
144   assert(length > 0);
145 
146   for (i = 0; i < length; i++) {
147     absolute = abs((int)vector[i]);
148 
149     if (absolute > maximum) {
150       maximum = absolute;
151       index = i;
152     }
153   }
154 
155   return index;
156 }
157 
158 // Index of maximum value in a word16 vector.
WebRtcSpl_MaxIndexW16(const int16_t * vector,size_t length)159 size_t WebRtcSpl_MaxIndexW16(const int16_t* vector, size_t length) {
160   size_t i = 0, index = 0;
161   int16_t maximum = WEBRTC_SPL_WORD16_MIN;
162 
163   assert(length > 0);
164 
165   for (i = 0; i < length; i++) {
166     if (vector[i] > maximum) {
167       maximum = vector[i];
168       index = i;
169     }
170   }
171 
172   return index;
173 }
174 
175 // Index of maximum value in a word32 vector.
WebRtcSpl_MaxIndexW32(const int32_t * vector,size_t length)176 size_t WebRtcSpl_MaxIndexW32(const int32_t* vector, size_t length) {
177   size_t i = 0, index = 0;
178   int32_t maximum = WEBRTC_SPL_WORD32_MIN;
179 
180   assert(length > 0);
181 
182   for (i = 0; i < length; i++) {
183     if (vector[i] > maximum) {
184       maximum = vector[i];
185       index = i;
186     }
187   }
188 
189   return index;
190 }
191 
192 // Index of minimum value in a word16 vector.
WebRtcSpl_MinIndexW16(const int16_t * vector,size_t length)193 size_t WebRtcSpl_MinIndexW16(const int16_t* vector, size_t length) {
194   size_t i = 0, index = 0;
195   int16_t minimum = WEBRTC_SPL_WORD16_MAX;
196 
197   assert(length > 0);
198 
199   for (i = 0; i < length; i++) {
200     if (vector[i] < minimum) {
201       minimum = vector[i];
202       index = i;
203     }
204   }
205 
206   return index;
207 }
208 
209 // Index of minimum value in a word32 vector.
WebRtcSpl_MinIndexW32(const int32_t * vector,size_t length)210 size_t WebRtcSpl_MinIndexW32(const int32_t* vector, size_t length) {
211   size_t i = 0, index = 0;
212   int32_t minimum = WEBRTC_SPL_WORD32_MAX;
213 
214   assert(length > 0);
215 
216   for (i = 0; i < length; i++) {
217     if (vector[i] < minimum) {
218       minimum = vector[i];
219       index = i;
220     }
221   }
222 
223   return index;
224 }
225