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 #include "webrtc/common_audio/vad/include/webrtc_vad.h"
12 
13 #include <stdlib.h>
14 #include <string.h>
15 
16 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
17 #include "webrtc/common_audio/vad/vad_core.h"
18 #include "webrtc/typedefs.h"
19 
20 static const int kInitCheck = 42;
21 static const int kValidRates[] = { 8000, 16000, 32000, 48000 };
22 static const size_t kRatesSize = sizeof(kValidRates) / sizeof(*kValidRates);
23 static const int kMaxFrameLengthMs = 30;
24 
WebRtcVad_Create()25 VadInst* WebRtcVad_Create() {
26   VadInstT* self = (VadInstT*)malloc(sizeof(VadInstT));
27 
28   WebRtcSpl_Init();
29   self->init_flag = 0;
30 
31   return (VadInst*)self;
32 }
33 
WebRtcVad_Free(VadInst * handle)34 void WebRtcVad_Free(VadInst* handle) {
35   free(handle);
36 }
37 
38 // TODO(bjornv): Move WebRtcVad_InitCore() code here.
WebRtcVad_Init(VadInst * handle)39 int WebRtcVad_Init(VadInst* handle) {
40   // Initialize the core VAD component.
41   return WebRtcVad_InitCore((VadInstT*) handle);
42 }
43 
44 // TODO(bjornv): Move WebRtcVad_set_mode_core() code here.
WebRtcVad_set_mode(VadInst * handle,int mode)45 int WebRtcVad_set_mode(VadInst* handle, int mode) {
46   VadInstT* self = (VadInstT*) handle;
47 
48   if (handle == NULL) {
49     return -1;
50   }
51   if (self->init_flag != kInitCheck) {
52     return -1;
53   }
54 
55   return WebRtcVad_set_mode_core(self, mode);
56 }
57 
WebRtcVad_Process(VadInst * handle,int fs,const int16_t * audio_frame,size_t frame_length)58 int WebRtcVad_Process(VadInst* handle, int fs, const int16_t* audio_frame,
59                       size_t frame_length) {
60   int vad = -1;
61   VadInstT* self = (VadInstT*) handle;
62 
63   if (handle == NULL) {
64     return -1;
65   }
66 
67   if (self->init_flag != kInitCheck) {
68     return -1;
69   }
70   if (audio_frame == NULL) {
71     return -1;
72   }
73   if (WebRtcVad_ValidRateAndFrameLength(fs, frame_length) != 0) {
74     return -1;
75   }
76 
77   if (fs == 48000) {
78       vad = WebRtcVad_CalcVad48khz(self, audio_frame, frame_length);
79   } else if (fs == 32000) {
80     vad = WebRtcVad_CalcVad32khz(self, audio_frame, frame_length);
81   } else if (fs == 16000) {
82     vad = WebRtcVad_CalcVad16khz(self, audio_frame, frame_length);
83   } else if (fs == 8000) {
84     vad = WebRtcVad_CalcVad8khz(self, audio_frame, frame_length);
85   }
86 
87   if (vad > 0) {
88     vad = 1;
89   }
90   return vad;
91 }
92 
WebRtcVad_ValidRateAndFrameLength(int rate,size_t frame_length)93 int WebRtcVad_ValidRateAndFrameLength(int rate, size_t frame_length) {
94   int return_value = -1;
95   size_t i;
96   int valid_length_ms;
97   size_t valid_length;
98 
99   // We only allow 10, 20 or 30 ms frames. Loop through valid frame rates and
100   // see if we have a matching pair.
101   for (i = 0; i < kRatesSize; i++) {
102     if (kValidRates[i] == rate) {
103       for (valid_length_ms = 10; valid_length_ms <= kMaxFrameLengthMs;
104           valid_length_ms += 10) {
105         valid_length = (size_t)(kValidRates[i] / 1000 * valid_length_ms);
106         if (frame_length == valid_length) {
107           return_value = 0;
108           break;
109         }
110       }
111       break;
112     }
113   }
114 
115   return return_value;
116 }
117