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