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  * Specifies the interface for the AEC core.
13  */
14 
15 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_H_
16 #define WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_H_
17 
18 #include <stddef.h>
19 
20 #include "webrtc/typedefs.h"
21 
22 #define FRAME_LEN 80
23 #define PART_LEN 64               // Length of partition
24 #define PART_LEN1 (PART_LEN + 1)  // Unique fft coefficients
25 #define PART_LEN2 (PART_LEN * 2)  // Length of partition * 2
26 #define NUM_HIGH_BANDS_MAX  2     // Max number of high bands
27 
28 typedef float complex_t[2];
29 // For performance reasons, some arrays of complex numbers are replaced by twice
30 // as long arrays of float, all the real parts followed by all the imaginary
31 // ones (complex_t[SIZE] -> float[2][SIZE]). This allows SIMD optimizations and
32 // is better than two arrays (one for the real parts and one for the imaginary
33 // parts) as this other way would require two pointers instead of one and cause
34 // extra register spilling. This also allows the offsets to be calculated at
35 // compile time.
36 
37 // Metrics
38 enum {
39   kOffsetLevel = -100
40 };
41 
42 typedef struct Stats {
43   float instant;
44   float average;
45   float min;
46   float max;
47   float sum;
48   float hisum;
49   float himean;
50   int counter;
51   int hicounter;
52 } Stats;
53 
54 typedef struct AecCore AecCore;
55 
56 AecCore* WebRtcAec_CreateAec();  // Returns NULL on error.
57 void WebRtcAec_FreeAec(AecCore* aec);
58 int WebRtcAec_InitAec(AecCore* aec, int sampFreq);
59 void WebRtcAec_InitAec_SSE2(void);
60 #if defined(MIPS_FPU_LE)
61 void WebRtcAec_InitAec_mips(void);
62 #endif
63 #if defined(WEBRTC_DETECT_NEON) || defined(WEBRTC_HAS_NEON)
64 void WebRtcAec_InitAec_neon(void);
65 #endif
66 
67 void WebRtcAec_BufferFarendPartition(AecCore* aec, const float* farend);
68 void WebRtcAec_ProcessFrames(AecCore* aec,
69                              const float* const* nearend,
70                              size_t num_bands,
71                              size_t num_samples,
72                              int knownDelay,
73                              float* const* out);
74 
75 // A helper function to call WebRtc_MoveReadPtr() for all far-end buffers.
76 // Returns the number of elements moved, and adjusts |system_delay| by the
77 // corresponding amount in ms.
78 int WebRtcAec_MoveFarReadPtr(AecCore* aec, int elements);
79 
80 // Calculates the median, standard deviation and amount of poor values among the
81 // delay estimates aggregated up to the first call to the function. After that
82 // first call the metrics are aggregated and updated every second. With poor
83 // values we mean values that most likely will cause the AEC to perform poorly.
84 // TODO(bjornv): Consider changing tests and tools to handle constant
85 // constant aggregation window throughout the session instead.
86 int WebRtcAec_GetDelayMetricsCore(AecCore* self, int* median, int* std,
87                                   float* fraction_poor_delays);
88 
89 // Returns the echo state (1: echo, 0: no echo).
90 int WebRtcAec_echo_state(AecCore* self);
91 
92 // Gets statistics of the echo metrics ERL, ERLE, A_NLP.
93 void WebRtcAec_GetEchoStats(AecCore* self,
94                             Stats* erl,
95                             Stats* erle,
96                             Stats* a_nlp);
97 #ifdef WEBRTC_AEC_DEBUG_DUMP
98 void* WebRtcAec_far_time_buf(AecCore* self);
99 #endif
100 
101 // Sets local configuration modes.
102 void WebRtcAec_SetConfigCore(AecCore* self,
103                              int nlp_mode,
104                              int metrics_mode,
105                              int delay_logging);
106 
107 // Non-zero enables, zero disables.
108 void WebRtcAec_enable_delay_agnostic(AecCore* self, int enable);
109 
110 // Returns non-zero if delay agnostic (i.e., signal based delay estimation) is
111 // enabled and zero if disabled.
112 int WebRtcAec_delay_agnostic_enabled(AecCore* self);
113 
114 // Enables or disables extended filter mode. Non-zero enables, zero disables.
115 void WebRtcAec_enable_extended_filter(AecCore* self, int enable);
116 
117 // Returns non-zero if extended filter mode is enabled and zero if disabled.
118 int WebRtcAec_extended_filter_enabled(AecCore* self);
119 
120 // Returns the current |system_delay|, i.e., the buffered difference between
121 // far-end and near-end.
122 int WebRtcAec_system_delay(AecCore* self);
123 
124 // Sets the |system_delay| to |value|.  Note that if the value is changed
125 // improperly, there can be a performance regression.  So it should be used with
126 // care.
127 void WebRtcAec_SetSystemDelay(AecCore* self, int delay);
128 
129 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_AEC_AEC_CORE_H_
130