File size: 6,712 Bytes
83418c6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188

/*
 * PortAudio Portable Real-Time Audio Library
 * Latest Version at: http://www.portaudio.com
 *
 * Copyright (c) 1999-2010 Phil Burk and Ross Bencina
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/*
 * The text above constitutes the entire PortAudio license; however,
 * the PortAudio community also makes the following non-binding requests:
 *
 * Any person wishing to distribute modifications to the Software is
 * requested to send the modifications to the original developer so that
 * they can be incorporated into the canonical version. It is also
 * requested that these non-binding requests be included along with the
 * license above.
 */

#ifndef _AUDIO_ANALYZER_H
#define _AUDIO_ANALYZER_H

#include "biquad_filter.h"

#define MATH_PI  (3.141592653589793238462643)
#define MATH_TWO_PI  (2.0 * MATH_PI)

typedef struct PaQaSineGenerator_s
{
    double    phase;
    double    phaseIncrement;
    double    frequency;
    double    amplitude;
} PaQaSineGenerator;

/** Container for a monophonic audio sample in memory. */
typedef struct PaQaRecording_s
{
    /** Maximum number of frames that can fit in the allocated buffer. */
    int       maxFrames;
    float    *buffer;
    /** Actual number of valid frames in the buffer. */
    int       numFrames;
    int       sampleRate;
} PaQaRecording;

typedef struct PaQaTestTone_s
{
    int       samplesPerFrame;
    int       startDelay;
    double    sampleRate;
    double    frequency;
    double    amplitude;
} PaQaTestTone;

typedef struct PaQaAnalysisResult_s
{
    int       valid;
    /** Latency in samples from output to input. */
    double    latency;
    double    amplitudeRatio;
    double    popAmplitude;
    double    popPosition;
    double    numDroppedFrames;
    double    droppedFramesPosition;
    double    numAddedFrames;
    double    addedFramesPosition;
} PaQaAnalysisResult;


/*================================================================*/
/*================= General DSP Tools ============================*/
/*================================================================*/
/**
 * Calculate Nth frequency of a series for use in testing multiple channels.
 * Series should avoid harmonic overlap between channels.
 */
double PaQa_GetNthFrequency( double baseFrequency, int index );

void PaQa_EraseBuffer( float *buffer, int numFrames, int samplesPerFrame );

void PaQa_MixSine( PaQaSineGenerator *generator, float *buffer, int numSamples, int stride );

void PaQa_WriteSine( float *buffer, int numSamples, int stride,
                     double frequency, double amplitude );

/**
 * Generate a signal with a sharp edge in the middle that can be recognized despite some phase shift.
 */
void PaQa_GenerateCrack( float *buffer, int numSamples, int stride );

double PaQa_ComputePhaseDifference( double phase1, double phase2 );

/**
 * Measure the area under the curve by summing absolute value of each value.
 */
double PaQa_MeasureArea( float *buffer, int numFrames, int stride  );

/**
 * Measure slope of the positive zero crossings.
 */
double PaQa_MeasureCrossingSlope( float *buffer, int numFrames );


/**
 * Prepare an oscillator that can generate a sine tone for testing.
 */
void PaQa_SetupSineGenerator( PaQaSineGenerator *generator, double frequency, double amplitude, double frameRate );

/*================================================================*/
/*================= Recordings ===================================*/
/*================================================================*/
/**
 * Allocate memory for containing a mono audio signal. Set up recording for writing.
 */
 int PaQa_InitializeRecording( PaQaRecording *recording, int maxSamples, int sampleRate );

/**
* Free memory allocated by PaQa_InitializeRecording.
 */
 void PaQa_TerminateRecording( PaQaRecording *recording );

/**
 * Apply a biquad filter to the audio from the input recording and write it to the output recording.
 */
void PaQa_FilterRecording( PaQaRecording *input, PaQaRecording *output, BiquadFilter *filter );


int PaQa_SaveRecordingToWaveFile( PaQaRecording *recording, const char *filename );

/**
 * @param stride is the spacing of samples to skip in the input buffer. To use every samples pass 1. To use every other sample pass 2.
 */
int PaQa_WriteRecording( PaQaRecording *recording, float *buffer, int numSamples, int stride );

/** Write zeros into a recording. */
int PaQa_WriteSilence( PaQaRecording *recording, int numSamples );

int PaQa_RecordFreeze( PaQaRecording *recording, int numSamples );

double PaQa_CorrelateSine( PaQaRecording *recording, double frequency, double frameRate,
                           int startFrame, int numSamples, double *phasePtr );

double PaQa_FindFirstMatch( PaQaRecording *recording, float *buffer, int numSamples, double tolerance  );

/**
 * Estimate the original amplitude of a clipped sine wave by measuring
 * its average slope at the zero crossings.
 */
double PaQa_MeasureSineAmplitudeBySlope( PaQaRecording *recording,
                                         double frequency, double frameRate,
                                         int startFrame, int numFrames );

double PaQa_MeasureRootMeanSquare( float *buffer, int numFrames );

/**
 * Compare the amplitudes of these two signals.
 * Return ratio of recorded signal over buffer signal.
 */
double PaQa_CompareAmplitudes( PaQaRecording *recording, int startAt, float *buffer, int numSamples );

/**
 * Analyse a recording of a sine wave.
 * Measure latency and look for dropped frames, etc.
 */
int PaQa_AnalyseRecording( PaQaRecording *recording, PaQaTestTone *testTone, PaQaAnalysisResult *analysisResult );

#endif /* _AUDIO_ANALYZER_H */