1 /*
2  *  Copyright (c) 2011 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 #ifndef WEBRTC_MODULES_AUDIO_PROCESSING_AGC_MAIN_INTERFACE_GAIN_CONTROL_H_
12 #define WEBRTC_MODULES_AUDIO_PROCESSING_AGC_MAIN_INTERFACE_GAIN_CONTROL_H_
13 
14 #include "typedefs.h"
15 
16 // Errors
17 #define AGC_UNSPECIFIED_ERROR           18000
18 #define AGC_UNSUPPORTED_FUNCTION_ERROR  18001
19 #define AGC_UNINITIALIZED_ERROR         18002
20 #define AGC_NULL_POINTER_ERROR          18003
21 #define AGC_BAD_PARAMETER_ERROR         18004
22 
23 // Warnings
24 #define AGC_BAD_PARAMETER_WARNING       18050
25 
26 enum
27 {
28     kAgcModeUnchanged,
29     kAgcModeAdaptiveAnalog,
30     kAgcModeAdaptiveDigital,
31     kAgcModeFixedDigital
32 };
33 
34 enum
35 {
36     kAgcFalse = 0,
37     kAgcTrue
38 };
39 
40 typedef struct
41 {
42     WebRtc_Word16 targetLevelDbfs;   // default 3 (-3 dBOv)
43     WebRtc_Word16 compressionGaindB; // default 9 dB
44     WebRtc_UWord8 limiterEnable;     // default kAgcTrue (on)
45 } WebRtcAgc_config_t;
46 
47 #if defined(__cplusplus)
48 extern "C"
49 {
50 #endif
51 
52 /*
53  * This function processes a 10/20ms frame of far-end speech to determine
54  * if there is active speech. Far-end speech length can be either 10ms or
55  * 20ms. The length of the input speech vector must be given in samples
56  * (80/160 when FS=8000, and 160/320 when FS=16000 or FS=32000).
57  *
58  * Input:
59  *      - agcInst           : AGC instance.
60  *      - inFar             : Far-end input speech vector (10 or 20ms)
61  *      - samples           : Number of samples in input vector
62  *
63  * Return value:
64  *                          :  0 - Normal operation.
65  *                          : -1 - Error
66  */
67 int WebRtcAgc_AddFarend(void* agcInst,
68                         const WebRtc_Word16* inFar,
69                         WebRtc_Word16 samples);
70 
71 /*
72  * This function processes a 10/20ms frame of microphone speech to determine
73  * if there is active speech. Microphone speech length can be either 10ms or
74  * 20ms. The length of the input speech vector must be given in samples
75  * (80/160 when FS=8000, and 160/320 when FS=16000 or FS=32000). For very low
76  * input levels, the input signal is increased in level by multiplying and
77  * overwriting the samples in inMic[].
78  *
79  * This function should be called before any further processing of the
80  * near-end microphone signal.
81  *
82  * Input:
83  *      - agcInst           : AGC instance.
84  *      - inMic             : Microphone input speech vector (10 or 20 ms) for
85  *                            L band
86  *      - inMic_H           : Microphone input speech vector (10 or 20 ms) for
87  *                            H band
88  *      - samples           : Number of samples in input vector
89  *
90  * Return value:
91  *                          :  0 - Normal operation.
92  *                          : -1 - Error
93  */
94 int WebRtcAgc_AddMic(void* agcInst,
95                      WebRtc_Word16* inMic,
96                      WebRtc_Word16* inMic_H,
97                      WebRtc_Word16 samples);
98 
99 /*
100  * This function replaces the analog microphone with a virtual one.
101  * It is a digital gain applied to the input signal and is used in the
102  * agcAdaptiveDigital mode where no microphone level is adjustable.
103  * Microphone speech length can be either 10ms or 20ms. The length of the
104  * input speech vector must be given in samples (80/160 when FS=8000, and
105  * 160/320 when FS=16000 or FS=32000).
106  *
107  * Input:
108  *      - agcInst           : AGC instance.
109  *      - inMic             : Microphone input speech vector for (10 or 20 ms)
110  *                            L band
111  *      - inMic_H           : Microphone input speech vector for (10 or 20 ms)
112  *                            H band
113  *      - samples           : Number of samples in input vector
114  *      - micLevelIn        : Input level of microphone (static)
115  *
116  * Output:
117  *      - inMic             : Microphone output after processing (L band)
118  *      - inMic_H           : Microphone output after processing (H band)
119  *      - micLevelOut       : Adjusted microphone level after processing
120  *
121  * Return value:
122  *                          :  0 - Normal operation.
123  *                          : -1 - Error
124  */
125 int WebRtcAgc_VirtualMic(void* agcInst,
126                          WebRtc_Word16* inMic,
127                          WebRtc_Word16* inMic_H,
128                          WebRtc_Word16 samples,
129                          WebRtc_Word32 micLevelIn,
130                          WebRtc_Word32* micLevelOut);
131 
132 /*
133  * This function processes a 10/20ms frame and adjusts (normalizes) the gain
134  * both analog and digitally. The gain adjustments are done only during
135  * active periods of speech. The input speech length can be either 10ms or
136  * 20ms and the output is of the same length. The length of the speech
137  * vectors must be given in samples (80/160 when FS=8000, and 160/320 when
138  * FS=16000 or FS=32000). The echo parameter can be used to ensure the AGC will
139  * not adjust upward in the presence of echo.
140  *
141  * This function should be called after processing the near-end microphone
142  * signal, in any case after any echo cancellation.
143  *
144  * Input:
145  *      - agcInst           : AGC instance
146  *      - inNear            : Near-end input speech vector (10 or 20 ms) for
147  *                            L band
148  *      - inNear_H          : Near-end input speech vector (10 or 20 ms) for
149  *                            H band
150  *      - samples           : Number of samples in input/output vector
151  *      - inMicLevel        : Current microphone volume level
152  *      - echo              : Set to 0 if the signal passed to add_mic is
153  *                            almost certainly free of echo; otherwise set
154  *                            to 1. If you have no information regarding echo
155  *                            set to 0.
156  *
157  * Output:
158  *      - outMicLevel       : Adjusted microphone volume level
159  *      - out               : Gain-adjusted near-end speech vector (L band)
160  *                          : May be the same vector as the input.
161  *      - out_H             : Gain-adjusted near-end speech vector (H band)
162  *      - saturationWarning : A returned value of 1 indicates a saturation event
163  *                            has occurred and the volume cannot be further
164  *                            reduced. Otherwise will be set to 0.
165  *
166  * Return value:
167  *                          :  0 - Normal operation.
168  *                          : -1 - Error
169  */
170 int WebRtcAgc_Process(void* agcInst,
171                       const WebRtc_Word16* inNear,
172                       const WebRtc_Word16* inNear_H,
173                       WebRtc_Word16 samples,
174                       WebRtc_Word16* out,
175                       WebRtc_Word16* out_H,
176                       WebRtc_Word32 inMicLevel,
177                       WebRtc_Word32* outMicLevel,
178                       WebRtc_Word16 echo,
179                       WebRtc_UWord8* saturationWarning);
180 
181 /*
182  * This function sets the config parameters (targetLevelDbfs,
183  * compressionGaindB and limiterEnable).
184  *
185  * Input:
186  *      - agcInst           : AGC instance
187  *      - config            : config struct
188  *
189  * Output:
190  *
191  * Return value:
192  *                          :  0 - Normal operation.
193  *                          : -1 - Error
194  */
195 int WebRtcAgc_set_config(void* agcInst, WebRtcAgc_config_t config);
196 
197 /*
198  * This function returns the config parameters (targetLevelDbfs,
199  * compressionGaindB and limiterEnable).
200  *
201  * Input:
202  *      - agcInst           : AGC instance
203  *
204  * Output:
205  *      - config            : config struct
206  *
207  * Return value:
208  *                          :  0 - Normal operation.
209  *                          : -1 - Error
210  */
211 int WebRtcAgc_get_config(void* agcInst, WebRtcAgc_config_t* config);
212 
213 /*
214  * This function creates an AGC instance, which will contain the state
215  * information for one (duplex) channel.
216  *
217  * Return value             : AGC instance if successful
218  *                          : 0 (i.e., a NULL pointer) if unsuccessful
219  */
220 int WebRtcAgc_Create(void **agcInst);
221 
222 /*
223  * This function frees the AGC instance created at the beginning.
224  *
225  * Input:
226  *      - agcInst           : AGC instance.
227  *
228  * Return value             :  0 - Ok
229  *                            -1 - Error
230  */
231 int WebRtcAgc_Free(void *agcInst);
232 
233 /*
234  * This function initializes an AGC instance.
235  *
236  * Input:
237  *      - agcInst           : AGC instance.
238  *      - minLevel          : Minimum possible mic level
239  *      - maxLevel          : Maximum possible mic level
240  *      - agcMode           : 0 - Unchanged
241  *                          : 1 - Adaptive Analog Automatic Gain Control -3dBOv
242  *                          : 2 - Adaptive Digital Automatic Gain Control -3dBOv
243  *                          : 3 - Fixed Digital Gain 0dB
244  *      - fs                : Sampling frequency
245  *
246  * Return value             :  0 - Ok
247  *                            -1 - Error
248  */
249 int WebRtcAgc_Init(void *agcInst,
250                    WebRtc_Word32 minLevel,
251                    WebRtc_Word32 maxLevel,
252                    WebRtc_Word16 agcMode,
253                    WebRtc_UWord32 fs);
254 
255 /*
256  * This function returns a text string containing the version.
257  *
258  * Input:
259  *      - length            : Length of the char array pointed to by version
260  * Output:
261  *      - version           : Pointer to a char array of to which the version
262  *                          : string will be copied.
263  *
264  * Return value             :  0 - OK
265  *                            -1 - Error
266  */
267 int WebRtcAgc_Version(WebRtc_Word8 *versionStr, WebRtc_Word16 length);
268 
269 #if defined(__cplusplus)
270 }
271 #endif
272 
273 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_AGC_MAIN_INTERFACE_GAIN_CONTROL_H_
274