1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <cinttypes>
18 #include <cmath>
19 #include <cstddef>
20
21 #include "chre/util/macros.h"
22 #include "chre/util/nanoapp/audio.h"
23 #include "chre/util/nanoapp/log.h"
24 #include "chre/util/time.h"
25 #include "chre_api/chre.h"
26 #include "kiss_fftr.h"
27
28 #define LOG_TAG "[AudioWorld]"
29
30 #ifdef CHRE_NANOAPP_INTERNAL
31 namespace chre {
32 namespace {
33 #endif // CHRE_NANOAPP_INTERNAL
34
35 using chre::Milliseconds;
36 using chre::Nanoseconds;
37
38 //! The number of frequencies to generate an FFT over.
39 constexpr size_t kNumFrequencies = 128;
40
41 //! True if audio has successfully been requested.
42 bool gAudioRequested = false;
43
44 //! The requested audio handle.
45 uint32_t gAudioHandle;
46
47 //! State for Kiss FFT and logging.
48 alignas(std::max_align_t) uint8_t gKissFftBuffer[4096];
49 kiss_fftr_cfg gKissFftConfig;
50 kiss_fft_cpx gKissFftOutput[(kNumFrequencies / 2) + 1];
51 Milliseconds gFirstAudioEventTimestamp = Milliseconds(0);
52
53 /**
54 * Returns a graphical representation of a uint16_t value.
55 *
56 * @param value the value to visualize.
57 * @return a character that visually represents the value.
58 */
getFftCharForValue(uint16_t value)59 char getFftCharForValue(uint16_t value) {
60 constexpr uint16_t kFftLowLimit = 128;
61 constexpr uint16_t kFftMedLimit = 256;
62 constexpr uint16_t kFftHighLimit = 512; // Texas Hold'em ༼⁰o⁰；༽
63 constexpr uint16_t kFftVeryHighLimit = 1024;
64
65 if (value < kFftLowLimit) {
66 return ' ';
67 } else if (value >= kFftLowLimit && value < kFftMedLimit) {
68 return '_';
69 } else if (value >= kFftMedLimit && value < kFftHighLimit) {
70 return '.';
71 } else if (value >= kFftHighLimit && value < kFftVeryHighLimit) {
72 return 'x';
73 } else {
74 return 'X';
75 }
76 }
77
78 /**
79 * Initializes Kiss FFT.
80 */
initKissFft()81 void initKissFft() {
82 size_t kissFftBufferSize = sizeof(gKissFftBuffer);
83 gKissFftConfig = kiss_fftr_alloc(kNumFrequencies, false, gKissFftBuffer,
84 &kissFftBufferSize);
85 if (gKissFftConfig == NULL) {
86 LOGE("Failed to init Kiss FFT, needs minimum %zu buffer size",
87 kissFftBufferSize);
88 } else {
89 LOGI("Initialized Kiss FFT, using %zu/%zu of the buffer", kissFftBufferSize,
90 sizeof(gKissFftBuffer));
91 }
92 }
93
94 /**
95 * Logs an audio data event with an FFT visualization of the received audio
96 * data.
97 *
98 * @param event the audio data event to log.
99 */
handleAudioDataEvent(const struct chreAudioDataEvent * event)100 void handleAudioDataEvent(const struct chreAudioDataEvent *event) {
101 kiss_fftr(gKissFftConfig, event->samplesS16, gKissFftOutput);
102
103 char fftStr[ARRAY_SIZE(gKissFftOutput) + 1];
104 fftStr[ARRAY_SIZE(gKissFftOutput)] = '\0';
105
106 for (size_t i = 0; i < ARRAY_SIZE(gKissFftOutput); i++) {
107 float value =
108 sqrtf(powf(gKissFftOutput[i].r, 2) + powf(gKissFftOutput[i].i, 2));
109 fftStr[i] = getFftCharForValue(static_cast<uint16_t>(value));
110 }
111
112 Milliseconds timestamp = Milliseconds(Nanoseconds(event->timestamp));
113 if (gFirstAudioEventTimestamp == Milliseconds(0)) {
114 gFirstAudioEventTimestamp = timestamp;
115 }
116
117 Milliseconds adjustedTimestamp = timestamp - gFirstAudioEventTimestamp;
118 LOGD("Audio data - FFT [%s] at %" PRIu64 "ms with %" PRIu32 " samples",
119 fftStr, adjustedTimestamp.getMilliseconds(), event->sampleCount);
120 }
121
handleAudioSamplingChangeEvent(const struct chreAudioSourceStatusEvent * event)122 void handleAudioSamplingChangeEvent(
123 const struct chreAudioSourceStatusEvent *event) {
124 LOGD("Audio sampling status event for handle %" PRIu32 ", suspended: %d",
125 event->handle, event->status.suspended);
126 }
127
handleAudioSettingChangedNotification(const struct chreUserSettingChangedEvent * event)128 void handleAudioSettingChangedNotification(
129 const struct chreUserSettingChangedEvent *event) {
130 // The following checks on event and setting are primarily meant for
131 // debugging and/or bring-up. Production nanoapps should not need to worry
132 // about these scenarios since CHRE guarantees that out-of-memory conditions
133 // are caught during event allocation before they're posted, and the setting
134 // is guaranteed to be a member of enum chreUserSettingState.
135 if (event != nullptr) {
136 if (event->setting != CHRE_USER_SETTING_MICROPHONE) {
137 LOGE("Unexpected setting ID: %u", event->setting);
138 } else {
139 LOGI("Microphone settings notification: status change to %d",
140 static_cast<int8_t>(event->settingState));
141 }
142 } else {
143 LOGE("Null event data for settings changed event");
144 }
145 }
146
nanoappStart()147 bool nanoappStart() {
148 LOGI("Started");
149
150 struct chreAudioSource audioSource;
151 for (uint32_t i = 0; chreAudioGetSource(i, &audioSource); i++) {
152 LOGI("Found audio source '%s' with %" PRIu32 "Hz %s data", audioSource.name,
153 audioSource.sampleRate,
154 chre::getChreAudioFormatString(audioSource.format));
155 LOGI(" buffer duration: [%" PRIu64 "ns, %" PRIu64 "ns]",
156 audioSource.minBufferDuration, audioSource.maxBufferDuration);
157
158 if (i == 0) {
159 // Only request audio data from the first source, but continue discovery.
160 if (chreAudioConfigureSource(i, true, audioSource.minBufferDuration,
161 audioSource.minBufferDuration)) {
162 gAudioRequested = true;
163 gAudioHandle = i;
164 LOGI("Requested audio from handle %" PRIu32 " successfully", i);
165 } else {
166 LOGE("Failed to request audio from handle %" PRIu32, i);
167 }
168 }
169 }
170
171 initKissFft();
172
173 int8_t settingState = chreUserSettingGetState(CHRE_USER_SETTING_MICROPHONE);
174 LOGD("Microphone setting status: %d", settingState);
175
176 chreUserSettingConfigureEvents(CHRE_USER_SETTING_MICROPHONE,
177 true /* enable */);
178
179 return true;
180 }
181
nanoappHandleEvent(uint32_t senderInstanceId,uint16_t eventType,const void * eventData)182 void nanoappHandleEvent(uint32_t senderInstanceId, uint16_t eventType,
183 const void *eventData) {
184 UNUSED_VAR(senderInstanceId);
185
186 switch (eventType) {
187 case CHRE_EVENT_AUDIO_DATA:
188 handleAudioDataEvent(
189 static_cast<const struct chreAudioDataEvent *>(eventData));
190 break;
191 case CHRE_EVENT_AUDIO_SAMPLING_CHANGE:
192 handleAudioSamplingChangeEvent(
193 static_cast<const struct chreAudioSourceStatusEvent *>(eventData));
194 break;
195
196 case CHRE_EVENT_SETTING_CHANGED_MICROPHONE:
197 handleAudioSettingChangedNotification(
198 static_cast<const struct chreUserSettingChangedEvent *>(eventData));
199 break;
200
201 default:
202 LOGW("Unknown event received");
203 break;
204 }
205 }
206
nanoappEnd()207 void nanoappEnd() {
208 if (gAudioRequested) {
209 chreAudioConfigureSource(gAudioHandle, false /* enable */,
210 0 /* bufferDuration */, 0 /* deliveryInterval */);
211 }
212
213 chreUserSettingConfigureEvents(CHRE_USER_SETTING_MICROPHONE,
214 false /* enable */);
215
216 LOGI("Stopped");
217 }
218
219 #ifdef CHRE_NANOAPP_INTERNAL
220 } // anonymous namespace
221 } // namespace chre
222
223 #include "chre/platform/static_nanoapp_init.h"
224 #include "chre/util/nanoapp/app_id.h"
225 #include "chre/util/system/napp_permissions.h"
226
227 CHRE_STATIC_NANOAPP_INIT(AudioWorld, chre::kAudioWorldAppId, 0,
228 chre::NanoappPermissions::CHRE_PERMS_AUDIO);
229 #endif // CHRE_NANOAPP_INTERNAL
230