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 <chre.h>
18 #include <cinttypes>
19 #include <cmath>
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 "kiss_fftr.h"
26
27 #define LOG_TAG "[AudioWorld]"
28
29 #ifdef CHRE_NANOAPP_INTERNAL
30 namespace chre {
31 namespace {
32 #endif // CHRE_NANOAPP_INTERNAL
33
34 using chre::Milliseconds;
35 using chre::Nanoseconds;
36
37 //! The number of frequencies to generate an FFT over.
38 constexpr size_t kNumFrequencies = 128;
39
40 //! State for Kiss FFT and logging.
41 uint8_t gKissFftBuffer[4096];
42 kiss_fftr_cfg gKissFftConfig;
43 kiss_fft_cpx gKissFftOutput[(kNumFrequencies / 2) + 1];
44 Milliseconds gFirstAudioEventTimestamp = Milliseconds(0);
45
46 /**
47 * Returns a graphical representation of a uint16_t value.
48 *
49 * @param value the value to visualize.
50 * @return a character that visually represents the value.
51 */
getFftCharForValue(uint16_t value)52 char getFftCharForValue(uint16_t value) {
53 constexpr uint16_t kFftLowLimit = 128;
54 constexpr uint16_t kFftMedLimit = 256;
55 constexpr uint16_t kFftHighLimit = 512; // Texas Hold'em ༼⁰o⁰；༽
56 constexpr uint16_t kFftVeryHighLimit = 1024;
57
58 if (value < kFftLowLimit) {
59 return ' ';
60 } else if (value >= kFftLowLimit && value < kFftMedLimit) {
61 return '_';
62 } else if (value >= kFftMedLimit && value < kFftHighLimit) {
63 return '.';
64 } else if (value >= kFftHighLimit && value < kFftVeryHighLimit) {
65 return 'x';
66 } else {
67 return 'X';
68 }
69 }
70
71 /**
72 * Initializes Kiss FFT.
73 */
initKissFft()74 void initKissFft() {
75 size_t kissFftBufferSize = sizeof(gKissFftBuffer);
76 gKissFftConfig = kiss_fftr_alloc(kNumFrequencies, false,
77 gKissFftBuffer, &kissFftBufferSize);
78 if (gKissFftConfig == NULL) {
79 LOGE("Failed to init Kiss FFT, needs minimum %zu buffer size",
80 kissFftBufferSize);
81 } else {
82 LOGI("Initialized Kiss FFT, using %zu/%zu of the buffer",
83 kissFftBufferSize, sizeof(gKissFftBuffer));
84 }
85 }
86
87 /**
88 * Logs an audio data event with an FFT visualization of the received audio
89 * data.
90 *
91 * @param event the audio data event to log.
92 */
handleAudioDataEvent(const struct chreAudioDataEvent * event)93 void handleAudioDataEvent(const struct chreAudioDataEvent *event) {
94 kiss_fftr(gKissFftConfig, event->samplesS16, gKissFftOutput);
95
96 char fftStr[ARRAY_SIZE(gKissFftOutput) + 1];
97 fftStr[ARRAY_SIZE(gKissFftOutput)] = '\0';
98
99 for (size_t i = 0; i < ARRAY_SIZE(gKissFftOutput); i++) {
100 float value = sqrtf(powf(gKissFftOutput[i].r, 2)
101 + powf(gKissFftOutput[i].i, 2));
102 fftStr[i] = getFftCharForValue(static_cast<uint16_t>(value));
103 }
104
105 Milliseconds timestamp = Milliseconds(Nanoseconds(event->timestamp));
106 if (gFirstAudioEventTimestamp == Milliseconds(0)) {
107 gFirstAudioEventTimestamp = timestamp;
108 }
109
110 Milliseconds adjustedTimestamp = timestamp - gFirstAudioEventTimestamp;
111 LOGD("Audio data - FFT [%s] at %" PRIu64 "ms with %" PRIu32 " samples",
112 fftStr, adjustedTimestamp.getMilliseconds(), event->sampleCount);
113 }
114
handleAudioSamplingChangeEvent(const struct chreAudioSourceStatusEvent * event)115 void handleAudioSamplingChangeEvent(
116 const struct chreAudioSourceStatusEvent *event) {
117 LOGD("Audio sampling status event for handle %" PRIu32 ", suspended: %d",
118 event->handle, event->status.suspended);
119 }
120
nanoappStart()121 bool nanoappStart() {
122 LOGI("Started");
123
124 struct chreAudioSource audioSource;
125 for (uint32_t i = 0; chreAudioGetSource(i, &audioSource); i++) {
126 LOGI("Found audio source '%s' with %" PRIu32 "Hz %s data",
127 audioSource.name, audioSource.sampleRate,
128 chre::getChreAudioFormatString(audioSource.format));
129 LOGI(" buffer duration: [%" PRIu64 "ns, %" PRIu64 "ns]",
130 audioSource.minBufferDuration, audioSource.maxBufferDuration);
131
132 if (i == 0) {
133 // Only request audio data from the first source, but continue discovery.
134 if (chreAudioConfigureSource(i, true,
135 audioSource.minBufferDuration, audioSource.minBufferDuration)) {
136 LOGI("Requested audio from handle %" PRIu32 " successfully", i);
137 } else {
138 LOGE("Failed to request audio from handle %" PRIu32, i);
139 }
140 }
141 }
142
143 initKissFft();
144 return true;
145 }
146
nanoappHandleEvent(uint32_t senderInstanceId,uint16_t eventType,const void * eventData)147 void nanoappHandleEvent(uint32_t senderInstanceId,
148 uint16_t eventType,
149 const void *eventData) {
150 switch (eventType) {
151 case CHRE_EVENT_AUDIO_DATA:
152 handleAudioDataEvent(
153 static_cast<const struct chreAudioDataEvent *>(eventData));
154 break;
155 case CHRE_EVENT_AUDIO_SAMPLING_CHANGE:
156 handleAudioSamplingChangeEvent(
157 static_cast<const struct chreAudioSourceStatusEvent *>(eventData));
158 break;
159 default:
160 LOGW("Unknown event received");
161 break;
162 }
163 }
164
nanoappEnd()165 void nanoappEnd() {
166 LOGI("Stopped");
167 }
168
169 #ifdef CHRE_NANOAPP_INTERNAL
170 } // anonymous namespace
171 } // namespace chre
172
173 #include "chre/util/nanoapp/app_id.h"
174 #include "chre/platform/static_nanoapp_init.h"
175
176 CHRE_STATIC_NANOAPP_INIT(AudioWorld, chre::kAudioWorldAppId, 0);
177 #endif // CHRE_NANOAPP_INTERNAL
178