1/*
2 * Copyright (C) 2010 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#define LOG_TAG "EffectVisualizer"
18//#define LOG_NDEBUG 0
19
20#include <assert.h>
21#include <inttypes.h>
22#include <math.h>
23#include <stdlib.h>
24#include <string.h>
25#include <time.h>
26
27#include <new>
28
29#include <log/log.h>
30
31#include <audio_effects/effect_visualizer.h>
32
33extern "C" {
34
35// effect_handle_t interface implementation for visualizer effect
36extern const struct effect_interface_s gVisualizerInterface;
37
38// Google Visualizer UUID: d069d9e0-8329-11df-9168-0002a5d5c51b
39const effect_descriptor_t gVisualizerDescriptor = {
40        {0xe46b26a0, 0xdddd, 0x11db, 0x8afd, {0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b}}, // type
41        {0xd069d9e0, 0x8329, 0x11df, 0x9168, {0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b}}, // uuid
42        EFFECT_CONTROL_API_VERSION,
43        (EFFECT_FLAG_TYPE_INSERT | EFFECT_FLAG_INSERT_FIRST),
44        0, // TODO
45        1,
46        "Visualizer",
47        "The Android Open Source Project",
48};
49
50enum visualizer_state_e {
51    VISUALIZER_STATE_UNINITIALIZED,
52    VISUALIZER_STATE_INITIALIZED,
53    VISUALIZER_STATE_ACTIVE,
54};
55
56// maximum time since last capture buffer update before resetting capture buffer. This means
57// that the framework has stopped playing audio and we must start returning silence
58#define MAX_STALL_TIME_MS 1000
59
60#define CAPTURE_BUF_SIZE 65536 // "64k should be enough for everyone"
61
62#define DISCARD_MEASUREMENTS_TIME_MS 2000 // discard measurements older than this number of ms
63
64#define MAX_LATENCY_MS 3000 // 3 seconds of latency for audio pipeline
65
66// maximum number of buffers for which we keep track of the measurements
67#define MEASUREMENT_WINDOW_MAX_SIZE_IN_BUFFERS 25 // note: buffer index is stored in uint8_t
68
69
70struct BufferStats {
71    bool mIsValid;
72    uint16_t mPeakU16; // the positive peak of the absolute value of the samples in a buffer
73    float mRmsSquared; // the average square of the samples in a buffer
74};
75
76struct VisualizerContext {
77    const struct effect_interface_s *mItfe;
78    effect_config_t mConfig;
79    uint32_t mCaptureIdx;
80    uint32_t mCaptureSize;
81    uint32_t mScalingMode;
82    uint8_t mState;
83    uint32_t mLastCaptureIdx;
84    uint32_t mLatency;
85    struct timespec mBufferUpdateTime;
86    uint8_t mCaptureBuf[CAPTURE_BUF_SIZE];
87    // for measurements
88    uint8_t mChannelCount; // to avoid recomputing it every time a buffer is processed
89    uint32_t mMeasurementMode;
90    uint8_t mMeasurementWindowSizeInBuffers;
91    uint8_t mMeasurementBufferIdx;
92    BufferStats mPastMeasurements[MEASUREMENT_WINDOW_MAX_SIZE_IN_BUFFERS];
93};
94
95//
96//--- Local functions
97//
98uint32_t Visualizer_getDeltaTimeMsFromUpdatedTime(VisualizerContext* pContext) {
99    uint32_t deltaMs = 0;
100    if (pContext->mBufferUpdateTime.tv_sec != 0) {
101        struct timespec ts;
102        if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
103            time_t secs = ts.tv_sec - pContext->mBufferUpdateTime.tv_sec;
104            long nsec = ts.tv_nsec - pContext->mBufferUpdateTime.tv_nsec;
105            if (nsec < 0) {
106                --secs;
107                nsec += 1000000000;
108            }
109            deltaMs = secs * 1000 + nsec / 1000000;
110        }
111    }
112    return deltaMs;
113}
114
115
116void Visualizer_reset(VisualizerContext *pContext)
117{
118    pContext->mCaptureIdx = 0;
119    pContext->mLastCaptureIdx = 0;
120    pContext->mBufferUpdateTime.tv_sec = 0;
121    pContext->mLatency = 0;
122    memset(pContext->mCaptureBuf, 0x80, CAPTURE_BUF_SIZE);
123}
124
125//----------------------------------------------------------------------------
126// Visualizer_setConfig()
127//----------------------------------------------------------------------------
128// Purpose: Set input and output audio configuration.
129//
130// Inputs:
131//  pContext:   effect engine context
132//  pConfig:    pointer to effect_config_t structure holding input and output
133//      configuration parameters
134//
135// Outputs:
136//
137//----------------------------------------------------------------------------
138
139int Visualizer_setConfig(VisualizerContext *pContext, effect_config_t *pConfig)
140{
141    ALOGV("Visualizer_setConfig start");
142
143    if (pConfig->inputCfg.samplingRate != pConfig->outputCfg.samplingRate) return -EINVAL;
144    if (pConfig->inputCfg.channels != pConfig->outputCfg.channels) return -EINVAL;
145    if (pConfig->inputCfg.format != pConfig->outputCfg.format) return -EINVAL;
146    if (pConfig->inputCfg.channels != AUDIO_CHANNEL_OUT_STEREO) return -EINVAL;
147    if (pConfig->outputCfg.accessMode != EFFECT_BUFFER_ACCESS_WRITE &&
148            pConfig->outputCfg.accessMode != EFFECT_BUFFER_ACCESS_ACCUMULATE) return -EINVAL;
149    if (pConfig->inputCfg.format != AUDIO_FORMAT_PCM_16_BIT) return -EINVAL;
150
151    pContext->mConfig = *pConfig;
152
153    Visualizer_reset(pContext);
154
155    return 0;
156}
157
158
159//----------------------------------------------------------------------------
160// Visualizer_getConfig()
161//----------------------------------------------------------------------------
162// Purpose: Get input and output audio configuration.
163//
164// Inputs:
165//  pContext:   effect engine context
166//  pConfig:    pointer to effect_config_t structure holding input and output
167//      configuration parameters
168//
169// Outputs:
170//
171//----------------------------------------------------------------------------
172
173void Visualizer_getConfig(VisualizerContext *pContext, effect_config_t *pConfig)
174{
175    *pConfig = pContext->mConfig;
176}
177
178
179//----------------------------------------------------------------------------
180// Visualizer_init()
181//----------------------------------------------------------------------------
182// Purpose: Initialize engine with default configuration.
183//
184// Inputs:
185//  pContext:   effect engine context
186//
187// Outputs:
188//
189//----------------------------------------------------------------------------
190
191int Visualizer_init(VisualizerContext *pContext)
192{
193    pContext->mConfig.inputCfg.accessMode = EFFECT_BUFFER_ACCESS_READ;
194    pContext->mConfig.inputCfg.channels = AUDIO_CHANNEL_OUT_STEREO;
195    pContext->mConfig.inputCfg.format = AUDIO_FORMAT_PCM_16_BIT;
196    pContext->mConfig.inputCfg.samplingRate = 44100;
197    pContext->mConfig.inputCfg.bufferProvider.getBuffer = NULL;
198    pContext->mConfig.inputCfg.bufferProvider.releaseBuffer = NULL;
199    pContext->mConfig.inputCfg.bufferProvider.cookie = NULL;
200    pContext->mConfig.inputCfg.mask = EFFECT_CONFIG_ALL;
201    pContext->mConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_ACCUMULATE;
202    pContext->mConfig.outputCfg.channels = AUDIO_CHANNEL_OUT_STEREO;
203    pContext->mConfig.outputCfg.format = AUDIO_FORMAT_PCM_16_BIT;
204    pContext->mConfig.outputCfg.samplingRate = 44100;
205    pContext->mConfig.outputCfg.bufferProvider.getBuffer = NULL;
206    pContext->mConfig.outputCfg.bufferProvider.releaseBuffer = NULL;
207    pContext->mConfig.outputCfg.bufferProvider.cookie = NULL;
208    pContext->mConfig.outputCfg.mask = EFFECT_CONFIG_ALL;
209
210    // visualization initialization
211    pContext->mCaptureSize = VISUALIZER_CAPTURE_SIZE_MAX;
212    pContext->mScalingMode = VISUALIZER_SCALING_MODE_NORMALIZED;
213
214    // measurement initialization
215    pContext->mChannelCount =
216            audio_channel_count_from_out_mask(pContext->mConfig.inputCfg.channels);
217    pContext->mMeasurementMode = MEASUREMENT_MODE_NONE;
218    pContext->mMeasurementWindowSizeInBuffers = MEASUREMENT_WINDOW_MAX_SIZE_IN_BUFFERS;
219    pContext->mMeasurementBufferIdx = 0;
220    for (uint32_t i=0 ; i<pContext->mMeasurementWindowSizeInBuffers ; i++) {
221        pContext->mPastMeasurements[i].mIsValid = false;
222        pContext->mPastMeasurements[i].mPeakU16 = 0;
223        pContext->mPastMeasurements[i].mRmsSquared = 0;
224    }
225
226    Visualizer_setConfig(pContext, &pContext->mConfig);
227
228    return 0;
229}
230
231//
232//--- Effect Library Interface Implementation
233//
234
235int VisualizerLib_Create(const effect_uuid_t *uuid,
236                         int32_t /*sessionId*/,
237                         int32_t /*ioId*/,
238                         effect_handle_t *pHandle) {
239    int ret;
240
241    if (pHandle == NULL || uuid == NULL) {
242        return -EINVAL;
243    }
244
245    if (memcmp(uuid, &gVisualizerDescriptor.uuid, sizeof(effect_uuid_t)) != 0) {
246        return -EINVAL;
247    }
248
249    VisualizerContext *pContext = new VisualizerContext;
250
251    pContext->mItfe = &gVisualizerInterface;
252    pContext->mState = VISUALIZER_STATE_UNINITIALIZED;
253
254    ret = Visualizer_init(pContext);
255    if (ret < 0) {
256        ALOGW("VisualizerLib_Create() init failed");
257        delete pContext;
258        return ret;
259    }
260
261    *pHandle = (effect_handle_t)pContext;
262
263    pContext->mState = VISUALIZER_STATE_INITIALIZED;
264
265    ALOGV("VisualizerLib_Create %p", pContext);
266
267    return 0;
268
269}
270
271int VisualizerLib_Release(effect_handle_t handle) {
272    VisualizerContext * pContext = (VisualizerContext *)handle;
273
274    ALOGV("VisualizerLib_Release %p", handle);
275    if (pContext == NULL) {
276        return -EINVAL;
277    }
278    pContext->mState = VISUALIZER_STATE_UNINITIALIZED;
279    delete pContext;
280
281    return 0;
282}
283
284int VisualizerLib_GetDescriptor(const effect_uuid_t *uuid,
285                                effect_descriptor_t *pDescriptor) {
286
287    if (pDescriptor == NULL || uuid == NULL){
288        ALOGV("VisualizerLib_GetDescriptor() called with NULL pointer");
289        return -EINVAL;
290    }
291
292    if (memcmp(uuid, &gVisualizerDescriptor.uuid, sizeof(effect_uuid_t)) == 0) {
293        *pDescriptor = gVisualizerDescriptor;
294        return 0;
295    }
296
297    return  -EINVAL;
298} /* end VisualizerLib_GetDescriptor */
299
300//
301//--- Effect Control Interface Implementation
302//
303
304static inline int16_t clamp16(int32_t sample)
305{
306    if ((sample>>15) ^ (sample>>31))
307        sample = 0x7FFF ^ (sample>>31);
308    return sample;
309}
310
311int Visualizer_process(
312        effect_handle_t self,audio_buffer_t *inBuffer, audio_buffer_t *outBuffer)
313{
314    VisualizerContext * pContext = (VisualizerContext *)self;
315
316    if (pContext == NULL) {
317        return -EINVAL;
318    }
319
320    if (inBuffer == NULL || inBuffer->raw == NULL ||
321        outBuffer == NULL || outBuffer->raw == NULL ||
322        inBuffer->frameCount != outBuffer->frameCount ||
323        inBuffer->frameCount == 0) {
324        return -EINVAL;
325    }
326
327    // perform measurements if needed
328    if (pContext->mMeasurementMode & MEASUREMENT_MODE_PEAK_RMS) {
329        // find the peak and RMS squared for the new buffer
330        uint32_t inIdx;
331        int16_t maxSample = 0;
332        float rmsSqAcc = 0;
333        for (inIdx = 0 ; inIdx < inBuffer->frameCount * pContext->mChannelCount ; inIdx++) {
334            if (inBuffer->s16[inIdx] > maxSample) {
335                maxSample = inBuffer->s16[inIdx];
336            } else if (-inBuffer->s16[inIdx] > maxSample) {
337                maxSample = -inBuffer->s16[inIdx];
338            }
339            rmsSqAcc += (inBuffer->s16[inIdx] * inBuffer->s16[inIdx]);
340        }
341        // store the measurement
342        pContext->mPastMeasurements[pContext->mMeasurementBufferIdx].mPeakU16 = (uint16_t)maxSample;
343        pContext->mPastMeasurements[pContext->mMeasurementBufferIdx].mRmsSquared =
344                rmsSqAcc / (inBuffer->frameCount * pContext->mChannelCount);
345        pContext->mPastMeasurements[pContext->mMeasurementBufferIdx].mIsValid = true;
346        if (++pContext->mMeasurementBufferIdx >= pContext->mMeasurementWindowSizeInBuffers) {
347            pContext->mMeasurementBufferIdx = 0;
348        }
349    }
350
351    // all code below assumes stereo 16 bit PCM output and input
352    int32_t shift;
353
354    if (pContext->mScalingMode == VISUALIZER_SCALING_MODE_NORMALIZED) {
355        // derive capture scaling factor from peak value in current buffer
356        // this gives more interesting captures for display.
357        shift = 32;
358        int len = inBuffer->frameCount * 2;
359        for (int i = 0; i < len; i++) {
360            int32_t smp = inBuffer->s16[i];
361            if (smp < 0) smp = -smp - 1; // take care to keep the max negative in range
362            int32_t clz = __builtin_clz(smp);
363            if (shift > clz) shift = clz;
364        }
365        // A maximum amplitude signal will have 17 leading zeros, which we want to
366        // translate to a shift of 8 (for converting 16 bit to 8 bit)
367        shift = 25 - shift;
368        // Never scale by less than 8 to avoid returning unaltered PCM signal.
369        if (shift < 3) {
370            shift = 3;
371        }
372        // add one to combine the division by 2 needed after summing left and right channels below
373        shift++;
374    } else {
375        assert(pContext->mScalingMode == VISUALIZER_SCALING_MODE_AS_PLAYED);
376        shift = 9;
377    }
378
379    uint32_t captIdx;
380    uint32_t inIdx;
381    uint8_t *buf = pContext->mCaptureBuf;
382    for (inIdx = 0, captIdx = pContext->mCaptureIdx;
383         inIdx < inBuffer->frameCount;
384         inIdx++, captIdx++) {
385        if (captIdx >= CAPTURE_BUF_SIZE) {
386            // wrap around
387            captIdx = 0;
388        }
389        int32_t smp = inBuffer->s16[2 * inIdx] + inBuffer->s16[2 * inIdx + 1];
390        smp = smp >> shift;
391        buf[captIdx] = ((uint8_t)smp)^0x80;
392    }
393
394    // XXX the following two should really be atomic, though it probably doesn't
395    // matter much for visualization purposes
396    pContext->mCaptureIdx = captIdx;
397    // update last buffer update time stamp
398    if (clock_gettime(CLOCK_MONOTONIC, &pContext->mBufferUpdateTime) < 0) {
399        pContext->mBufferUpdateTime.tv_sec = 0;
400    }
401
402    if (inBuffer->raw != outBuffer->raw) {
403        if (pContext->mConfig.outputCfg.accessMode == EFFECT_BUFFER_ACCESS_ACCUMULATE) {
404            for (size_t i = 0; i < outBuffer->frameCount*2; i++) {
405                outBuffer->s16[i] = clamp16(outBuffer->s16[i] + inBuffer->s16[i]);
406            }
407        } else {
408            memcpy(outBuffer->raw, inBuffer->raw, outBuffer->frameCount * 2 * sizeof(int16_t));
409        }
410    }
411    if (pContext->mState != VISUALIZER_STATE_ACTIVE) {
412        return -ENODATA;
413    }
414    return 0;
415}   // end Visualizer_process
416
417int Visualizer_command(effect_handle_t self, uint32_t cmdCode, uint32_t cmdSize,
418        void *pCmdData, uint32_t *replySize, void *pReplyData) {
419
420    VisualizerContext * pContext = (VisualizerContext *)self;
421
422    if (pContext == NULL || pContext->mState == VISUALIZER_STATE_UNINITIALIZED) {
423        return -EINVAL;
424    }
425
426//    ALOGV("Visualizer_command command %" PRIu32 " cmdSize %" PRIu32, cmdCode, cmdSize);
427
428    switch (cmdCode) {
429    case EFFECT_CMD_INIT:
430        if (pReplyData == NULL || replySize == NULL || *replySize != sizeof(int)) {
431            return -EINVAL;
432        }
433        *(int *) pReplyData = Visualizer_init(pContext);
434        break;
435    case EFFECT_CMD_SET_CONFIG:
436        if (pCmdData == NULL || cmdSize != sizeof(effect_config_t)
437                || pReplyData == NULL || replySize == NULL || *replySize != sizeof(int)) {
438            return -EINVAL;
439        }
440        *(int *) pReplyData = Visualizer_setConfig(pContext,
441                (effect_config_t *) pCmdData);
442        break;
443    case EFFECT_CMD_GET_CONFIG:
444        if (pReplyData == NULL || replySize == NULL ||
445            *replySize != sizeof(effect_config_t)) {
446            return -EINVAL;
447        }
448        Visualizer_getConfig(pContext, (effect_config_t *)pReplyData);
449        break;
450    case EFFECT_CMD_RESET:
451        Visualizer_reset(pContext);
452        break;
453    case EFFECT_CMD_ENABLE:
454        if (pReplyData == NULL || replySize == NULL || *replySize != sizeof(int)) {
455            return -EINVAL;
456        }
457        if (pContext->mState != VISUALIZER_STATE_INITIALIZED) {
458            return -ENOSYS;
459        }
460        pContext->mState = VISUALIZER_STATE_ACTIVE;
461        ALOGV("EFFECT_CMD_ENABLE() OK");
462        *(int *)pReplyData = 0;
463        break;
464    case EFFECT_CMD_DISABLE:
465        if (pReplyData == NULL || replySize == NULL || *replySize != sizeof(int)) {
466            return -EINVAL;
467        }
468        if (pContext->mState != VISUALIZER_STATE_ACTIVE) {
469            return -ENOSYS;
470        }
471        pContext->mState = VISUALIZER_STATE_INITIALIZED;
472        ALOGV("EFFECT_CMD_DISABLE() OK");
473        *(int *)pReplyData = 0;
474        break;
475    case EFFECT_CMD_GET_PARAM: {
476        if (pCmdData == NULL ||
477            cmdSize != (int)(sizeof(effect_param_t) + sizeof(uint32_t)) ||
478            pReplyData == NULL || replySize == NULL ||
479            *replySize < (int)(sizeof(effect_param_t) + sizeof(uint32_t) + sizeof(uint32_t))) {
480            return -EINVAL;
481        }
482        memcpy(pReplyData, pCmdData, sizeof(effect_param_t) + sizeof(uint32_t));
483        effect_param_t *p = (effect_param_t *)pReplyData;
484        p->status = 0;
485        *replySize = sizeof(effect_param_t) + sizeof(uint32_t);
486        if (p->psize != sizeof(uint32_t)) {
487            p->status = -EINVAL;
488            break;
489        }
490        switch (*(uint32_t *)p->data) {
491        case VISUALIZER_PARAM_CAPTURE_SIZE:
492            ALOGV("get mCaptureSize = %" PRIu32, pContext->mCaptureSize);
493            *((uint32_t *)p->data + 1) = pContext->mCaptureSize;
494            p->vsize = sizeof(uint32_t);
495            *replySize += sizeof(uint32_t);
496            break;
497        case VISUALIZER_PARAM_SCALING_MODE:
498            ALOGV("get mScalingMode = %" PRIu32, pContext->mScalingMode);
499            *((uint32_t *)p->data + 1) = pContext->mScalingMode;
500            p->vsize = sizeof(uint32_t);
501            *replySize += sizeof(uint32_t);
502            break;
503        case VISUALIZER_PARAM_MEASUREMENT_MODE:
504            ALOGV("get mMeasurementMode = %" PRIu32, pContext->mMeasurementMode);
505            *((uint32_t *)p->data + 1) = pContext->mMeasurementMode;
506            p->vsize = sizeof(uint32_t);
507            *replySize += sizeof(uint32_t);
508            break;
509        default:
510            p->status = -EINVAL;
511        }
512        } break;
513    case EFFECT_CMD_SET_PARAM: {
514        if (pCmdData == NULL ||
515            cmdSize != (int)(sizeof(effect_param_t) + sizeof(uint32_t) + sizeof(uint32_t)) ||
516            pReplyData == NULL || replySize == NULL || *replySize != sizeof(int32_t)) {
517            return -EINVAL;
518        }
519        *(int32_t *)pReplyData = 0;
520        effect_param_t *p = (effect_param_t *)pCmdData;
521        if (p->psize != sizeof(uint32_t) || p->vsize != sizeof(uint32_t)) {
522            *(int32_t *)pReplyData = -EINVAL;
523            break;
524        }
525        switch (*(uint32_t *)p->data) {
526        case VISUALIZER_PARAM_CAPTURE_SIZE: {
527            const uint32_t captureSize = *((uint32_t *)p->data + 1);
528            if (captureSize > VISUALIZER_CAPTURE_SIZE_MAX) {
529                android_errorWriteLog(0x534e4554, "31781965");
530                *(int32_t *)pReplyData = -EINVAL;
531                ALOGW("set mCaptureSize = %u > %u", captureSize, VISUALIZER_CAPTURE_SIZE_MAX);
532            } else {
533                pContext->mCaptureSize = captureSize;
534                ALOGV("set mCaptureSize = %u", captureSize);
535            }
536            } break;
537        case VISUALIZER_PARAM_SCALING_MODE:
538            pContext->mScalingMode = *((uint32_t *)p->data + 1);
539            ALOGV("set mScalingMode = %" PRIu32, pContext->mScalingMode);
540            break;
541        case VISUALIZER_PARAM_LATENCY: {
542            uint32_t latency = *((uint32_t *)p->data + 1);
543            if (latency > MAX_LATENCY_MS) {
544                latency = MAX_LATENCY_MS; // clamp latency b/31781965
545            }
546            pContext->mLatency = latency;
547            ALOGV("set mLatency = %u", latency);
548            } break;
549        case VISUALIZER_PARAM_MEASUREMENT_MODE:
550            pContext->mMeasurementMode = *((uint32_t *)p->data + 1);
551            ALOGV("set mMeasurementMode = %" PRIu32, pContext->mMeasurementMode);
552            break;
553        default:
554            *(int32_t *)pReplyData = -EINVAL;
555        }
556        } break;
557    case EFFECT_CMD_SET_DEVICE:
558    case EFFECT_CMD_SET_VOLUME:
559    case EFFECT_CMD_SET_AUDIO_MODE:
560        break;
561
562
563    case VISUALIZER_CMD_CAPTURE: {
564        uint32_t captureSize = pContext->mCaptureSize;
565        if (pReplyData == NULL || replySize == NULL || *replySize != captureSize) {
566            ALOGV("VISUALIZER_CMD_CAPTURE() error *replySize %" PRIu32 " captureSize %" PRIu32,
567                    *replySize, captureSize);
568            return -EINVAL;
569        }
570        if (pContext->mState == VISUALIZER_STATE_ACTIVE) {
571            const uint32_t deltaMs = Visualizer_getDeltaTimeMsFromUpdatedTime(pContext);
572
573            // if audio framework has stopped playing audio although the effect is still
574            // active we must clear the capture buffer to return silence
575            if ((pContext->mLastCaptureIdx == pContext->mCaptureIdx) &&
576                    (pContext->mBufferUpdateTime.tv_sec != 0) &&
577                    (deltaMs > MAX_STALL_TIME_MS)) {
578                    ALOGV("capture going to idle");
579                    pContext->mBufferUpdateTime.tv_sec = 0;
580                    memset(pReplyData, 0x80, captureSize);
581            } else {
582                int32_t latencyMs = pContext->mLatency;
583                latencyMs -= deltaMs;
584                if (latencyMs < 0) {
585                    latencyMs = 0;
586                }
587                uint32_t deltaSmpl = captureSize
588                        + pContext->mConfig.inputCfg.samplingRate * latencyMs / 1000;
589
590                // large sample rate, latency, or capture size, could cause overflow.
591                // do not offset more than the size of buffer.
592                if (deltaSmpl > CAPTURE_BUF_SIZE) {
593                    android_errorWriteLog(0x534e4554, "31781965");
594                    deltaSmpl = CAPTURE_BUF_SIZE;
595                }
596
597                int32_t capturePoint = pContext->mCaptureIdx - deltaSmpl;
598                // a negative capturePoint means we wrap the buffer.
599                if (capturePoint < 0) {
600                    uint32_t size = -capturePoint;
601                    if (size > captureSize) {
602                        size = captureSize;
603                    }
604                    memcpy(pReplyData,
605                           pContext->mCaptureBuf + CAPTURE_BUF_SIZE + capturePoint,
606                           size);
607                    pReplyData = (char *)pReplyData + size;
608                    captureSize -= size;
609                    capturePoint = 0;
610                }
611                memcpy(pReplyData,
612                       pContext->mCaptureBuf + capturePoint,
613                       captureSize);
614            }
615
616            pContext->mLastCaptureIdx = pContext->mCaptureIdx;
617        } else {
618            memset(pReplyData, 0x80, captureSize);
619        }
620
621        } break;
622
623    case VISUALIZER_CMD_MEASURE: {
624        if (pReplyData == NULL || replySize == NULL ||
625                *replySize < (sizeof(int32_t) * MEASUREMENT_COUNT)) {
626            if (replySize == NULL) {
627                ALOGV("VISUALIZER_CMD_MEASURE() error replySize NULL");
628            } else {
629                ALOGV("VISUALIZER_CMD_MEASURE() error *replySize %" PRIu32
630                        " < (sizeof(int32_t) * MEASUREMENT_COUNT) %" PRIu32,
631                        *replySize,
632                        uint32_t(sizeof(int32_t)) * MEASUREMENT_COUNT);
633            }
634            android_errorWriteLog(0x534e4554, "30229821");
635            return -EINVAL;
636        }
637        uint16_t peakU16 = 0;
638        float sumRmsSquared = 0.0f;
639        uint8_t nbValidMeasurements = 0;
640        // reset measurements if last measurement was too long ago (which implies stored
641        // measurements aren't relevant anymore and shouldn't bias the new one)
642        const int32_t delayMs = Visualizer_getDeltaTimeMsFromUpdatedTime(pContext);
643        if (delayMs > DISCARD_MEASUREMENTS_TIME_MS) {
644            ALOGV("Discarding measurements, last measurement is %" PRId32 "ms old", delayMs);
645            for (uint32_t i=0 ; i<pContext->mMeasurementWindowSizeInBuffers ; i++) {
646                pContext->mPastMeasurements[i].mIsValid = false;
647                pContext->mPastMeasurements[i].mPeakU16 = 0;
648                pContext->mPastMeasurements[i].mRmsSquared = 0;
649            }
650            pContext->mMeasurementBufferIdx = 0;
651        } else {
652            // only use actual measurements, otherwise the first RMS measure happening before
653            // MEASUREMENT_WINDOW_MAX_SIZE_IN_BUFFERS have been played will always be artificially
654            // low
655            for (uint32_t i=0 ; i < pContext->mMeasurementWindowSizeInBuffers ; i++) {
656                if (pContext->mPastMeasurements[i].mIsValid) {
657                    if (pContext->mPastMeasurements[i].mPeakU16 > peakU16) {
658                        peakU16 = pContext->mPastMeasurements[i].mPeakU16;
659                    }
660                    sumRmsSquared += pContext->mPastMeasurements[i].mRmsSquared;
661                    nbValidMeasurements++;
662                }
663            }
664        }
665        float rms = nbValidMeasurements == 0 ? 0.0f : sqrtf(sumRmsSquared / nbValidMeasurements);
666        int32_t* pIntReplyData = (int32_t*)pReplyData;
667        // convert from I16 sample values to mB and write results
668        if (rms < 0.000016f) {
669            pIntReplyData[MEASUREMENT_IDX_RMS] = -9600; //-96dB
670        } else {
671            pIntReplyData[MEASUREMENT_IDX_RMS] = (int32_t) (2000 * log10(rms / 32767.0f));
672        }
673        if (peakU16 == 0) {
674            pIntReplyData[MEASUREMENT_IDX_PEAK] = -9600; //-96dB
675        } else {
676            pIntReplyData[MEASUREMENT_IDX_PEAK] = (int32_t) (2000 * log10(peakU16 / 32767.0f));
677        }
678        ALOGV("VISUALIZER_CMD_MEASURE peak=%" PRIu16 " (%" PRId32 "mB), rms=%.1f (%" PRId32 "mB)",
679                peakU16, pIntReplyData[MEASUREMENT_IDX_PEAK],
680                rms, pIntReplyData[MEASUREMENT_IDX_RMS]);
681        }
682        break;
683
684    default:
685        ALOGW("Visualizer_command invalid command %" PRIu32, cmdCode);
686        return -EINVAL;
687    }
688
689    return 0;
690}
691
692/* Effect Control Interface Implementation: get_descriptor */
693int Visualizer_getDescriptor(effect_handle_t   self,
694                                    effect_descriptor_t *pDescriptor)
695{
696    VisualizerContext * pContext = (VisualizerContext *) self;
697
698    if (pContext == NULL || pDescriptor == NULL) {
699        ALOGV("Visualizer_getDescriptor() invalid param");
700        return -EINVAL;
701    }
702
703    *pDescriptor = gVisualizerDescriptor;
704
705    return 0;
706}   /* end Visualizer_getDescriptor */
707
708// effect_handle_t interface implementation for visualizer effect
709const struct effect_interface_s gVisualizerInterface = {
710        Visualizer_process,
711        Visualizer_command,
712        Visualizer_getDescriptor,
713        NULL,
714};
715
716// This is the only symbol that needs to be exported
717__attribute__ ((visibility ("default")))
718audio_effect_library_t AUDIO_EFFECT_LIBRARY_INFO_SYM = {
719    .tag = AUDIO_EFFECT_LIBRARY_TAG,
720    .version = EFFECT_LIBRARY_API_VERSION,
721    .name = "Visualizer Library",
722    .implementor = "The Android Open Source Project",
723    .create_effect = VisualizerLib_Create,
724    .release_effect = VisualizerLib_Release,
725    .get_descriptor = VisualizerLib_GetDescriptor,
726};
727
728}; // extern "C"
729