AudioMixer.cpp revision 1d6fa7af1288b550faabe4ec2cf98684236723db
1/*
2**
3** Copyright 2007, The Android Open Source Project
4**
5** Licensed under the Apache License, Version 2.0 (the "License");
6** you may not use this file except in compliance with the License.
7** You may obtain a copy of the License at
8**
9**     http://www.apache.org/licenses/LICENSE-2.0
10**
11** Unless required by applicable law or agreed to in writing, software
12** distributed under the License is distributed on an "AS IS" BASIS,
13** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14** See the License for the specific language governing permissions and
15** limitations under the License.
16*/
17
18#define LOG_TAG "AudioMixer"
19//#define LOG_NDEBUG 0
20
21#include "Configuration.h"
22#include <stdint.h>
23#include <string.h>
24#include <stdlib.h>
25#include <sys/types.h>
26
27#include <utils/Errors.h>
28#include <utils/Log.h>
29
30#include <cutils/bitops.h>
31#include <cutils/compiler.h>
32#include <utils/Debug.h>
33
34#include <system/audio.h>
35
36#include <audio_utils/primitives.h>
37#include <common_time/local_clock.h>
38#include <common_time/cc_helper.h>
39
40#include <media/EffectsFactoryApi.h>
41
42#include "AudioMixer.h"
43
44namespace android {
45
46// ----------------------------------------------------------------------------
47AudioMixer::DownmixerBufferProvider::DownmixerBufferProvider() : AudioBufferProvider(),
48        mTrackBufferProvider(NULL), mDownmixHandle(NULL)
49{
50}
51
52AudioMixer::DownmixerBufferProvider::~DownmixerBufferProvider()
53{
54    ALOGV("AudioMixer deleting DownmixerBufferProvider (%p)", this);
55    EffectRelease(mDownmixHandle);
56}
57
58status_t AudioMixer::DownmixerBufferProvider::getNextBuffer(AudioBufferProvider::Buffer *pBuffer,
59        int64_t pts) {
60    //ALOGV("DownmixerBufferProvider::getNextBuffer()");
61    if (mTrackBufferProvider != NULL) {
62        status_t res = mTrackBufferProvider->getNextBuffer(pBuffer, pts);
63        if (res == OK) {
64            mDownmixConfig.inputCfg.buffer.frameCount = pBuffer->frameCount;
65            mDownmixConfig.inputCfg.buffer.raw = pBuffer->raw;
66            mDownmixConfig.outputCfg.buffer.frameCount = pBuffer->frameCount;
67            mDownmixConfig.outputCfg.buffer.raw = mDownmixConfig.inputCfg.buffer.raw;
68            // in-place so overwrite the buffer contents, has been set in prepareTrackForDownmix()
69            //mDownmixConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_WRITE;
70
71            res = (*mDownmixHandle)->process(mDownmixHandle,
72                    &mDownmixConfig.inputCfg.buffer, &mDownmixConfig.outputCfg.buffer);
73            //ALOGV("getNextBuffer is downmixing");
74        }
75        return res;
76    } else {
77        ALOGE("DownmixerBufferProvider::getNextBuffer() error: NULL track buffer provider");
78        return NO_INIT;
79    }
80}
81
82void AudioMixer::DownmixerBufferProvider::releaseBuffer(AudioBufferProvider::Buffer *pBuffer) {
83    //ALOGV("DownmixerBufferProvider::releaseBuffer()");
84    if (mTrackBufferProvider != NULL) {
85        mTrackBufferProvider->releaseBuffer(pBuffer);
86    } else {
87        ALOGE("DownmixerBufferProvider::releaseBuffer() error: NULL track buffer provider");
88    }
89}
90
91
92// ----------------------------------------------------------------------------
93bool AudioMixer::sIsMultichannelCapable = false;
94
95effect_descriptor_t AudioMixer::sDwnmFxDesc;
96
97// Ensure mConfiguredNames bitmask is initialized properly on all architectures.
98// The value of 1 << x is undefined in C when x >= 32.
99
100AudioMixer::AudioMixer(size_t frameCount, uint32_t sampleRate, uint32_t maxNumTracks)
101    :   mTrackNames(0), mConfiguredNames((maxNumTracks >= 32 ? 0 : 1 << maxNumTracks) - 1),
102        mSampleRate(sampleRate)
103{
104    // AudioMixer is not yet capable of multi-channel beyond stereo
105    COMPILE_TIME_ASSERT_FUNCTION_SCOPE(2 == MAX_NUM_CHANNELS);
106
107    ALOG_ASSERT(maxNumTracks <= MAX_NUM_TRACKS, "maxNumTracks %u > MAX_NUM_TRACKS %u",
108            maxNumTracks, MAX_NUM_TRACKS);
109
110    // AudioMixer is not yet capable of more than 32 active track inputs
111    ALOG_ASSERT(32 >= MAX_NUM_TRACKS, "bad MAX_NUM_TRACKS %d", MAX_NUM_TRACKS);
112
113    // AudioMixer is not yet capable of multi-channel output beyond stereo
114    ALOG_ASSERT(2 == MAX_NUM_CHANNELS, "bad MAX_NUM_CHANNELS %d", MAX_NUM_CHANNELS);
115
116    pthread_once(&sOnceControl, &sInitRoutine);
117
118    mState.enabledTracks= 0;
119    mState.needsChanged = 0;
120    mState.frameCount   = frameCount;
121    mState.hook         = process__nop;
122    mState.outputTemp   = NULL;
123    mState.resampleTemp = NULL;
124    mState.mLog         = &mDummyLog;
125    // mState.reserved
126
127    // FIXME Most of the following initialization is probably redundant since
128    // tracks[i] should only be referenced if (mTrackNames & (1 << i)) != 0
129    // and mTrackNames is initially 0.  However, leave it here until that's verified.
130    track_t* t = mState.tracks;
131    for (unsigned i=0 ; i < MAX_NUM_TRACKS ; i++) {
132        t->resampler = NULL;
133        t->downmixerBufferProvider = NULL;
134        t++;
135    }
136
137}
138
139AudioMixer::~AudioMixer()
140{
141    track_t* t = mState.tracks;
142    for (unsigned i=0 ; i < MAX_NUM_TRACKS ; i++) {
143        delete t->resampler;
144        delete t->downmixerBufferProvider;
145        t++;
146    }
147    delete [] mState.outputTemp;
148    delete [] mState.resampleTemp;
149}
150
151void AudioMixer::setLog(NBLog::Writer *log)
152{
153    mState.mLog = log;
154}
155
156int AudioMixer::getTrackName(audio_channel_mask_t channelMask, int sessionId)
157{
158    uint32_t names = (~mTrackNames) & mConfiguredNames;
159    if (names != 0) {
160        int n = __builtin_ctz(names);
161        ALOGV("add track (%d)", n);
162        mTrackNames |= 1 << n;
163        // assume default parameters for the track, except where noted below
164        track_t* t = &mState.tracks[n];
165        t->needs = 0;
166        t->volume[0] = UNITY_GAIN;
167        t->volume[1] = UNITY_GAIN;
168        // no initialization needed
169        // t->prevVolume[0]
170        // t->prevVolume[1]
171        t->volumeInc[0] = 0;
172        t->volumeInc[1] = 0;
173        t->auxLevel = 0;
174        t->auxInc = 0;
175        // no initialization needed
176        // t->prevAuxLevel
177        // t->frameCount
178        t->channelCount = 2;
179        t->enabled = false;
180        t->format = 16;
181        t->channelMask = AUDIO_CHANNEL_OUT_STEREO;
182        t->sessionId = sessionId;
183        // setBufferProvider(name, AudioBufferProvider *) is required before enable(name)
184        t->bufferProvider = NULL;
185        t->buffer.raw = NULL;
186        // no initialization needed
187        // t->buffer.frameCount
188        t->hook = NULL;
189        t->in = NULL;
190        t->resampler = NULL;
191        t->sampleRate = mSampleRate;
192        // setParameter(name, TRACK, MAIN_BUFFER, mixBuffer) is required before enable(name)
193        t->mainBuffer = NULL;
194        t->auxBuffer = NULL;
195        t->downmixerBufferProvider = NULL;
196
197        status_t status = initTrackDownmix(&mState.tracks[n], n, channelMask);
198        if (status == OK) {
199            return TRACK0 + n;
200        }
201        ALOGE("AudioMixer::getTrackName(0x%x) failed, error preparing track for downmix",
202                channelMask);
203    }
204    return -1;
205}
206
207void AudioMixer::invalidateState(uint32_t mask)
208{
209    if (mask != 0) {
210        mState.needsChanged |= mask;
211        mState.hook = process__validate;
212    }
213 }
214
215status_t AudioMixer::initTrackDownmix(track_t* pTrack, int trackNum, audio_channel_mask_t mask)
216{
217    uint32_t channelCount = popcount(mask);
218    ALOG_ASSERT((channelCount <= MAX_NUM_CHANNELS_TO_DOWNMIX) && channelCount);
219    status_t status = OK;
220    if (channelCount > MAX_NUM_CHANNELS) {
221        pTrack->channelMask = mask;
222        pTrack->channelCount = channelCount;
223        ALOGV("initTrackDownmix(track=%d, mask=0x%x) calls prepareTrackForDownmix()",
224                trackNum, mask);
225        status = prepareTrackForDownmix(pTrack, trackNum);
226    } else {
227        unprepareTrackForDownmix(pTrack, trackNum);
228    }
229    return status;
230}
231
232void AudioMixer::unprepareTrackForDownmix(track_t* pTrack, int trackName __unused) {
233    ALOGV("AudioMixer::unprepareTrackForDownmix(%d)", trackName);
234
235    if (pTrack->downmixerBufferProvider != NULL) {
236        // this track had previously been configured with a downmixer, delete it
237        ALOGV(" deleting old downmixer");
238        pTrack->bufferProvider = pTrack->downmixerBufferProvider->mTrackBufferProvider;
239        delete pTrack->downmixerBufferProvider;
240        pTrack->downmixerBufferProvider = NULL;
241    } else {
242        ALOGV(" nothing to do, no downmixer to delete");
243    }
244}
245
246status_t AudioMixer::prepareTrackForDownmix(track_t* pTrack, int trackName)
247{
248    ALOGV("AudioMixer::prepareTrackForDownmix(%d) with mask 0x%x", trackName, pTrack->channelMask);
249
250    // discard the previous downmixer if there was one
251    unprepareTrackForDownmix(pTrack, trackName);
252
253    DownmixerBufferProvider* pDbp = new DownmixerBufferProvider();
254    int32_t status;
255
256    if (!sIsMultichannelCapable) {
257        ALOGE("prepareTrackForDownmix(%d) fails: mixer doesn't support multichannel content",
258                trackName);
259        goto noDownmixForActiveTrack;
260    }
261
262    if (EffectCreate(&sDwnmFxDesc.uuid,
263            pTrack->sessionId /*sessionId*/, -2 /*ioId not relevant here, using random value*/,
264            &pDbp->mDownmixHandle/*pHandle*/) != 0) {
265        ALOGE("prepareTrackForDownmix(%d) fails: error creating downmixer effect", trackName);
266        goto noDownmixForActiveTrack;
267    }
268
269    // channel input configuration will be overridden per-track
270    pDbp->mDownmixConfig.inputCfg.channels = pTrack->channelMask;
271    pDbp->mDownmixConfig.outputCfg.channels = AUDIO_CHANNEL_OUT_STEREO;
272    pDbp->mDownmixConfig.inputCfg.format = AUDIO_FORMAT_PCM_16_BIT;
273    pDbp->mDownmixConfig.outputCfg.format = AUDIO_FORMAT_PCM_16_BIT;
274    pDbp->mDownmixConfig.inputCfg.samplingRate = pTrack->sampleRate;
275    pDbp->mDownmixConfig.outputCfg.samplingRate = pTrack->sampleRate;
276    pDbp->mDownmixConfig.inputCfg.accessMode = EFFECT_BUFFER_ACCESS_READ;
277    pDbp->mDownmixConfig.outputCfg.accessMode = EFFECT_BUFFER_ACCESS_WRITE;
278    // input and output buffer provider, and frame count will not be used as the downmix effect
279    // process() function is called directly (see DownmixerBufferProvider::getNextBuffer())
280    pDbp->mDownmixConfig.inputCfg.mask = EFFECT_CONFIG_SMP_RATE | EFFECT_CONFIG_CHANNELS |
281            EFFECT_CONFIG_FORMAT | EFFECT_CONFIG_ACC_MODE;
282    pDbp->mDownmixConfig.outputCfg.mask = pDbp->mDownmixConfig.inputCfg.mask;
283
284    {// scope for local variables that are not used in goto label "noDownmixForActiveTrack"
285        int cmdStatus;
286        uint32_t replySize = sizeof(int);
287
288        // Configure and enable downmixer
289        status = (*pDbp->mDownmixHandle)->command(pDbp->mDownmixHandle,
290                EFFECT_CMD_SET_CONFIG /*cmdCode*/, sizeof(effect_config_t) /*cmdSize*/,
291                &pDbp->mDownmixConfig /*pCmdData*/,
292                &replySize /*replySize*/, &cmdStatus /*pReplyData*/);
293        if ((status != 0) || (cmdStatus != 0)) {
294            ALOGE("error %d while configuring downmixer for track %d", status, trackName);
295            goto noDownmixForActiveTrack;
296        }
297        replySize = sizeof(int);
298        status = (*pDbp->mDownmixHandle)->command(pDbp->mDownmixHandle,
299                EFFECT_CMD_ENABLE /*cmdCode*/, 0 /*cmdSize*/, NULL /*pCmdData*/,
300                &replySize /*replySize*/, &cmdStatus /*pReplyData*/);
301        if ((status != 0) || (cmdStatus != 0)) {
302            ALOGE("error %d while enabling downmixer for track %d", status, trackName);
303            goto noDownmixForActiveTrack;
304        }
305
306        // Set downmix type
307        // parameter size rounded for padding on 32bit boundary
308        const int psizePadded = ((sizeof(downmix_params_t) - 1)/sizeof(int) + 1) * sizeof(int);
309        const int downmixParamSize =
310                sizeof(effect_param_t) + psizePadded + sizeof(downmix_type_t);
311        effect_param_t * const param = (effect_param_t *) malloc(downmixParamSize);
312        param->psize = sizeof(downmix_params_t);
313        const downmix_params_t downmixParam = DOWNMIX_PARAM_TYPE;
314        memcpy(param->data, &downmixParam, param->psize);
315        const downmix_type_t downmixType = DOWNMIX_TYPE_FOLD;
316        param->vsize = sizeof(downmix_type_t);
317        memcpy(param->data + psizePadded, &downmixType, param->vsize);
318
319        status = (*pDbp->mDownmixHandle)->command(pDbp->mDownmixHandle,
320                EFFECT_CMD_SET_PARAM /* cmdCode */, downmixParamSize/* cmdSize */,
321                param /*pCmndData*/, &replySize /*replySize*/, &cmdStatus /*pReplyData*/);
322
323        free(param);
324
325        if ((status != 0) || (cmdStatus != 0)) {
326            ALOGE("error %d while setting downmix type for track %d", status, trackName);
327            goto noDownmixForActiveTrack;
328        } else {
329            ALOGV("downmix type set to %d for track %d", (int) downmixType, trackName);
330        }
331    }// end of scope for local variables that are not used in goto label "noDownmixForActiveTrack"
332
333    // initialization successful:
334    // - keep track of the real buffer provider in case it was set before
335    pDbp->mTrackBufferProvider = pTrack->bufferProvider;
336    // - we'll use the downmix effect integrated inside this
337    //    track's buffer provider, and we'll use it as the track's buffer provider
338    pTrack->downmixerBufferProvider = pDbp;
339    pTrack->bufferProvider = pDbp;
340
341    return NO_ERROR;
342
343noDownmixForActiveTrack:
344    delete pDbp;
345    pTrack->downmixerBufferProvider = NULL;
346    return NO_INIT;
347}
348
349void AudioMixer::deleteTrackName(int name)
350{
351    ALOGV("AudioMixer::deleteTrackName(%d)", name);
352    name -= TRACK0;
353    ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
354    ALOGV("deleteTrackName(%d)", name);
355    track_t& track(mState.tracks[ name ]);
356    if (track.enabled) {
357        track.enabled = false;
358        invalidateState(1<<name);
359    }
360    // delete the resampler
361    delete track.resampler;
362    track.resampler = NULL;
363    // delete the downmixer
364    unprepareTrackForDownmix(&mState.tracks[name], name);
365
366    mTrackNames &= ~(1<<name);
367}
368
369void AudioMixer::enable(int name)
370{
371    name -= TRACK0;
372    ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
373    track_t& track = mState.tracks[name];
374
375    if (!track.enabled) {
376        track.enabled = true;
377        ALOGV("enable(%d)", name);
378        invalidateState(1 << name);
379    }
380}
381
382void AudioMixer::disable(int name)
383{
384    name -= TRACK0;
385    ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
386    track_t& track = mState.tracks[name];
387
388    if (track.enabled) {
389        track.enabled = false;
390        ALOGV("disable(%d)", name);
391        invalidateState(1 << name);
392    }
393}
394
395void AudioMixer::setParameter(int name, int target, int param, void *value)
396{
397    name -= TRACK0;
398    ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
399    track_t& track = mState.tracks[name];
400
401    int valueInt = static_cast<int>(reinterpret_cast<uintptr_t>(value));
402    int32_t *valueBuf = reinterpret_cast<int32_t*>(value);
403
404    switch (target) {
405
406    case TRACK:
407        switch (param) {
408        case CHANNEL_MASK: {
409            audio_channel_mask_t mask =
410                static_cast<audio_channel_mask_t>(reinterpret_cast<uintptr_t>(value));
411            if (track.channelMask != mask) {
412                uint32_t channelCount = popcount(mask);
413                ALOG_ASSERT((channelCount <= MAX_NUM_CHANNELS_TO_DOWNMIX) && channelCount);
414                track.channelMask = mask;
415                track.channelCount = channelCount;
416                // the mask has changed, does this track need a downmixer?
417                initTrackDownmix(&mState.tracks[name], name, mask);
418                ALOGV("setParameter(TRACK, CHANNEL_MASK, %x)", mask);
419                invalidateState(1 << name);
420            }
421            } break;
422        case MAIN_BUFFER:
423            if (track.mainBuffer != valueBuf) {
424                track.mainBuffer = valueBuf;
425                ALOGV("setParameter(TRACK, MAIN_BUFFER, %p)", valueBuf);
426                invalidateState(1 << name);
427            }
428            break;
429        case AUX_BUFFER:
430            if (track.auxBuffer != valueBuf) {
431                track.auxBuffer = valueBuf;
432                ALOGV("setParameter(TRACK, AUX_BUFFER, %p)", valueBuf);
433                invalidateState(1 << name);
434            }
435            break;
436        case FORMAT:
437            ALOG_ASSERT(valueInt == AUDIO_FORMAT_PCM_16_BIT);
438            break;
439        // FIXME do we want to support setting the downmix type from AudioFlinger?
440        //         for a specific track? or per mixer?
441        /* case DOWNMIX_TYPE:
442            break          */
443        default:
444            LOG_FATAL("bad param");
445        }
446        break;
447
448    case RESAMPLE:
449        switch (param) {
450        case SAMPLE_RATE:
451            ALOG_ASSERT(valueInt > 0, "bad sample rate %d", valueInt);
452            if (track.setResampler(uint32_t(valueInt), mSampleRate)) {
453                ALOGV("setParameter(RESAMPLE, SAMPLE_RATE, %u)",
454                        uint32_t(valueInt));
455                invalidateState(1 << name);
456            }
457            break;
458        case RESET:
459            track.resetResampler();
460            invalidateState(1 << name);
461            break;
462        case REMOVE:
463            delete track.resampler;
464            track.resampler = NULL;
465            track.sampleRate = mSampleRate;
466            invalidateState(1 << name);
467            break;
468        default:
469            LOG_FATAL("bad param");
470        }
471        break;
472
473    case RAMP_VOLUME:
474    case VOLUME:
475        switch (param) {
476        case VOLUME0:
477        case VOLUME1:
478            if (track.volume[param-VOLUME0] != valueInt) {
479                ALOGV("setParameter(VOLUME, VOLUME0/1: %04x)", valueInt);
480                track.prevVolume[param-VOLUME0] = track.volume[param-VOLUME0] << 16;
481                track.volume[param-VOLUME0] = valueInt;
482                if (target == VOLUME) {
483                    track.prevVolume[param-VOLUME0] = valueInt << 16;
484                    track.volumeInc[param-VOLUME0] = 0;
485                } else {
486                    int32_t d = (valueInt<<16) - track.prevVolume[param-VOLUME0];
487                    int32_t volInc = d / int32_t(mState.frameCount);
488                    track.volumeInc[param-VOLUME0] = volInc;
489                    if (volInc == 0) {
490                        track.prevVolume[param-VOLUME0] = valueInt << 16;
491                    }
492                }
493                invalidateState(1 << name);
494            }
495            break;
496        case AUXLEVEL:
497            //ALOG_ASSERT(0 <= valueInt && valueInt <= MAX_GAIN_INT, "bad aux level %d", valueInt);
498            if (track.auxLevel != valueInt) {
499                ALOGV("setParameter(VOLUME, AUXLEVEL: %04x)", valueInt);
500                track.prevAuxLevel = track.auxLevel << 16;
501                track.auxLevel = valueInt;
502                if (target == VOLUME) {
503                    track.prevAuxLevel = valueInt << 16;
504                    track.auxInc = 0;
505                } else {
506                    int32_t d = (valueInt<<16) - track.prevAuxLevel;
507                    int32_t volInc = d / int32_t(mState.frameCount);
508                    track.auxInc = volInc;
509                    if (volInc == 0) {
510                        track.prevAuxLevel = valueInt << 16;
511                    }
512                }
513                invalidateState(1 << name);
514            }
515            break;
516        default:
517            LOG_FATAL("bad param");
518        }
519        break;
520
521    default:
522        LOG_FATAL("bad target");
523    }
524}
525
526bool AudioMixer::track_t::setResampler(uint32_t value, uint32_t devSampleRate)
527{
528    if (value != devSampleRate || resampler != NULL) {
529        if (sampleRate != value) {
530            sampleRate = value;
531            if (resampler == NULL) {
532                ALOGV("creating resampler from track %d Hz to device %d Hz", value, devSampleRate);
533                AudioResampler::src_quality quality;
534                // force lowest quality level resampler if use case isn't music or video
535                // FIXME this is flawed for dynamic sample rates, as we choose the resampler
536                // quality level based on the initial ratio, but that could change later.
537                // Should have a way to distinguish tracks with static ratios vs. dynamic ratios.
538                if (!((value == 44100 && devSampleRate == 48000) ||
539                      (value == 48000 && devSampleRate == 44100))) {
540                    quality = AudioResampler::DYN_LOW_QUALITY;
541                } else {
542                    quality = AudioResampler::DEFAULT_QUALITY;
543                }
544                resampler = AudioResampler::create(
545                        format,
546                        // the resampler sees the number of channels after the downmixer, if any
547                        (int) (downmixerBufferProvider != NULL ? MAX_NUM_CHANNELS : channelCount),
548                        devSampleRate, quality);
549                resampler->setLocalTimeFreq(sLocalTimeFreq);
550            }
551            return true;
552        }
553    }
554    return false;
555}
556
557inline
558void AudioMixer::track_t::adjustVolumeRamp(bool aux)
559{
560    for (uint32_t i=0 ; i<MAX_NUM_CHANNELS ; i++) {
561        if (((volumeInc[i]>0) && (((prevVolume[i]+volumeInc[i])>>16) >= volume[i])) ||
562            ((volumeInc[i]<0) && (((prevVolume[i]+volumeInc[i])>>16) <= volume[i]))) {
563            volumeInc[i] = 0;
564            prevVolume[i] = volume[i]<<16;
565        }
566    }
567    if (aux) {
568        if (((auxInc>0) && (((prevAuxLevel+auxInc)>>16) >= auxLevel)) ||
569            ((auxInc<0) && (((prevAuxLevel+auxInc)>>16) <= auxLevel))) {
570            auxInc = 0;
571            prevAuxLevel = auxLevel<<16;
572        }
573    }
574}
575
576size_t AudioMixer::getUnreleasedFrames(int name) const
577{
578    name -= TRACK0;
579    if (uint32_t(name) < MAX_NUM_TRACKS) {
580        return mState.tracks[name].getUnreleasedFrames();
581    }
582    return 0;
583}
584
585void AudioMixer::setBufferProvider(int name, AudioBufferProvider* bufferProvider)
586{
587    name -= TRACK0;
588    ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
589
590    if (mState.tracks[name].downmixerBufferProvider != NULL) {
591        // update required?
592        if (mState.tracks[name].downmixerBufferProvider->mTrackBufferProvider != bufferProvider) {
593            ALOGV("AudioMixer::setBufferProvider(%p) for downmix", bufferProvider);
594            // setting the buffer provider for a track that gets downmixed consists in:
595            //  1/ setting the buffer provider to the "downmix / buffer provider" wrapper
596            //     so it's the one that gets called when the buffer provider is needed,
597            mState.tracks[name].bufferProvider = mState.tracks[name].downmixerBufferProvider;
598            //  2/ saving the buffer provider for the track so the wrapper can use it
599            //     when it downmixes.
600            mState.tracks[name].downmixerBufferProvider->mTrackBufferProvider = bufferProvider;
601        }
602    } else {
603        mState.tracks[name].bufferProvider = bufferProvider;
604    }
605}
606
607
608void AudioMixer::process(int64_t pts)
609{
610    mState.hook(&mState, pts);
611}
612
613
614void AudioMixer::process__validate(state_t* state, int64_t pts)
615{
616    ALOGW_IF(!state->needsChanged,
617        "in process__validate() but nothing's invalid");
618
619    uint32_t changed = state->needsChanged;
620    state->needsChanged = 0; // clear the validation flag
621
622    // recompute which tracks are enabled / disabled
623    uint32_t enabled = 0;
624    uint32_t disabled = 0;
625    while (changed) {
626        const int i = 31 - __builtin_clz(changed);
627        const uint32_t mask = 1<<i;
628        changed &= ~mask;
629        track_t& t = state->tracks[i];
630        (t.enabled ? enabled : disabled) |= mask;
631    }
632    state->enabledTracks &= ~disabled;
633    state->enabledTracks |=  enabled;
634
635    // compute everything we need...
636    int countActiveTracks = 0;
637    bool all16BitsStereoNoResample = true;
638    bool resampling = false;
639    bool volumeRamp = false;
640    uint32_t en = state->enabledTracks;
641    while (en) {
642        const int i = 31 - __builtin_clz(en);
643        en &= ~(1<<i);
644
645        countActiveTracks++;
646        track_t& t = state->tracks[i];
647        uint32_t n = 0;
648        // FIXME can overflow (mask is only 3 bits)
649        n |= NEEDS_CHANNEL_1 + t.channelCount - 1;
650        if (t.doesResample()) {
651            n |= NEEDS_RESAMPLE;
652        }
653        if (t.auxLevel != 0 && t.auxBuffer != NULL) {
654            n |= NEEDS_AUX;
655        }
656
657        if (t.volumeInc[0]|t.volumeInc[1]) {
658            volumeRamp = true;
659        } else if (!t.doesResample() && t.volumeRL == 0) {
660            n |= NEEDS_MUTE;
661        }
662        t.needs = n;
663
664        if (n & NEEDS_MUTE) {
665            t.hook = track__nop;
666        } else {
667            if (n & NEEDS_AUX) {
668                all16BitsStereoNoResample = false;
669            }
670            if (n & NEEDS_RESAMPLE) {
671                all16BitsStereoNoResample = false;
672                resampling = true;
673                t.hook = track__genericResample;
674                ALOGV_IF((n & NEEDS_CHANNEL_COUNT__MASK) > NEEDS_CHANNEL_2,
675                        "Track %d needs downmix + resample", i);
676            } else {
677                if ((n & NEEDS_CHANNEL_COUNT__MASK) == NEEDS_CHANNEL_1){
678                    t.hook = track__16BitsMono;
679                    all16BitsStereoNoResample = false;
680                }
681                if ((n & NEEDS_CHANNEL_COUNT__MASK) >= NEEDS_CHANNEL_2){
682                    t.hook = track__16BitsStereo;
683                    ALOGV_IF((n & NEEDS_CHANNEL_COUNT__MASK) > NEEDS_CHANNEL_2,
684                            "Track %d needs downmix", i);
685                }
686            }
687        }
688    }
689
690    // select the processing hooks
691    state->hook = process__nop;
692    if (countActiveTracks > 0) {
693        if (resampling) {
694            if (!state->outputTemp) {
695                state->outputTemp = new int32_t[MAX_NUM_CHANNELS * state->frameCount];
696            }
697            if (!state->resampleTemp) {
698                state->resampleTemp = new int32_t[MAX_NUM_CHANNELS * state->frameCount];
699            }
700            state->hook = process__genericResampling;
701        } else {
702            if (state->outputTemp) {
703                delete [] state->outputTemp;
704                state->outputTemp = NULL;
705            }
706            if (state->resampleTemp) {
707                delete [] state->resampleTemp;
708                state->resampleTemp = NULL;
709            }
710            state->hook = process__genericNoResampling;
711            if (all16BitsStereoNoResample && !volumeRamp) {
712                if (countActiveTracks == 1) {
713                    state->hook = process__OneTrack16BitsStereoNoResampling;
714                }
715            }
716        }
717    }
718
719    ALOGV("mixer configuration change: %d activeTracks (%08x) "
720        "all16BitsStereoNoResample=%d, resampling=%d, volumeRamp=%d",
721        countActiveTracks, state->enabledTracks,
722        all16BitsStereoNoResample, resampling, volumeRamp);
723
724   state->hook(state, pts);
725
726    // Now that the volume ramp has been done, set optimal state and
727    // track hooks for subsequent mixer process
728    if (countActiveTracks > 0) {
729        bool allMuted = true;
730        uint32_t en = state->enabledTracks;
731        while (en) {
732            const int i = 31 - __builtin_clz(en);
733            en &= ~(1<<i);
734            track_t& t = state->tracks[i];
735            if (!t.doesResample() && t.volumeRL == 0) {
736                t.needs |= NEEDS_MUTE;
737                t.hook = track__nop;
738            } else {
739                allMuted = false;
740            }
741        }
742        if (allMuted) {
743            state->hook = process__nop;
744        } else if (all16BitsStereoNoResample) {
745            if (countActiveTracks == 1) {
746                state->hook = process__OneTrack16BitsStereoNoResampling;
747            }
748        }
749    }
750}
751
752
753void AudioMixer::track__genericResample(track_t* t, int32_t* out, size_t outFrameCount,
754        int32_t* temp, int32_t* aux)
755{
756    t->resampler->setSampleRate(t->sampleRate);
757
758    // ramp gain - resample to temp buffer and scale/mix in 2nd step
759    if (aux != NULL) {
760        // always resample with unity gain when sending to auxiliary buffer to be able
761        // to apply send level after resampling
762        // TODO: modify each resampler to support aux channel?
763        t->resampler->setVolume(UNITY_GAIN, UNITY_GAIN);
764        memset(temp, 0, outFrameCount * MAX_NUM_CHANNELS * sizeof(int32_t));
765        t->resampler->resample(temp, outFrameCount, t->bufferProvider);
766        if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
767            volumeRampStereo(t, out, outFrameCount, temp, aux);
768        } else {
769            volumeStereo(t, out, outFrameCount, temp, aux);
770        }
771    } else {
772        if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
773            t->resampler->setVolume(UNITY_GAIN, UNITY_GAIN);
774            memset(temp, 0, outFrameCount * MAX_NUM_CHANNELS * sizeof(int32_t));
775            t->resampler->resample(temp, outFrameCount, t->bufferProvider);
776            volumeRampStereo(t, out, outFrameCount, temp, aux);
777        }
778
779        // constant gain
780        else {
781            t->resampler->setVolume(t->volume[0], t->volume[1]);
782            t->resampler->resample(out, outFrameCount, t->bufferProvider);
783        }
784    }
785}
786
787void AudioMixer::track__nop(track_t* t __unused, int32_t* out __unused,
788        size_t outFrameCount __unused, int32_t* temp __unused, int32_t* aux __unused)
789{
790}
791
792void AudioMixer::volumeRampStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
793        int32_t* aux)
794{
795    int32_t vl = t->prevVolume[0];
796    int32_t vr = t->prevVolume[1];
797    const int32_t vlInc = t->volumeInc[0];
798    const int32_t vrInc = t->volumeInc[1];
799
800    //ALOGD("[0] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
801    //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
802    //       (vl + vlInc*frameCount)/65536.0f, frameCount);
803
804    // ramp volume
805    if (CC_UNLIKELY(aux != NULL)) {
806        int32_t va = t->prevAuxLevel;
807        const int32_t vaInc = t->auxInc;
808        int32_t l;
809        int32_t r;
810
811        do {
812            l = (*temp++ >> 12);
813            r = (*temp++ >> 12);
814            *out++ += (vl >> 16) * l;
815            *out++ += (vr >> 16) * r;
816            *aux++ += (va >> 17) * (l + r);
817            vl += vlInc;
818            vr += vrInc;
819            va += vaInc;
820        } while (--frameCount);
821        t->prevAuxLevel = va;
822    } else {
823        do {
824            *out++ += (vl >> 16) * (*temp++ >> 12);
825            *out++ += (vr >> 16) * (*temp++ >> 12);
826            vl += vlInc;
827            vr += vrInc;
828        } while (--frameCount);
829    }
830    t->prevVolume[0] = vl;
831    t->prevVolume[1] = vr;
832    t->adjustVolumeRamp(aux != NULL);
833}
834
835void AudioMixer::volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
836        int32_t* aux)
837{
838    const int16_t vl = t->volume[0];
839    const int16_t vr = t->volume[1];
840
841    if (CC_UNLIKELY(aux != NULL)) {
842        const int16_t va = t->auxLevel;
843        do {
844            int16_t l = (int16_t)(*temp++ >> 12);
845            int16_t r = (int16_t)(*temp++ >> 12);
846            out[0] = mulAdd(l, vl, out[0]);
847            int16_t a = (int16_t)(((int32_t)l + r) >> 1);
848            out[1] = mulAdd(r, vr, out[1]);
849            out += 2;
850            aux[0] = mulAdd(a, va, aux[0]);
851            aux++;
852        } while (--frameCount);
853    } else {
854        do {
855            int16_t l = (int16_t)(*temp++ >> 12);
856            int16_t r = (int16_t)(*temp++ >> 12);
857            out[0] = mulAdd(l, vl, out[0]);
858            out[1] = mulAdd(r, vr, out[1]);
859            out += 2;
860        } while (--frameCount);
861    }
862}
863
864void AudioMixer::track__16BitsStereo(track_t* t, int32_t* out, size_t frameCount,
865        int32_t* temp __unused, int32_t* aux)
866{
867    const int16_t *in = static_cast<const int16_t *>(t->in);
868
869    if (CC_UNLIKELY(aux != NULL)) {
870        int32_t l;
871        int32_t r;
872        // ramp gain
873        if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
874            int32_t vl = t->prevVolume[0];
875            int32_t vr = t->prevVolume[1];
876            int32_t va = t->prevAuxLevel;
877            const int32_t vlInc = t->volumeInc[0];
878            const int32_t vrInc = t->volumeInc[1];
879            const int32_t vaInc = t->auxInc;
880            // ALOGD("[1] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
881            //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
882            //        (vl + vlInc*frameCount)/65536.0f, frameCount);
883
884            do {
885                l = (int32_t)*in++;
886                r = (int32_t)*in++;
887                *out++ += (vl >> 16) * l;
888                *out++ += (vr >> 16) * r;
889                *aux++ += (va >> 17) * (l + r);
890                vl += vlInc;
891                vr += vrInc;
892                va += vaInc;
893            } while (--frameCount);
894
895            t->prevVolume[0] = vl;
896            t->prevVolume[1] = vr;
897            t->prevAuxLevel = va;
898            t->adjustVolumeRamp(true);
899        }
900
901        // constant gain
902        else {
903            const uint32_t vrl = t->volumeRL;
904            const int16_t va = (int16_t)t->auxLevel;
905            do {
906                uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
907                int16_t a = (int16_t)(((int32_t)in[0] + in[1]) >> 1);
908                in += 2;
909                out[0] = mulAddRL(1, rl, vrl, out[0]);
910                out[1] = mulAddRL(0, rl, vrl, out[1]);
911                out += 2;
912                aux[0] = mulAdd(a, va, aux[0]);
913                aux++;
914            } while (--frameCount);
915        }
916    } else {
917        // ramp gain
918        if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
919            int32_t vl = t->prevVolume[0];
920            int32_t vr = t->prevVolume[1];
921            const int32_t vlInc = t->volumeInc[0];
922            const int32_t vrInc = t->volumeInc[1];
923
924            // ALOGD("[1] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
925            //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
926            //        (vl + vlInc*frameCount)/65536.0f, frameCount);
927
928            do {
929                *out++ += (vl >> 16) * (int32_t) *in++;
930                *out++ += (vr >> 16) * (int32_t) *in++;
931                vl += vlInc;
932                vr += vrInc;
933            } while (--frameCount);
934
935            t->prevVolume[0] = vl;
936            t->prevVolume[1] = vr;
937            t->adjustVolumeRamp(false);
938        }
939
940        // constant gain
941        else {
942            const uint32_t vrl = t->volumeRL;
943            do {
944                uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
945                in += 2;
946                out[0] = mulAddRL(1, rl, vrl, out[0]);
947                out[1] = mulAddRL(0, rl, vrl, out[1]);
948                out += 2;
949            } while (--frameCount);
950        }
951    }
952    t->in = in;
953}
954
955void AudioMixer::track__16BitsMono(track_t* t, int32_t* out, size_t frameCount,
956        int32_t* temp __unused, int32_t* aux)
957{
958    const int16_t *in = static_cast<int16_t const *>(t->in);
959
960    if (CC_UNLIKELY(aux != NULL)) {
961        // ramp gain
962        if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
963            int32_t vl = t->prevVolume[0];
964            int32_t vr = t->prevVolume[1];
965            int32_t va = t->prevAuxLevel;
966            const int32_t vlInc = t->volumeInc[0];
967            const int32_t vrInc = t->volumeInc[1];
968            const int32_t vaInc = t->auxInc;
969
970            // ALOGD("[2] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
971            //         t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
972            //         (vl + vlInc*frameCount)/65536.0f, frameCount);
973
974            do {
975                int32_t l = *in++;
976                *out++ += (vl >> 16) * l;
977                *out++ += (vr >> 16) * l;
978                *aux++ += (va >> 16) * l;
979                vl += vlInc;
980                vr += vrInc;
981                va += vaInc;
982            } while (--frameCount);
983
984            t->prevVolume[0] = vl;
985            t->prevVolume[1] = vr;
986            t->prevAuxLevel = va;
987            t->adjustVolumeRamp(true);
988        }
989        // constant gain
990        else {
991            const int16_t vl = t->volume[0];
992            const int16_t vr = t->volume[1];
993            const int16_t va = (int16_t)t->auxLevel;
994            do {
995                int16_t l = *in++;
996                out[0] = mulAdd(l, vl, out[0]);
997                out[1] = mulAdd(l, vr, out[1]);
998                out += 2;
999                aux[0] = mulAdd(l, va, aux[0]);
1000                aux++;
1001            } while (--frameCount);
1002        }
1003    } else {
1004        // ramp gain
1005        if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
1006            int32_t vl = t->prevVolume[0];
1007            int32_t vr = t->prevVolume[1];
1008            const int32_t vlInc = t->volumeInc[0];
1009            const int32_t vrInc = t->volumeInc[1];
1010
1011            // ALOGD("[2] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
1012            //         t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
1013            //         (vl + vlInc*frameCount)/65536.0f, frameCount);
1014
1015            do {
1016                int32_t l = *in++;
1017                *out++ += (vl >> 16) * l;
1018                *out++ += (vr >> 16) * l;
1019                vl += vlInc;
1020                vr += vrInc;
1021            } while (--frameCount);
1022
1023            t->prevVolume[0] = vl;
1024            t->prevVolume[1] = vr;
1025            t->adjustVolumeRamp(false);
1026        }
1027        // constant gain
1028        else {
1029            const int16_t vl = t->volume[0];
1030            const int16_t vr = t->volume[1];
1031            do {
1032                int16_t l = *in++;
1033                out[0] = mulAdd(l, vl, out[0]);
1034                out[1] = mulAdd(l, vr, out[1]);
1035                out += 2;
1036            } while (--frameCount);
1037        }
1038    }
1039    t->in = in;
1040}
1041
1042// no-op case
1043void AudioMixer::process__nop(state_t* state, int64_t pts)
1044{
1045    uint32_t e0 = state->enabledTracks;
1046    size_t bufSize = state->frameCount * sizeof(int16_t) * MAX_NUM_CHANNELS;
1047    while (e0) {
1048        // process by group of tracks with same output buffer to
1049        // avoid multiple memset() on same buffer
1050        uint32_t e1 = e0, e2 = e0;
1051        int i = 31 - __builtin_clz(e1);
1052        {
1053            track_t& t1 = state->tracks[i];
1054            e2 &= ~(1<<i);
1055            while (e2) {
1056                i = 31 - __builtin_clz(e2);
1057                e2 &= ~(1<<i);
1058                track_t& t2 = state->tracks[i];
1059                if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
1060                    e1 &= ~(1<<i);
1061                }
1062            }
1063            e0 &= ~(e1);
1064
1065            memset(t1.mainBuffer, 0, bufSize);
1066        }
1067
1068        while (e1) {
1069            i = 31 - __builtin_clz(e1);
1070            e1 &= ~(1<<i);
1071            {
1072                track_t& t3 = state->tracks[i];
1073                size_t outFrames = state->frameCount;
1074                while (outFrames) {
1075                    t3.buffer.frameCount = outFrames;
1076                    int64_t outputPTS = calculateOutputPTS(
1077                        t3, pts, state->frameCount - outFrames);
1078                    t3.bufferProvider->getNextBuffer(&t3.buffer, outputPTS);
1079                    if (t3.buffer.raw == NULL) break;
1080                    outFrames -= t3.buffer.frameCount;
1081                    t3.bufferProvider->releaseBuffer(&t3.buffer);
1082                }
1083            }
1084        }
1085    }
1086}
1087
1088// generic code without resampling
1089void AudioMixer::process__genericNoResampling(state_t* state, int64_t pts)
1090{
1091    int32_t outTemp[BLOCKSIZE * MAX_NUM_CHANNELS] __attribute__((aligned(32)));
1092
1093    // acquire each track's buffer
1094    uint32_t enabledTracks = state->enabledTracks;
1095    uint32_t e0 = enabledTracks;
1096    while (e0) {
1097        const int i = 31 - __builtin_clz(e0);
1098        e0 &= ~(1<<i);
1099        track_t& t = state->tracks[i];
1100        t.buffer.frameCount = state->frameCount;
1101        t.bufferProvider->getNextBuffer(&t.buffer, pts);
1102        t.frameCount = t.buffer.frameCount;
1103        t.in = t.buffer.raw;
1104    }
1105
1106    e0 = enabledTracks;
1107    while (e0) {
1108        // process by group of tracks with same output buffer to
1109        // optimize cache use
1110        uint32_t e1 = e0, e2 = e0;
1111        int j = 31 - __builtin_clz(e1);
1112        track_t& t1 = state->tracks[j];
1113        e2 &= ~(1<<j);
1114        while (e2) {
1115            j = 31 - __builtin_clz(e2);
1116            e2 &= ~(1<<j);
1117            track_t& t2 = state->tracks[j];
1118            if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
1119                e1 &= ~(1<<j);
1120            }
1121        }
1122        e0 &= ~(e1);
1123        // this assumes output 16 bits stereo, no resampling
1124        int32_t *out = t1.mainBuffer;
1125        size_t numFrames = 0;
1126        do {
1127            memset(outTemp, 0, sizeof(outTemp));
1128            e2 = e1;
1129            while (e2) {
1130                const int i = 31 - __builtin_clz(e2);
1131                e2 &= ~(1<<i);
1132                track_t& t = state->tracks[i];
1133                size_t outFrames = BLOCKSIZE;
1134                int32_t *aux = NULL;
1135                if (CC_UNLIKELY(t.needs & NEEDS_AUX)) {
1136                    aux = t.auxBuffer + numFrames;
1137                }
1138                while (outFrames) {
1139                    // t.in == NULL can happen if the track was flushed just after having
1140                    // been enabled for mixing.
1141                   if (t.in == NULL) {
1142                        enabledTracks &= ~(1<<i);
1143                        e1 &= ~(1<<i);
1144                        break;
1145                    }
1146                    size_t inFrames = (t.frameCount > outFrames)?outFrames:t.frameCount;
1147                    if (inFrames > 0) {
1148                        t.hook(&t, outTemp + (BLOCKSIZE-outFrames)*MAX_NUM_CHANNELS, inFrames,
1149                                state->resampleTemp, aux);
1150                        t.frameCount -= inFrames;
1151                        outFrames -= inFrames;
1152                        if (CC_UNLIKELY(aux != NULL)) {
1153                            aux += inFrames;
1154                        }
1155                    }
1156                    if (t.frameCount == 0 && outFrames) {
1157                        t.bufferProvider->releaseBuffer(&t.buffer);
1158                        t.buffer.frameCount = (state->frameCount - numFrames) -
1159                                (BLOCKSIZE - outFrames);
1160                        int64_t outputPTS = calculateOutputPTS(
1161                            t, pts, numFrames + (BLOCKSIZE - outFrames));
1162                        t.bufferProvider->getNextBuffer(&t.buffer, outputPTS);
1163                        t.in = t.buffer.raw;
1164                        if (t.in == NULL) {
1165                            enabledTracks &= ~(1<<i);
1166                            e1 &= ~(1<<i);
1167                            break;
1168                        }
1169                        t.frameCount = t.buffer.frameCount;
1170                    }
1171                }
1172            }
1173            ditherAndClamp(out, outTemp, BLOCKSIZE);
1174            out += BLOCKSIZE;
1175            numFrames += BLOCKSIZE;
1176        } while (numFrames < state->frameCount);
1177    }
1178
1179    // release each track's buffer
1180    e0 = enabledTracks;
1181    while (e0) {
1182        const int i = 31 - __builtin_clz(e0);
1183        e0 &= ~(1<<i);
1184        track_t& t = state->tracks[i];
1185        t.bufferProvider->releaseBuffer(&t.buffer);
1186    }
1187}
1188
1189
1190// generic code with resampling
1191void AudioMixer::process__genericResampling(state_t* state, int64_t pts)
1192{
1193    // this const just means that local variable outTemp doesn't change
1194    int32_t* const outTemp = state->outputTemp;
1195    const size_t size = sizeof(int32_t) * MAX_NUM_CHANNELS * state->frameCount;
1196
1197    size_t numFrames = state->frameCount;
1198
1199    uint32_t e0 = state->enabledTracks;
1200    while (e0) {
1201        // process by group of tracks with same output buffer
1202        // to optimize cache use
1203        uint32_t e1 = e0, e2 = e0;
1204        int j = 31 - __builtin_clz(e1);
1205        track_t& t1 = state->tracks[j];
1206        e2 &= ~(1<<j);
1207        while (e2) {
1208            j = 31 - __builtin_clz(e2);
1209            e2 &= ~(1<<j);
1210            track_t& t2 = state->tracks[j];
1211            if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
1212                e1 &= ~(1<<j);
1213            }
1214        }
1215        e0 &= ~(e1);
1216        int32_t *out = t1.mainBuffer;
1217        memset(outTemp, 0, size);
1218        while (e1) {
1219            const int i = 31 - __builtin_clz(e1);
1220            e1 &= ~(1<<i);
1221            track_t& t = state->tracks[i];
1222            int32_t *aux = NULL;
1223            if (CC_UNLIKELY(t.needs & NEEDS_AUX)) {
1224                aux = t.auxBuffer;
1225            }
1226
1227            // this is a little goofy, on the resampling case we don't
1228            // acquire/release the buffers because it's done by
1229            // the resampler.
1230            if (t.needs & NEEDS_RESAMPLE) {
1231                t.resampler->setPTS(pts);
1232                t.hook(&t, outTemp, numFrames, state->resampleTemp, aux);
1233            } else {
1234
1235                size_t outFrames = 0;
1236
1237                while (outFrames < numFrames) {
1238                    t.buffer.frameCount = numFrames - outFrames;
1239                    int64_t outputPTS = calculateOutputPTS(t, pts, outFrames);
1240                    t.bufferProvider->getNextBuffer(&t.buffer, outputPTS);
1241                    t.in = t.buffer.raw;
1242                    // t.in == NULL can happen if the track was flushed just after having
1243                    // been enabled for mixing.
1244                    if (t.in == NULL) break;
1245
1246                    if (CC_UNLIKELY(aux != NULL)) {
1247                        aux += outFrames;
1248                    }
1249                    t.hook(&t, outTemp + outFrames*MAX_NUM_CHANNELS, t.buffer.frameCount,
1250                            state->resampleTemp, aux);
1251                    outFrames += t.buffer.frameCount;
1252                    t.bufferProvider->releaseBuffer(&t.buffer);
1253                }
1254            }
1255        }
1256        ditherAndClamp(out, outTemp, numFrames);
1257    }
1258}
1259
1260// one track, 16 bits stereo without resampling is the most common case
1261void AudioMixer::process__OneTrack16BitsStereoNoResampling(state_t* state,
1262                                                           int64_t pts)
1263{
1264    // This method is only called when state->enabledTracks has exactly
1265    // one bit set.  The asserts below would verify this, but are commented out
1266    // since the whole point of this method is to optimize performance.
1267    //ALOG_ASSERT(0 != state->enabledTracks, "no tracks enabled");
1268    const int i = 31 - __builtin_clz(state->enabledTracks);
1269    //ALOG_ASSERT((1 << i) == state->enabledTracks, "more than 1 track enabled");
1270    const track_t& t = state->tracks[i];
1271
1272    AudioBufferProvider::Buffer& b(t.buffer);
1273
1274    int32_t* out = t.mainBuffer;
1275    size_t numFrames = state->frameCount;
1276
1277    const int16_t vl = t.volume[0];
1278    const int16_t vr = t.volume[1];
1279    const uint32_t vrl = t.volumeRL;
1280    while (numFrames) {
1281        b.frameCount = numFrames;
1282        int64_t outputPTS = calculateOutputPTS(t, pts, out - t.mainBuffer);
1283        t.bufferProvider->getNextBuffer(&b, outputPTS);
1284        const int16_t *in = b.i16;
1285
1286        // in == NULL can happen if the track was flushed just after having
1287        // been enabled for mixing.
1288        if (in == NULL || ((unsigned long)in & 3)) {
1289            memset(out, 0, numFrames*MAX_NUM_CHANNELS*sizeof(int16_t));
1290            ALOGE_IF(((unsigned long)in & 3), "process stereo track: input buffer alignment pb: "
1291                                              "buffer %p track %d, channels %d, needs %08x",
1292                    in, i, t.channelCount, t.needs);
1293            return;
1294        }
1295        size_t outFrames = b.frameCount;
1296
1297        if (CC_UNLIKELY(uint32_t(vl) > UNITY_GAIN || uint32_t(vr) > UNITY_GAIN)) {
1298            // volume is boosted, so we might need to clamp even though
1299            // we process only one track.
1300            do {
1301                uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
1302                in += 2;
1303                int32_t l = mulRL(1, rl, vrl) >> 12;
1304                int32_t r = mulRL(0, rl, vrl) >> 12;
1305                // clamping...
1306                l = clamp16(l);
1307                r = clamp16(r);
1308                *out++ = (r<<16) | (l & 0xFFFF);
1309            } while (--outFrames);
1310        } else {
1311            do {
1312                uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
1313                in += 2;
1314                int32_t l = mulRL(1, rl, vrl) >> 12;
1315                int32_t r = mulRL(0, rl, vrl) >> 12;
1316                *out++ = (r<<16) | (l & 0xFFFF);
1317            } while (--outFrames);
1318        }
1319        numFrames -= b.frameCount;
1320        t.bufferProvider->releaseBuffer(&b);
1321    }
1322}
1323
1324#if 0
1325// 2 tracks is also a common case
1326// NEVER used in current implementation of process__validate()
1327// only use if the 2 tracks have the same output buffer
1328void AudioMixer::process__TwoTracks16BitsStereoNoResampling(state_t* state,
1329                                                            int64_t pts)
1330{
1331    int i;
1332    uint32_t en = state->enabledTracks;
1333
1334    i = 31 - __builtin_clz(en);
1335    const track_t& t0 = state->tracks[i];
1336    AudioBufferProvider::Buffer& b0(t0.buffer);
1337
1338    en &= ~(1<<i);
1339    i = 31 - __builtin_clz(en);
1340    const track_t& t1 = state->tracks[i];
1341    AudioBufferProvider::Buffer& b1(t1.buffer);
1342
1343    const int16_t *in0;
1344    const int16_t vl0 = t0.volume[0];
1345    const int16_t vr0 = t0.volume[1];
1346    size_t frameCount0 = 0;
1347
1348    const int16_t *in1;
1349    const int16_t vl1 = t1.volume[0];
1350    const int16_t vr1 = t1.volume[1];
1351    size_t frameCount1 = 0;
1352
1353    //FIXME: only works if two tracks use same buffer
1354    int32_t* out = t0.mainBuffer;
1355    size_t numFrames = state->frameCount;
1356    const int16_t *buff = NULL;
1357
1358
1359    while (numFrames) {
1360
1361        if (frameCount0 == 0) {
1362            b0.frameCount = numFrames;
1363            int64_t outputPTS = calculateOutputPTS(t0, pts,
1364                                                   out - t0.mainBuffer);
1365            t0.bufferProvider->getNextBuffer(&b0, outputPTS);
1366            if (b0.i16 == NULL) {
1367                if (buff == NULL) {
1368                    buff = new int16_t[MAX_NUM_CHANNELS * state->frameCount];
1369                }
1370                in0 = buff;
1371                b0.frameCount = numFrames;
1372            } else {
1373                in0 = b0.i16;
1374            }
1375            frameCount0 = b0.frameCount;
1376        }
1377        if (frameCount1 == 0) {
1378            b1.frameCount = numFrames;
1379            int64_t outputPTS = calculateOutputPTS(t1, pts,
1380                                                   out - t0.mainBuffer);
1381            t1.bufferProvider->getNextBuffer(&b1, outputPTS);
1382            if (b1.i16 == NULL) {
1383                if (buff == NULL) {
1384                    buff = new int16_t[MAX_NUM_CHANNELS * state->frameCount];
1385                }
1386                in1 = buff;
1387                b1.frameCount = numFrames;
1388            } else {
1389                in1 = b1.i16;
1390            }
1391            frameCount1 = b1.frameCount;
1392        }
1393
1394        size_t outFrames = frameCount0 < frameCount1?frameCount0:frameCount1;
1395
1396        numFrames -= outFrames;
1397        frameCount0 -= outFrames;
1398        frameCount1 -= outFrames;
1399
1400        do {
1401            int32_t l0 = *in0++;
1402            int32_t r0 = *in0++;
1403            l0 = mul(l0, vl0);
1404            r0 = mul(r0, vr0);
1405            int32_t l = *in1++;
1406            int32_t r = *in1++;
1407            l = mulAdd(l, vl1, l0) >> 12;
1408            r = mulAdd(r, vr1, r0) >> 12;
1409            // clamping...
1410            l = clamp16(l);
1411            r = clamp16(r);
1412            *out++ = (r<<16) | (l & 0xFFFF);
1413        } while (--outFrames);
1414
1415        if (frameCount0 == 0) {
1416            t0.bufferProvider->releaseBuffer(&b0);
1417        }
1418        if (frameCount1 == 0) {
1419            t1.bufferProvider->releaseBuffer(&b1);
1420        }
1421    }
1422
1423    delete [] buff;
1424}
1425#endif
1426
1427int64_t AudioMixer::calculateOutputPTS(const track_t& t, int64_t basePTS,
1428                                       int outputFrameIndex)
1429{
1430    if (AudioBufferProvider::kInvalidPTS == basePTS) {
1431        return AudioBufferProvider::kInvalidPTS;
1432    }
1433
1434    return basePTS + ((outputFrameIndex * sLocalTimeFreq) / t.sampleRate);
1435}
1436
1437/*static*/ uint64_t AudioMixer::sLocalTimeFreq;
1438/*static*/ pthread_once_t AudioMixer::sOnceControl = PTHREAD_ONCE_INIT;
1439
1440/*static*/ void AudioMixer::sInitRoutine()
1441{
1442    LocalClock lc;
1443    sLocalTimeFreq = lc.getLocalFreq();
1444
1445    // find multichannel downmix effect if we have to play multichannel content
1446    uint32_t numEffects = 0;
1447    int ret = EffectQueryNumberEffects(&numEffects);
1448    if (ret != 0) {
1449        ALOGE("AudioMixer() error %d querying number of effects", ret);
1450        return;
1451    }
1452    ALOGV("EffectQueryNumberEffects() numEffects=%d", numEffects);
1453
1454    for (uint32_t i = 0 ; i < numEffects ; i++) {
1455        if (EffectQueryEffect(i, &sDwnmFxDesc) == 0) {
1456            ALOGV("effect %d is called %s", i, sDwnmFxDesc.name);
1457            if (memcmp(&sDwnmFxDesc.type, EFFECT_UIID_DOWNMIX, sizeof(effect_uuid_t)) == 0) {
1458                ALOGI("found effect \"%s\" from %s",
1459                        sDwnmFxDesc.name, sDwnmFxDesc.implementor);
1460                sIsMultichannelCapable = true;
1461                break;
1462            }
1463        }
1464    }
1465    ALOGW_IF(!sIsMultichannelCapable, "unable to find downmix effect");
1466}
1467
1468// ----------------------------------------------------------------------------
1469}; // namespace android
1470