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      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 <math.h>
     26 #include <sys/types.h>
     27 
     28 #include <utils/Errors.h>
     29 #include <utils/Log.h>
     30 
     31 #include <cutils/bitops.h>
     32 #include <cutils/compiler.h>
     33 #include <utils/Debug.h>
     34 
     35 #include <system/audio.h>
     36 
     37 #include <audio_utils/primitives.h>
     38 #include <audio_utils/format.h>
     39 #include <common_time/local_clock.h>
     40 #include <common_time/cc_helper.h>
     41 
     42 #include "AudioMixerOps.h"
     43 #include "AudioMixer.h"
     44 
     45 // The FCC_2 macro refers to the Fixed Channel Count of 2 for the legacy integer mixer.
     46 #ifndef FCC_2
     47 #define FCC_2 2
     48 #endif
     49 
     50 // Look for MONO_HACK for any Mono hack involving legacy mono channel to
     51 // stereo channel conversion.
     52 
     53 /* VERY_VERY_VERBOSE_LOGGING will show exactly which process hook and track hook is
     54  * being used. This is a considerable amount of log spam, so don't enable unless you
     55  * are verifying the hook based code.
     56  */
     57 //#define VERY_VERY_VERBOSE_LOGGING
     58 #ifdef VERY_VERY_VERBOSE_LOGGING
     59 #define ALOGVV ALOGV
     60 //define ALOGVV printf  // for test-mixer.cpp
     61 #else
     62 #define ALOGVV(a...) do { } while (0)
     63 #endif
     64 
     65 #ifndef ARRAY_SIZE
     66 #define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))
     67 #endif
     68 
     69 // TODO: Move these macro/inlines to a header file.
     70 template <typename T>
     71 static inline
     72 T max(const T& x, const T& y) {
     73     return x > y ? x : y;
     74 }
     75 
     76 // Set kUseNewMixer to true to use the new mixer engine always. Otherwise the
     77 // original code will be used for stereo sinks, the new mixer for multichannel.
     78 static const bool kUseNewMixer = true;
     79 
     80 // Set kUseFloat to true to allow floating input into the mixer engine.
     81 // If kUseNewMixer is false, this is ignored or may be overridden internally
     82 // because of downmix/upmix support.
     83 static const bool kUseFloat = true;
     84 
     85 // Set to default copy buffer size in frames for input processing.
     86 static const size_t kCopyBufferFrameCount = 256;
     87 
     88 namespace android {
     89 
     90 // ----------------------------------------------------------------------------
     91 
     92 template <typename T>
     93 T min(const T& a, const T& b)
     94 {
     95     return a < b ? a : b;
     96 }
     97 
     98 // ----------------------------------------------------------------------------
     99 
    100 // Ensure mConfiguredNames bitmask is initialized properly on all architectures.
    101 // The value of 1 << x is undefined in C when x >= 32.
    102 
    103 AudioMixer::AudioMixer(size_t frameCount, uint32_t sampleRate, uint32_t maxNumTracks)
    104     :   mTrackNames(0), mConfiguredNames((maxNumTracks >= 32 ? 0 : 1 << maxNumTracks) - 1),
    105         mSampleRate(sampleRate)
    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     pthread_once(&sOnceControl, &sInitRoutine);
    114 
    115     mState.enabledTracks= 0;
    116     mState.needsChanged = 0;
    117     mState.frameCount   = frameCount;
    118     mState.hook         = process__nop;
    119     mState.outputTemp   = NULL;
    120     mState.resampleTemp = NULL;
    121     mState.mLog         = &mDummyLog;
    122     // mState.reserved
    123 
    124     // FIXME Most of the following initialization is probably redundant since
    125     // tracks[i] should only be referenced if (mTrackNames & (1 << i)) != 0
    126     // and mTrackNames is initially 0.  However, leave it here until that's verified.
    127     track_t* t = mState.tracks;
    128     for (unsigned i=0 ; i < MAX_NUM_TRACKS ; i++) {
    129         t->resampler = NULL;
    130         t->downmixerBufferProvider = NULL;
    131         t->mReformatBufferProvider = NULL;
    132         t->mTimestretchBufferProvider = NULL;
    133         t++;
    134     }
    135 
    136 }
    137 
    138 AudioMixer::~AudioMixer()
    139 {
    140     track_t* t = mState.tracks;
    141     for (unsigned i=0 ; i < MAX_NUM_TRACKS ; i++) {
    142         delete t->resampler;
    143         delete t->downmixerBufferProvider;
    144         delete t->mReformatBufferProvider;
    145         delete t->mTimestretchBufferProvider;
    146         t++;
    147     }
    148     delete [] mState.outputTemp;
    149     delete [] mState.resampleTemp;
    150 }
    151 
    152 void AudioMixer::setLog(NBLog::Writer *log)
    153 {
    154     mState.mLog = log;
    155 }
    156 
    157 static inline audio_format_t selectMixerInFormat(audio_format_t inputFormat __unused) {
    158     return kUseFloat && kUseNewMixer ? AUDIO_FORMAT_PCM_FLOAT : AUDIO_FORMAT_PCM_16_BIT;
    159 }
    160 
    161 int AudioMixer::getTrackName(audio_channel_mask_t channelMask,
    162         audio_format_t format, int sessionId)
    163 {
    164     if (!isValidPcmTrackFormat(format)) {
    165         ALOGE("AudioMixer::getTrackName invalid format (%#x)", format);
    166         return -1;
    167     }
    168     uint32_t names = (~mTrackNames) & mConfiguredNames;
    169     if (names != 0) {
    170         int n = __builtin_ctz(names);
    171         ALOGV("add track (%d)", n);
    172         // assume default parameters for the track, except where noted below
    173         track_t* t = &mState.tracks[n];
    174         t->needs = 0;
    175 
    176         // Integer volume.
    177         // Currently integer volume is kept for the legacy integer mixer.
    178         // Will be removed when the legacy mixer path is removed.
    179         t->volume[0] = UNITY_GAIN_INT;
    180         t->volume[1] = UNITY_GAIN_INT;
    181         t->prevVolume[0] = UNITY_GAIN_INT << 16;
    182         t->prevVolume[1] = UNITY_GAIN_INT << 16;
    183         t->volumeInc[0] = 0;
    184         t->volumeInc[1] = 0;
    185         t->auxLevel = 0;
    186         t->auxInc = 0;
    187         t->prevAuxLevel = 0;
    188 
    189         // Floating point volume.
    190         t->mVolume[0] = UNITY_GAIN_FLOAT;
    191         t->mVolume[1] = UNITY_GAIN_FLOAT;
    192         t->mPrevVolume[0] = UNITY_GAIN_FLOAT;
    193         t->mPrevVolume[1] = UNITY_GAIN_FLOAT;
    194         t->mVolumeInc[0] = 0.;
    195         t->mVolumeInc[1] = 0.;
    196         t->mAuxLevel = 0.;
    197         t->mAuxInc = 0.;
    198         t->mPrevAuxLevel = 0.;
    199 
    200         // no initialization needed
    201         // t->frameCount
    202         t->channelCount = audio_channel_count_from_out_mask(channelMask);
    203         t->enabled = false;
    204         ALOGV_IF(audio_channel_mask_get_bits(channelMask) != AUDIO_CHANNEL_OUT_STEREO,
    205                 "Non-stereo channel mask: %d\n", channelMask);
    206         t->channelMask = channelMask;
    207         t->sessionId = sessionId;
    208         // setBufferProvider(name, AudioBufferProvider *) is required before enable(name)
    209         t->bufferProvider = NULL;
    210         t->buffer.raw = NULL;
    211         // no initialization needed
    212         // t->buffer.frameCount
    213         t->hook = NULL;
    214         t->in = NULL;
    215         t->resampler = NULL;
    216         t->sampleRate = mSampleRate;
    217         // setParameter(name, TRACK, MAIN_BUFFER, mixBuffer) is required before enable(name)
    218         t->mainBuffer = NULL;
    219         t->auxBuffer = NULL;
    220         t->mInputBufferProvider = NULL;
    221         t->mReformatBufferProvider = NULL;
    222         t->downmixerBufferProvider = NULL;
    223         t->mPostDownmixReformatBufferProvider = NULL;
    224         t->mTimestretchBufferProvider = NULL;
    225         t->mMixerFormat = AUDIO_FORMAT_PCM_16_BIT;
    226         t->mFormat = format;
    227         t->mMixerInFormat = selectMixerInFormat(format);
    228         t->mDownmixRequiresFormat = AUDIO_FORMAT_INVALID; // no format required
    229         t->mMixerChannelMask = audio_channel_mask_from_representation_and_bits(
    230                 AUDIO_CHANNEL_REPRESENTATION_POSITION, AUDIO_CHANNEL_OUT_STEREO);
    231         t->mMixerChannelCount = audio_channel_count_from_out_mask(t->mMixerChannelMask);
    232         t->mPlaybackRate = AUDIO_PLAYBACK_RATE_DEFAULT;
    233         // Check the downmixing (or upmixing) requirements.
    234         status_t status = t->prepareForDownmix();
    235         if (status != OK) {
    236             ALOGE("AudioMixer::getTrackName invalid channelMask (%#x)", channelMask);
    237             return -1;
    238         }
    239         // prepareForDownmix() may change mDownmixRequiresFormat
    240         ALOGVV("mMixerFormat:%#x  mMixerInFormat:%#x\n", t->mMixerFormat, t->mMixerInFormat);
    241         t->prepareForReformat();
    242         mTrackNames |= 1 << n;
    243         return TRACK0 + n;
    244     }
    245     ALOGE("AudioMixer::getTrackName out of available tracks");
    246     return -1;
    247 }
    248 
    249 void AudioMixer::invalidateState(uint32_t mask)
    250 {
    251     if (mask != 0) {
    252         mState.needsChanged |= mask;
    253         mState.hook = process__validate;
    254     }
    255  }
    256 
    257 // Called when channel masks have changed for a track name
    258 // TODO: Fix DownmixerBufferProvider not to (possibly) change mixer input format,
    259 // which will simplify this logic.
    260 bool AudioMixer::setChannelMasks(int name,
    261         audio_channel_mask_t trackChannelMask, audio_channel_mask_t mixerChannelMask) {
    262     track_t &track = mState.tracks[name];
    263 
    264     if (trackChannelMask == track.channelMask
    265             && mixerChannelMask == track.mMixerChannelMask) {
    266         return false;  // no need to change
    267     }
    268     // always recompute for both channel masks even if only one has changed.
    269     const uint32_t trackChannelCount = audio_channel_count_from_out_mask(trackChannelMask);
    270     const uint32_t mixerChannelCount = audio_channel_count_from_out_mask(mixerChannelMask);
    271     const bool mixerChannelCountChanged = track.mMixerChannelCount != mixerChannelCount;
    272 
    273     ALOG_ASSERT((trackChannelCount <= MAX_NUM_CHANNELS_TO_DOWNMIX)
    274             && trackChannelCount
    275             && mixerChannelCount);
    276     track.channelMask = trackChannelMask;
    277     track.channelCount = trackChannelCount;
    278     track.mMixerChannelMask = mixerChannelMask;
    279     track.mMixerChannelCount = mixerChannelCount;
    280 
    281     // channel masks have changed, does this track need a downmixer?
    282     // update to try using our desired format (if we aren't already using it)
    283     const audio_format_t prevDownmixerFormat = track.mDownmixRequiresFormat;
    284     const status_t status = mState.tracks[name].prepareForDownmix();
    285     ALOGE_IF(status != OK,
    286             "prepareForDownmix error %d, track channel mask %#x, mixer channel mask %#x",
    287             status, track.channelMask, track.mMixerChannelMask);
    288 
    289     if (prevDownmixerFormat != track.mDownmixRequiresFormat) {
    290         track.prepareForReformat(); // because of downmixer, track format may change!
    291     }
    292 
    293     if (track.resampler && mixerChannelCountChanged) {
    294         // resampler channels may have changed.
    295         const uint32_t resetToSampleRate = track.sampleRate;
    296         delete track.resampler;
    297         track.resampler = NULL;
    298         track.sampleRate = mSampleRate; // without resampler, track rate is device sample rate.
    299         // recreate the resampler with updated format, channels, saved sampleRate.
    300         track.setResampler(resetToSampleRate /*trackSampleRate*/, mSampleRate /*devSampleRate*/);
    301     }
    302     return true;
    303 }
    304 
    305 void AudioMixer::track_t::unprepareForDownmix() {
    306     ALOGV("AudioMixer::unprepareForDownmix(%p)", this);
    307 
    308     mDownmixRequiresFormat = AUDIO_FORMAT_INVALID;
    309     if (downmixerBufferProvider != NULL) {
    310         // this track had previously been configured with a downmixer, delete it
    311         ALOGV(" deleting old downmixer");
    312         delete downmixerBufferProvider;
    313         downmixerBufferProvider = NULL;
    314         reconfigureBufferProviders();
    315     } else {
    316         ALOGV(" nothing to do, no downmixer to delete");
    317     }
    318 }
    319 
    320 status_t AudioMixer::track_t::prepareForDownmix()
    321 {
    322     ALOGV("AudioMixer::prepareForDownmix(%p) with mask 0x%x",
    323             this, channelMask);
    324 
    325     // discard the previous downmixer if there was one
    326     unprepareForDownmix();
    327     // MONO_HACK Only remix (upmix or downmix) if the track and mixer/device channel masks
    328     // are not the same and not handled internally, as mono -> stereo currently is.
    329     if (channelMask == mMixerChannelMask
    330             || (channelMask == AUDIO_CHANNEL_OUT_MONO
    331                     && mMixerChannelMask == AUDIO_CHANNEL_OUT_STEREO)) {
    332         return NO_ERROR;
    333     }
    334     // DownmixerBufferProvider is only used for position masks.
    335     if (audio_channel_mask_get_representation(channelMask)
    336                 == AUDIO_CHANNEL_REPRESENTATION_POSITION
    337             && DownmixerBufferProvider::isMultichannelCapable()) {
    338         DownmixerBufferProvider* pDbp = new DownmixerBufferProvider(channelMask,
    339                 mMixerChannelMask,
    340                 AUDIO_FORMAT_PCM_16_BIT /* TODO: use mMixerInFormat, now only PCM 16 */,
    341                 sampleRate, sessionId, kCopyBufferFrameCount);
    342 
    343         if (pDbp->isValid()) { // if constructor completed properly
    344             mDownmixRequiresFormat = AUDIO_FORMAT_PCM_16_BIT; // PCM 16 bit required for downmix
    345             downmixerBufferProvider = pDbp;
    346             reconfigureBufferProviders();
    347             return NO_ERROR;
    348         }
    349         delete pDbp;
    350     }
    351 
    352     // Effect downmixer does not accept the channel conversion.  Let's use our remixer.
    353     RemixBufferProvider* pRbp = new RemixBufferProvider(channelMask,
    354             mMixerChannelMask, mMixerInFormat, kCopyBufferFrameCount);
    355     // Remix always finds a conversion whereas Downmixer effect above may fail.
    356     downmixerBufferProvider = pRbp;
    357     reconfigureBufferProviders();
    358     return NO_ERROR;
    359 }
    360 
    361 void AudioMixer::track_t::unprepareForReformat() {
    362     ALOGV("AudioMixer::unprepareForReformat(%p)", this);
    363     bool requiresReconfigure = false;
    364     if (mReformatBufferProvider != NULL) {
    365         delete mReformatBufferProvider;
    366         mReformatBufferProvider = NULL;
    367         requiresReconfigure = true;
    368     }
    369     if (mPostDownmixReformatBufferProvider != NULL) {
    370         delete mPostDownmixReformatBufferProvider;
    371         mPostDownmixReformatBufferProvider = NULL;
    372         requiresReconfigure = true;
    373     }
    374     if (requiresReconfigure) {
    375         reconfigureBufferProviders();
    376     }
    377 }
    378 
    379 status_t AudioMixer::track_t::prepareForReformat()
    380 {
    381     ALOGV("AudioMixer::prepareForReformat(%p) with format %#x", this, mFormat);
    382     // discard previous reformatters
    383     unprepareForReformat();
    384     // only configure reformatters as needed
    385     const audio_format_t targetFormat = mDownmixRequiresFormat != AUDIO_FORMAT_INVALID
    386             ? mDownmixRequiresFormat : mMixerInFormat;
    387     bool requiresReconfigure = false;
    388     if (mFormat != targetFormat) {
    389         mReformatBufferProvider = new ReformatBufferProvider(
    390                 audio_channel_count_from_out_mask(channelMask),
    391                 mFormat,
    392                 targetFormat,
    393                 kCopyBufferFrameCount);
    394         requiresReconfigure = true;
    395     }
    396     if (targetFormat != mMixerInFormat) {
    397         mPostDownmixReformatBufferProvider = new ReformatBufferProvider(
    398                 audio_channel_count_from_out_mask(mMixerChannelMask),
    399                 targetFormat,
    400                 mMixerInFormat,
    401                 kCopyBufferFrameCount);
    402         requiresReconfigure = true;
    403     }
    404     if (requiresReconfigure) {
    405         reconfigureBufferProviders();
    406     }
    407     return NO_ERROR;
    408 }
    409 
    410 void AudioMixer::track_t::reconfigureBufferProviders()
    411 {
    412     bufferProvider = mInputBufferProvider;
    413     if (mReformatBufferProvider) {
    414         mReformatBufferProvider->setBufferProvider(bufferProvider);
    415         bufferProvider = mReformatBufferProvider;
    416     }
    417     if (downmixerBufferProvider) {
    418         downmixerBufferProvider->setBufferProvider(bufferProvider);
    419         bufferProvider = downmixerBufferProvider;
    420     }
    421     if (mPostDownmixReformatBufferProvider) {
    422         mPostDownmixReformatBufferProvider->setBufferProvider(bufferProvider);
    423         bufferProvider = mPostDownmixReformatBufferProvider;
    424     }
    425     if (mTimestretchBufferProvider) {
    426         mTimestretchBufferProvider->setBufferProvider(bufferProvider);
    427         bufferProvider = mTimestretchBufferProvider;
    428     }
    429 }
    430 
    431 void AudioMixer::deleteTrackName(int name)
    432 {
    433     ALOGV("AudioMixer::deleteTrackName(%d)", name);
    434     name -= TRACK0;
    435     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    436     ALOGV("deleteTrackName(%d)", name);
    437     track_t& track(mState.tracks[ name ]);
    438     if (track.enabled) {
    439         track.enabled = false;
    440         invalidateState(1<<name);
    441     }
    442     // delete the resampler
    443     delete track.resampler;
    444     track.resampler = NULL;
    445     // delete the downmixer
    446     mState.tracks[name].unprepareForDownmix();
    447     // delete the reformatter
    448     mState.tracks[name].unprepareForReformat();
    449     // delete the timestretch provider
    450     delete track.mTimestretchBufferProvider;
    451     track.mTimestretchBufferProvider = NULL;
    452     mTrackNames &= ~(1<<name);
    453 }
    454 
    455 void AudioMixer::enable(int name)
    456 {
    457     name -= TRACK0;
    458     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    459     track_t& track = mState.tracks[name];
    460 
    461     if (!track.enabled) {
    462         track.enabled = true;
    463         ALOGV("enable(%d)", name);
    464         invalidateState(1 << name);
    465     }
    466 }
    467 
    468 void AudioMixer::disable(int name)
    469 {
    470     name -= TRACK0;
    471     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    472     track_t& track = mState.tracks[name];
    473 
    474     if (track.enabled) {
    475         track.enabled = false;
    476         ALOGV("disable(%d)", name);
    477         invalidateState(1 << name);
    478     }
    479 }
    480 
    481 /* Sets the volume ramp variables for the AudioMixer.
    482  *
    483  * The volume ramp variables are used to transition from the previous
    484  * volume to the set volume.  ramp controls the duration of the transition.
    485  * Its value is typically one state framecount period, but may also be 0,
    486  * meaning "immediate."
    487  *
    488  * FIXME: 1) Volume ramp is enabled only if there is a nonzero integer increment
    489  * even if there is a nonzero floating point increment (in that case, the volume
    490  * change is immediate).  This restriction should be changed when the legacy mixer
    491  * is removed (see #2).
    492  * FIXME: 2) Integer volume variables are used for Legacy mixing and should be removed
    493  * when no longer needed.
    494  *
    495  * @param newVolume set volume target in floating point [0.0, 1.0].
    496  * @param ramp number of frames to increment over. if ramp is 0, the volume
    497  * should be set immediately.  Currently ramp should not exceed 65535 (frames).
    498  * @param pIntSetVolume pointer to the U4.12 integer target volume, set on return.
    499  * @param pIntPrevVolume pointer to the U4.28 integer previous volume, set on return.
    500  * @param pIntVolumeInc pointer to the U4.28 increment per output audio frame, set on return.
    501  * @param pSetVolume pointer to the float target volume, set on return.
    502  * @param pPrevVolume pointer to the float previous volume, set on return.
    503  * @param pVolumeInc pointer to the float increment per output audio frame, set on return.
    504  * @return true if the volume has changed, false if volume is same.
    505  */
    506 static inline bool setVolumeRampVariables(float newVolume, int32_t ramp,
    507         int16_t *pIntSetVolume, int32_t *pIntPrevVolume, int32_t *pIntVolumeInc,
    508         float *pSetVolume, float *pPrevVolume, float *pVolumeInc) {
    509     // check floating point volume to see if it is identical to the previously
    510     // set volume.
    511     // We do not use a tolerance here (and reject changes too small)
    512     // as it may be confusing to use a different value than the one set.
    513     // If the resulting volume is too small to ramp, it is a direct set of the volume.
    514     if (newVolume == *pSetVolume) {
    515         return false;
    516     }
    517     if (newVolume < 0) {
    518         newVolume = 0; // should not have negative volumes
    519     } else {
    520         switch (fpclassify(newVolume)) {
    521         case FP_SUBNORMAL:
    522         case FP_NAN:
    523             newVolume = 0;
    524             break;
    525         case FP_ZERO:
    526             break; // zero volume is fine
    527         case FP_INFINITE:
    528             // Infinite volume could be handled consistently since
    529             // floating point math saturates at infinities,
    530             // but we limit volume to unity gain float.
    531             // ramp = 0; break;
    532             //
    533             newVolume = AudioMixer::UNITY_GAIN_FLOAT;
    534             break;
    535         case FP_NORMAL:
    536         default:
    537             // Floating point does not have problems with overflow wrap
    538             // that integer has.  However, we limit the volume to
    539             // unity gain here.
    540             // TODO: Revisit the volume limitation and perhaps parameterize.
    541             if (newVolume > AudioMixer::UNITY_GAIN_FLOAT) {
    542                 newVolume = AudioMixer::UNITY_GAIN_FLOAT;
    543             }
    544             break;
    545         }
    546     }
    547 
    548     // set floating point volume ramp
    549     if (ramp != 0) {
    550         // when the ramp completes, *pPrevVolume is set to *pSetVolume, so there
    551         // is no computational mismatch; hence equality is checked here.
    552         ALOGD_IF(*pPrevVolume != *pSetVolume, "previous float ramp hasn't finished,"
    553                 " prev:%f  set_to:%f", *pPrevVolume, *pSetVolume);
    554         const float inc = (newVolume - *pPrevVolume) / ramp; // could be inf, nan, subnormal
    555         const float maxv = max(newVolume, *pPrevVolume); // could be inf, cannot be nan, subnormal
    556 
    557         if (isnormal(inc) // inc must be a normal number (no subnormals, infinite, nan)
    558                 && maxv + inc != maxv) { // inc must make forward progress
    559             *pVolumeInc = inc;
    560             // ramp is set now.
    561             // Note: if newVolume is 0, then near the end of the ramp,
    562             // it may be possible that the ramped volume may be subnormal or
    563             // temporarily negative by a small amount or subnormal due to floating
    564             // point inaccuracies.
    565         } else {
    566             ramp = 0; // ramp not allowed
    567         }
    568     }
    569 
    570     // compute and check integer volume, no need to check negative values
    571     // The integer volume is limited to "unity_gain" to avoid wrapping and other
    572     // audio artifacts, so it never reaches the range limit of U4.28.
    573     // We safely use signed 16 and 32 bit integers here.
    574     const float scaledVolume = newVolume * AudioMixer::UNITY_GAIN_INT; // not neg, subnormal, nan
    575     const int32_t intVolume = (scaledVolume >= (float)AudioMixer::UNITY_GAIN_INT) ?
    576             AudioMixer::UNITY_GAIN_INT : (int32_t)scaledVolume;
    577 
    578     // set integer volume ramp
    579     if (ramp != 0) {
    580         // integer volume is U4.12 (to use 16 bit multiplies), but ramping uses U4.28.
    581         // when the ramp completes, *pIntPrevVolume is set to *pIntSetVolume << 16, so there
    582         // is no computational mismatch; hence equality is checked here.
    583         ALOGD_IF(*pIntPrevVolume != *pIntSetVolume << 16, "previous int ramp hasn't finished,"
    584                 " prev:%d  set_to:%d", *pIntPrevVolume, *pIntSetVolume << 16);
    585         const int32_t inc = ((intVolume << 16) - *pIntPrevVolume) / ramp;
    586 
    587         if (inc != 0) { // inc must make forward progress
    588             *pIntVolumeInc = inc;
    589         } else {
    590             ramp = 0; // ramp not allowed
    591         }
    592     }
    593 
    594     // if no ramp, or ramp not allowed, then clear float and integer increments
    595     if (ramp == 0) {
    596         *pVolumeInc = 0;
    597         *pPrevVolume = newVolume;
    598         *pIntVolumeInc = 0;
    599         *pIntPrevVolume = intVolume << 16;
    600     }
    601     *pSetVolume = newVolume;
    602     *pIntSetVolume = intVolume;
    603     return true;
    604 }
    605 
    606 void AudioMixer::setParameter(int name, int target, int param, void *value)
    607 {
    608     name -= TRACK0;
    609     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    610     track_t& track = mState.tracks[name];
    611 
    612     int valueInt = static_cast<int>(reinterpret_cast<uintptr_t>(value));
    613     int32_t *valueBuf = reinterpret_cast<int32_t*>(value);
    614 
    615     switch (target) {
    616 
    617     case TRACK:
    618         switch (param) {
    619         case CHANNEL_MASK: {
    620             const audio_channel_mask_t trackChannelMask =
    621                 static_cast<audio_channel_mask_t>(valueInt);
    622             if (setChannelMasks(name, trackChannelMask, track.mMixerChannelMask)) {
    623                 ALOGV("setParameter(TRACK, CHANNEL_MASK, %x)", trackChannelMask);
    624                 invalidateState(1 << name);
    625             }
    626             } break;
    627         case MAIN_BUFFER:
    628             if (track.mainBuffer != valueBuf) {
    629                 track.mainBuffer = valueBuf;
    630                 ALOGV("setParameter(TRACK, MAIN_BUFFER, %p)", valueBuf);
    631                 invalidateState(1 << name);
    632             }
    633             break;
    634         case AUX_BUFFER:
    635             if (track.auxBuffer != valueBuf) {
    636                 track.auxBuffer = valueBuf;
    637                 ALOGV("setParameter(TRACK, AUX_BUFFER, %p)", valueBuf);
    638                 invalidateState(1 << name);
    639             }
    640             break;
    641         case FORMAT: {
    642             audio_format_t format = static_cast<audio_format_t>(valueInt);
    643             if (track.mFormat != format) {
    644                 ALOG_ASSERT(audio_is_linear_pcm(format), "Invalid format %#x", format);
    645                 track.mFormat = format;
    646                 ALOGV("setParameter(TRACK, FORMAT, %#x)", format);
    647                 track.prepareForReformat();
    648                 invalidateState(1 << name);
    649             }
    650             } break;
    651         // FIXME do we want to support setting the downmix type from AudioFlinger?
    652         //         for a specific track? or per mixer?
    653         /* case DOWNMIX_TYPE:
    654             break          */
    655         case MIXER_FORMAT: {
    656             audio_format_t format = static_cast<audio_format_t>(valueInt);
    657             if (track.mMixerFormat != format) {
    658                 track.mMixerFormat = format;
    659                 ALOGV("setParameter(TRACK, MIXER_FORMAT, %#x)", format);
    660             }
    661             } break;
    662         case MIXER_CHANNEL_MASK: {
    663             const audio_channel_mask_t mixerChannelMask =
    664                     static_cast<audio_channel_mask_t>(valueInt);
    665             if (setChannelMasks(name, track.channelMask, mixerChannelMask)) {
    666                 ALOGV("setParameter(TRACK, MIXER_CHANNEL_MASK, %#x)", mixerChannelMask);
    667                 invalidateState(1 << name);
    668             }
    669             } break;
    670         default:
    671             LOG_ALWAYS_FATAL("setParameter track: bad param %d", param);
    672         }
    673         break;
    674 
    675     case RESAMPLE:
    676         switch (param) {
    677         case SAMPLE_RATE:
    678             ALOG_ASSERT(valueInt > 0, "bad sample rate %d", valueInt);
    679             if (track.setResampler(uint32_t(valueInt), mSampleRate)) {
    680                 ALOGV("setParameter(RESAMPLE, SAMPLE_RATE, %u)",
    681                         uint32_t(valueInt));
    682                 invalidateState(1 << name);
    683             }
    684             break;
    685         case RESET:
    686             track.resetResampler();
    687             invalidateState(1 << name);
    688             break;
    689         case REMOVE:
    690             delete track.resampler;
    691             track.resampler = NULL;
    692             track.sampleRate = mSampleRate;
    693             invalidateState(1 << name);
    694             break;
    695         default:
    696             LOG_ALWAYS_FATAL("setParameter resample: bad param %d", param);
    697         }
    698         break;
    699 
    700     case RAMP_VOLUME:
    701     case VOLUME:
    702         switch (param) {
    703         case AUXLEVEL:
    704             if (setVolumeRampVariables(*reinterpret_cast<float*>(value),
    705                     target == RAMP_VOLUME ? mState.frameCount : 0,
    706                     &track.auxLevel, &track.prevAuxLevel, &track.auxInc,
    707                     &track.mAuxLevel, &track.mPrevAuxLevel, &track.mAuxInc)) {
    708                 ALOGV("setParameter(%s, AUXLEVEL: %04x)",
    709                         target == VOLUME ? "VOLUME" : "RAMP_VOLUME", track.auxLevel);
    710                 invalidateState(1 << name);
    711             }
    712             break;
    713         default:
    714             if ((unsigned)param >= VOLUME0 && (unsigned)param < VOLUME0 + MAX_NUM_VOLUMES) {
    715                 if (setVolumeRampVariables(*reinterpret_cast<float*>(value),
    716                         target == RAMP_VOLUME ? mState.frameCount : 0,
    717                         &track.volume[param - VOLUME0], &track.prevVolume[param - VOLUME0],
    718                         &track.volumeInc[param - VOLUME0],
    719                         &track.mVolume[param - VOLUME0], &track.mPrevVolume[param - VOLUME0],
    720                         &track.mVolumeInc[param - VOLUME0])) {
    721                     ALOGV("setParameter(%s, VOLUME%d: %04x)",
    722                             target == VOLUME ? "VOLUME" : "RAMP_VOLUME", param - VOLUME0,
    723                                     track.volume[param - VOLUME0]);
    724                     invalidateState(1 << name);
    725                 }
    726             } else {
    727                 LOG_ALWAYS_FATAL("setParameter volume: bad param %d", param);
    728             }
    729         }
    730         break;
    731         case TIMESTRETCH:
    732             switch (param) {
    733             case PLAYBACK_RATE: {
    734                 const AudioPlaybackRate *playbackRate =
    735                         reinterpret_cast<AudioPlaybackRate*>(value);
    736                 ALOGW_IF(!isAudioPlaybackRateValid(*playbackRate),
    737                         "bad parameters speed %f, pitch %f",playbackRate->mSpeed,
    738                         playbackRate->mPitch);
    739                 if (track.setPlaybackRate(*playbackRate)) {
    740                     ALOGV("setParameter(TIMESTRETCH, PLAYBACK_RATE, STRETCH_MODE, FALLBACK_MODE "
    741                             "%f %f %d %d",
    742                             playbackRate->mSpeed,
    743                             playbackRate->mPitch,
    744                             playbackRate->mStretchMode,
    745                             playbackRate->mFallbackMode);
    746                     // invalidateState(1 << name);
    747                 }
    748             } break;
    749             default:
    750                 LOG_ALWAYS_FATAL("setParameter timestretch: bad param %d", param);
    751             }
    752             break;
    753 
    754     default:
    755         LOG_ALWAYS_FATAL("setParameter: bad target %d", target);
    756     }
    757 }
    758 
    759 bool AudioMixer::track_t::setResampler(uint32_t trackSampleRate, uint32_t devSampleRate)
    760 {
    761     if (trackSampleRate != devSampleRate || resampler != NULL) {
    762         if (sampleRate != trackSampleRate) {
    763             sampleRate = trackSampleRate;
    764             if (resampler == NULL) {
    765                 ALOGV("Creating resampler from track %d Hz to device %d Hz",
    766                         trackSampleRate, devSampleRate);
    767                 AudioResampler::src_quality quality;
    768                 // force lowest quality level resampler if use case isn't music or video
    769                 // FIXME this is flawed for dynamic sample rates, as we choose the resampler
    770                 // quality level based on the initial ratio, but that could change later.
    771                 // Should have a way to distinguish tracks with static ratios vs. dynamic ratios.
    772                 if (isMusicRate(trackSampleRate)) {
    773                     quality = AudioResampler::DEFAULT_QUALITY;
    774                 } else {
    775                     quality = AudioResampler::DYN_LOW_QUALITY;
    776                 }
    777 
    778                 // TODO: Remove MONO_HACK. Resampler sees #channels after the downmixer
    779                 // but if none exists, it is the channel count (1 for mono).
    780                 const int resamplerChannelCount = downmixerBufferProvider != NULL
    781                         ? mMixerChannelCount : channelCount;
    782                 ALOGVV("Creating resampler:"
    783                         " format(%#x) channels(%d) devSampleRate(%u) quality(%d)\n",
    784                         mMixerInFormat, resamplerChannelCount, devSampleRate, quality);
    785                 resampler = AudioResampler::create(
    786                         mMixerInFormat,
    787                         resamplerChannelCount,
    788                         devSampleRate, quality);
    789                 resampler->setLocalTimeFreq(sLocalTimeFreq);
    790             }
    791             return true;
    792         }
    793     }
    794     return false;
    795 }
    796 
    797 bool AudioMixer::track_t::setPlaybackRate(const AudioPlaybackRate &playbackRate)
    798 {
    799     if ((mTimestretchBufferProvider == NULL &&
    800             fabs(playbackRate.mSpeed - mPlaybackRate.mSpeed) < AUDIO_TIMESTRETCH_SPEED_MIN_DELTA &&
    801             fabs(playbackRate.mPitch - mPlaybackRate.mPitch) < AUDIO_TIMESTRETCH_PITCH_MIN_DELTA) ||
    802             isAudioPlaybackRateEqual(playbackRate, mPlaybackRate)) {
    803         return false;
    804     }
    805     mPlaybackRate = playbackRate;
    806     if (mTimestretchBufferProvider == NULL) {
    807         // TODO: Remove MONO_HACK. Resampler sees #channels after the downmixer
    808         // but if none exists, it is the channel count (1 for mono).
    809         const int timestretchChannelCount = downmixerBufferProvider != NULL
    810                 ? mMixerChannelCount : channelCount;
    811         mTimestretchBufferProvider = new TimestretchBufferProvider(timestretchChannelCount,
    812                 mMixerInFormat, sampleRate, playbackRate);
    813         reconfigureBufferProviders();
    814     } else {
    815         reinterpret_cast<TimestretchBufferProvider*>(mTimestretchBufferProvider)
    816                 ->setPlaybackRate(playbackRate);
    817     }
    818     return true;
    819 }
    820 
    821 /* Checks to see if the volume ramp has completed and clears the increment
    822  * variables appropriately.
    823  *
    824  * FIXME: There is code to handle int/float ramp variable switchover should it not
    825  * complete within a mixer buffer processing call, but it is preferred to avoid switchover
    826  * due to precision issues.  The switchover code is included for legacy code purposes
    827  * and can be removed once the integer volume is removed.
    828  *
    829  * It is not sufficient to clear only the volumeInc integer variable because
    830  * if one channel requires ramping, all channels are ramped.
    831  *
    832  * There is a bit of duplicated code here, but it keeps backward compatibility.
    833  */
    834 inline void AudioMixer::track_t::adjustVolumeRamp(bool aux, bool useFloat)
    835 {
    836     if (useFloat) {
    837         for (uint32_t i = 0; i < MAX_NUM_VOLUMES; i++) {
    838             if ((mVolumeInc[i] > 0 && mPrevVolume[i] + mVolumeInc[i] >= mVolume[i]) ||
    839                      (mVolumeInc[i] < 0 && mPrevVolume[i] + mVolumeInc[i] <= mVolume[i])) {
    840                 volumeInc[i] = 0;
    841                 prevVolume[i] = volume[i] << 16;
    842                 mVolumeInc[i] = 0.;
    843                 mPrevVolume[i] = mVolume[i];
    844             } else {
    845                 //ALOGV("ramp: %f %f %f", mVolume[i], mPrevVolume[i], mVolumeInc[i]);
    846                 prevVolume[i] = u4_28_from_float(mPrevVolume[i]);
    847             }
    848         }
    849     } else {
    850         for (uint32_t i = 0; i < MAX_NUM_VOLUMES; i++) {
    851             if (((volumeInc[i]>0) && (((prevVolume[i]+volumeInc[i])>>16) >= volume[i])) ||
    852                     ((volumeInc[i]<0) && (((prevVolume[i]+volumeInc[i])>>16) <= volume[i]))) {
    853                 volumeInc[i] = 0;
    854                 prevVolume[i] = volume[i] << 16;
    855                 mVolumeInc[i] = 0.;
    856                 mPrevVolume[i] = mVolume[i];
    857             } else {
    858                 //ALOGV("ramp: %d %d %d", volume[i] << 16, prevVolume[i], volumeInc[i]);
    859                 mPrevVolume[i]  = float_from_u4_28(prevVolume[i]);
    860             }
    861         }
    862     }
    863     /* TODO: aux is always integer regardless of output buffer type */
    864     if (aux) {
    865         if (((auxInc>0) && (((prevAuxLevel+auxInc)>>16) >= auxLevel)) ||
    866                 ((auxInc<0) && (((prevAuxLevel+auxInc)>>16) <= auxLevel))) {
    867             auxInc = 0;
    868             prevAuxLevel = auxLevel << 16;
    869             mAuxInc = 0.;
    870             mPrevAuxLevel = mAuxLevel;
    871         } else {
    872             //ALOGV("aux ramp: %d %d %d", auxLevel << 16, prevAuxLevel, auxInc);
    873         }
    874     }
    875 }
    876 
    877 size_t AudioMixer::getUnreleasedFrames(int name) const
    878 {
    879     name -= TRACK0;
    880     if (uint32_t(name) < MAX_NUM_TRACKS) {
    881         return mState.tracks[name].getUnreleasedFrames();
    882     }
    883     return 0;
    884 }
    885 
    886 void AudioMixer::setBufferProvider(int name, AudioBufferProvider* bufferProvider)
    887 {
    888     name -= TRACK0;
    889     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    890 
    891     if (mState.tracks[name].mInputBufferProvider == bufferProvider) {
    892         return; // don't reset any buffer providers if identical.
    893     }
    894     if (mState.tracks[name].mReformatBufferProvider != NULL) {
    895         mState.tracks[name].mReformatBufferProvider->reset();
    896     } else if (mState.tracks[name].downmixerBufferProvider != NULL) {
    897         mState.tracks[name].downmixerBufferProvider->reset();
    898     } else if (mState.tracks[name].mPostDownmixReformatBufferProvider != NULL) {
    899         mState.tracks[name].mPostDownmixReformatBufferProvider->reset();
    900     } else if (mState.tracks[name].mTimestretchBufferProvider != NULL) {
    901         mState.tracks[name].mTimestretchBufferProvider->reset();
    902     }
    903 
    904     mState.tracks[name].mInputBufferProvider = bufferProvider;
    905     mState.tracks[name].reconfigureBufferProviders();
    906 }
    907 
    908 
    909 void AudioMixer::process(int64_t pts)
    910 {
    911     mState.hook(&mState, pts);
    912 }
    913 
    914 
    915 void AudioMixer::process__validate(state_t* state, int64_t pts)
    916 {
    917     ALOGW_IF(!state->needsChanged,
    918         "in process__validate() but nothing's invalid");
    919 
    920     uint32_t changed = state->needsChanged;
    921     state->needsChanged = 0; // clear the validation flag
    922 
    923     // recompute which tracks are enabled / disabled
    924     uint32_t enabled = 0;
    925     uint32_t disabled = 0;
    926     while (changed) {
    927         const int i = 31 - __builtin_clz(changed);
    928         const uint32_t mask = 1<<i;
    929         changed &= ~mask;
    930         track_t& t = state->tracks[i];
    931         (t.enabled ? enabled : disabled) |= mask;
    932     }
    933     state->enabledTracks &= ~disabled;
    934     state->enabledTracks |=  enabled;
    935 
    936     // compute everything we need...
    937     int countActiveTracks = 0;
    938     // TODO: fix all16BitsStereNoResample logic to
    939     // either properly handle muted tracks (it should ignore them)
    940     // or remove altogether as an obsolete optimization.
    941     bool all16BitsStereoNoResample = true;
    942     bool resampling = false;
    943     bool volumeRamp = false;
    944     uint32_t en = state->enabledTracks;
    945     while (en) {
    946         const int i = 31 - __builtin_clz(en);
    947         en &= ~(1<<i);
    948 
    949         countActiveTracks++;
    950         track_t& t = state->tracks[i];
    951         uint32_t n = 0;
    952         // FIXME can overflow (mask is only 3 bits)
    953         n |= NEEDS_CHANNEL_1 + t.channelCount - 1;
    954         if (t.doesResample()) {
    955             n |= NEEDS_RESAMPLE;
    956         }
    957         if (t.auxLevel != 0 && t.auxBuffer != NULL) {
    958             n |= NEEDS_AUX;
    959         }
    960 
    961         if (t.volumeInc[0]|t.volumeInc[1]) {
    962             volumeRamp = true;
    963         } else if (!t.doesResample() && t.volumeRL == 0) {
    964             n |= NEEDS_MUTE;
    965         }
    966         t.needs = n;
    967 
    968         if (n & NEEDS_MUTE) {
    969             t.hook = track__nop;
    970         } else {
    971             if (n & NEEDS_AUX) {
    972                 all16BitsStereoNoResample = false;
    973             }
    974             if (n & NEEDS_RESAMPLE) {
    975                 all16BitsStereoNoResample = false;
    976                 resampling = true;
    977                 t.hook = getTrackHook(TRACKTYPE_RESAMPLE, t.mMixerChannelCount,
    978                         t.mMixerInFormat, t.mMixerFormat);
    979                 ALOGV_IF((n & NEEDS_CHANNEL_COUNT__MASK) > NEEDS_CHANNEL_2,
    980                         "Track %d needs downmix + resample", i);
    981             } else {
    982                 if ((n & NEEDS_CHANNEL_COUNT__MASK) == NEEDS_CHANNEL_1){
    983                     t.hook = getTrackHook(
    984                             (t.mMixerChannelMask == AUDIO_CHANNEL_OUT_STEREO  // TODO: MONO_HACK
    985                                     && t.channelMask == AUDIO_CHANNEL_OUT_MONO)
    986                                 ? TRACKTYPE_NORESAMPLEMONO : TRACKTYPE_NORESAMPLE,
    987                             t.mMixerChannelCount,
    988                             t.mMixerInFormat, t.mMixerFormat);
    989                     all16BitsStereoNoResample = false;
    990                 }
    991                 if ((n & NEEDS_CHANNEL_COUNT__MASK) >= NEEDS_CHANNEL_2){
    992                     t.hook = getTrackHook(TRACKTYPE_NORESAMPLE, t.mMixerChannelCount,
    993                             t.mMixerInFormat, t.mMixerFormat);
    994                     ALOGV_IF((n & NEEDS_CHANNEL_COUNT__MASK) > NEEDS_CHANNEL_2,
    995                             "Track %d needs downmix", i);
    996                 }
    997             }
    998         }
    999     }
   1000 
   1001     // select the processing hooks
   1002     state->hook = process__nop;
   1003     if (countActiveTracks > 0) {
   1004         if (resampling) {
   1005             if (!state->outputTemp) {
   1006                 state->outputTemp = new int32_t[MAX_NUM_CHANNELS * state->frameCount];
   1007             }
   1008             if (!state->resampleTemp) {
   1009                 state->resampleTemp = new int32_t[MAX_NUM_CHANNELS * state->frameCount];
   1010             }
   1011             state->hook = process__genericResampling;
   1012         } else {
   1013             if (state->outputTemp) {
   1014                 delete [] state->outputTemp;
   1015                 state->outputTemp = NULL;
   1016             }
   1017             if (state->resampleTemp) {
   1018                 delete [] state->resampleTemp;
   1019                 state->resampleTemp = NULL;
   1020             }
   1021             state->hook = process__genericNoResampling;
   1022             if (all16BitsStereoNoResample && !volumeRamp) {
   1023                 if (countActiveTracks == 1) {
   1024                     const int i = 31 - __builtin_clz(state->enabledTracks);
   1025                     track_t& t = state->tracks[i];
   1026                     if ((t.needs & NEEDS_MUTE) == 0) {
   1027                         // The check prevents a muted track from acquiring a process hook.
   1028                         //
   1029                         // This is dangerous if the track is MONO as that requires
   1030                         // special case handling due to implicit channel duplication.
   1031                         // Stereo or Multichannel should actually be fine here.
   1032                         state->hook = getProcessHook(PROCESSTYPE_NORESAMPLEONETRACK,
   1033                                 t.mMixerChannelCount, t.mMixerInFormat, t.mMixerFormat);
   1034                     }
   1035                 }
   1036             }
   1037         }
   1038     }
   1039 
   1040     ALOGV("mixer configuration change: %d activeTracks (%08x) "
   1041         "all16BitsStereoNoResample=%d, resampling=%d, volumeRamp=%d",
   1042         countActiveTracks, state->enabledTracks,
   1043         all16BitsStereoNoResample, resampling, volumeRamp);
   1044 
   1045    state->hook(state, pts);
   1046 
   1047     // Now that the volume ramp has been done, set optimal state and
   1048     // track hooks for subsequent mixer process
   1049     if (countActiveTracks > 0) {
   1050         bool allMuted = true;
   1051         uint32_t en = state->enabledTracks;
   1052         while (en) {
   1053             const int i = 31 - __builtin_clz(en);
   1054             en &= ~(1<<i);
   1055             track_t& t = state->tracks[i];
   1056             if (!t.doesResample() && t.volumeRL == 0) {
   1057                 t.needs |= NEEDS_MUTE;
   1058                 t.hook = track__nop;
   1059             } else {
   1060                 allMuted = false;
   1061             }
   1062         }
   1063         if (allMuted) {
   1064             state->hook = process__nop;
   1065         } else if (all16BitsStereoNoResample) {
   1066             if (countActiveTracks == 1) {
   1067                 const int i = 31 - __builtin_clz(state->enabledTracks);
   1068                 track_t& t = state->tracks[i];
   1069                 // Muted single tracks handled by allMuted above.
   1070                 state->hook = getProcessHook(PROCESSTYPE_NORESAMPLEONETRACK,
   1071                         t.mMixerChannelCount, t.mMixerInFormat, t.mMixerFormat);
   1072             }
   1073         }
   1074     }
   1075 }
   1076 
   1077 
   1078 void AudioMixer::track__genericResample(track_t* t, int32_t* out, size_t outFrameCount,
   1079         int32_t* temp, int32_t* aux)
   1080 {
   1081     ALOGVV("track__genericResample\n");
   1082     t->resampler->setSampleRate(t->sampleRate);
   1083 
   1084     // ramp gain - resample to temp buffer and scale/mix in 2nd step
   1085     if (aux != NULL) {
   1086         // always resample with unity gain when sending to auxiliary buffer to be able
   1087         // to apply send level after resampling
   1088         t->resampler->setVolume(UNITY_GAIN_FLOAT, UNITY_GAIN_FLOAT);
   1089         memset(temp, 0, outFrameCount * t->mMixerChannelCount * sizeof(int32_t));
   1090         t->resampler->resample(temp, outFrameCount, t->bufferProvider);
   1091         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
   1092             volumeRampStereo(t, out, outFrameCount, temp, aux);
   1093         } else {
   1094             volumeStereo(t, out, outFrameCount, temp, aux);
   1095         }
   1096     } else {
   1097         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
   1098             t->resampler->setVolume(UNITY_GAIN_FLOAT, UNITY_GAIN_FLOAT);
   1099             memset(temp, 0, outFrameCount * MAX_NUM_CHANNELS * sizeof(int32_t));
   1100             t->resampler->resample(temp, outFrameCount, t->bufferProvider);
   1101             volumeRampStereo(t, out, outFrameCount, temp, aux);
   1102         }
   1103 
   1104         // constant gain
   1105         else {
   1106             t->resampler->setVolume(t->mVolume[0], t->mVolume[1]);
   1107             t->resampler->resample(out, outFrameCount, t->bufferProvider);
   1108         }
   1109     }
   1110 }
   1111 
   1112 void AudioMixer::track__nop(track_t* t __unused, int32_t* out __unused,
   1113         size_t outFrameCount __unused, int32_t* temp __unused, int32_t* aux __unused)
   1114 {
   1115 }
   1116 
   1117 void AudioMixer::volumeRampStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
   1118         int32_t* aux)
   1119 {
   1120     int32_t vl = t->prevVolume[0];
   1121     int32_t vr = t->prevVolume[1];
   1122     const int32_t vlInc = t->volumeInc[0];
   1123     const int32_t vrInc = t->volumeInc[1];
   1124 
   1125     //ALOGD("[0] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1126     //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1127     //       (vl + vlInc*frameCount)/65536.0f, frameCount);
   1128 
   1129     // ramp volume
   1130     if (CC_UNLIKELY(aux != NULL)) {
   1131         int32_t va = t->prevAuxLevel;
   1132         const int32_t vaInc = t->auxInc;
   1133         int32_t l;
   1134         int32_t r;
   1135 
   1136         do {
   1137             l = (*temp++ >> 12);
   1138             r = (*temp++ >> 12);
   1139             *out++ += (vl >> 16) * l;
   1140             *out++ += (vr >> 16) * r;
   1141             *aux++ += (va >> 17) * (l + r);
   1142             vl += vlInc;
   1143             vr += vrInc;
   1144             va += vaInc;
   1145         } while (--frameCount);
   1146         t->prevAuxLevel = va;
   1147     } else {
   1148         do {
   1149             *out++ += (vl >> 16) * (*temp++ >> 12);
   1150             *out++ += (vr >> 16) * (*temp++ >> 12);
   1151             vl += vlInc;
   1152             vr += vrInc;
   1153         } while (--frameCount);
   1154     }
   1155     t->prevVolume[0] = vl;
   1156     t->prevVolume[1] = vr;
   1157     t->adjustVolumeRamp(aux != NULL);
   1158 }
   1159 
   1160 void AudioMixer::volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
   1161         int32_t* aux)
   1162 {
   1163     const int16_t vl = t->volume[0];
   1164     const int16_t vr = t->volume[1];
   1165 
   1166     if (CC_UNLIKELY(aux != NULL)) {
   1167         const int16_t va = t->auxLevel;
   1168         do {
   1169             int16_t l = (int16_t)(*temp++ >> 12);
   1170             int16_t r = (int16_t)(*temp++ >> 12);
   1171             out[0] = mulAdd(l, vl, out[0]);
   1172             int16_t a = (int16_t)(((int32_t)l + r) >> 1);
   1173             out[1] = mulAdd(r, vr, out[1]);
   1174             out += 2;
   1175             aux[0] = mulAdd(a, va, aux[0]);
   1176             aux++;
   1177         } while (--frameCount);
   1178     } else {
   1179         do {
   1180             int16_t l = (int16_t)(*temp++ >> 12);
   1181             int16_t r = (int16_t)(*temp++ >> 12);
   1182             out[0] = mulAdd(l, vl, out[0]);
   1183             out[1] = mulAdd(r, vr, out[1]);
   1184             out += 2;
   1185         } while (--frameCount);
   1186     }
   1187 }
   1188 
   1189 void AudioMixer::track__16BitsStereo(track_t* t, int32_t* out, size_t frameCount,
   1190         int32_t* temp __unused, int32_t* aux)
   1191 {
   1192     ALOGVV("track__16BitsStereo\n");
   1193     const int16_t *in = static_cast<const int16_t *>(t->in);
   1194 
   1195     if (CC_UNLIKELY(aux != NULL)) {
   1196         int32_t l;
   1197         int32_t r;
   1198         // ramp gain
   1199         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
   1200             int32_t vl = t->prevVolume[0];
   1201             int32_t vr = t->prevVolume[1];
   1202             int32_t va = t->prevAuxLevel;
   1203             const int32_t vlInc = t->volumeInc[0];
   1204             const int32_t vrInc = t->volumeInc[1];
   1205             const int32_t vaInc = t->auxInc;
   1206             // ALOGD("[1] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1207             //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1208             //        (vl + vlInc*frameCount)/65536.0f, frameCount);
   1209 
   1210             do {
   1211                 l = (int32_t)*in++;
   1212                 r = (int32_t)*in++;
   1213                 *out++ += (vl >> 16) * l;
   1214                 *out++ += (vr >> 16) * r;
   1215                 *aux++ += (va >> 17) * (l + r);
   1216                 vl += vlInc;
   1217                 vr += vrInc;
   1218                 va += vaInc;
   1219             } while (--frameCount);
   1220 
   1221             t->prevVolume[0] = vl;
   1222             t->prevVolume[1] = vr;
   1223             t->prevAuxLevel = va;
   1224             t->adjustVolumeRamp(true);
   1225         }
   1226 
   1227         // constant gain
   1228         else {
   1229             const uint32_t vrl = t->volumeRL;
   1230             const int16_t va = (int16_t)t->auxLevel;
   1231             do {
   1232                 uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1233                 int16_t a = (int16_t)(((int32_t)in[0] + in[1]) >> 1);
   1234                 in += 2;
   1235                 out[0] = mulAddRL(1, rl, vrl, out[0]);
   1236                 out[1] = mulAddRL(0, rl, vrl, out[1]);
   1237                 out += 2;
   1238                 aux[0] = mulAdd(a, va, aux[0]);
   1239                 aux++;
   1240             } while (--frameCount);
   1241         }
   1242     } else {
   1243         // ramp gain
   1244         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
   1245             int32_t vl = t->prevVolume[0];
   1246             int32_t vr = t->prevVolume[1];
   1247             const int32_t vlInc = t->volumeInc[0];
   1248             const int32_t vrInc = t->volumeInc[1];
   1249 
   1250             // ALOGD("[1] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1251             //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1252             //        (vl + vlInc*frameCount)/65536.0f, frameCount);
   1253 
   1254             do {
   1255                 *out++ += (vl >> 16) * (int32_t) *in++;
   1256                 *out++ += (vr >> 16) * (int32_t) *in++;
   1257                 vl += vlInc;
   1258                 vr += vrInc;
   1259             } while (--frameCount);
   1260 
   1261             t->prevVolume[0] = vl;
   1262             t->prevVolume[1] = vr;
   1263             t->adjustVolumeRamp(false);
   1264         }
   1265 
   1266         // constant gain
   1267         else {
   1268             const uint32_t vrl = t->volumeRL;
   1269             do {
   1270                 uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1271                 in += 2;
   1272                 out[0] = mulAddRL(1, rl, vrl, out[0]);
   1273                 out[1] = mulAddRL(0, rl, vrl, out[1]);
   1274                 out += 2;
   1275             } while (--frameCount);
   1276         }
   1277     }
   1278     t->in = in;
   1279 }
   1280 
   1281 void AudioMixer::track__16BitsMono(track_t* t, int32_t* out, size_t frameCount,
   1282         int32_t* temp __unused, int32_t* aux)
   1283 {
   1284     ALOGVV("track__16BitsMono\n");
   1285     const int16_t *in = static_cast<int16_t const *>(t->in);
   1286 
   1287     if (CC_UNLIKELY(aux != NULL)) {
   1288         // ramp gain
   1289         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
   1290             int32_t vl = t->prevVolume[0];
   1291             int32_t vr = t->prevVolume[1];
   1292             int32_t va = t->prevAuxLevel;
   1293             const int32_t vlInc = t->volumeInc[0];
   1294             const int32_t vrInc = t->volumeInc[1];
   1295             const int32_t vaInc = t->auxInc;
   1296 
   1297             // ALOGD("[2] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1298             //         t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1299             //         (vl + vlInc*frameCount)/65536.0f, frameCount);
   1300 
   1301             do {
   1302                 int32_t l = *in++;
   1303                 *out++ += (vl >> 16) * l;
   1304                 *out++ += (vr >> 16) * l;
   1305                 *aux++ += (va >> 16) * l;
   1306                 vl += vlInc;
   1307                 vr += vrInc;
   1308                 va += vaInc;
   1309             } while (--frameCount);
   1310 
   1311             t->prevVolume[0] = vl;
   1312             t->prevVolume[1] = vr;
   1313             t->prevAuxLevel = va;
   1314             t->adjustVolumeRamp(true);
   1315         }
   1316         // constant gain
   1317         else {
   1318             const int16_t vl = t->volume[0];
   1319             const int16_t vr = t->volume[1];
   1320             const int16_t va = (int16_t)t->auxLevel;
   1321             do {
   1322                 int16_t l = *in++;
   1323                 out[0] = mulAdd(l, vl, out[0]);
   1324                 out[1] = mulAdd(l, vr, out[1]);
   1325                 out += 2;
   1326                 aux[0] = mulAdd(l, va, aux[0]);
   1327                 aux++;
   1328             } while (--frameCount);
   1329         }
   1330     } else {
   1331         // ramp gain
   1332         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
   1333             int32_t vl = t->prevVolume[0];
   1334             int32_t vr = t->prevVolume[1];
   1335             const int32_t vlInc = t->volumeInc[0];
   1336             const int32_t vrInc = t->volumeInc[1];
   1337 
   1338             // ALOGD("[2] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1339             //         t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1340             //         (vl + vlInc*frameCount)/65536.0f, frameCount);
   1341 
   1342             do {
   1343                 int32_t l = *in++;
   1344                 *out++ += (vl >> 16) * l;
   1345                 *out++ += (vr >> 16) * l;
   1346                 vl += vlInc;
   1347                 vr += vrInc;
   1348             } while (--frameCount);
   1349 
   1350             t->prevVolume[0] = vl;
   1351             t->prevVolume[1] = vr;
   1352             t->adjustVolumeRamp(false);
   1353         }
   1354         // constant gain
   1355         else {
   1356             const int16_t vl = t->volume[0];
   1357             const int16_t vr = t->volume[1];
   1358             do {
   1359                 int16_t l = *in++;
   1360                 out[0] = mulAdd(l, vl, out[0]);
   1361                 out[1] = mulAdd(l, vr, out[1]);
   1362                 out += 2;
   1363             } while (--frameCount);
   1364         }
   1365     }
   1366     t->in = in;
   1367 }
   1368 
   1369 // no-op case
   1370 void AudioMixer::process__nop(state_t* state, int64_t pts)
   1371 {
   1372     ALOGVV("process__nop\n");
   1373     uint32_t e0 = state->enabledTracks;
   1374     while (e0) {
   1375         // process by group of tracks with same output buffer to
   1376         // avoid multiple memset() on same buffer
   1377         uint32_t e1 = e0, e2 = e0;
   1378         int i = 31 - __builtin_clz(e1);
   1379         {
   1380             track_t& t1 = state->tracks[i];
   1381             e2 &= ~(1<<i);
   1382             while (e2) {
   1383                 i = 31 - __builtin_clz(e2);
   1384                 e2 &= ~(1<<i);
   1385                 track_t& t2 = state->tracks[i];
   1386                 if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
   1387                     e1 &= ~(1<<i);
   1388                 }
   1389             }
   1390             e0 &= ~(e1);
   1391 
   1392             memset(t1.mainBuffer, 0, state->frameCount * t1.mMixerChannelCount
   1393                     * audio_bytes_per_sample(t1.mMixerFormat));
   1394         }
   1395 
   1396         while (e1) {
   1397             i = 31 - __builtin_clz(e1);
   1398             e1 &= ~(1<<i);
   1399             {
   1400                 track_t& t3 = state->tracks[i];
   1401                 size_t outFrames = state->frameCount;
   1402                 while (outFrames) {
   1403                     t3.buffer.frameCount = outFrames;
   1404                     int64_t outputPTS = calculateOutputPTS(
   1405                         t3, pts, state->frameCount - outFrames);
   1406                     t3.bufferProvider->getNextBuffer(&t3.buffer, outputPTS);
   1407                     if (t3.buffer.raw == NULL) break;
   1408                     outFrames -= t3.buffer.frameCount;
   1409                     t3.bufferProvider->releaseBuffer(&t3.buffer);
   1410                 }
   1411             }
   1412         }
   1413     }
   1414 }
   1415 
   1416 // generic code without resampling
   1417 void AudioMixer::process__genericNoResampling(state_t* state, int64_t pts)
   1418 {
   1419     ALOGVV("process__genericNoResampling\n");
   1420     int32_t outTemp[BLOCKSIZE * MAX_NUM_CHANNELS] __attribute__((aligned(32)));
   1421 
   1422     // acquire each track's buffer
   1423     uint32_t enabledTracks = state->enabledTracks;
   1424     uint32_t e0 = enabledTracks;
   1425     while (e0) {
   1426         const int i = 31 - __builtin_clz(e0);
   1427         e0 &= ~(1<<i);
   1428         track_t& t = state->tracks[i];
   1429         t.buffer.frameCount = state->frameCount;
   1430         t.bufferProvider->getNextBuffer(&t.buffer, pts);
   1431         t.frameCount = t.buffer.frameCount;
   1432         t.in = t.buffer.raw;
   1433     }
   1434 
   1435     e0 = enabledTracks;
   1436     while (e0) {
   1437         // process by group of tracks with same output buffer to
   1438         // optimize cache use
   1439         uint32_t e1 = e0, e2 = e0;
   1440         int j = 31 - __builtin_clz(e1);
   1441         track_t& t1 = state->tracks[j];
   1442         e2 &= ~(1<<j);
   1443         while (e2) {
   1444             j = 31 - __builtin_clz(e2);
   1445             e2 &= ~(1<<j);
   1446             track_t& t2 = state->tracks[j];
   1447             if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
   1448                 e1 &= ~(1<<j);
   1449             }
   1450         }
   1451         e0 &= ~(e1);
   1452         // this assumes output 16 bits stereo, no resampling
   1453         int32_t *out = t1.mainBuffer;
   1454         size_t numFrames = 0;
   1455         do {
   1456             memset(outTemp, 0, sizeof(outTemp));
   1457             e2 = e1;
   1458             while (e2) {
   1459                 const int i = 31 - __builtin_clz(e2);
   1460                 e2 &= ~(1<<i);
   1461                 track_t& t = state->tracks[i];
   1462                 size_t outFrames = BLOCKSIZE;
   1463                 int32_t *aux = NULL;
   1464                 if (CC_UNLIKELY(t.needs & NEEDS_AUX)) {
   1465                     aux = t.auxBuffer + numFrames;
   1466                 }
   1467                 while (outFrames) {
   1468                     // t.in == NULL can happen if the track was flushed just after having
   1469                     // been enabled for mixing.
   1470                    if (t.in == NULL) {
   1471                         enabledTracks &= ~(1<<i);
   1472                         e1 &= ~(1<<i);
   1473                         break;
   1474                     }
   1475                     size_t inFrames = (t.frameCount > outFrames)?outFrames:t.frameCount;
   1476                     if (inFrames > 0) {
   1477                         t.hook(&t, outTemp + (BLOCKSIZE - outFrames) * t.mMixerChannelCount,
   1478                                 inFrames, state->resampleTemp, aux);
   1479                         t.frameCount -= inFrames;
   1480                         outFrames -= inFrames;
   1481                         if (CC_UNLIKELY(aux != NULL)) {
   1482                             aux += inFrames;
   1483                         }
   1484                     }
   1485                     if (t.frameCount == 0 && outFrames) {
   1486                         t.bufferProvider->releaseBuffer(&t.buffer);
   1487                         t.buffer.frameCount = (state->frameCount - numFrames) -
   1488                                 (BLOCKSIZE - outFrames);
   1489                         int64_t outputPTS = calculateOutputPTS(
   1490                             t, pts, numFrames + (BLOCKSIZE - outFrames));
   1491                         t.bufferProvider->getNextBuffer(&t.buffer, outputPTS);
   1492                         t.in = t.buffer.raw;
   1493                         if (t.in == NULL) {
   1494                             enabledTracks &= ~(1<<i);
   1495                             e1 &= ~(1<<i);
   1496                             break;
   1497                         }
   1498                         t.frameCount = t.buffer.frameCount;
   1499                     }
   1500                 }
   1501             }
   1502 
   1503             convertMixerFormat(out, t1.mMixerFormat, outTemp, t1.mMixerInFormat,
   1504                     BLOCKSIZE * t1.mMixerChannelCount);
   1505             // TODO: fix ugly casting due to choice of out pointer type
   1506             out = reinterpret_cast<int32_t*>((uint8_t*)out
   1507                     + BLOCKSIZE * t1.mMixerChannelCount
   1508                         * audio_bytes_per_sample(t1.mMixerFormat));
   1509             numFrames += BLOCKSIZE;
   1510         } while (numFrames < state->frameCount);
   1511     }
   1512 
   1513     // release each track's buffer
   1514     e0 = enabledTracks;
   1515     while (e0) {
   1516         const int i = 31 - __builtin_clz(e0);
   1517         e0 &= ~(1<<i);
   1518         track_t& t = state->tracks[i];
   1519         t.bufferProvider->releaseBuffer(&t.buffer);
   1520     }
   1521 }
   1522 
   1523 
   1524 // generic code with resampling
   1525 void AudioMixer::process__genericResampling(state_t* state, int64_t pts)
   1526 {
   1527     ALOGVV("process__genericResampling\n");
   1528     // this const just means that local variable outTemp doesn't change
   1529     int32_t* const outTemp = state->outputTemp;
   1530     size_t numFrames = state->frameCount;
   1531 
   1532     uint32_t e0 = state->enabledTracks;
   1533     while (e0) {
   1534         // process by group of tracks with same output buffer
   1535         // to optimize cache use
   1536         uint32_t e1 = e0, e2 = e0;
   1537         int j = 31 - __builtin_clz(e1);
   1538         track_t& t1 = state->tracks[j];
   1539         e2 &= ~(1<<j);
   1540         while (e2) {
   1541             j = 31 - __builtin_clz(e2);
   1542             e2 &= ~(1<<j);
   1543             track_t& t2 = state->tracks[j];
   1544             if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
   1545                 e1 &= ~(1<<j);
   1546             }
   1547         }
   1548         e0 &= ~(e1);
   1549         int32_t *out = t1.mainBuffer;
   1550         memset(outTemp, 0, sizeof(*outTemp) * t1.mMixerChannelCount * state->frameCount);
   1551         while (e1) {
   1552             const int i = 31 - __builtin_clz(e1);
   1553             e1 &= ~(1<<i);
   1554             track_t& t = state->tracks[i];
   1555             int32_t *aux = NULL;
   1556             if (CC_UNLIKELY(t.needs & NEEDS_AUX)) {
   1557                 aux = t.auxBuffer;
   1558             }
   1559 
   1560             // this is a little goofy, on the resampling case we don't
   1561             // acquire/release the buffers because it's done by
   1562             // the resampler.
   1563             if (t.needs & NEEDS_RESAMPLE) {
   1564                 t.resampler->setPTS(pts);
   1565                 t.hook(&t, outTemp, numFrames, state->resampleTemp, aux);
   1566             } else {
   1567 
   1568                 size_t outFrames = 0;
   1569 
   1570                 while (outFrames < numFrames) {
   1571                     t.buffer.frameCount = numFrames - outFrames;
   1572                     int64_t outputPTS = calculateOutputPTS(t, pts, outFrames);
   1573                     t.bufferProvider->getNextBuffer(&t.buffer, outputPTS);
   1574                     t.in = t.buffer.raw;
   1575                     // t.in == NULL can happen if the track was flushed just after having
   1576                     // been enabled for mixing.
   1577                     if (t.in == NULL) break;
   1578 
   1579                     if (CC_UNLIKELY(aux != NULL)) {
   1580                         aux += outFrames;
   1581                     }
   1582                     t.hook(&t, outTemp + outFrames * t.mMixerChannelCount, t.buffer.frameCount,
   1583                             state->resampleTemp, aux);
   1584                     outFrames += t.buffer.frameCount;
   1585                     t.bufferProvider->releaseBuffer(&t.buffer);
   1586                 }
   1587             }
   1588         }
   1589         convertMixerFormat(out, t1.mMixerFormat,
   1590                 outTemp, t1.mMixerInFormat, numFrames * t1.mMixerChannelCount);
   1591     }
   1592 }
   1593 
   1594 // one track, 16 bits stereo without resampling is the most common case
   1595 void AudioMixer::process__OneTrack16BitsStereoNoResampling(state_t* state,
   1596                                                            int64_t pts)
   1597 {
   1598     ALOGVV("process__OneTrack16BitsStereoNoResampling\n");
   1599     // This method is only called when state->enabledTracks has exactly
   1600     // one bit set.  The asserts below would verify this, but are commented out
   1601     // since the whole point of this method is to optimize performance.
   1602     //ALOG_ASSERT(0 != state->enabledTracks, "no tracks enabled");
   1603     const int i = 31 - __builtin_clz(state->enabledTracks);
   1604     //ALOG_ASSERT((1 << i) == state->enabledTracks, "more than 1 track enabled");
   1605     const track_t& t = state->tracks[i];
   1606 
   1607     AudioBufferProvider::Buffer& b(t.buffer);
   1608 
   1609     int32_t* out = t.mainBuffer;
   1610     float *fout = reinterpret_cast<float*>(out);
   1611     size_t numFrames = state->frameCount;
   1612 
   1613     const int16_t vl = t.volume[0];
   1614     const int16_t vr = t.volume[1];
   1615     const uint32_t vrl = t.volumeRL;
   1616     while (numFrames) {
   1617         b.frameCount = numFrames;
   1618         int64_t outputPTS = calculateOutputPTS(t, pts, out - t.mainBuffer);
   1619         t.bufferProvider->getNextBuffer(&b, outputPTS);
   1620         const int16_t *in = b.i16;
   1621 
   1622         // in == NULL can happen if the track was flushed just after having
   1623         // been enabled for mixing.
   1624         if (in == NULL || (((uintptr_t)in) & 3)) {
   1625             memset(out, 0, numFrames
   1626                     * t.mMixerChannelCount * audio_bytes_per_sample(t.mMixerFormat));
   1627             ALOGE_IF((((uintptr_t)in) & 3),
   1628                     "process__OneTrack16BitsStereoNoResampling: misaligned buffer"
   1629                     " %p track %d, channels %d, needs %08x, volume %08x vfl %f vfr %f",
   1630                     in, i, t.channelCount, t.needs, vrl, t.mVolume[0], t.mVolume[1]);
   1631             return;
   1632         }
   1633         size_t outFrames = b.frameCount;
   1634 
   1635         switch (t.mMixerFormat) {
   1636         case AUDIO_FORMAT_PCM_FLOAT:
   1637             do {
   1638                 uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1639                 in += 2;
   1640                 int32_t l = mulRL(1, rl, vrl);
   1641                 int32_t r = mulRL(0, rl, vrl);
   1642                 *fout++ = float_from_q4_27(l);
   1643                 *fout++ = float_from_q4_27(r);
   1644                 // Note: In case of later int16_t sink output,
   1645                 // conversion and clamping is done by memcpy_to_i16_from_float().
   1646             } while (--outFrames);
   1647             break;
   1648         case AUDIO_FORMAT_PCM_16_BIT:
   1649             if (CC_UNLIKELY(uint32_t(vl) > UNITY_GAIN_INT || uint32_t(vr) > UNITY_GAIN_INT)) {
   1650                 // volume is boosted, so we might need to clamp even though
   1651                 // we process only one track.
   1652                 do {
   1653                     uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1654                     in += 2;
   1655                     int32_t l = mulRL(1, rl, vrl) >> 12;
   1656                     int32_t r = mulRL(0, rl, vrl) >> 12;
   1657                     // clamping...
   1658                     l = clamp16(l);
   1659                     r = clamp16(r);
   1660                     *out++ = (r<<16) | (l & 0xFFFF);
   1661                 } while (--outFrames);
   1662             } else {
   1663                 do {
   1664                     uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1665                     in += 2;
   1666                     int32_t l = mulRL(1, rl, vrl) >> 12;
   1667                     int32_t r = mulRL(0, rl, vrl) >> 12;
   1668                     *out++ = (r<<16) | (l & 0xFFFF);
   1669                 } while (--outFrames);
   1670             }
   1671             break;
   1672         default:
   1673             LOG_ALWAYS_FATAL("bad mixer format: %d", t.mMixerFormat);
   1674         }
   1675         numFrames -= b.frameCount;
   1676         t.bufferProvider->releaseBuffer(&b);
   1677     }
   1678 }
   1679 
   1680 int64_t AudioMixer::calculateOutputPTS(const track_t& t, int64_t basePTS,
   1681                                        int outputFrameIndex)
   1682 {
   1683     if (AudioBufferProvider::kInvalidPTS == basePTS) {
   1684         return AudioBufferProvider::kInvalidPTS;
   1685     }
   1686 
   1687     return basePTS + ((outputFrameIndex * sLocalTimeFreq) / t.sampleRate);
   1688 }
   1689 
   1690 /*static*/ uint64_t AudioMixer::sLocalTimeFreq;
   1691 /*static*/ pthread_once_t AudioMixer::sOnceControl = PTHREAD_ONCE_INIT;
   1692 
   1693 /*static*/ void AudioMixer::sInitRoutine()
   1694 {
   1695     LocalClock lc;
   1696     sLocalTimeFreq = lc.getLocalFreq(); // for the resampler
   1697 
   1698     DownmixerBufferProvider::init(); // for the downmixer
   1699 }
   1700 
   1701 /* TODO: consider whether this level of optimization is necessary.
   1702  * Perhaps just stick with a single for loop.
   1703  */
   1704 
   1705 // Needs to derive a compile time constant (constexpr).  Could be targeted to go
   1706 // to a MONOVOL mixtype based on MAX_NUM_VOLUMES, but that's an unnecessary complication.
   1707 #define MIXTYPE_MONOVOL(mixtype) (mixtype == MIXTYPE_MULTI ? MIXTYPE_MULTI_MONOVOL : \
   1708         mixtype == MIXTYPE_MULTI_SAVEONLY ? MIXTYPE_MULTI_SAVEONLY_MONOVOL : mixtype)
   1709 
   1710 /* MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1711  * TO: int32_t (Q4.27) or float
   1712  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1713  * TA: int32_t (Q4.27)
   1714  */
   1715 template <int MIXTYPE,
   1716         typename TO, typename TI, typename TV, typename TA, typename TAV>
   1717 static void volumeRampMulti(uint32_t channels, TO* out, size_t frameCount,
   1718         const TI* in, TA* aux, TV *vol, const TV *volinc, TAV *vola, TAV volainc)
   1719 {
   1720     switch (channels) {
   1721     case 1:
   1722         volumeRampMulti<MIXTYPE, 1>(out, frameCount, in, aux, vol, volinc, vola, volainc);
   1723         break;
   1724     case 2:
   1725         volumeRampMulti<MIXTYPE, 2>(out, frameCount, in, aux, vol, volinc, vola, volainc);
   1726         break;
   1727     case 3:
   1728         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 3>(out,
   1729                 frameCount, in, aux, vol, volinc, vola, volainc);
   1730         break;
   1731     case 4:
   1732         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 4>(out,
   1733                 frameCount, in, aux, vol, volinc, vola, volainc);
   1734         break;
   1735     case 5:
   1736         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 5>(out,
   1737                 frameCount, in, aux, vol, volinc, vola, volainc);
   1738         break;
   1739     case 6:
   1740         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 6>(out,
   1741                 frameCount, in, aux, vol, volinc, vola, volainc);
   1742         break;
   1743     case 7:
   1744         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 7>(out,
   1745                 frameCount, in, aux, vol, volinc, vola, volainc);
   1746         break;
   1747     case 8:
   1748         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 8>(out,
   1749                 frameCount, in, aux, vol, volinc, vola, volainc);
   1750         break;
   1751     }
   1752 }
   1753 
   1754 /* MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1755  * TO: int32_t (Q4.27) or float
   1756  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1757  * TA: int32_t (Q4.27)
   1758  */
   1759 template <int MIXTYPE,
   1760         typename TO, typename TI, typename TV, typename TA, typename TAV>
   1761 static void volumeMulti(uint32_t channels, TO* out, size_t frameCount,
   1762         const TI* in, TA* aux, const TV *vol, TAV vola)
   1763 {
   1764     switch (channels) {
   1765     case 1:
   1766         volumeMulti<MIXTYPE, 1>(out, frameCount, in, aux, vol, vola);
   1767         break;
   1768     case 2:
   1769         volumeMulti<MIXTYPE, 2>(out, frameCount, in, aux, vol, vola);
   1770         break;
   1771     case 3:
   1772         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 3>(out, frameCount, in, aux, vol, vola);
   1773         break;
   1774     case 4:
   1775         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 4>(out, frameCount, in, aux, vol, vola);
   1776         break;
   1777     case 5:
   1778         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 5>(out, frameCount, in, aux, vol, vola);
   1779         break;
   1780     case 6:
   1781         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 6>(out, frameCount, in, aux, vol, vola);
   1782         break;
   1783     case 7:
   1784         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 7>(out, frameCount, in, aux, vol, vola);
   1785         break;
   1786     case 8:
   1787         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 8>(out, frameCount, in, aux, vol, vola);
   1788         break;
   1789     }
   1790 }
   1791 
   1792 /* MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1793  * USEFLOATVOL (set to true if float volume is used)
   1794  * ADJUSTVOL   (set to true if volume ramp parameters needs adjustment afterwards)
   1795  * TO: int32_t (Q4.27) or float
   1796  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1797  * TA: int32_t (Q4.27)
   1798  */
   1799 template <int MIXTYPE, bool USEFLOATVOL, bool ADJUSTVOL,
   1800     typename TO, typename TI, typename TA>
   1801 void AudioMixer::volumeMix(TO *out, size_t outFrames,
   1802         const TI *in, TA *aux, bool ramp, AudioMixer::track_t *t)
   1803 {
   1804     if (USEFLOATVOL) {
   1805         if (ramp) {
   1806             volumeRampMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1807                     t->mPrevVolume, t->mVolumeInc, &t->prevAuxLevel, t->auxInc);
   1808             if (ADJUSTVOL) {
   1809                 t->adjustVolumeRamp(aux != NULL, true);
   1810             }
   1811         } else {
   1812             volumeMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1813                     t->mVolume, t->auxLevel);
   1814         }
   1815     } else {
   1816         if (ramp) {
   1817             volumeRampMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1818                     t->prevVolume, t->volumeInc, &t->prevAuxLevel, t->auxInc);
   1819             if (ADJUSTVOL) {
   1820                 t->adjustVolumeRamp(aux != NULL);
   1821             }
   1822         } else {
   1823             volumeMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1824                     t->volume, t->auxLevel);
   1825         }
   1826     }
   1827 }
   1828 
   1829 /* This process hook is called when there is a single track without
   1830  * aux buffer, volume ramp, or resampling.
   1831  * TODO: Update the hook selection: this can properly handle aux and ramp.
   1832  *
   1833  * MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1834  * TO: int32_t (Q4.27) or float
   1835  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1836  * TA: int32_t (Q4.27)
   1837  */
   1838 template <int MIXTYPE, typename TO, typename TI, typename TA>
   1839 void AudioMixer::process_NoResampleOneTrack(state_t* state, int64_t pts)
   1840 {
   1841     ALOGVV("process_NoResampleOneTrack\n");
   1842     // CLZ is faster than CTZ on ARM, though really not sure if true after 31 - clz.
   1843     const int i = 31 - __builtin_clz(state->enabledTracks);
   1844     ALOG_ASSERT((1 << i) == state->enabledTracks, "more than 1 track enabled");
   1845     track_t *t = &state->tracks[i];
   1846     const uint32_t channels = t->mMixerChannelCount;
   1847     TO* out = reinterpret_cast<TO*>(t->mainBuffer);
   1848     TA* aux = reinterpret_cast<TA*>(t->auxBuffer);
   1849     const bool ramp = t->needsRamp();
   1850 
   1851     for (size_t numFrames = state->frameCount; numFrames; ) {
   1852         AudioBufferProvider::Buffer& b(t->buffer);
   1853         // get input buffer
   1854         b.frameCount = numFrames;
   1855         const int64_t outputPTS = calculateOutputPTS(*t, pts, state->frameCount - numFrames);
   1856         t->bufferProvider->getNextBuffer(&b, outputPTS);
   1857         const TI *in = reinterpret_cast<TI*>(b.raw);
   1858 
   1859         // in == NULL can happen if the track was flushed just after having
   1860         // been enabled for mixing.
   1861         if (in == NULL || (((uintptr_t)in) & 3)) {
   1862             memset(out, 0, numFrames
   1863                     * channels * audio_bytes_per_sample(t->mMixerFormat));
   1864             ALOGE_IF((((uintptr_t)in) & 3), "process_NoResampleOneTrack: bus error: "
   1865                     "buffer %p track %p, channels %d, needs %#x",
   1866                     in, t, t->channelCount, t->needs);
   1867             return;
   1868         }
   1869 
   1870         const size_t outFrames = b.frameCount;
   1871         volumeMix<MIXTYPE, is_same<TI, float>::value, false> (
   1872                 out, outFrames, in, aux, ramp, t);
   1873 
   1874         out += outFrames * channels;
   1875         if (aux != NULL) {
   1876             aux += channels;
   1877         }
   1878         numFrames -= b.frameCount;
   1879 
   1880         // release buffer
   1881         t->bufferProvider->releaseBuffer(&b);
   1882     }
   1883     if (ramp) {
   1884         t->adjustVolumeRamp(aux != NULL, is_same<TI, float>::value);
   1885     }
   1886 }
   1887 
   1888 /* This track hook is called to do resampling then mixing,
   1889  * pulling from the track's upstream AudioBufferProvider.
   1890  *
   1891  * MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1892  * TO: int32_t (Q4.27) or float
   1893  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1894  * TA: int32_t (Q4.27)
   1895  */
   1896 template <int MIXTYPE, typename TO, typename TI, typename TA>
   1897 void AudioMixer::track__Resample(track_t* t, TO* out, size_t outFrameCount, TO* temp, TA* aux)
   1898 {
   1899     ALOGVV("track__Resample\n");
   1900     t->resampler->setSampleRate(t->sampleRate);
   1901     const bool ramp = t->needsRamp();
   1902     if (ramp || aux != NULL) {
   1903         // if ramp:        resample with unity gain to temp buffer and scale/mix in 2nd step.
   1904         // if aux != NULL: resample with unity gain to temp buffer then apply send level.
   1905 
   1906         t->resampler->setVolume(UNITY_GAIN_FLOAT, UNITY_GAIN_FLOAT);
   1907         memset(temp, 0, outFrameCount * t->mMixerChannelCount * sizeof(TO));
   1908         t->resampler->resample((int32_t*)temp, outFrameCount, t->bufferProvider);
   1909 
   1910         volumeMix<MIXTYPE, is_same<TI, float>::value, true>(
   1911                 out, outFrameCount, temp, aux, ramp, t);
   1912 
   1913     } else { // constant volume gain
   1914         t->resampler->setVolume(t->mVolume[0], t->mVolume[1]);
   1915         t->resampler->resample((int32_t*)out, outFrameCount, t->bufferProvider);
   1916     }
   1917 }
   1918 
   1919 /* This track hook is called to mix a track, when no resampling is required.
   1920  * The input buffer should be present in t->in.
   1921  *
   1922  * MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1923  * TO: int32_t (Q4.27) or float
   1924  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1925  * TA: int32_t (Q4.27)
   1926  */
   1927 template <int MIXTYPE, typename TO, typename TI, typename TA>
   1928 void AudioMixer::track__NoResample(track_t* t, TO* out, size_t frameCount,
   1929         TO* temp __unused, TA* aux)
   1930 {
   1931     ALOGVV("track__NoResample\n");
   1932     const TI *in = static_cast<const TI *>(t->in);
   1933 
   1934     volumeMix<MIXTYPE, is_same<TI, float>::value, true>(
   1935             out, frameCount, in, aux, t->needsRamp(), t);
   1936 
   1937     // MIXTYPE_MONOEXPAND reads a single input channel and expands to NCHAN output channels.
   1938     // MIXTYPE_MULTI reads NCHAN input channels and places to NCHAN output channels.
   1939     in += (MIXTYPE == MIXTYPE_MONOEXPAND) ? frameCount : frameCount * t->mMixerChannelCount;
   1940     t->in = in;
   1941 }
   1942 
   1943 /* The Mixer engine generates either int32_t (Q4_27) or float data.
   1944  * We use this function to convert the engine buffers
   1945  * to the desired mixer output format, either int16_t (Q.15) or float.
   1946  */
   1947 void AudioMixer::convertMixerFormat(void *out, audio_format_t mixerOutFormat,
   1948         void *in, audio_format_t mixerInFormat, size_t sampleCount)
   1949 {
   1950     switch (mixerInFormat) {
   1951     case AUDIO_FORMAT_PCM_FLOAT:
   1952         switch (mixerOutFormat) {
   1953         case AUDIO_FORMAT_PCM_FLOAT:
   1954             memcpy(out, in, sampleCount * sizeof(float)); // MEMCPY. TODO optimize out
   1955             break;
   1956         case AUDIO_FORMAT_PCM_16_BIT:
   1957             memcpy_to_i16_from_float((int16_t*)out, (float*)in, sampleCount);
   1958             break;
   1959         default:
   1960             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   1961             break;
   1962         }
   1963         break;
   1964     case AUDIO_FORMAT_PCM_16_BIT:
   1965         switch (mixerOutFormat) {
   1966         case AUDIO_FORMAT_PCM_FLOAT:
   1967             memcpy_to_float_from_q4_27((float*)out, (int32_t*)in, sampleCount);
   1968             break;
   1969         case AUDIO_FORMAT_PCM_16_BIT:
   1970             // two int16_t are produced per iteration
   1971             ditherAndClamp((int32_t*)out, (int32_t*)in, sampleCount >> 1);
   1972             break;
   1973         default:
   1974             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   1975             break;
   1976         }
   1977         break;
   1978     default:
   1979         LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   1980         break;
   1981     }
   1982 }
   1983 
   1984 /* Returns the proper track hook to use for mixing the track into the output buffer.
   1985  */
   1986 AudioMixer::hook_t AudioMixer::getTrackHook(int trackType, uint32_t channelCount,
   1987         audio_format_t mixerInFormat, audio_format_t mixerOutFormat __unused)
   1988 {
   1989     if (!kUseNewMixer && channelCount == FCC_2 && mixerInFormat == AUDIO_FORMAT_PCM_16_BIT) {
   1990         switch (trackType) {
   1991         case TRACKTYPE_NOP:
   1992             return track__nop;
   1993         case TRACKTYPE_RESAMPLE:
   1994             return track__genericResample;
   1995         case TRACKTYPE_NORESAMPLEMONO:
   1996             return track__16BitsMono;
   1997         case TRACKTYPE_NORESAMPLE:
   1998             return track__16BitsStereo;
   1999         default:
   2000             LOG_ALWAYS_FATAL("bad trackType: %d", trackType);
   2001             break;
   2002         }
   2003     }
   2004     LOG_ALWAYS_FATAL_IF(channelCount > MAX_NUM_CHANNELS);
   2005     switch (trackType) {
   2006     case TRACKTYPE_NOP:
   2007         return track__nop;
   2008     case TRACKTYPE_RESAMPLE:
   2009         switch (mixerInFormat) {
   2010         case AUDIO_FORMAT_PCM_FLOAT:
   2011             return (AudioMixer::hook_t)
   2012                     track__Resample<MIXTYPE_MULTI, float /*TO*/, float /*TI*/, int32_t /*TA*/>;
   2013         case AUDIO_FORMAT_PCM_16_BIT:
   2014             return (AudioMixer::hook_t)\
   2015                     track__Resample<MIXTYPE_MULTI, int32_t, int16_t, int32_t>;
   2016         default:
   2017             LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2018             break;
   2019         }
   2020         break;
   2021     case TRACKTYPE_NORESAMPLEMONO:
   2022         switch (mixerInFormat) {
   2023         case AUDIO_FORMAT_PCM_FLOAT:
   2024             return (AudioMixer::hook_t)
   2025                     track__NoResample<MIXTYPE_MONOEXPAND, float, float, int32_t>;
   2026         case AUDIO_FORMAT_PCM_16_BIT:
   2027             return (AudioMixer::hook_t)
   2028                     track__NoResample<MIXTYPE_MONOEXPAND, int32_t, int16_t, int32_t>;
   2029         default:
   2030             LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2031             break;
   2032         }
   2033         break;
   2034     case TRACKTYPE_NORESAMPLE:
   2035         switch (mixerInFormat) {
   2036         case AUDIO_FORMAT_PCM_FLOAT:
   2037             return (AudioMixer::hook_t)
   2038                     track__NoResample<MIXTYPE_MULTI, float, float, int32_t>;
   2039         case AUDIO_FORMAT_PCM_16_BIT:
   2040             return (AudioMixer::hook_t)
   2041                     track__NoResample<MIXTYPE_MULTI, int32_t, int16_t, int32_t>;
   2042         default:
   2043             LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2044             break;
   2045         }
   2046         break;
   2047     default:
   2048         LOG_ALWAYS_FATAL("bad trackType: %d", trackType);
   2049         break;
   2050     }
   2051     return NULL;
   2052 }
   2053 
   2054 /* Returns the proper process hook for mixing tracks. Currently works only for
   2055  * PROCESSTYPE_NORESAMPLEONETRACK, a mix involving one track, no resampling.
   2056  *
   2057  * TODO: Due to the special mixing considerations of duplicating to
   2058  * a stereo output track, the input track cannot be MONO.  This should be
   2059  * prevented by the caller.
   2060  */
   2061 AudioMixer::process_hook_t AudioMixer::getProcessHook(int processType, uint32_t channelCount,
   2062         audio_format_t mixerInFormat, audio_format_t mixerOutFormat)
   2063 {
   2064     if (processType != PROCESSTYPE_NORESAMPLEONETRACK) { // Only NORESAMPLEONETRACK
   2065         LOG_ALWAYS_FATAL("bad processType: %d", processType);
   2066         return NULL;
   2067     }
   2068     if (!kUseNewMixer && channelCount == FCC_2 && mixerInFormat == AUDIO_FORMAT_PCM_16_BIT) {
   2069         return process__OneTrack16BitsStereoNoResampling;
   2070     }
   2071     LOG_ALWAYS_FATAL_IF(channelCount > MAX_NUM_CHANNELS);
   2072     switch (mixerInFormat) {
   2073     case AUDIO_FORMAT_PCM_FLOAT:
   2074         switch (mixerOutFormat) {
   2075         case AUDIO_FORMAT_PCM_FLOAT:
   2076             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2077                     float /*TO*/, float /*TI*/, int32_t /*TA*/>;
   2078         case AUDIO_FORMAT_PCM_16_BIT:
   2079             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2080                     int16_t, float, int32_t>;
   2081         default:
   2082             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   2083             break;
   2084         }
   2085         break;
   2086     case AUDIO_FORMAT_PCM_16_BIT:
   2087         switch (mixerOutFormat) {
   2088         case AUDIO_FORMAT_PCM_FLOAT:
   2089             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2090                     float, int16_t, int32_t>;
   2091         case AUDIO_FORMAT_PCM_16_BIT:
   2092             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2093                     int16_t, int16_t, int32_t>;
   2094         default:
   2095             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   2096             break;
   2097         }
   2098         break;
   2099     default:
   2100         LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2101         break;
   2102     }
   2103     return NULL;
   2104 }
   2105 
   2106 // ----------------------------------------------------------------------------
   2107 } // namespace android
   2108