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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 <stdint.h>
     22 #include <string.h>
     23 #include <stdlib.h>
     24 #include <math.h>
     25 #include <sys/types.h>
     26 
     27 #include <utils/Errors.h>
     28 #include <utils/Log.h>
     29 
     30 #include <cutils/compiler.h>
     31 #include <utils/Debug.h>
     32 
     33 #include <system/audio.h>
     34 
     35 #include <audio_utils/primitives.h>
     36 #include <audio_utils/format.h>
     37 #include <media/AudioMixer.h>
     38 
     39 #include "AudioMixerOps.h"
     40 
     41 // The FCC_2 macro refers to the Fixed Channel Count of 2 for the legacy integer mixer.
     42 #ifndef FCC_2
     43 #define FCC_2 2
     44 #endif
     45 
     46 // Look for MONO_HACK for any Mono hack involving legacy mono channel to
     47 // stereo channel conversion.
     48 
     49 /* VERY_VERY_VERBOSE_LOGGING will show exactly which process hook and track hook is
     50  * being used. This is a considerable amount of log spam, so don't enable unless you
     51  * are verifying the hook based code.
     52  */
     53 //#define VERY_VERY_VERBOSE_LOGGING
     54 #ifdef VERY_VERY_VERBOSE_LOGGING
     55 #define ALOGVV ALOGV
     56 //define ALOGVV printf  // for test-mixer.cpp
     57 #else
     58 #define ALOGVV(a...) do { } while (0)
     59 #endif
     60 
     61 #ifndef ARRAY_SIZE
     62 #define ARRAY_SIZE(x) (sizeof(x)/sizeof((x)[0]))
     63 #endif
     64 
     65 // TODO: Move these macro/inlines to a header file.
     66 template <typename T>
     67 static inline
     68 T max(const T& x, const T& y) {
     69     return x > y ? x : y;
     70 }
     71 
     72 // Set kUseNewMixer to true to use the new mixer engine always. Otherwise the
     73 // original code will be used for stereo sinks, the new mixer for multichannel.
     74 static const bool kUseNewMixer = true;
     75 
     76 // Set kUseFloat to true to allow floating input into the mixer engine.
     77 // If kUseNewMixer is false, this is ignored or may be overridden internally
     78 // because of downmix/upmix support.
     79 static const bool kUseFloat = true;
     80 
     81 // Set to default copy buffer size in frames for input processing.
     82 static const size_t kCopyBufferFrameCount = 256;
     83 
     84 namespace android {
     85 
     86 // ----------------------------------------------------------------------------
     87 
     88 template <typename T>
     89 T min(const T& a, const T& b)
     90 {
     91     return a < b ? a : b;
     92 }
     93 
     94 // ----------------------------------------------------------------------------
     95 
     96 // Ensure mConfiguredNames bitmask is initialized properly on all architectures.
     97 // The value of 1 << x is undefined in C when x >= 32.
     98 
     99 AudioMixer::AudioMixer(size_t frameCount, uint32_t sampleRate, uint32_t maxNumTracks)
    100     :   mTrackNames(0), mConfiguredNames((maxNumTracks >= 32 ? 0 : 1 << maxNumTracks) - 1),
    101         mSampleRate(sampleRate)
    102 {
    103     ALOG_ASSERT(maxNumTracks <= MAX_NUM_TRACKS, "maxNumTracks %u > MAX_NUM_TRACKS %u",
    104             maxNumTracks, MAX_NUM_TRACKS);
    105 
    106     // AudioMixer is not yet capable of more than 32 active track inputs
    107     ALOG_ASSERT(32 >= MAX_NUM_TRACKS, "bad MAX_NUM_TRACKS %d", MAX_NUM_TRACKS);
    108 
    109     pthread_once(&sOnceControl, &sInitRoutine);
    110 
    111     mState.enabledTracks= 0;
    112     mState.needsChanged = 0;
    113     mState.frameCount   = frameCount;
    114     mState.hook         = process__nop;
    115     mState.outputTemp   = NULL;
    116     mState.resampleTemp = NULL;
    117     mState.mNBLogWriter = &mDummyLogWriter;
    118     // mState.reserved
    119 
    120     // FIXME Most of the following initialization is probably redundant since
    121     // tracks[i] should only be referenced if (mTrackNames & (1 << i)) != 0
    122     // and mTrackNames is initially 0.  However, leave it here until that's verified.
    123     track_t* t = mState.tracks;
    124     for (unsigned i=0 ; i < MAX_NUM_TRACKS ; i++) {
    125         t->resampler = NULL;
    126         t->downmixerBufferProvider = NULL;
    127         t->mReformatBufferProvider = NULL;
    128         t->mTimestretchBufferProvider = NULL;
    129         t++;
    130     }
    131 
    132 }
    133 
    134 AudioMixer::~AudioMixer()
    135 {
    136     track_t* t = mState.tracks;
    137     for (unsigned i=0 ; i < MAX_NUM_TRACKS ; i++) {
    138         delete t->resampler;
    139         delete t->downmixerBufferProvider;
    140         delete t->mReformatBufferProvider;
    141         delete t->mTimestretchBufferProvider;
    142         t++;
    143     }
    144     delete [] mState.outputTemp;
    145     delete [] mState.resampleTemp;
    146 }
    147 
    148 void AudioMixer::setNBLogWriter(NBLog::Writer *logWriter)
    149 {
    150     mState.mNBLogWriter = logWriter;
    151 }
    152 
    153 static inline audio_format_t selectMixerInFormat(audio_format_t inputFormat __unused) {
    154     return kUseFloat && kUseNewMixer ? AUDIO_FORMAT_PCM_FLOAT : AUDIO_FORMAT_PCM_16_BIT;
    155 }
    156 
    157 int AudioMixer::getTrackName(audio_channel_mask_t channelMask,
    158         audio_format_t format, int sessionId)
    159 {
    160     if (!isValidPcmTrackFormat(format)) {
    161         ALOGE("AudioMixer::getTrackName invalid format (%#x)", format);
    162         return -1;
    163     }
    164     uint32_t names = (~mTrackNames) & mConfiguredNames;
    165     if (names != 0) {
    166         int n = __builtin_ctz(names);
    167         ALOGV("add track (%d)", n);
    168         // assume default parameters for the track, except where noted below
    169         track_t* t = &mState.tracks[n];
    170         t->needs = 0;
    171 
    172         // Integer volume.
    173         // Currently integer volume is kept for the legacy integer mixer.
    174         // Will be removed when the legacy mixer path is removed.
    175         t->volume[0] = UNITY_GAIN_INT;
    176         t->volume[1] = UNITY_GAIN_INT;
    177         t->prevVolume[0] = UNITY_GAIN_INT << 16;
    178         t->prevVolume[1] = UNITY_GAIN_INT << 16;
    179         t->volumeInc[0] = 0;
    180         t->volumeInc[1] = 0;
    181         t->auxLevel = 0;
    182         t->auxInc = 0;
    183         t->prevAuxLevel = 0;
    184 
    185         // Floating point volume.
    186         t->mVolume[0] = UNITY_GAIN_FLOAT;
    187         t->mVolume[1] = UNITY_GAIN_FLOAT;
    188         t->mPrevVolume[0] = UNITY_GAIN_FLOAT;
    189         t->mPrevVolume[1] = UNITY_GAIN_FLOAT;
    190         t->mVolumeInc[0] = 0.;
    191         t->mVolumeInc[1] = 0.;
    192         t->mAuxLevel = 0.;
    193         t->mAuxInc = 0.;
    194         t->mPrevAuxLevel = 0.;
    195 
    196         // no initialization needed
    197         // t->frameCount
    198         t->channelCount = audio_channel_count_from_out_mask(channelMask);
    199         t->enabled = false;
    200         ALOGV_IF(audio_channel_mask_get_bits(channelMask) != AUDIO_CHANNEL_OUT_STEREO,
    201                 "Non-stereo channel mask: %d\n", channelMask);
    202         t->channelMask = channelMask;
    203         t->sessionId = sessionId;
    204         // setBufferProvider(name, AudioBufferProvider *) is required before enable(name)
    205         t->bufferProvider = NULL;
    206         t->buffer.raw = NULL;
    207         // no initialization needed
    208         // t->buffer.frameCount
    209         t->hook = NULL;
    210         t->in = NULL;
    211         t->resampler = NULL;
    212         t->sampleRate = mSampleRate;
    213         // setParameter(name, TRACK, MAIN_BUFFER, mixBuffer) is required before enable(name)
    214         t->mainBuffer = NULL;
    215         t->auxBuffer = NULL;
    216         t->mInputBufferProvider = NULL;
    217         t->mReformatBufferProvider = NULL;
    218         t->downmixerBufferProvider = NULL;
    219         t->mPostDownmixReformatBufferProvider = NULL;
    220         t->mTimestretchBufferProvider = NULL;
    221         t->mMixerFormat = AUDIO_FORMAT_PCM_16_BIT;
    222         t->mFormat = format;
    223         t->mMixerInFormat = selectMixerInFormat(format);
    224         t->mDownmixRequiresFormat = AUDIO_FORMAT_INVALID; // no format required
    225         t->mMixerChannelMask = audio_channel_mask_from_representation_and_bits(
    226                 AUDIO_CHANNEL_REPRESENTATION_POSITION, AUDIO_CHANNEL_OUT_STEREO);
    227         t->mMixerChannelCount = audio_channel_count_from_out_mask(t->mMixerChannelMask);
    228         t->mPlaybackRate = AUDIO_PLAYBACK_RATE_DEFAULT;
    229         // Check the downmixing (or upmixing) requirements.
    230         status_t status = t->prepareForDownmix();
    231         if (status != OK) {
    232             ALOGE("AudioMixer::getTrackName invalid channelMask (%#x)", channelMask);
    233             return -1;
    234         }
    235         // prepareForDownmix() may change mDownmixRequiresFormat
    236         ALOGVV("mMixerFormat:%#x  mMixerInFormat:%#x\n", t->mMixerFormat, t->mMixerInFormat);
    237         t->prepareForReformat();
    238         mTrackNames |= 1 << n;
    239         return TRACK0 + n;
    240     }
    241     ALOGE("AudioMixer::getTrackName out of available tracks");
    242     return -1;
    243 }
    244 
    245 void AudioMixer::invalidateState(uint32_t mask)
    246 {
    247     if (mask != 0) {
    248         mState.needsChanged |= mask;
    249         mState.hook = process__validate;
    250     }
    251  }
    252 
    253 // Called when channel masks have changed for a track name
    254 // TODO: Fix DownmixerBufferProvider not to (possibly) change mixer input format,
    255 // which will simplify this logic.
    256 bool AudioMixer::setChannelMasks(int name,
    257         audio_channel_mask_t trackChannelMask, audio_channel_mask_t mixerChannelMask) {
    258     track_t &track = mState.tracks[name];
    259 
    260     if (trackChannelMask == track.channelMask
    261             && mixerChannelMask == track.mMixerChannelMask) {
    262         return false;  // no need to change
    263     }
    264     // always recompute for both channel masks even if only one has changed.
    265     const uint32_t trackChannelCount = audio_channel_count_from_out_mask(trackChannelMask);
    266     const uint32_t mixerChannelCount = audio_channel_count_from_out_mask(mixerChannelMask);
    267     const bool mixerChannelCountChanged = track.mMixerChannelCount != mixerChannelCount;
    268 
    269     ALOG_ASSERT((trackChannelCount <= MAX_NUM_CHANNELS_TO_DOWNMIX)
    270             && trackChannelCount
    271             && mixerChannelCount);
    272     track.channelMask = trackChannelMask;
    273     track.channelCount = trackChannelCount;
    274     track.mMixerChannelMask = mixerChannelMask;
    275     track.mMixerChannelCount = mixerChannelCount;
    276 
    277     // channel masks have changed, does this track need a downmixer?
    278     // update to try using our desired format (if we aren't already using it)
    279     const audio_format_t prevDownmixerFormat = track.mDownmixRequiresFormat;
    280     const status_t status = mState.tracks[name].prepareForDownmix();
    281     ALOGE_IF(status != OK,
    282             "prepareForDownmix error %d, track channel mask %#x, mixer channel mask %#x",
    283             status, track.channelMask, track.mMixerChannelMask);
    284 
    285     if (prevDownmixerFormat != track.mDownmixRequiresFormat) {
    286         track.prepareForReformat(); // because of downmixer, track format may change!
    287     }
    288 
    289     if (track.resampler && mixerChannelCountChanged) {
    290         // resampler channels may have changed.
    291         const uint32_t resetToSampleRate = track.sampleRate;
    292         delete track.resampler;
    293         track.resampler = NULL;
    294         track.sampleRate = mSampleRate; // without resampler, track rate is device sample rate.
    295         // recreate the resampler with updated format, channels, saved sampleRate.
    296         track.setResampler(resetToSampleRate /*trackSampleRate*/, mSampleRate /*devSampleRate*/);
    297     }
    298     return true;
    299 }
    300 
    301 void AudioMixer::track_t::unprepareForDownmix() {
    302     ALOGV("AudioMixer::unprepareForDownmix(%p)", this);
    303 
    304     if (mPostDownmixReformatBufferProvider != nullptr) {
    305         // release any buffers held by the mPostDownmixReformatBufferProvider
    306         // before deallocating the downmixerBufferProvider.
    307         mPostDownmixReformatBufferProvider->reset();
    308     }
    309 
    310     mDownmixRequiresFormat = AUDIO_FORMAT_INVALID;
    311     if (downmixerBufferProvider != NULL) {
    312         // this track had previously been configured with a downmixer, delete it
    313         ALOGV(" deleting old downmixer");
    314         delete downmixerBufferProvider;
    315         downmixerBufferProvider = NULL;
    316         reconfigureBufferProviders();
    317     } else {
    318         ALOGV(" nothing to do, no downmixer to delete");
    319     }
    320 }
    321 
    322 status_t AudioMixer::track_t::prepareForDownmix()
    323 {
    324     ALOGV("AudioMixer::prepareForDownmix(%p) with mask 0x%x",
    325             this, channelMask);
    326 
    327     // discard the previous downmixer if there was one
    328     unprepareForDownmix();
    329     // MONO_HACK Only remix (upmix or downmix) if the track and mixer/device channel masks
    330     // are not the same and not handled internally, as mono -> stereo currently is.
    331     if (channelMask == mMixerChannelMask
    332             || (channelMask == AUDIO_CHANNEL_OUT_MONO
    333                     && mMixerChannelMask == AUDIO_CHANNEL_OUT_STEREO)) {
    334         return NO_ERROR;
    335     }
    336     // DownmixerBufferProvider is only used for position masks.
    337     if (audio_channel_mask_get_representation(channelMask)
    338                 == AUDIO_CHANNEL_REPRESENTATION_POSITION
    339             && DownmixerBufferProvider::isMultichannelCapable()) {
    340         DownmixerBufferProvider* pDbp = new DownmixerBufferProvider(channelMask,
    341                 mMixerChannelMask,
    342                 AUDIO_FORMAT_PCM_16_BIT /* TODO: use mMixerInFormat, now only PCM 16 */,
    343                 sampleRate, sessionId, kCopyBufferFrameCount);
    344 
    345         if (pDbp->isValid()) { // if constructor completed properly
    346             mDownmixRequiresFormat = AUDIO_FORMAT_PCM_16_BIT; // PCM 16 bit required for downmix
    347             downmixerBufferProvider = pDbp;
    348             reconfigureBufferProviders();
    349             return NO_ERROR;
    350         }
    351         delete pDbp;
    352     }
    353 
    354     // Effect downmixer does not accept the channel conversion.  Let's use our remixer.
    355     RemixBufferProvider* pRbp = new RemixBufferProvider(channelMask,
    356             mMixerChannelMask, mMixerInFormat, kCopyBufferFrameCount);
    357     // Remix always finds a conversion whereas Downmixer effect above may fail.
    358     downmixerBufferProvider = pRbp;
    359     reconfigureBufferProviders();
    360     return NO_ERROR;
    361 }
    362 
    363 void AudioMixer::track_t::unprepareForReformat() {
    364     ALOGV("AudioMixer::unprepareForReformat(%p)", this);
    365     bool requiresReconfigure = false;
    366     if (mReformatBufferProvider != NULL) {
    367         delete mReformatBufferProvider;
    368         mReformatBufferProvider = NULL;
    369         requiresReconfigure = true;
    370     }
    371     if (mPostDownmixReformatBufferProvider != NULL) {
    372         delete mPostDownmixReformatBufferProvider;
    373         mPostDownmixReformatBufferProvider = NULL;
    374         requiresReconfigure = true;
    375     }
    376     if (requiresReconfigure) {
    377         reconfigureBufferProviders();
    378     }
    379 }
    380 
    381 status_t AudioMixer::track_t::prepareForReformat()
    382 {
    383     ALOGV("AudioMixer::prepareForReformat(%p) with format %#x", this, mFormat);
    384     // discard previous reformatters
    385     unprepareForReformat();
    386     // only configure reformatters as needed
    387     const audio_format_t targetFormat = mDownmixRequiresFormat != AUDIO_FORMAT_INVALID
    388             ? mDownmixRequiresFormat : mMixerInFormat;
    389     bool requiresReconfigure = false;
    390     if (mFormat != targetFormat) {
    391         mReformatBufferProvider = new ReformatBufferProvider(
    392                 audio_channel_count_from_out_mask(channelMask),
    393                 mFormat,
    394                 targetFormat,
    395                 kCopyBufferFrameCount);
    396         requiresReconfigure = true;
    397     }
    398     if (targetFormat != mMixerInFormat) {
    399         mPostDownmixReformatBufferProvider = new ReformatBufferProvider(
    400                 audio_channel_count_from_out_mask(mMixerChannelMask),
    401                 targetFormat,
    402                 mMixerInFormat,
    403                 kCopyBufferFrameCount);
    404         requiresReconfigure = true;
    405     }
    406     if (requiresReconfigure) {
    407         reconfigureBufferProviders();
    408     }
    409     return NO_ERROR;
    410 }
    411 
    412 void AudioMixer::track_t::reconfigureBufferProviders()
    413 {
    414     bufferProvider = mInputBufferProvider;
    415     if (mReformatBufferProvider) {
    416         mReformatBufferProvider->setBufferProvider(bufferProvider);
    417         bufferProvider = mReformatBufferProvider;
    418     }
    419     if (downmixerBufferProvider) {
    420         downmixerBufferProvider->setBufferProvider(bufferProvider);
    421         bufferProvider = downmixerBufferProvider;
    422     }
    423     if (mPostDownmixReformatBufferProvider) {
    424         mPostDownmixReformatBufferProvider->setBufferProvider(bufferProvider);
    425         bufferProvider = mPostDownmixReformatBufferProvider;
    426     }
    427     if (mTimestretchBufferProvider) {
    428         mTimestretchBufferProvider->setBufferProvider(bufferProvider);
    429         bufferProvider = mTimestretchBufferProvider;
    430     }
    431 }
    432 
    433 void AudioMixer::deleteTrackName(int name)
    434 {
    435     ALOGV("AudioMixer::deleteTrackName(%d)", name);
    436     name -= TRACK0;
    437     LOG_ALWAYS_FATAL_IF(name < 0 || name >= (int)MAX_NUM_TRACKS, "bad track name %d", name);
    438     ALOGV("deleteTrackName(%d)", name);
    439     track_t& track(mState.tracks[ name ]);
    440     if (track.enabled) {
    441         track.enabled = false;
    442         invalidateState(1<<name);
    443     }
    444     // delete the resampler
    445     delete track.resampler;
    446     track.resampler = NULL;
    447     // delete the downmixer
    448     mState.tracks[name].unprepareForDownmix();
    449     // delete the reformatter
    450     mState.tracks[name].unprepareForReformat();
    451     // delete the timestretch provider
    452     delete track.mTimestretchBufferProvider;
    453     track.mTimestretchBufferProvider = NULL;
    454     mTrackNames &= ~(1<<name);
    455 }
    456 
    457 void AudioMixer::enable(int name)
    458 {
    459     name -= TRACK0;
    460     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    461     track_t& track = mState.tracks[name];
    462 
    463     if (!track.enabled) {
    464         track.enabled = true;
    465         ALOGV("enable(%d)", name);
    466         invalidateState(1 << name);
    467     }
    468 }
    469 
    470 void AudioMixer::disable(int name)
    471 {
    472     name -= TRACK0;
    473     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    474     track_t& track = mState.tracks[name];
    475 
    476     if (track.enabled) {
    477         track.enabled = false;
    478         ALOGV("disable(%d)", name);
    479         invalidateState(1 << name);
    480     }
    481 }
    482 
    483 /* Sets the volume ramp variables for the AudioMixer.
    484  *
    485  * The volume ramp variables are used to transition from the previous
    486  * volume to the set volume.  ramp controls the duration of the transition.
    487  * Its value is typically one state framecount period, but may also be 0,
    488  * meaning "immediate."
    489  *
    490  * FIXME: 1) Volume ramp is enabled only if there is a nonzero integer increment
    491  * even if there is a nonzero floating point increment (in that case, the volume
    492  * change is immediate).  This restriction should be changed when the legacy mixer
    493  * is removed (see #2).
    494  * FIXME: 2) Integer volume variables are used for Legacy mixing and should be removed
    495  * when no longer needed.
    496  *
    497  * @param newVolume set volume target in floating point [0.0, 1.0].
    498  * @param ramp number of frames to increment over. if ramp is 0, the volume
    499  * should be set immediately.  Currently ramp should not exceed 65535 (frames).
    500  * @param pIntSetVolume pointer to the U4.12 integer target volume, set on return.
    501  * @param pIntPrevVolume pointer to the U4.28 integer previous volume, set on return.
    502  * @param pIntVolumeInc pointer to the U4.28 increment per output audio frame, set on return.
    503  * @param pSetVolume pointer to the float target volume, set on return.
    504  * @param pPrevVolume pointer to the float previous volume, set on return.
    505  * @param pVolumeInc pointer to the float increment per output audio frame, set on return.
    506  * @return true if the volume has changed, false if volume is same.
    507  */
    508 static inline bool setVolumeRampVariables(float newVolume, int32_t ramp,
    509         int16_t *pIntSetVolume, int32_t *pIntPrevVolume, int32_t *pIntVolumeInc,
    510         float *pSetVolume, float *pPrevVolume, float *pVolumeInc) {
    511     // check floating point volume to see if it is identical to the previously
    512     // set volume.
    513     // We do not use a tolerance here (and reject changes too small)
    514     // as it may be confusing to use a different value than the one set.
    515     // If the resulting volume is too small to ramp, it is a direct set of the volume.
    516     if (newVolume == *pSetVolume) {
    517         return false;
    518     }
    519     if (newVolume < 0) {
    520         newVolume = 0; // should not have negative volumes
    521     } else {
    522         switch (fpclassify(newVolume)) {
    523         case FP_SUBNORMAL:
    524         case FP_NAN:
    525             newVolume = 0;
    526             break;
    527         case FP_ZERO:
    528             break; // zero volume is fine
    529         case FP_INFINITE:
    530             // Infinite volume could be handled consistently since
    531             // floating point math saturates at infinities,
    532             // but we limit volume to unity gain float.
    533             // ramp = 0; break;
    534             //
    535             newVolume = AudioMixer::UNITY_GAIN_FLOAT;
    536             break;
    537         case FP_NORMAL:
    538         default:
    539             // Floating point does not have problems with overflow wrap
    540             // that integer has.  However, we limit the volume to
    541             // unity gain here.
    542             // TODO: Revisit the volume limitation and perhaps parameterize.
    543             if (newVolume > AudioMixer::UNITY_GAIN_FLOAT) {
    544                 newVolume = AudioMixer::UNITY_GAIN_FLOAT;
    545             }
    546             break;
    547         }
    548     }
    549 
    550     // set floating point volume ramp
    551     if (ramp != 0) {
    552         // when the ramp completes, *pPrevVolume is set to *pSetVolume, so there
    553         // is no computational mismatch; hence equality is checked here.
    554         ALOGD_IF(*pPrevVolume != *pSetVolume, "previous float ramp hasn't finished,"
    555                 " prev:%f  set_to:%f", *pPrevVolume, *pSetVolume);
    556         const float inc = (newVolume - *pPrevVolume) / ramp; // could be inf, nan, subnormal
    557         const float maxv = max(newVolume, *pPrevVolume); // could be inf, cannot be nan, subnormal
    558 
    559         if (isnormal(inc) // inc must be a normal number (no subnormals, infinite, nan)
    560                 && maxv + inc != maxv) { // inc must make forward progress
    561             *pVolumeInc = inc;
    562             // ramp is set now.
    563             // Note: if newVolume is 0, then near the end of the ramp,
    564             // it may be possible that the ramped volume may be subnormal or
    565             // temporarily negative by a small amount or subnormal due to floating
    566             // point inaccuracies.
    567         } else {
    568             ramp = 0; // ramp not allowed
    569         }
    570     }
    571 
    572     // compute and check integer volume, no need to check negative values
    573     // The integer volume is limited to "unity_gain" to avoid wrapping and other
    574     // audio artifacts, so it never reaches the range limit of U4.28.
    575     // We safely use signed 16 and 32 bit integers here.
    576     const float scaledVolume = newVolume * AudioMixer::UNITY_GAIN_INT; // not neg, subnormal, nan
    577     const int32_t intVolume = (scaledVolume >= (float)AudioMixer::UNITY_GAIN_INT) ?
    578             AudioMixer::UNITY_GAIN_INT : (int32_t)scaledVolume;
    579 
    580     // set integer volume ramp
    581     if (ramp != 0) {
    582         // integer volume is U4.12 (to use 16 bit multiplies), but ramping uses U4.28.
    583         // when the ramp completes, *pIntPrevVolume is set to *pIntSetVolume << 16, so there
    584         // is no computational mismatch; hence equality is checked here.
    585         ALOGD_IF(*pIntPrevVolume != *pIntSetVolume << 16, "previous int ramp hasn't finished,"
    586                 " prev:%d  set_to:%d", *pIntPrevVolume, *pIntSetVolume << 16);
    587         const int32_t inc = ((intVolume << 16) - *pIntPrevVolume) / ramp;
    588 
    589         if (inc != 0) { // inc must make forward progress
    590             *pIntVolumeInc = inc;
    591         } else {
    592             ramp = 0; // ramp not allowed
    593         }
    594     }
    595 
    596     // if no ramp, or ramp not allowed, then clear float and integer increments
    597     if (ramp == 0) {
    598         *pVolumeInc = 0;
    599         *pPrevVolume = newVolume;
    600         *pIntVolumeInc = 0;
    601         *pIntPrevVolume = intVolume << 16;
    602     }
    603     *pSetVolume = newVolume;
    604     *pIntSetVolume = intVolume;
    605     return true;
    606 }
    607 
    608 void AudioMixer::setParameter(int name, int target, int param, void *value)
    609 {
    610     name -= TRACK0;
    611     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    612     track_t& track = mState.tracks[name];
    613 
    614     int valueInt = static_cast<int>(reinterpret_cast<uintptr_t>(value));
    615     int32_t *valueBuf = reinterpret_cast<int32_t*>(value);
    616 
    617     switch (target) {
    618 
    619     case TRACK:
    620         switch (param) {
    621         case CHANNEL_MASK: {
    622             const audio_channel_mask_t trackChannelMask =
    623                 static_cast<audio_channel_mask_t>(valueInt);
    624             if (setChannelMasks(name, trackChannelMask, track.mMixerChannelMask)) {
    625                 ALOGV("setParameter(TRACK, CHANNEL_MASK, %x)", trackChannelMask);
    626                 invalidateState(1 << name);
    627             }
    628             } break;
    629         case MAIN_BUFFER:
    630             if (track.mainBuffer != valueBuf) {
    631                 track.mainBuffer = valueBuf;
    632                 ALOGV("setParameter(TRACK, MAIN_BUFFER, %p)", valueBuf);
    633                 invalidateState(1 << name);
    634             }
    635             break;
    636         case AUX_BUFFER:
    637             if (track.auxBuffer != valueBuf) {
    638                 track.auxBuffer = valueBuf;
    639                 ALOGV("setParameter(TRACK, AUX_BUFFER, %p)", valueBuf);
    640                 invalidateState(1 << name);
    641             }
    642             break;
    643         case FORMAT: {
    644             audio_format_t format = static_cast<audio_format_t>(valueInt);
    645             if (track.mFormat != format) {
    646                 ALOG_ASSERT(audio_is_linear_pcm(format), "Invalid format %#x", format);
    647                 track.mFormat = format;
    648                 ALOGV("setParameter(TRACK, FORMAT, %#x)", format);
    649                 track.prepareForReformat();
    650                 invalidateState(1 << name);
    651             }
    652             } break;
    653         // FIXME do we want to support setting the downmix type from AudioFlinger?
    654         //         for a specific track? or per mixer?
    655         /* case DOWNMIX_TYPE:
    656             break          */
    657         case MIXER_FORMAT: {
    658             audio_format_t format = static_cast<audio_format_t>(valueInt);
    659             if (track.mMixerFormat != format) {
    660                 track.mMixerFormat = format;
    661                 ALOGV("setParameter(TRACK, MIXER_FORMAT, %#x)", format);
    662             }
    663             } break;
    664         case MIXER_CHANNEL_MASK: {
    665             const audio_channel_mask_t mixerChannelMask =
    666                     static_cast<audio_channel_mask_t>(valueInt);
    667             if (setChannelMasks(name, track.channelMask, mixerChannelMask)) {
    668                 ALOGV("setParameter(TRACK, MIXER_CHANNEL_MASK, %#x)", mixerChannelMask);
    669                 invalidateState(1 << name);
    670             }
    671             } break;
    672         default:
    673             LOG_ALWAYS_FATAL("setParameter track: bad param %d", param);
    674         }
    675         break;
    676 
    677     case RESAMPLE:
    678         switch (param) {
    679         case SAMPLE_RATE:
    680             ALOG_ASSERT(valueInt > 0, "bad sample rate %d", valueInt);
    681             if (track.setResampler(uint32_t(valueInt), mSampleRate)) {
    682                 ALOGV("setParameter(RESAMPLE, SAMPLE_RATE, %u)",
    683                         uint32_t(valueInt));
    684                 invalidateState(1 << name);
    685             }
    686             break;
    687         case RESET:
    688             track.resetResampler();
    689             invalidateState(1 << name);
    690             break;
    691         case REMOVE:
    692             delete track.resampler;
    693             track.resampler = NULL;
    694             track.sampleRate = mSampleRate;
    695             invalidateState(1 << name);
    696             break;
    697         default:
    698             LOG_ALWAYS_FATAL("setParameter resample: bad param %d", param);
    699         }
    700         break;
    701 
    702     case RAMP_VOLUME:
    703     case VOLUME:
    704         switch (param) {
    705         case AUXLEVEL:
    706             if (setVolumeRampVariables(*reinterpret_cast<float*>(value),
    707                     target == RAMP_VOLUME ? mState.frameCount : 0,
    708                     &track.auxLevel, &track.prevAuxLevel, &track.auxInc,
    709                     &track.mAuxLevel, &track.mPrevAuxLevel, &track.mAuxInc)) {
    710                 ALOGV("setParameter(%s, AUXLEVEL: %04x)",
    711                         target == VOLUME ? "VOLUME" : "RAMP_VOLUME", track.auxLevel);
    712                 invalidateState(1 << name);
    713             }
    714             break;
    715         default:
    716             if ((unsigned)param >= VOLUME0 && (unsigned)param < VOLUME0 + MAX_NUM_VOLUMES) {
    717                 if (setVolumeRampVariables(*reinterpret_cast<float*>(value),
    718                         target == RAMP_VOLUME ? mState.frameCount : 0,
    719                         &track.volume[param - VOLUME0], &track.prevVolume[param - VOLUME0],
    720                         &track.volumeInc[param - VOLUME0],
    721                         &track.mVolume[param - VOLUME0], &track.mPrevVolume[param - VOLUME0],
    722                         &track.mVolumeInc[param - VOLUME0])) {
    723                     ALOGV("setParameter(%s, VOLUME%d: %04x)",
    724                             target == VOLUME ? "VOLUME" : "RAMP_VOLUME", param - VOLUME0,
    725                                     track.volume[param - VOLUME0]);
    726                     invalidateState(1 << name);
    727                 }
    728             } else {
    729                 LOG_ALWAYS_FATAL("setParameter volume: bad param %d", param);
    730             }
    731         }
    732         break;
    733         case TIMESTRETCH:
    734             switch (param) {
    735             case PLAYBACK_RATE: {
    736                 const AudioPlaybackRate *playbackRate =
    737                         reinterpret_cast<AudioPlaybackRate*>(value);
    738                 ALOGW_IF(!isAudioPlaybackRateValid(*playbackRate),
    739                         "bad parameters speed %f, pitch %f",playbackRate->mSpeed,
    740                         playbackRate->mPitch);
    741                 if (track.setPlaybackRate(*playbackRate)) {
    742                     ALOGV("setParameter(TIMESTRETCH, PLAYBACK_RATE, STRETCH_MODE, FALLBACK_MODE "
    743                             "%f %f %d %d",
    744                             playbackRate->mSpeed,
    745                             playbackRate->mPitch,
    746                             playbackRate->mStretchMode,
    747                             playbackRate->mFallbackMode);
    748                     // invalidateState(1 << name);
    749                 }
    750             } break;
    751             default:
    752                 LOG_ALWAYS_FATAL("setParameter timestretch: bad param %d", param);
    753             }
    754             break;
    755 
    756     default:
    757         LOG_ALWAYS_FATAL("setParameter: bad target %d", target);
    758     }
    759 }
    760 
    761 bool AudioMixer::track_t::setResampler(uint32_t trackSampleRate, uint32_t devSampleRate)
    762 {
    763     if (trackSampleRate != devSampleRate || resampler != NULL) {
    764         if (sampleRate != trackSampleRate) {
    765             sampleRate = trackSampleRate;
    766             if (resampler == NULL) {
    767                 ALOGV("Creating resampler from track %d Hz to device %d Hz",
    768                         trackSampleRate, devSampleRate);
    769                 AudioResampler::src_quality quality;
    770                 // force lowest quality level resampler if use case isn't music or video
    771                 // FIXME this is flawed for dynamic sample rates, as we choose the resampler
    772                 // quality level based on the initial ratio, but that could change later.
    773                 // Should have a way to distinguish tracks with static ratios vs. dynamic ratios.
    774                 if (isMusicRate(trackSampleRate)) {
    775                     quality = AudioResampler::DEFAULT_QUALITY;
    776                 } else {
    777                     quality = AudioResampler::DYN_LOW_QUALITY;
    778                 }
    779 
    780                 // TODO: Remove MONO_HACK. Resampler sees #channels after the downmixer
    781                 // but if none exists, it is the channel count (1 for mono).
    782                 const int resamplerChannelCount = downmixerBufferProvider != NULL
    783                         ? mMixerChannelCount : channelCount;
    784                 ALOGVV("Creating resampler:"
    785                         " format(%#x) channels(%d) devSampleRate(%u) quality(%d)\n",
    786                         mMixerInFormat, resamplerChannelCount, devSampleRate, quality);
    787                 resampler = AudioResampler::create(
    788                         mMixerInFormat,
    789                         resamplerChannelCount,
    790                         devSampleRate, quality);
    791             }
    792             return true;
    793         }
    794     }
    795     return false;
    796 }
    797 
    798 bool AudioMixer::track_t::setPlaybackRate(const AudioPlaybackRate &playbackRate)
    799 {
    800     if ((mTimestretchBufferProvider == NULL &&
    801             fabs(playbackRate.mSpeed - mPlaybackRate.mSpeed) < AUDIO_TIMESTRETCH_SPEED_MIN_DELTA &&
    802             fabs(playbackRate.mPitch - mPlaybackRate.mPitch) < AUDIO_TIMESTRETCH_PITCH_MIN_DELTA) ||
    803             isAudioPlaybackRateEqual(playbackRate, mPlaybackRate)) {
    804         return false;
    805     }
    806     mPlaybackRate = playbackRate;
    807     if (mTimestretchBufferProvider == NULL) {
    808         // TODO: Remove MONO_HACK. Resampler sees #channels after the downmixer
    809         // but if none exists, it is the channel count (1 for mono).
    810         const int timestretchChannelCount = downmixerBufferProvider != NULL
    811                 ? mMixerChannelCount : channelCount;
    812         mTimestretchBufferProvider = new TimestretchBufferProvider(timestretchChannelCount,
    813                 mMixerInFormat, sampleRate, playbackRate);
    814         reconfigureBufferProviders();
    815     } else {
    816         reinterpret_cast<TimestretchBufferProvider*>(mTimestretchBufferProvider)
    817                 ->setPlaybackRate(playbackRate);
    818     }
    819     return true;
    820 }
    821 
    822 /* Checks to see if the volume ramp has completed and clears the increment
    823  * variables appropriately.
    824  *
    825  * FIXME: There is code to handle int/float ramp variable switchover should it not
    826  * complete within a mixer buffer processing call, but it is preferred to avoid switchover
    827  * due to precision issues.  The switchover code is included for legacy code purposes
    828  * and can be removed once the integer volume is removed.
    829  *
    830  * It is not sufficient to clear only the volumeInc integer variable because
    831  * if one channel requires ramping, all channels are ramped.
    832  *
    833  * There is a bit of duplicated code here, but it keeps backward compatibility.
    834  */
    835 inline void AudioMixer::track_t::adjustVolumeRamp(bool aux, bool useFloat)
    836 {
    837     if (useFloat) {
    838         for (uint32_t i = 0; i < MAX_NUM_VOLUMES; i++) {
    839             if ((mVolumeInc[i] > 0 && mPrevVolume[i] + mVolumeInc[i] >= mVolume[i]) ||
    840                      (mVolumeInc[i] < 0 && mPrevVolume[i] + mVolumeInc[i] <= mVolume[i])) {
    841                 volumeInc[i] = 0;
    842                 prevVolume[i] = volume[i] << 16;
    843                 mVolumeInc[i] = 0.;
    844                 mPrevVolume[i] = mVolume[i];
    845             } else {
    846                 //ALOGV("ramp: %f %f %f", mVolume[i], mPrevVolume[i], mVolumeInc[i]);
    847                 prevVolume[i] = u4_28_from_float(mPrevVolume[i]);
    848             }
    849         }
    850     } else {
    851         for (uint32_t i = 0; i < MAX_NUM_VOLUMES; i++) {
    852             if (((volumeInc[i]>0) && (((prevVolume[i]+volumeInc[i])>>16) >= volume[i])) ||
    853                     ((volumeInc[i]<0) && (((prevVolume[i]+volumeInc[i])>>16) <= volume[i]))) {
    854                 volumeInc[i] = 0;
    855                 prevVolume[i] = volume[i] << 16;
    856                 mVolumeInc[i] = 0.;
    857                 mPrevVolume[i] = mVolume[i];
    858             } else {
    859                 //ALOGV("ramp: %d %d %d", volume[i] << 16, prevVolume[i], volumeInc[i]);
    860                 mPrevVolume[i]  = float_from_u4_28(prevVolume[i]);
    861             }
    862         }
    863     }
    864     /* TODO: aux is always integer regardless of output buffer type */
    865     if (aux) {
    866         if (((auxInc>0) && (((prevAuxLevel+auxInc)>>16) >= auxLevel)) ||
    867                 ((auxInc<0) && (((prevAuxLevel+auxInc)>>16) <= auxLevel))) {
    868             auxInc = 0;
    869             prevAuxLevel = auxLevel << 16;
    870             mAuxInc = 0.;
    871             mPrevAuxLevel = mAuxLevel;
    872         } else {
    873             //ALOGV("aux ramp: %d %d %d", auxLevel << 16, prevAuxLevel, auxInc);
    874         }
    875     }
    876 }
    877 
    878 size_t AudioMixer::getUnreleasedFrames(int name) const
    879 {
    880     name -= TRACK0;
    881     if (uint32_t(name) < MAX_NUM_TRACKS) {
    882         return mState.tracks[name].getUnreleasedFrames();
    883     }
    884     return 0;
    885 }
    886 
    887 void AudioMixer::setBufferProvider(int name, AudioBufferProvider* bufferProvider)
    888 {
    889     name -= TRACK0;
    890     ALOG_ASSERT(uint32_t(name) < MAX_NUM_TRACKS, "bad track name %d", name);
    891 
    892     if (mState.tracks[name].mInputBufferProvider == bufferProvider) {
    893         return; // don't reset any buffer providers if identical.
    894     }
    895     if (mState.tracks[name].mReformatBufferProvider != NULL) {
    896         mState.tracks[name].mReformatBufferProvider->reset();
    897     } else if (mState.tracks[name].downmixerBufferProvider != NULL) {
    898         mState.tracks[name].downmixerBufferProvider->reset();
    899     } else if (mState.tracks[name].mPostDownmixReformatBufferProvider != NULL) {
    900         mState.tracks[name].mPostDownmixReformatBufferProvider->reset();
    901     } else if (mState.tracks[name].mTimestretchBufferProvider != NULL) {
    902         mState.tracks[name].mTimestretchBufferProvider->reset();
    903     }
    904 
    905     mState.tracks[name].mInputBufferProvider = bufferProvider;
    906     mState.tracks[name].reconfigureBufferProviders();
    907 }
    908 
    909 
    910 void AudioMixer::process()
    911 {
    912     mState.hook(&mState);
    913 }
    914 
    915 
    916 void AudioMixer::process__validate(state_t* state)
    917 {
    918     ALOGW_IF(!state->needsChanged,
    919         "in process__validate() but nothing's invalid");
    920 
    921     uint32_t changed = state->needsChanged;
    922     state->needsChanged = 0; // clear the validation flag
    923 
    924     // recompute which tracks are enabled / disabled
    925     uint32_t enabled = 0;
    926     uint32_t disabled = 0;
    927     while (changed) {
    928         const int i = 31 - __builtin_clz(changed);
    929         const uint32_t mask = 1<<i;
    930         changed &= ~mask;
    931         track_t& t = state->tracks[i];
    932         (t.enabled ? enabled : disabled) |= mask;
    933     }
    934     state->enabledTracks &= ~disabled;
    935     state->enabledTracks |=  enabled;
    936 
    937     // compute everything we need...
    938     int countActiveTracks = 0;
    939     // TODO: fix all16BitsStereNoResample logic to
    940     // either properly handle muted tracks (it should ignore them)
    941     // or remove altogether as an obsolete optimization.
    942     bool all16BitsStereoNoResample = true;
    943     bool resampling = false;
    944     bool volumeRamp = false;
    945     uint32_t en = state->enabledTracks;
    946     while (en) {
    947         const int i = 31 - __builtin_clz(en);
    948         en &= ~(1<<i);
    949 
    950         countActiveTracks++;
    951         track_t& t = state->tracks[i];
    952         uint32_t n = 0;
    953         // FIXME can overflow (mask is only 3 bits)
    954         n |= NEEDS_CHANNEL_1 + t.channelCount - 1;
    955         if (t.doesResample()) {
    956             n |= NEEDS_RESAMPLE;
    957         }
    958         if (t.auxLevel != 0 && t.auxBuffer != NULL) {
    959             n |= NEEDS_AUX;
    960         }
    961 
    962         if (t.volumeInc[0]|t.volumeInc[1]) {
    963             volumeRamp = true;
    964         } else if (!t.doesResample() && t.volumeRL == 0) {
    965             n |= NEEDS_MUTE;
    966         }
    967         t.needs = n;
    968 
    969         if (n & NEEDS_MUTE) {
    970             t.hook = track__nop;
    971         } else {
    972             if (n & NEEDS_AUX) {
    973                 all16BitsStereoNoResample = false;
    974             }
    975             if (n & NEEDS_RESAMPLE) {
    976                 all16BitsStereoNoResample = false;
    977                 resampling = true;
    978                 t.hook = getTrackHook(TRACKTYPE_RESAMPLE, t.mMixerChannelCount,
    979                         t.mMixerInFormat, t.mMixerFormat);
    980                 ALOGV_IF((n & NEEDS_CHANNEL_COUNT__MASK) > NEEDS_CHANNEL_2,
    981                         "Track %d needs downmix + resample", i);
    982             } else {
    983                 if ((n & NEEDS_CHANNEL_COUNT__MASK) == NEEDS_CHANNEL_1){
    984                     t.hook = getTrackHook(
    985                             (t.mMixerChannelMask == AUDIO_CHANNEL_OUT_STEREO  // TODO: MONO_HACK
    986                                     && t.channelMask == AUDIO_CHANNEL_OUT_MONO)
    987                                 ? TRACKTYPE_NORESAMPLEMONO : TRACKTYPE_NORESAMPLE,
    988                             t.mMixerChannelCount,
    989                             t.mMixerInFormat, t.mMixerFormat);
    990                     all16BitsStereoNoResample = false;
    991                 }
    992                 if ((n & NEEDS_CHANNEL_COUNT__MASK) >= NEEDS_CHANNEL_2){
    993                     t.hook = getTrackHook(TRACKTYPE_NORESAMPLE, t.mMixerChannelCount,
    994                             t.mMixerInFormat, t.mMixerFormat);
    995                     ALOGV_IF((n & NEEDS_CHANNEL_COUNT__MASK) > NEEDS_CHANNEL_2,
    996                             "Track %d needs downmix", i);
    997                 }
    998             }
    999         }
   1000     }
   1001 
   1002     // select the processing hooks
   1003     state->hook = process__nop;
   1004     if (countActiveTracks > 0) {
   1005         if (resampling) {
   1006             if (!state->outputTemp) {
   1007                 state->outputTemp = new int32_t[MAX_NUM_CHANNELS * state->frameCount];
   1008             }
   1009             if (!state->resampleTemp) {
   1010                 state->resampleTemp = new int32_t[MAX_NUM_CHANNELS * state->frameCount];
   1011             }
   1012             state->hook = process__genericResampling;
   1013         } else {
   1014             if (state->outputTemp) {
   1015                 delete [] state->outputTemp;
   1016                 state->outputTemp = NULL;
   1017             }
   1018             if (state->resampleTemp) {
   1019                 delete [] state->resampleTemp;
   1020                 state->resampleTemp = NULL;
   1021             }
   1022             state->hook = process__genericNoResampling;
   1023             if (all16BitsStereoNoResample && !volumeRamp) {
   1024                 if (countActiveTracks == 1) {
   1025                     const int i = 31 - __builtin_clz(state->enabledTracks);
   1026                     track_t& t = state->tracks[i];
   1027                     if ((t.needs & NEEDS_MUTE) == 0) {
   1028                         // The check prevents a muted track from acquiring a process hook.
   1029                         //
   1030                         // This is dangerous if the track is MONO as that requires
   1031                         // special case handling due to implicit channel duplication.
   1032                         // Stereo or Multichannel should actually be fine here.
   1033                         state->hook = getProcessHook(PROCESSTYPE_NORESAMPLEONETRACK,
   1034                                 t.mMixerChannelCount, t.mMixerInFormat, t.mMixerFormat);
   1035                     }
   1036                 }
   1037             }
   1038         }
   1039     }
   1040 
   1041     ALOGV("mixer configuration change: %d activeTracks (%08x) "
   1042         "all16BitsStereoNoResample=%d, resampling=%d, volumeRamp=%d",
   1043         countActiveTracks, state->enabledTracks,
   1044         all16BitsStereoNoResample, resampling, volumeRamp);
   1045 
   1046    state->hook(state);
   1047 
   1048     // Now that the volume ramp has been done, set optimal state and
   1049     // track hooks for subsequent mixer process
   1050     if (countActiveTracks > 0) {
   1051         bool allMuted = true;
   1052         uint32_t en = state->enabledTracks;
   1053         while (en) {
   1054             const int i = 31 - __builtin_clz(en);
   1055             en &= ~(1<<i);
   1056             track_t& t = state->tracks[i];
   1057             if (!t.doesResample() && t.volumeRL == 0) {
   1058                 t.needs |= NEEDS_MUTE;
   1059                 t.hook = track__nop;
   1060             } else {
   1061                 allMuted = false;
   1062             }
   1063         }
   1064         if (allMuted) {
   1065             state->hook = process__nop;
   1066         } else if (all16BitsStereoNoResample) {
   1067             if (countActiveTracks == 1) {
   1068                 const int i = 31 - __builtin_clz(state->enabledTracks);
   1069                 track_t& t = state->tracks[i];
   1070                 // Muted single tracks handled by allMuted above.
   1071                 state->hook = getProcessHook(PROCESSTYPE_NORESAMPLEONETRACK,
   1072                         t.mMixerChannelCount, t.mMixerInFormat, t.mMixerFormat);
   1073             }
   1074         }
   1075     }
   1076 }
   1077 
   1078 
   1079 void AudioMixer::track__genericResample(track_t* t, int32_t* out, size_t outFrameCount,
   1080         int32_t* temp, int32_t* aux)
   1081 {
   1082     ALOGVV("track__genericResample\n");
   1083     t->resampler->setSampleRate(t->sampleRate);
   1084 
   1085     // ramp gain - resample to temp buffer and scale/mix in 2nd step
   1086     if (aux != NULL) {
   1087         // always resample with unity gain when sending to auxiliary buffer to be able
   1088         // to apply send level after resampling
   1089         t->resampler->setVolume(UNITY_GAIN_FLOAT, UNITY_GAIN_FLOAT);
   1090         memset(temp, 0, outFrameCount * t->mMixerChannelCount * sizeof(int32_t));
   1091         t->resampler->resample(temp, outFrameCount, t->bufferProvider);
   1092         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
   1093             volumeRampStereo(t, out, outFrameCount, temp, aux);
   1094         } else {
   1095             volumeStereo(t, out, outFrameCount, temp, aux);
   1096         }
   1097     } else {
   1098         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
   1099             t->resampler->setVolume(UNITY_GAIN_FLOAT, UNITY_GAIN_FLOAT);
   1100             memset(temp, 0, outFrameCount * MAX_NUM_CHANNELS * sizeof(int32_t));
   1101             t->resampler->resample(temp, outFrameCount, t->bufferProvider);
   1102             volumeRampStereo(t, out, outFrameCount, temp, aux);
   1103         }
   1104 
   1105         // constant gain
   1106         else {
   1107             t->resampler->setVolume(t->mVolume[0], t->mVolume[1]);
   1108             t->resampler->resample(out, outFrameCount, t->bufferProvider);
   1109         }
   1110     }
   1111 }
   1112 
   1113 void AudioMixer::track__nop(track_t* t __unused, int32_t* out __unused,
   1114         size_t outFrameCount __unused, int32_t* temp __unused, int32_t* aux __unused)
   1115 {
   1116 }
   1117 
   1118 void AudioMixer::volumeRampStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
   1119         int32_t* aux)
   1120 {
   1121     int32_t vl = t->prevVolume[0];
   1122     int32_t vr = t->prevVolume[1];
   1123     const int32_t vlInc = t->volumeInc[0];
   1124     const int32_t vrInc = t->volumeInc[1];
   1125 
   1126     //ALOGD("[0] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1127     //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1128     //       (vl + vlInc*frameCount)/65536.0f, frameCount);
   1129 
   1130     // ramp volume
   1131     if (CC_UNLIKELY(aux != NULL)) {
   1132         int32_t va = t->prevAuxLevel;
   1133         const int32_t vaInc = t->auxInc;
   1134         int32_t l;
   1135         int32_t r;
   1136 
   1137         do {
   1138             l = (*temp++ >> 12);
   1139             r = (*temp++ >> 12);
   1140             *out++ += (vl >> 16) * l;
   1141             *out++ += (vr >> 16) * r;
   1142             *aux++ += (va >> 17) * (l + r);
   1143             vl += vlInc;
   1144             vr += vrInc;
   1145             va += vaInc;
   1146         } while (--frameCount);
   1147         t->prevAuxLevel = va;
   1148     } else {
   1149         do {
   1150             *out++ += (vl >> 16) * (*temp++ >> 12);
   1151             *out++ += (vr >> 16) * (*temp++ >> 12);
   1152             vl += vlInc;
   1153             vr += vrInc;
   1154         } while (--frameCount);
   1155     }
   1156     t->prevVolume[0] = vl;
   1157     t->prevVolume[1] = vr;
   1158     t->adjustVolumeRamp(aux != NULL);
   1159 }
   1160 
   1161 void AudioMixer::volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
   1162         int32_t* aux)
   1163 {
   1164     const int16_t vl = t->volume[0];
   1165     const int16_t vr = t->volume[1];
   1166 
   1167     if (CC_UNLIKELY(aux != NULL)) {
   1168         const int16_t va = t->auxLevel;
   1169         do {
   1170             int16_t l = (int16_t)(*temp++ >> 12);
   1171             int16_t r = (int16_t)(*temp++ >> 12);
   1172             out[0] = mulAdd(l, vl, out[0]);
   1173             int16_t a = (int16_t)(((int32_t)l + r) >> 1);
   1174             out[1] = mulAdd(r, vr, out[1]);
   1175             out += 2;
   1176             aux[0] = mulAdd(a, va, aux[0]);
   1177             aux++;
   1178         } while (--frameCount);
   1179     } else {
   1180         do {
   1181             int16_t l = (int16_t)(*temp++ >> 12);
   1182             int16_t r = (int16_t)(*temp++ >> 12);
   1183             out[0] = mulAdd(l, vl, out[0]);
   1184             out[1] = mulAdd(r, vr, out[1]);
   1185             out += 2;
   1186         } while (--frameCount);
   1187     }
   1188 }
   1189 
   1190 void AudioMixer::track__16BitsStereo(track_t* t, int32_t* out, size_t frameCount,
   1191         int32_t* temp __unused, int32_t* aux)
   1192 {
   1193     ALOGVV("track__16BitsStereo\n");
   1194     const int16_t *in = static_cast<const int16_t *>(t->in);
   1195 
   1196     if (CC_UNLIKELY(aux != NULL)) {
   1197         int32_t l;
   1198         int32_t r;
   1199         // ramp gain
   1200         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
   1201             int32_t vl = t->prevVolume[0];
   1202             int32_t vr = t->prevVolume[1];
   1203             int32_t va = t->prevAuxLevel;
   1204             const int32_t vlInc = t->volumeInc[0];
   1205             const int32_t vrInc = t->volumeInc[1];
   1206             const int32_t vaInc = t->auxInc;
   1207             // ALOGD("[1] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1208             //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1209             //        (vl + vlInc*frameCount)/65536.0f, frameCount);
   1210 
   1211             do {
   1212                 l = (int32_t)*in++;
   1213                 r = (int32_t)*in++;
   1214                 *out++ += (vl >> 16) * l;
   1215                 *out++ += (vr >> 16) * r;
   1216                 *aux++ += (va >> 17) * (l + r);
   1217                 vl += vlInc;
   1218                 vr += vrInc;
   1219                 va += vaInc;
   1220             } while (--frameCount);
   1221 
   1222             t->prevVolume[0] = vl;
   1223             t->prevVolume[1] = vr;
   1224             t->prevAuxLevel = va;
   1225             t->adjustVolumeRamp(true);
   1226         }
   1227 
   1228         // constant gain
   1229         else {
   1230             const uint32_t vrl = t->volumeRL;
   1231             const int16_t va = (int16_t)t->auxLevel;
   1232             do {
   1233                 uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1234                 int16_t a = (int16_t)(((int32_t)in[0] + in[1]) >> 1);
   1235                 in += 2;
   1236                 out[0] = mulAddRL(1, rl, vrl, out[0]);
   1237                 out[1] = mulAddRL(0, rl, vrl, out[1]);
   1238                 out += 2;
   1239                 aux[0] = mulAdd(a, va, aux[0]);
   1240                 aux++;
   1241             } while (--frameCount);
   1242         }
   1243     } else {
   1244         // ramp gain
   1245         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
   1246             int32_t vl = t->prevVolume[0];
   1247             int32_t vr = t->prevVolume[1];
   1248             const int32_t vlInc = t->volumeInc[0];
   1249             const int32_t vrInc = t->volumeInc[1];
   1250 
   1251             // ALOGD("[1] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1252             //        t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1253             //        (vl + vlInc*frameCount)/65536.0f, frameCount);
   1254 
   1255             do {
   1256                 *out++ += (vl >> 16) * (int32_t) *in++;
   1257                 *out++ += (vr >> 16) * (int32_t) *in++;
   1258                 vl += vlInc;
   1259                 vr += vrInc;
   1260             } while (--frameCount);
   1261 
   1262             t->prevVolume[0] = vl;
   1263             t->prevVolume[1] = vr;
   1264             t->adjustVolumeRamp(false);
   1265         }
   1266 
   1267         // constant gain
   1268         else {
   1269             const uint32_t vrl = t->volumeRL;
   1270             do {
   1271                 uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1272                 in += 2;
   1273                 out[0] = mulAddRL(1, rl, vrl, out[0]);
   1274                 out[1] = mulAddRL(0, rl, vrl, out[1]);
   1275                 out += 2;
   1276             } while (--frameCount);
   1277         }
   1278     }
   1279     t->in = in;
   1280 }
   1281 
   1282 void AudioMixer::track__16BitsMono(track_t* t, int32_t* out, size_t frameCount,
   1283         int32_t* temp __unused, int32_t* aux)
   1284 {
   1285     ALOGVV("track__16BitsMono\n");
   1286     const int16_t *in = static_cast<int16_t const *>(t->in);
   1287 
   1288     if (CC_UNLIKELY(aux != NULL)) {
   1289         // ramp gain
   1290         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1]|t->auxInc)) {
   1291             int32_t vl = t->prevVolume[0];
   1292             int32_t vr = t->prevVolume[1];
   1293             int32_t va = t->prevAuxLevel;
   1294             const int32_t vlInc = t->volumeInc[0];
   1295             const int32_t vrInc = t->volumeInc[1];
   1296             const int32_t vaInc = t->auxInc;
   1297 
   1298             // ALOGD("[2] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1299             //         t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1300             //         (vl + vlInc*frameCount)/65536.0f, frameCount);
   1301 
   1302             do {
   1303                 int32_t l = *in++;
   1304                 *out++ += (vl >> 16) * l;
   1305                 *out++ += (vr >> 16) * l;
   1306                 *aux++ += (va >> 16) * l;
   1307                 vl += vlInc;
   1308                 vr += vrInc;
   1309                 va += vaInc;
   1310             } while (--frameCount);
   1311 
   1312             t->prevVolume[0] = vl;
   1313             t->prevVolume[1] = vr;
   1314             t->prevAuxLevel = va;
   1315             t->adjustVolumeRamp(true);
   1316         }
   1317         // constant gain
   1318         else {
   1319             const int16_t vl = t->volume[0];
   1320             const int16_t vr = t->volume[1];
   1321             const int16_t va = (int16_t)t->auxLevel;
   1322             do {
   1323                 int16_t l = *in++;
   1324                 out[0] = mulAdd(l, vl, out[0]);
   1325                 out[1] = mulAdd(l, vr, out[1]);
   1326                 out += 2;
   1327                 aux[0] = mulAdd(l, va, aux[0]);
   1328                 aux++;
   1329             } while (--frameCount);
   1330         }
   1331     } else {
   1332         // ramp gain
   1333         if (CC_UNLIKELY(t->volumeInc[0]|t->volumeInc[1])) {
   1334             int32_t vl = t->prevVolume[0];
   1335             int32_t vr = t->prevVolume[1];
   1336             const int32_t vlInc = t->volumeInc[0];
   1337             const int32_t vrInc = t->volumeInc[1];
   1338 
   1339             // ALOGD("[2] %p: inc=%f, v0=%f, v1=%d, final=%f, count=%d",
   1340             //         t, vlInc/65536.0f, vl/65536.0f, t->volume[0],
   1341             //         (vl + vlInc*frameCount)/65536.0f, frameCount);
   1342 
   1343             do {
   1344                 int32_t l = *in++;
   1345                 *out++ += (vl >> 16) * l;
   1346                 *out++ += (vr >> 16) * l;
   1347                 vl += vlInc;
   1348                 vr += vrInc;
   1349             } while (--frameCount);
   1350 
   1351             t->prevVolume[0] = vl;
   1352             t->prevVolume[1] = vr;
   1353             t->adjustVolumeRamp(false);
   1354         }
   1355         // constant gain
   1356         else {
   1357             const int16_t vl = t->volume[0];
   1358             const int16_t vr = t->volume[1];
   1359             do {
   1360                 int16_t l = *in++;
   1361                 out[0] = mulAdd(l, vl, out[0]);
   1362                 out[1] = mulAdd(l, vr, out[1]);
   1363                 out += 2;
   1364             } while (--frameCount);
   1365         }
   1366     }
   1367     t->in = in;
   1368 }
   1369 
   1370 // no-op case
   1371 void AudioMixer::process__nop(state_t* state)
   1372 {
   1373     ALOGVV("process__nop\n");
   1374     uint32_t e0 = state->enabledTracks;
   1375     while (e0) {
   1376         // process by group of tracks with same output buffer to
   1377         // avoid multiple memset() on same buffer
   1378         uint32_t e1 = e0, e2 = e0;
   1379         int i = 31 - __builtin_clz(e1);
   1380         {
   1381             track_t& t1 = state->tracks[i];
   1382             e2 &= ~(1<<i);
   1383             while (e2) {
   1384                 i = 31 - __builtin_clz(e2);
   1385                 e2 &= ~(1<<i);
   1386                 track_t& t2 = state->tracks[i];
   1387                 if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
   1388                     e1 &= ~(1<<i);
   1389                 }
   1390             }
   1391             e0 &= ~(e1);
   1392 
   1393             memset(t1.mainBuffer, 0, state->frameCount * t1.mMixerChannelCount
   1394                     * audio_bytes_per_sample(t1.mMixerFormat));
   1395         }
   1396 
   1397         while (e1) {
   1398             i = 31 - __builtin_clz(e1);
   1399             e1 &= ~(1<<i);
   1400             {
   1401                 track_t& t3 = state->tracks[i];
   1402                 size_t outFrames = state->frameCount;
   1403                 while (outFrames) {
   1404                     t3.buffer.frameCount = outFrames;
   1405                     t3.bufferProvider->getNextBuffer(&t3.buffer);
   1406                     if (t3.buffer.raw == NULL) break;
   1407                     outFrames -= t3.buffer.frameCount;
   1408                     t3.bufferProvider->releaseBuffer(&t3.buffer);
   1409                 }
   1410             }
   1411         }
   1412     }
   1413 }
   1414 
   1415 // generic code without resampling
   1416 void AudioMixer::process__genericNoResampling(state_t* state)
   1417 {
   1418     ALOGVV("process__genericNoResampling\n");
   1419     int32_t outTemp[BLOCKSIZE * MAX_NUM_CHANNELS] __attribute__((aligned(32)));
   1420 
   1421     // acquire each track's buffer
   1422     uint32_t enabledTracks = state->enabledTracks;
   1423     uint32_t e0 = enabledTracks;
   1424     while (e0) {
   1425         const int i = 31 - __builtin_clz(e0);
   1426         e0 &= ~(1<<i);
   1427         track_t& t = state->tracks[i];
   1428         t.buffer.frameCount = state->frameCount;
   1429         t.bufferProvider->getNextBuffer(&t.buffer);
   1430         t.frameCount = t.buffer.frameCount;
   1431         t.in = t.buffer.raw;
   1432     }
   1433 
   1434     e0 = enabledTracks;
   1435     while (e0) {
   1436         // process by group of tracks with same output buffer to
   1437         // optimize cache use
   1438         uint32_t e1 = e0, e2 = e0;
   1439         int j = 31 - __builtin_clz(e1);
   1440         track_t& t1 = state->tracks[j];
   1441         e2 &= ~(1<<j);
   1442         while (e2) {
   1443             j = 31 - __builtin_clz(e2);
   1444             e2 &= ~(1<<j);
   1445             track_t& t2 = state->tracks[j];
   1446             if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
   1447                 e1 &= ~(1<<j);
   1448             }
   1449         }
   1450         e0 &= ~(e1);
   1451         // this assumes output 16 bits stereo, no resampling
   1452         int32_t *out = t1.mainBuffer;
   1453         size_t numFrames = 0;
   1454         do {
   1455             memset(outTemp, 0, sizeof(outTemp));
   1456             e2 = e1;
   1457             while (e2) {
   1458                 const int i = 31 - __builtin_clz(e2);
   1459                 e2 &= ~(1<<i);
   1460                 track_t& t = state->tracks[i];
   1461                 size_t outFrames = BLOCKSIZE;
   1462                 int32_t *aux = NULL;
   1463                 if (CC_UNLIKELY(t.needs & NEEDS_AUX)) {
   1464                     aux = t.auxBuffer + numFrames;
   1465                 }
   1466                 while (outFrames) {
   1467                     // t.in == NULL can happen if the track was flushed just after having
   1468                     // been enabled for mixing.
   1469                    if (t.in == NULL) {
   1470                         enabledTracks &= ~(1<<i);
   1471                         e1 &= ~(1<<i);
   1472                         break;
   1473                     }
   1474                     size_t inFrames = (t.frameCount > outFrames)?outFrames:t.frameCount;
   1475                     if (inFrames > 0) {
   1476                         t.hook(&t, outTemp + (BLOCKSIZE - outFrames) * t.mMixerChannelCount,
   1477                                 inFrames, state->resampleTemp, aux);
   1478                         t.frameCount -= inFrames;
   1479                         outFrames -= inFrames;
   1480                         if (CC_UNLIKELY(aux != NULL)) {
   1481                             aux += inFrames;
   1482                         }
   1483                     }
   1484                     if (t.frameCount == 0 && outFrames) {
   1485                         t.bufferProvider->releaseBuffer(&t.buffer);
   1486                         t.buffer.frameCount = (state->frameCount - numFrames) -
   1487                                 (BLOCKSIZE - outFrames);
   1488                         t.bufferProvider->getNextBuffer(&t.buffer);
   1489                         t.in = t.buffer.raw;
   1490                         if (t.in == NULL) {
   1491                             enabledTracks &= ~(1<<i);
   1492                             e1 &= ~(1<<i);
   1493                             break;
   1494                         }
   1495                         t.frameCount = t.buffer.frameCount;
   1496                     }
   1497                 }
   1498             }
   1499 
   1500             convertMixerFormat(out, t1.mMixerFormat, outTemp, t1.mMixerInFormat,
   1501                     BLOCKSIZE * t1.mMixerChannelCount);
   1502             // TODO: fix ugly casting due to choice of out pointer type
   1503             out = reinterpret_cast<int32_t*>((uint8_t*)out
   1504                     + BLOCKSIZE * t1.mMixerChannelCount
   1505                         * audio_bytes_per_sample(t1.mMixerFormat));
   1506             numFrames += BLOCKSIZE;
   1507         } while (numFrames < state->frameCount);
   1508     }
   1509 
   1510     // release each track's buffer
   1511     e0 = enabledTracks;
   1512     while (e0) {
   1513         const int i = 31 - __builtin_clz(e0);
   1514         e0 &= ~(1<<i);
   1515         track_t& t = state->tracks[i];
   1516         t.bufferProvider->releaseBuffer(&t.buffer);
   1517     }
   1518 }
   1519 
   1520 
   1521 // generic code with resampling
   1522 void AudioMixer::process__genericResampling(state_t* state)
   1523 {
   1524     ALOGVV("process__genericResampling\n");
   1525     // this const just means that local variable outTemp doesn't change
   1526     int32_t* const outTemp = state->outputTemp;
   1527     size_t numFrames = state->frameCount;
   1528 
   1529     uint32_t e0 = state->enabledTracks;
   1530     while (e0) {
   1531         // process by group of tracks with same output buffer
   1532         // to optimize cache use
   1533         uint32_t e1 = e0, e2 = e0;
   1534         int j = 31 - __builtin_clz(e1);
   1535         track_t& t1 = state->tracks[j];
   1536         e2 &= ~(1<<j);
   1537         while (e2) {
   1538             j = 31 - __builtin_clz(e2);
   1539             e2 &= ~(1<<j);
   1540             track_t& t2 = state->tracks[j];
   1541             if (CC_UNLIKELY(t2.mainBuffer != t1.mainBuffer)) {
   1542                 e1 &= ~(1<<j);
   1543             }
   1544         }
   1545         e0 &= ~(e1);
   1546         int32_t *out = t1.mainBuffer;
   1547         memset(outTemp, 0, sizeof(*outTemp) * t1.mMixerChannelCount * state->frameCount);
   1548         while (e1) {
   1549             const int i = 31 - __builtin_clz(e1);
   1550             e1 &= ~(1<<i);
   1551             track_t& t = state->tracks[i];
   1552             int32_t *aux = NULL;
   1553             if (CC_UNLIKELY(t.needs & NEEDS_AUX)) {
   1554                 aux = t.auxBuffer;
   1555             }
   1556 
   1557             // this is a little goofy, on the resampling case we don't
   1558             // acquire/release the buffers because it's done by
   1559             // the resampler.
   1560             if (t.needs & NEEDS_RESAMPLE) {
   1561                 t.hook(&t, outTemp, numFrames, state->resampleTemp, aux);
   1562             } else {
   1563 
   1564                 size_t outFrames = 0;
   1565 
   1566                 while (outFrames < numFrames) {
   1567                     t.buffer.frameCount = numFrames - outFrames;
   1568                     t.bufferProvider->getNextBuffer(&t.buffer);
   1569                     t.in = t.buffer.raw;
   1570                     // t.in == NULL can happen if the track was flushed just after having
   1571                     // been enabled for mixing.
   1572                     if (t.in == NULL) break;
   1573 
   1574                     if (CC_UNLIKELY(aux != NULL)) {
   1575                         aux += outFrames;
   1576                     }
   1577                     t.hook(&t, outTemp + outFrames * t.mMixerChannelCount, t.buffer.frameCount,
   1578                             state->resampleTemp, aux);
   1579                     outFrames += t.buffer.frameCount;
   1580                     t.bufferProvider->releaseBuffer(&t.buffer);
   1581                 }
   1582             }
   1583         }
   1584         convertMixerFormat(out, t1.mMixerFormat,
   1585                 outTemp, t1.mMixerInFormat, numFrames * t1.mMixerChannelCount);
   1586     }
   1587 }
   1588 
   1589 // one track, 16 bits stereo without resampling is the most common case
   1590 void AudioMixer::process__OneTrack16BitsStereoNoResampling(state_t* state)
   1591 {
   1592     ALOGVV("process__OneTrack16BitsStereoNoResampling\n");
   1593     // This method is only called when state->enabledTracks has exactly
   1594     // one bit set.  The asserts below would verify this, but are commented out
   1595     // since the whole point of this method is to optimize performance.
   1596     //ALOG_ASSERT(0 != state->enabledTracks, "no tracks enabled");
   1597     const int i = 31 - __builtin_clz(state->enabledTracks);
   1598     //ALOG_ASSERT((1 << i) == state->enabledTracks, "more than 1 track enabled");
   1599     const track_t& t = state->tracks[i];
   1600 
   1601     AudioBufferProvider::Buffer& b(t.buffer);
   1602 
   1603     int32_t* out = t.mainBuffer;
   1604     float *fout = reinterpret_cast<float*>(out);
   1605     size_t numFrames = state->frameCount;
   1606 
   1607     const int16_t vl = t.volume[0];
   1608     const int16_t vr = t.volume[1];
   1609     const uint32_t vrl = t.volumeRL;
   1610     while (numFrames) {
   1611         b.frameCount = numFrames;
   1612         t.bufferProvider->getNextBuffer(&b);
   1613         const int16_t *in = b.i16;
   1614 
   1615         // in == NULL can happen if the track was flushed just after having
   1616         // been enabled for mixing.
   1617         if (in == NULL || (((uintptr_t)in) & 3)) {
   1618             if ( AUDIO_FORMAT_PCM_FLOAT == t.mMixerFormat ) {
   1619                  memset((char*)fout, 0, numFrames
   1620                          * t.mMixerChannelCount * audio_bytes_per_sample(t.mMixerFormat));
   1621             } else {
   1622                  memset((char*)out, 0, numFrames
   1623                          * t.mMixerChannelCount * audio_bytes_per_sample(t.mMixerFormat));
   1624             }
   1625             ALOGE_IF((((uintptr_t)in) & 3),
   1626                     "process__OneTrack16BitsStereoNoResampling: misaligned buffer"
   1627                     " %p track %d, channels %d, needs %08x, volume %08x vfl %f vfr %f",
   1628                     in, i, t.channelCount, t.needs, vrl, t.mVolume[0], t.mVolume[1]);
   1629             return;
   1630         }
   1631         size_t outFrames = b.frameCount;
   1632 
   1633         switch (t.mMixerFormat) {
   1634         case AUDIO_FORMAT_PCM_FLOAT:
   1635             do {
   1636                 uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1637                 in += 2;
   1638                 int32_t l = mulRL(1, rl, vrl);
   1639                 int32_t r = mulRL(0, rl, vrl);
   1640                 *fout++ = float_from_q4_27(l);
   1641                 *fout++ = float_from_q4_27(r);
   1642                 // Note: In case of later int16_t sink output,
   1643                 // conversion and clamping is done by memcpy_to_i16_from_float().
   1644             } while (--outFrames);
   1645             break;
   1646         case AUDIO_FORMAT_PCM_16_BIT:
   1647             if (CC_UNLIKELY(uint32_t(vl) > UNITY_GAIN_INT || uint32_t(vr) > UNITY_GAIN_INT)) {
   1648                 // volume is boosted, so we might need to clamp even though
   1649                 // we process only one track.
   1650                 do {
   1651                     uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1652                     in += 2;
   1653                     int32_t l = mulRL(1, rl, vrl) >> 12;
   1654                     int32_t r = mulRL(0, rl, vrl) >> 12;
   1655                     // clamping...
   1656                     l = clamp16(l);
   1657                     r = clamp16(r);
   1658                     *out++ = (r<<16) | (l & 0xFFFF);
   1659                 } while (--outFrames);
   1660             } else {
   1661                 do {
   1662                     uint32_t rl = *reinterpret_cast<const uint32_t *>(in);
   1663                     in += 2;
   1664                     int32_t l = mulRL(1, rl, vrl) >> 12;
   1665                     int32_t r = mulRL(0, rl, vrl) >> 12;
   1666                     *out++ = (r<<16) | (l & 0xFFFF);
   1667                 } while (--outFrames);
   1668             }
   1669             break;
   1670         default:
   1671             LOG_ALWAYS_FATAL("bad mixer format: %d", t.mMixerFormat);
   1672         }
   1673         numFrames -= b.frameCount;
   1674         t.bufferProvider->releaseBuffer(&b);
   1675     }
   1676 }
   1677 
   1678 /*static*/ pthread_once_t AudioMixer::sOnceControl = PTHREAD_ONCE_INIT;
   1679 
   1680 /*static*/ void AudioMixer::sInitRoutine()
   1681 {
   1682     DownmixerBufferProvider::init(); // for the downmixer
   1683 }
   1684 
   1685 /* TODO: consider whether this level of optimization is necessary.
   1686  * Perhaps just stick with a single for loop.
   1687  */
   1688 
   1689 // Needs to derive a compile time constant (constexpr).  Could be targeted to go
   1690 // to a MONOVOL mixtype based on MAX_NUM_VOLUMES, but that's an unnecessary complication.
   1691 #define MIXTYPE_MONOVOL(mixtype) ((mixtype) == MIXTYPE_MULTI ? MIXTYPE_MULTI_MONOVOL : \
   1692         (mixtype) == MIXTYPE_MULTI_SAVEONLY ? MIXTYPE_MULTI_SAVEONLY_MONOVOL : (mixtype))
   1693 
   1694 /* MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1695  * TO: int32_t (Q4.27) or float
   1696  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1697  * TA: int32_t (Q4.27)
   1698  */
   1699 template <int MIXTYPE,
   1700         typename TO, typename TI, typename TV, typename TA, typename TAV>
   1701 static void volumeRampMulti(uint32_t channels, TO* out, size_t frameCount,
   1702         const TI* in, TA* aux, TV *vol, const TV *volinc, TAV *vola, TAV volainc)
   1703 {
   1704     switch (channels) {
   1705     case 1:
   1706         volumeRampMulti<MIXTYPE, 1>(out, frameCount, in, aux, vol, volinc, vola, volainc);
   1707         break;
   1708     case 2:
   1709         volumeRampMulti<MIXTYPE, 2>(out, frameCount, in, aux, vol, volinc, vola, volainc);
   1710         break;
   1711     case 3:
   1712         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 3>(out,
   1713                 frameCount, in, aux, vol, volinc, vola, volainc);
   1714         break;
   1715     case 4:
   1716         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 4>(out,
   1717                 frameCount, in, aux, vol, volinc, vola, volainc);
   1718         break;
   1719     case 5:
   1720         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 5>(out,
   1721                 frameCount, in, aux, vol, volinc, vola, volainc);
   1722         break;
   1723     case 6:
   1724         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 6>(out,
   1725                 frameCount, in, aux, vol, volinc, vola, volainc);
   1726         break;
   1727     case 7:
   1728         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 7>(out,
   1729                 frameCount, in, aux, vol, volinc, vola, volainc);
   1730         break;
   1731     case 8:
   1732         volumeRampMulti<MIXTYPE_MONOVOL(MIXTYPE), 8>(out,
   1733                 frameCount, in, aux, vol, volinc, vola, volainc);
   1734         break;
   1735     }
   1736 }
   1737 
   1738 /* MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1739  * TO: int32_t (Q4.27) or float
   1740  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1741  * TA: int32_t (Q4.27)
   1742  */
   1743 template <int MIXTYPE,
   1744         typename TO, typename TI, typename TV, typename TA, typename TAV>
   1745 static void volumeMulti(uint32_t channels, TO* out, size_t frameCount,
   1746         const TI* in, TA* aux, const TV *vol, TAV vola)
   1747 {
   1748     switch (channels) {
   1749     case 1:
   1750         volumeMulti<MIXTYPE, 1>(out, frameCount, in, aux, vol, vola);
   1751         break;
   1752     case 2:
   1753         volumeMulti<MIXTYPE, 2>(out, frameCount, in, aux, vol, vola);
   1754         break;
   1755     case 3:
   1756         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 3>(out, frameCount, in, aux, vol, vola);
   1757         break;
   1758     case 4:
   1759         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 4>(out, frameCount, in, aux, vol, vola);
   1760         break;
   1761     case 5:
   1762         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 5>(out, frameCount, in, aux, vol, vola);
   1763         break;
   1764     case 6:
   1765         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 6>(out, frameCount, in, aux, vol, vola);
   1766         break;
   1767     case 7:
   1768         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 7>(out, frameCount, in, aux, vol, vola);
   1769         break;
   1770     case 8:
   1771         volumeMulti<MIXTYPE_MONOVOL(MIXTYPE), 8>(out, frameCount, in, aux, vol, vola);
   1772         break;
   1773     }
   1774 }
   1775 
   1776 /* MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1777  * USEFLOATVOL (set to true if float volume is used)
   1778  * ADJUSTVOL   (set to true if volume ramp parameters needs adjustment afterwards)
   1779  * TO: int32_t (Q4.27) or float
   1780  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1781  * TA: int32_t (Q4.27)
   1782  */
   1783 template <int MIXTYPE, bool USEFLOATVOL, bool ADJUSTVOL,
   1784     typename TO, typename TI, typename TA>
   1785 void AudioMixer::volumeMix(TO *out, size_t outFrames,
   1786         const TI *in, TA *aux, bool ramp, AudioMixer::track_t *t)
   1787 {
   1788     if (USEFLOATVOL) {
   1789         if (ramp) {
   1790             volumeRampMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1791                     t->mPrevVolume, t->mVolumeInc, &t->prevAuxLevel, t->auxInc);
   1792             if (ADJUSTVOL) {
   1793                 t->adjustVolumeRamp(aux != NULL, true);
   1794             }
   1795         } else {
   1796             volumeMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1797                     t->mVolume, t->auxLevel);
   1798         }
   1799     } else {
   1800         if (ramp) {
   1801             volumeRampMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1802                     t->prevVolume, t->volumeInc, &t->prevAuxLevel, t->auxInc);
   1803             if (ADJUSTVOL) {
   1804                 t->adjustVolumeRamp(aux != NULL);
   1805             }
   1806         } else {
   1807             volumeMulti<MIXTYPE>(t->mMixerChannelCount, out, outFrames, in, aux,
   1808                     t->volume, t->auxLevel);
   1809         }
   1810     }
   1811 }
   1812 
   1813 /* This process hook is called when there is a single track without
   1814  * aux buffer, volume ramp, or resampling.
   1815  * TODO: Update the hook selection: this can properly handle aux and ramp.
   1816  *
   1817  * MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1818  * TO: int32_t (Q4.27) or float
   1819  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1820  * TA: int32_t (Q4.27)
   1821  */
   1822 template <int MIXTYPE, typename TO, typename TI, typename TA>
   1823 void AudioMixer::process_NoResampleOneTrack(state_t* state)
   1824 {
   1825     ALOGVV("process_NoResampleOneTrack\n");
   1826     // CLZ is faster than CTZ on ARM, though really not sure if true after 31 - clz.
   1827     const int i = 31 - __builtin_clz(state->enabledTracks);
   1828     ALOG_ASSERT((1 << i) == state->enabledTracks, "more than 1 track enabled");
   1829     track_t *t = &state->tracks[i];
   1830     const uint32_t channels = t->mMixerChannelCount;
   1831     TO* out = reinterpret_cast<TO*>(t->mainBuffer);
   1832     TA* aux = reinterpret_cast<TA*>(t->auxBuffer);
   1833     const bool ramp = t->needsRamp();
   1834 
   1835     for (size_t numFrames = state->frameCount; numFrames; ) {
   1836         AudioBufferProvider::Buffer& b(t->buffer);
   1837         // get input buffer
   1838         b.frameCount = numFrames;
   1839         t->bufferProvider->getNextBuffer(&b);
   1840         const TI *in = reinterpret_cast<TI*>(b.raw);
   1841 
   1842         // in == NULL can happen if the track was flushed just after having
   1843         // been enabled for mixing.
   1844         if (in == NULL || (((uintptr_t)in) & 3)) {
   1845             memset(out, 0, numFrames
   1846                     * channels * audio_bytes_per_sample(t->mMixerFormat));
   1847             ALOGE_IF((((uintptr_t)in) & 3), "process_NoResampleOneTrack: bus error: "
   1848                     "buffer %p track %p, channels %d, needs %#x",
   1849                     in, t, t->channelCount, t->needs);
   1850             return;
   1851         }
   1852 
   1853         const size_t outFrames = b.frameCount;
   1854         volumeMix<MIXTYPE, is_same<TI, float>::value, false> (
   1855                 out, outFrames, in, aux, ramp, t);
   1856 
   1857         out += outFrames * channels;
   1858         if (aux != NULL) {
   1859             aux += channels;
   1860         }
   1861         numFrames -= b.frameCount;
   1862 
   1863         // release buffer
   1864         t->bufferProvider->releaseBuffer(&b);
   1865     }
   1866     if (ramp) {
   1867         t->adjustVolumeRamp(aux != NULL, is_same<TI, float>::value);
   1868     }
   1869 }
   1870 
   1871 /* This track hook is called to do resampling then mixing,
   1872  * pulling from the track's upstream AudioBufferProvider.
   1873  *
   1874  * MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1875  * TO: int32_t (Q4.27) or float
   1876  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1877  * TA: int32_t (Q4.27)
   1878  */
   1879 template <int MIXTYPE, typename TO, typename TI, typename TA>
   1880 void AudioMixer::track__Resample(track_t* t, TO* out, size_t outFrameCount, TO* temp, TA* aux)
   1881 {
   1882     ALOGVV("track__Resample\n");
   1883     t->resampler->setSampleRate(t->sampleRate);
   1884     const bool ramp = t->needsRamp();
   1885     if (ramp || aux != NULL) {
   1886         // if ramp:        resample with unity gain to temp buffer and scale/mix in 2nd step.
   1887         // if aux != NULL: resample with unity gain to temp buffer then apply send level.
   1888 
   1889         t->resampler->setVolume(UNITY_GAIN_FLOAT, UNITY_GAIN_FLOAT);
   1890         memset(temp, 0, outFrameCount * t->mMixerChannelCount * sizeof(TO));
   1891         t->resampler->resample((int32_t*)temp, outFrameCount, t->bufferProvider);
   1892 
   1893         volumeMix<MIXTYPE, is_same<TI, float>::value, true>(
   1894                 out, outFrameCount, temp, aux, ramp, t);
   1895 
   1896     } else { // constant volume gain
   1897         t->resampler->setVolume(t->mVolume[0], t->mVolume[1]);
   1898         t->resampler->resample((int32_t*)out, outFrameCount, t->bufferProvider);
   1899     }
   1900 }
   1901 
   1902 /* This track hook is called to mix a track, when no resampling is required.
   1903  * The input buffer should be present in t->in.
   1904  *
   1905  * MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
   1906  * TO: int32_t (Q4.27) or float
   1907  * TI: int32_t (Q4.27) or int16_t (Q0.15) or float
   1908  * TA: int32_t (Q4.27)
   1909  */
   1910 template <int MIXTYPE, typename TO, typename TI, typename TA>
   1911 void AudioMixer::track__NoResample(track_t* t, TO* out, size_t frameCount,
   1912         TO* temp __unused, TA* aux)
   1913 {
   1914     ALOGVV("track__NoResample\n");
   1915     const TI *in = static_cast<const TI *>(t->in);
   1916 
   1917     volumeMix<MIXTYPE, is_same<TI, float>::value, true>(
   1918             out, frameCount, in, aux, t->needsRamp(), t);
   1919 
   1920     // MIXTYPE_MONOEXPAND reads a single input channel and expands to NCHAN output channels.
   1921     // MIXTYPE_MULTI reads NCHAN input channels and places to NCHAN output channels.
   1922     in += (MIXTYPE == MIXTYPE_MONOEXPAND) ? frameCount : frameCount * t->mMixerChannelCount;
   1923     t->in = in;
   1924 }
   1925 
   1926 /* The Mixer engine generates either int32_t (Q4_27) or float data.
   1927  * We use this function to convert the engine buffers
   1928  * to the desired mixer output format, either int16_t (Q.15) or float.
   1929  */
   1930 void AudioMixer::convertMixerFormat(void *out, audio_format_t mixerOutFormat,
   1931         void *in, audio_format_t mixerInFormat, size_t sampleCount)
   1932 {
   1933     switch (mixerInFormat) {
   1934     case AUDIO_FORMAT_PCM_FLOAT:
   1935         switch (mixerOutFormat) {
   1936         case AUDIO_FORMAT_PCM_FLOAT:
   1937             memcpy(out, in, sampleCount * sizeof(float)); // MEMCPY. TODO optimize out
   1938             break;
   1939         case AUDIO_FORMAT_PCM_16_BIT:
   1940             memcpy_to_i16_from_float((int16_t*)out, (float*)in, sampleCount);
   1941             break;
   1942         default:
   1943             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   1944             break;
   1945         }
   1946         break;
   1947     case AUDIO_FORMAT_PCM_16_BIT:
   1948         switch (mixerOutFormat) {
   1949         case AUDIO_FORMAT_PCM_FLOAT:
   1950             memcpy_to_float_from_q4_27((float*)out, (int32_t*)in, sampleCount);
   1951             break;
   1952         case AUDIO_FORMAT_PCM_16_BIT:
   1953             // two int16_t are produced per iteration
   1954             ditherAndClamp((int32_t*)out, (int32_t*)in, sampleCount >> 1);
   1955             break;
   1956         default:
   1957             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   1958             break;
   1959         }
   1960         break;
   1961     default:
   1962         LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   1963         break;
   1964     }
   1965 }
   1966 
   1967 /* Returns the proper track hook to use for mixing the track into the output buffer.
   1968  */
   1969 AudioMixer::hook_t AudioMixer::getTrackHook(int trackType, uint32_t channelCount,
   1970         audio_format_t mixerInFormat, audio_format_t mixerOutFormat __unused)
   1971 {
   1972     if (!kUseNewMixer && channelCount == FCC_2 && mixerInFormat == AUDIO_FORMAT_PCM_16_BIT) {
   1973         switch (trackType) {
   1974         case TRACKTYPE_NOP:
   1975             return track__nop;
   1976         case TRACKTYPE_RESAMPLE:
   1977             return track__genericResample;
   1978         case TRACKTYPE_NORESAMPLEMONO:
   1979             return track__16BitsMono;
   1980         case TRACKTYPE_NORESAMPLE:
   1981             return track__16BitsStereo;
   1982         default:
   1983             LOG_ALWAYS_FATAL("bad trackType: %d", trackType);
   1984             break;
   1985         }
   1986     }
   1987     LOG_ALWAYS_FATAL_IF(channelCount > MAX_NUM_CHANNELS);
   1988     switch (trackType) {
   1989     case TRACKTYPE_NOP:
   1990         return track__nop;
   1991     case TRACKTYPE_RESAMPLE:
   1992         switch (mixerInFormat) {
   1993         case AUDIO_FORMAT_PCM_FLOAT:
   1994             return (AudioMixer::hook_t)
   1995                     track__Resample<MIXTYPE_MULTI, float /*TO*/, float /*TI*/, int32_t /*TA*/>;
   1996         case AUDIO_FORMAT_PCM_16_BIT:
   1997             return (AudioMixer::hook_t)\
   1998                     track__Resample<MIXTYPE_MULTI, int32_t, int16_t, int32_t>;
   1999         default:
   2000             LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2001             break;
   2002         }
   2003         break;
   2004     case TRACKTYPE_NORESAMPLEMONO:
   2005         switch (mixerInFormat) {
   2006         case AUDIO_FORMAT_PCM_FLOAT:
   2007             return (AudioMixer::hook_t)
   2008                     track__NoResample<MIXTYPE_MONOEXPAND, float, float, int32_t>;
   2009         case AUDIO_FORMAT_PCM_16_BIT:
   2010             return (AudioMixer::hook_t)
   2011                     track__NoResample<MIXTYPE_MONOEXPAND, int32_t, int16_t, int32_t>;
   2012         default:
   2013             LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2014             break;
   2015         }
   2016         break;
   2017     case TRACKTYPE_NORESAMPLE:
   2018         switch (mixerInFormat) {
   2019         case AUDIO_FORMAT_PCM_FLOAT:
   2020             return (AudioMixer::hook_t)
   2021                     track__NoResample<MIXTYPE_MULTI, float, float, int32_t>;
   2022         case AUDIO_FORMAT_PCM_16_BIT:
   2023             return (AudioMixer::hook_t)
   2024                     track__NoResample<MIXTYPE_MULTI, int32_t, int16_t, int32_t>;
   2025         default:
   2026             LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2027             break;
   2028         }
   2029         break;
   2030     default:
   2031         LOG_ALWAYS_FATAL("bad trackType: %d", trackType);
   2032         break;
   2033     }
   2034     return NULL;
   2035 }
   2036 
   2037 /* Returns the proper process hook for mixing tracks. Currently works only for
   2038  * PROCESSTYPE_NORESAMPLEONETRACK, a mix involving one track, no resampling.
   2039  *
   2040  * TODO: Due to the special mixing considerations of duplicating to
   2041  * a stereo output track, the input track cannot be MONO.  This should be
   2042  * prevented by the caller.
   2043  */
   2044 AudioMixer::process_hook_t AudioMixer::getProcessHook(int processType, uint32_t channelCount,
   2045         audio_format_t mixerInFormat, audio_format_t mixerOutFormat)
   2046 {
   2047     if (processType != PROCESSTYPE_NORESAMPLEONETRACK) { // Only NORESAMPLEONETRACK
   2048         LOG_ALWAYS_FATAL("bad processType: %d", processType);
   2049         return NULL;
   2050     }
   2051     if (!kUseNewMixer && channelCount == FCC_2 && mixerInFormat == AUDIO_FORMAT_PCM_16_BIT) {
   2052         return process__OneTrack16BitsStereoNoResampling;
   2053     }
   2054     LOG_ALWAYS_FATAL_IF(channelCount > MAX_NUM_CHANNELS);
   2055     switch (mixerInFormat) {
   2056     case AUDIO_FORMAT_PCM_FLOAT:
   2057         switch (mixerOutFormat) {
   2058         case AUDIO_FORMAT_PCM_FLOAT:
   2059             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2060                     float /*TO*/, float /*TI*/, int32_t /*TA*/>;
   2061         case AUDIO_FORMAT_PCM_16_BIT:
   2062             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2063                     int16_t, float, int32_t>;
   2064         default:
   2065             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   2066             break;
   2067         }
   2068         break;
   2069     case AUDIO_FORMAT_PCM_16_BIT:
   2070         switch (mixerOutFormat) {
   2071         case AUDIO_FORMAT_PCM_FLOAT:
   2072             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2073                     float, int16_t, int32_t>;
   2074         case AUDIO_FORMAT_PCM_16_BIT:
   2075             return process_NoResampleOneTrack<MIXTYPE_MULTI_SAVEONLY,
   2076                     int16_t, int16_t, int32_t>;
   2077         default:
   2078             LOG_ALWAYS_FATAL("bad mixerOutFormat: %#x", mixerOutFormat);
   2079             break;
   2080         }
   2081         break;
   2082     default:
   2083         LOG_ALWAYS_FATAL("bad mixerInFormat: %#x", mixerInFormat);
   2084         break;
   2085     }
   2086     return NULL;
   2087 }
   2088 
   2089 // ----------------------------------------------------------------------------
   2090 } // namespace android
   2091