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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 #ifndef ANDROID_AUDIO_MIXER_H
     19 #define ANDROID_AUDIO_MIXER_H
     20 
     21 #include <stdint.h>
     22 #include <sys/types.h>
     23 
     24 #include <hardware/audio_effect.h>
     25 #include <media/AudioBufferProvider.h>
     26 #include <media/AudioResamplerPublic.h>
     27 #include <media/nbaio/NBLog.h>
     28 #include <system/audio.h>
     29 #include <utils/Compat.h>
     30 #include <utils/threads.h>
     31 
     32 #include "AudioResampler.h"
     33 #include "BufferProviders.h"
     34 
     35 // FIXME This is actually unity gain, which might not be max in future, expressed in U.12
     36 #define MAX_GAIN_INT AudioMixer::UNITY_GAIN_INT
     37 
     38 namespace android {
     39 
     40 // ----------------------------------------------------------------------------
     41 
     42 class AudioMixer
     43 {
     44 public:
     45                             AudioMixer(size_t frameCount, uint32_t sampleRate,
     46                                        uint32_t maxNumTracks = MAX_NUM_TRACKS);
     47 
     48     /*virtual*/             ~AudioMixer();  // non-virtual saves a v-table, restore if sub-classed
     49 
     50 
     51     // This mixer has a hard-coded upper limit of 32 active track inputs.
     52     // Adding support for > 32 tracks would require more than simply changing this value.
     53     static const uint32_t MAX_NUM_TRACKS = 32;
     54     // maximum number of channels supported by the mixer
     55 
     56     // This mixer has a hard-coded upper limit of 8 channels for output.
     57     static const uint32_t MAX_NUM_CHANNELS = 8;
     58     static const uint32_t MAX_NUM_VOLUMES = 2; // stereo volume only
     59     // maximum number of channels supported for the content
     60     static const uint32_t MAX_NUM_CHANNELS_TO_DOWNMIX = AUDIO_CHANNEL_COUNT_MAX;
     61 
     62     static const uint16_t UNITY_GAIN_INT = 0x1000;
     63     static const CONSTEXPR float UNITY_GAIN_FLOAT = 1.0f;
     64 
     65     enum { // names
     66 
     67         // track names (MAX_NUM_TRACKS units)
     68         TRACK0          = 0x1000,
     69 
     70         // 0x2000 is unused
     71 
     72         // setParameter targets
     73         TRACK           = 0x3000,
     74         RESAMPLE        = 0x3001,
     75         RAMP_VOLUME     = 0x3002, // ramp to new volume
     76         VOLUME          = 0x3003, // don't ramp
     77         TIMESTRETCH     = 0x3004,
     78 
     79         // set Parameter names
     80         // for target TRACK
     81         CHANNEL_MASK    = 0x4000,
     82         FORMAT          = 0x4001,
     83         MAIN_BUFFER     = 0x4002,
     84         AUX_BUFFER      = 0x4003,
     85         DOWNMIX_TYPE    = 0X4004,
     86         MIXER_FORMAT    = 0x4005, // AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
     87         MIXER_CHANNEL_MASK = 0x4006, // Channel mask for mixer output
     88         // for target RESAMPLE
     89         SAMPLE_RATE     = 0x4100, // Configure sample rate conversion on this track name;
     90                                   // parameter 'value' is the new sample rate in Hz.
     91                                   // Only creates a sample rate converter the first time that
     92                                   // the track sample rate is different from the mix sample rate.
     93                                   // If the new sample rate is the same as the mix sample rate,
     94                                   // and a sample rate converter already exists,
     95                                   // then the sample rate converter remains present but is a no-op.
     96         RESET           = 0x4101, // Reset sample rate converter without changing sample rate.
     97                                   // This clears out the resampler's input buffer.
     98         REMOVE          = 0x4102, // Remove the sample rate converter on this track name;
     99                                   // the track is restored to the mix sample rate.
    100         // for target RAMP_VOLUME and VOLUME (8 channels max)
    101         // FIXME use float for these 3 to improve the dynamic range
    102         VOLUME0         = 0x4200,
    103         VOLUME1         = 0x4201,
    104         AUXLEVEL        = 0x4210,
    105         // for target TIMESTRETCH
    106         PLAYBACK_RATE   = 0x4300, // Configure timestretch on this track name;
    107                                   // parameter 'value' is a pointer to the new playback rate.
    108     };
    109 
    110 
    111     // For all APIs with "name": TRACK0 <= name < TRACK0 + MAX_NUM_TRACKS
    112 
    113     // Allocate a track name.  Returns new track name if successful, -1 on failure.
    114     // The failure could be because of an invalid channelMask or format, or that
    115     // the track capacity of the mixer is exceeded.
    116     int         getTrackName(audio_channel_mask_t channelMask,
    117                              audio_format_t format, int sessionId);
    118 
    119     // Free an allocated track by name
    120     void        deleteTrackName(int name);
    121 
    122     // Enable or disable an allocated track by name
    123     void        enable(int name);
    124     void        disable(int name);
    125 
    126     void        setParameter(int name, int target, int param, void *value);
    127 
    128     void        setBufferProvider(int name, AudioBufferProvider* bufferProvider);
    129     void        process();
    130 
    131     uint32_t    trackNames() const { return mTrackNames; }
    132 
    133     size_t      getUnreleasedFrames(int name) const;
    134 
    135     static inline bool isValidPcmTrackFormat(audio_format_t format) {
    136         switch (format) {
    137         case AUDIO_FORMAT_PCM_8_BIT:
    138         case AUDIO_FORMAT_PCM_16_BIT:
    139         case AUDIO_FORMAT_PCM_24_BIT_PACKED:
    140         case AUDIO_FORMAT_PCM_32_BIT:
    141         case AUDIO_FORMAT_PCM_FLOAT:
    142             return true;
    143         default:
    144             return false;
    145         }
    146     }
    147 
    148 private:
    149 
    150     enum {
    151         // FIXME this representation permits up to 8 channels
    152         NEEDS_CHANNEL_COUNT__MASK   = 0x00000007,
    153     };
    154 
    155     enum {
    156         NEEDS_CHANNEL_1             = 0x00000000,   // mono
    157         NEEDS_CHANNEL_2             = 0x00000001,   // stereo
    158 
    159         // sample format is not explicitly specified, and is assumed to be AUDIO_FORMAT_PCM_16_BIT
    160 
    161         NEEDS_MUTE                  = 0x00000100,
    162         NEEDS_RESAMPLE              = 0x00001000,
    163         NEEDS_AUX                   = 0x00010000,
    164     };
    165 
    166     struct state_t;
    167     struct track_t;
    168 
    169     typedef void (*hook_t)(track_t* t, int32_t* output, size_t numOutFrames, int32_t* temp,
    170                            int32_t* aux);
    171     static const int BLOCKSIZE = 16; // 4 cache lines
    172 
    173     struct track_t {
    174         uint32_t    needs;
    175 
    176         // TODO: Eventually remove legacy integer volume settings
    177         union {
    178         int16_t     volume[MAX_NUM_VOLUMES]; // U4.12 fixed point (top bit should be zero)
    179         int32_t     volumeRL;
    180         };
    181 
    182         int32_t     prevVolume[MAX_NUM_VOLUMES];
    183 
    184         // 16-byte boundary
    185 
    186         int32_t     volumeInc[MAX_NUM_VOLUMES];
    187         int32_t     auxInc;
    188         int32_t     prevAuxLevel;
    189 
    190         // 16-byte boundary
    191 
    192         int16_t     auxLevel;       // 0 <= auxLevel <= MAX_GAIN_INT, but signed for mul performance
    193         uint16_t    frameCount;
    194 
    195         uint8_t     channelCount;   // 1 or 2, redundant with (needs & NEEDS_CHANNEL_COUNT__MASK)
    196         uint8_t     unused_padding; // formerly format, was always 16
    197         uint16_t    enabled;        // actually bool
    198         audio_channel_mask_t channelMask;
    199 
    200         // actual buffer provider used by the track hooks, see DownmixerBufferProvider below
    201         //  for how the Track buffer provider is wrapped by another one when dowmixing is required
    202         AudioBufferProvider*                bufferProvider;
    203 
    204         // 16-byte boundary
    205 
    206         mutable AudioBufferProvider::Buffer buffer; // 8 bytes
    207 
    208         hook_t      hook;
    209         const void* in;             // current location in buffer
    210 
    211         // 16-byte boundary
    212 
    213         AudioResampler*     resampler;
    214         uint32_t            sampleRate;
    215         int32_t*           mainBuffer;
    216         int32_t*           auxBuffer;
    217 
    218         // 16-byte boundary
    219 
    220         /* Buffer providers are constructed to translate the track input data as needed.
    221          *
    222          * TODO: perhaps make a single PlaybackConverterProvider class to move
    223          * all pre-mixer track buffer conversions outside the AudioMixer class.
    224          *
    225          * 1) mInputBufferProvider: The AudioTrack buffer provider.
    226          * 2) mReformatBufferProvider: If not NULL, performs the audio reformat to
    227          *    match either mMixerInFormat or mDownmixRequiresFormat, if the downmixer
    228          *    requires reformat. For example, it may convert floating point input to
    229          *    PCM_16_bit if that's required by the downmixer.
    230          * 3) downmixerBufferProvider: If not NULL, performs the channel remixing to match
    231          *    the number of channels required by the mixer sink.
    232          * 4) mPostDownmixReformatBufferProvider: If not NULL, performs reformatting from
    233          *    the downmixer requirements to the mixer engine input requirements.
    234          * 5) mTimestretchBufferProvider: Adds timestretching for playback rate
    235          */
    236         AudioBufferProvider*     mInputBufferProvider;    // externally provided buffer provider.
    237         PassthruBufferProvider*  mReformatBufferProvider; // provider wrapper for reformatting.
    238         PassthruBufferProvider*  downmixerBufferProvider; // wrapper for channel conversion.
    239         PassthruBufferProvider*  mPostDownmixReformatBufferProvider;
    240         PassthruBufferProvider*  mTimestretchBufferProvider;
    241 
    242         int32_t     sessionId;
    243 
    244         audio_format_t mMixerFormat;     // output mix format: AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
    245         audio_format_t mFormat;          // input track format
    246         audio_format_t mMixerInFormat;   // mix internal format AUDIO_FORMAT_PCM_(FLOAT|16_BIT)
    247                                          // each track must be converted to this format.
    248         audio_format_t mDownmixRequiresFormat;  // required downmixer format
    249                                                 // AUDIO_FORMAT_PCM_16_BIT if 16 bit necessary
    250                                                 // AUDIO_FORMAT_INVALID if no required format
    251 
    252         float          mVolume[MAX_NUM_VOLUMES];     // floating point set volume
    253         float          mPrevVolume[MAX_NUM_VOLUMES]; // floating point previous volume
    254         float          mVolumeInc[MAX_NUM_VOLUMES];  // floating point volume increment
    255 
    256         float          mAuxLevel;                     // floating point set aux level
    257         float          mPrevAuxLevel;                 // floating point prev aux level
    258         float          mAuxInc;                       // floating point aux increment
    259 
    260         audio_channel_mask_t mMixerChannelMask;
    261         uint32_t             mMixerChannelCount;
    262 
    263         AudioPlaybackRate    mPlaybackRate;
    264 
    265         bool        needsRamp() { return (volumeInc[0] | volumeInc[1] | auxInc) != 0; }
    266         bool        setResampler(uint32_t trackSampleRate, uint32_t devSampleRate);
    267         bool        doesResample() const { return resampler != NULL; }
    268         void        resetResampler() { if (resampler != NULL) resampler->reset(); }
    269         void        adjustVolumeRamp(bool aux, bool useFloat = false);
    270         size_t      getUnreleasedFrames() const { return resampler != NULL ?
    271                                                     resampler->getUnreleasedFrames() : 0; };
    272 
    273         status_t    prepareForDownmix();
    274         void        unprepareForDownmix();
    275         status_t    prepareForReformat();
    276         void        unprepareForReformat();
    277         bool        setPlaybackRate(const AudioPlaybackRate &playbackRate);
    278         void        reconfigureBufferProviders();
    279     };
    280 
    281     typedef void (*process_hook_t)(state_t* state);
    282 
    283     // pad to 32-bytes to fill cache line
    284     struct state_t {
    285         uint32_t        enabledTracks;
    286         uint32_t        needsChanged;
    287         size_t          frameCount;
    288         process_hook_t  hook;   // one of process__*, never NULL
    289         int32_t         *outputTemp;
    290         int32_t         *resampleTemp;
    291         NBLog::Writer*  mLog;
    292         int32_t         reserved[1];
    293         // FIXME allocate dynamically to save some memory when maxNumTracks < MAX_NUM_TRACKS
    294         track_t         tracks[MAX_NUM_TRACKS] __attribute__((aligned(32)));
    295     };
    296 
    297     // bitmask of allocated track names, where bit 0 corresponds to TRACK0 etc.
    298     uint32_t        mTrackNames;
    299 
    300     // bitmask of configured track names; ~0 if maxNumTracks == MAX_NUM_TRACKS,
    301     // but will have fewer bits set if maxNumTracks < MAX_NUM_TRACKS
    302     const uint32_t  mConfiguredNames;
    303 
    304     const uint32_t  mSampleRate;
    305 
    306     NBLog::Writer   mDummyLog;
    307 public:
    308     void            setLog(NBLog::Writer* log);
    309 private:
    310     state_t         mState __attribute__((aligned(32)));
    311 
    312     // Call after changing either the enabled status of a track, or parameters of an enabled track.
    313     // OK to call more often than that, but unnecessary.
    314     void invalidateState(uint32_t mask);
    315 
    316     bool setChannelMasks(int name,
    317             audio_channel_mask_t trackChannelMask, audio_channel_mask_t mixerChannelMask);
    318 
    319     static void track__genericResample(track_t* t, int32_t* out, size_t numFrames, int32_t* temp,
    320             int32_t* aux);
    321     static void track__nop(track_t* t, int32_t* out, size_t numFrames, int32_t* temp, int32_t* aux);
    322     static void track__16BitsStereo(track_t* t, int32_t* out, size_t numFrames, int32_t* temp,
    323             int32_t* aux);
    324     static void track__16BitsMono(track_t* t, int32_t* out, size_t numFrames, int32_t* temp,
    325             int32_t* aux);
    326     static void volumeRampStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
    327             int32_t* aux);
    328     static void volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp,
    329             int32_t* aux);
    330 
    331     static void process__validate(state_t* state);
    332     static void process__nop(state_t* state);
    333     static void process__genericNoResampling(state_t* state);
    334     static void process__genericResampling(state_t* state);
    335     static void process__OneTrack16BitsStereoNoResampling(state_t* state);
    336 
    337     static pthread_once_t   sOnceControl;
    338     static void             sInitRoutine();
    339 
    340     /* multi-format volume mixing function (calls template functions
    341      * in AudioMixerOps.h).  The template parameters are as follows:
    342      *
    343      *   MIXTYPE     (see AudioMixerOps.h MIXTYPE_* enumeration)
    344      *   USEFLOATVOL (set to true if float volume is used)
    345      *   ADJUSTVOL   (set to true if volume ramp parameters needs adjustment afterwards)
    346      *   TO: int32_t (Q4.27) or float
    347      *   TI: int32_t (Q4.27) or int16_t (Q0.15) or float
    348      *   TA: int32_t (Q4.27)
    349      */
    350     template <int MIXTYPE, bool USEFLOATVOL, bool ADJUSTVOL,
    351         typename TO, typename TI, typename TA>
    352     static void volumeMix(TO *out, size_t outFrames,
    353             const TI *in, TA *aux, bool ramp, AudioMixer::track_t *t);
    354 
    355     // multi-format process hooks
    356     template <int MIXTYPE, typename TO, typename TI, typename TA>
    357     static void process_NoResampleOneTrack(state_t* state);
    358 
    359     // multi-format track hooks
    360     template <int MIXTYPE, typename TO, typename TI, typename TA>
    361     static void track__Resample(track_t* t, TO* out, size_t frameCount,
    362             TO* temp __unused, TA* aux);
    363     template <int MIXTYPE, typename TO, typename TI, typename TA>
    364     static void track__NoResample(track_t* t, TO* out, size_t frameCount,
    365             TO* temp __unused, TA* aux);
    366 
    367     static void convertMixerFormat(void *out, audio_format_t mixerOutFormat,
    368             void *in, audio_format_t mixerInFormat, size_t sampleCount);
    369 
    370     // hook types
    371     enum {
    372         PROCESSTYPE_NORESAMPLEONETRACK,
    373     };
    374     enum {
    375         TRACKTYPE_NOP,
    376         TRACKTYPE_RESAMPLE,
    377         TRACKTYPE_NORESAMPLE,
    378         TRACKTYPE_NORESAMPLEMONO,
    379     };
    380 
    381     // functions for determining the proper process and track hooks.
    382     static process_hook_t getProcessHook(int processType, uint32_t channelCount,
    383             audio_format_t mixerInFormat, audio_format_t mixerOutFormat);
    384     static hook_t getTrackHook(int trackType, uint32_t channelCount,
    385             audio_format_t mixerInFormat, audio_format_t mixerOutFormat);
    386 };
    387 
    388 // ----------------------------------------------------------------------------
    389 } // namespace android
    390 
    391 #endif // ANDROID_AUDIO_MIXER_H
    392