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      1 /* //device/include/server/AudioFlinger/AudioMixer.h
      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 "AudioBufferProvider.h"
     25 #include "AudioResampler.h"
     26 
     27 namespace android {
     28 
     29 // ----------------------------------------------------------------------------
     30 
     31 #define LIKELY( exp )       (__builtin_expect( (exp) != 0, true  ))
     32 #define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))
     33 
     34 // ----------------------------------------------------------------------------
     35 
     36 class AudioMixer
     37 {
     38 public:
     39                             AudioMixer(size_t frameCount, uint32_t sampleRate);
     40 
     41                             ~AudioMixer();
     42 
     43     static const uint32_t MAX_NUM_TRACKS = 32;
     44     static const uint32_t MAX_NUM_CHANNELS = 2;
     45 
     46     static const uint16_t UNITY_GAIN = 0x1000;
     47 
     48     enum { // names
     49 
     50         // track units (32 units)
     51         TRACK0          = 0x1000,
     52 
     53         // enable/disable
     54         MIXING          = 0x2000,
     55 
     56         // setParameter targets
     57         TRACK           = 0x3000,
     58         RESAMPLE        = 0x3001,
     59         RAMP_VOLUME     = 0x3002, // ramp to new volume
     60         VOLUME          = 0x3003, // don't ramp
     61 
     62         // set Parameter names
     63         // for target TRACK
     64         CHANNEL_MASK    = 0x4000,
     65         FORMAT          = 0x4001,
     66         MAIN_BUFFER     = 0x4002,
     67         AUX_BUFFER      = 0x4003,
     68         // for TARGET RESAMPLE
     69         SAMPLE_RATE     = 0x4100,
     70         RESET           = 0x4101,
     71         // for TARGET VOLUME (8 channels max)
     72         VOLUME0         = 0x4200,
     73         VOLUME1         = 0x4201,
     74         AUXLEVEL        = 0x4210,
     75     };
     76 
     77 
     78     int         getTrackName();
     79     void        deleteTrackName(int name);
     80 
     81     status_t    enable(int name);
     82     status_t    disable(int name);
     83 
     84     status_t    setActiveTrack(int track);
     85     status_t    setParameter(int target, int name, void *value);
     86 
     87     status_t    setBufferProvider(AudioBufferProvider* bufferProvider);
     88     void        process();
     89 
     90     uint32_t    trackNames() const { return mTrackNames; }
     91 
     92     static void ditherAndClamp(int32_t* out, int32_t const *sums, size_t c);
     93 
     94 private:
     95 
     96     enum {
     97         NEEDS_CHANNEL_COUNT__MASK   = 0x00000003,
     98         NEEDS_FORMAT__MASK          = 0x000000F0,
     99         NEEDS_MUTE__MASK            = 0x00000100,
    100         NEEDS_RESAMPLE__MASK        = 0x00001000,
    101         NEEDS_AUX__MASK             = 0x00010000,
    102     };
    103 
    104     enum {
    105         NEEDS_CHANNEL_1             = 0x00000000,
    106         NEEDS_CHANNEL_2             = 0x00000001,
    107 
    108         NEEDS_FORMAT_16             = 0x00000010,
    109 
    110         NEEDS_MUTE_DISABLED         = 0x00000000,
    111         NEEDS_MUTE_ENABLED          = 0x00000100,
    112 
    113         NEEDS_RESAMPLE_DISABLED     = 0x00000000,
    114         NEEDS_RESAMPLE_ENABLED      = 0x00001000,
    115 
    116         NEEDS_AUX_DISABLED     = 0x00000000,
    117         NEEDS_AUX_ENABLED      = 0x00010000,
    118     };
    119 
    120     static inline int32_t applyVolume(int32_t in, int32_t v) {
    121         return in * v;
    122     }
    123 
    124 
    125     struct state_t;
    126     struct track_t;
    127 
    128     typedef void (*mix_t)(state_t* state);
    129     typedef void (*hook_t)(track_t* t, int32_t* output, size_t numOutFrames, int32_t* temp, int32_t* aux);
    130     static const int BLOCKSIZE = 16; // 4 cache lines
    131 
    132     struct track_t {
    133         uint32_t    needs;
    134 
    135         union {
    136         int16_t     volume[2];      // [0]3.12 fixed point
    137         int32_t     volumeRL;
    138         };
    139 
    140         int32_t     prevVolume[2];
    141 
    142         int32_t     volumeInc[2];
    143         int32_t     auxLevel;
    144         int32_t     auxInc;
    145         int32_t     prevAuxLevel;
    146 
    147         uint16_t    frameCount;
    148 
    149         uint8_t     channelCount : 4;
    150         uint8_t     enabled      : 1;
    151         uint8_t     reserved0    : 3;
    152         uint8_t     format;
    153         uint32_t    channelMask;
    154 
    155         AudioBufferProvider*                bufferProvider;
    156         mutable AudioBufferProvider::Buffer buffer;
    157 
    158         hook_t      hook;
    159         void const* in;             // current location in buffer
    160 
    161         AudioResampler*     resampler;
    162         uint32_t            sampleRate;
    163         int32_t*           mainBuffer;
    164         int32_t*           auxBuffer;
    165 
    166         bool        setResampler(uint32_t sampleRate, uint32_t devSampleRate);
    167         bool        doesResample() const;
    168         void        resetResampler();
    169         void        adjustVolumeRamp(bool aux);
    170     };
    171 
    172     // pad to 32-bytes to fill cache line
    173     struct state_t {
    174         uint32_t        enabledTracks;
    175         uint32_t        needsChanged;
    176         size_t          frameCount;
    177         mix_t           hook;
    178         int32_t         *outputTemp;
    179         int32_t         *resampleTemp;
    180         int32_t         reserved[2];
    181         track_t         tracks[32]; __attribute__((aligned(32)));
    182     };
    183 
    184     int             mActiveTrack;
    185     uint32_t        mTrackNames;
    186     const uint32_t  mSampleRate;
    187 
    188     state_t         mState __attribute__((aligned(32)));
    189 
    190     void invalidateState(uint32_t mask);
    191 
    192     static void track__genericResample(track_t* t, int32_t* out, size_t numFrames, int32_t* temp, int32_t* aux);
    193     static void track__nop(track_t* t, int32_t* out, size_t numFrames, int32_t* temp, int32_t* aux);
    194     static void track__16BitsStereo(track_t* t, int32_t* out, size_t numFrames, int32_t* temp, int32_t* aux);
    195     static void track__16BitsMono(track_t* t, int32_t* out, size_t numFrames, int32_t* temp, int32_t* aux);
    196     static void volumeRampStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp, int32_t* aux);
    197     static void volumeStereo(track_t* t, int32_t* out, size_t frameCount, int32_t* temp, int32_t* aux);
    198 
    199     static void process__validate(state_t* state);
    200     static void process__nop(state_t* state);
    201     static void process__genericNoResampling(state_t* state);
    202     static void process__genericResampling(state_t* state);
    203     static void process__OneTrack16BitsStereoNoResampling(state_t* state);
    204     static void process__TwoTracks16BitsStereoNoResampling(state_t* state);
    205 };
    206 
    207 // ----------------------------------------------------------------------------
    208 }; // namespace android
    209 
    210 #endif // ANDROID_AUDIO_MIXER_H
    211