AudioMixer.h revision 0d255b2d9061ba31f13ada3fc0f7e51916407176 
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
27namespace 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
36class AudioMixer
37{
38public:
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
94private:
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