TrackBase.h revision 35cc4f3127322ad3e3dd1e15e8ae29ff4b4a3af6 
1/*
2**
3** Copyright 2012, 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 INCLUDING_FROM_AUDIOFLINGER_H
19    #error This header file should only be included from AudioFlinger.h
20#endif
21
22// base for record and playback
23class TrackBase : public ExtendedAudioBufferProvider, public RefBase {
24
25public:
26    enum track_state {
27        IDLE,
28        FLUSHED,
29        STOPPED,
30        // next 2 states are currently used for fast tracks
31        // and offloaded tracks only
32        STOPPING_1,     // waiting for first underrun
33        STOPPING_2,     // waiting for presentation complete
34        RESUMING,
35        ACTIVE,
36        PAUSING,
37        PAUSED
38    };
39
40                        TrackBase(ThreadBase *thread,
41                                const sp<Client>& client,
42                                uint32_t sampleRate,
43                                audio_format_t format,
44                                audio_channel_mask_t channelMask,
45                                size_t frameCount,
46                                const sp<IMemory>& sharedBuffer,
47                                int sessionId,
48                                bool isOut);
49    virtual             ~TrackBase();
50
51    virtual status_t    start(AudioSystem::sync_event_t event,
52                             int triggerSession) = 0;
53    virtual void        stop() = 0;
54            sp<IMemory> getCblk() const { return mCblkMemory; }
55            audio_track_cblk_t* cblk() const { return mCblk; }
56            int         sessionId() const { return mSessionId; }
57    virtual status_t    setSyncEvent(const sp<SyncEvent>& event);
58
59protected:
60                        TrackBase(const TrackBase&);
61                        TrackBase& operator = (const TrackBase&);
62
63    // AudioBufferProvider interface
64    virtual status_t getNextBuffer(AudioBufferProvider::Buffer* buffer, int64_t pts) = 0;
65    virtual void releaseBuffer(AudioBufferProvider::Buffer* buffer);
66
67    // ExtendedAudioBufferProvider interface is only needed for Track,
68    // but putting it in TrackBase avoids the complexity of virtual inheritance
69    virtual size_t  framesReady() const { return SIZE_MAX; }
70
71    audio_format_t format() const { return mFormat; }
72
73    uint32_t channelCount() const { return mChannelCount; }
74
75    audio_channel_mask_t channelMask() const { return mChannelMask; }
76
77    virtual uint32_t sampleRate() const { return mSampleRate; }
78
79    // Return a pointer to the start of a contiguous slice of the track buffer.
80    // Parameter 'offset' is the requested start position, expressed in
81    // monotonically increasing frame units relative to the track epoch.
82    // Parameter 'frames' is the requested length, also in frame units.
83    // Always returns non-NULL.  It is the caller's responsibility to
84    // verify that this will be successful; the result of calling this
85    // function with invalid 'offset' or 'frames' is undefined.
86    void* getBuffer(uint32_t offset, uint32_t frames) const;
87
88    bool isStopped() const {
89        return (mState == STOPPED || mState == FLUSHED);
90    }
91
92    // for fast tracks and offloaded tracks only
93    bool isStopping() const {
94        return mState == STOPPING_1 || mState == STOPPING_2;
95    }
96    bool isStopping_1() const {
97        return mState == STOPPING_1;
98    }
99    bool isStopping_2() const {
100        return mState == STOPPING_2;
101    }
102
103    bool isTerminated() const {
104        return mTerminated;
105    }
106
107    void terminate() {
108        mTerminated = true;
109    }
110
111    bool isOut() const { return mIsOut; }
112                                    // true for Track and TimedTrack, false for RecordTrack,
113                                    // this could be a track type if needed later
114
115    const wp<ThreadBase> mThread;
116    /*const*/ sp<Client> mClient;   // see explanation at ~TrackBase() why not const
117    sp<IMemory>         mCblkMemory;
118    audio_track_cblk_t* mCblk;
119    void*               mBuffer;    // start of track buffer, typically in shared memory
120                                    // except for OutputTrack when it is in local memory
121    // we don't really need a lock for these
122    track_state         mState;
123    const uint32_t      mSampleRate;    // initial sample rate only; for tracks which
124                        // support dynamic rates, the current value is in control block
125    const audio_format_t mFormat;
126    const audio_channel_mask_t mChannelMask;
127    const uint8_t       mChannelCount;
128    const size_t        mFrameSize; // AudioFlinger's view of frame size in shared memory,
129                                    // where for AudioTrack (but not AudioRecord),
130                                    // 8-bit PCM samples are stored as 16-bit
131    const size_t        mFrameCount;// size of track buffer given at createTrack() or
132                                    // openRecord(), and then adjusted as needed
133
134    const int           mSessionId;
135    Vector < sp<SyncEvent> >mSyncEvents;
136    const bool          mIsOut;
137    ServerProxy*        mServerProxy;
138    const int           mId;
139    sp<NBAIO_Sink>      mTeeSink;
140    sp<NBAIO_Source>    mTeeSource;
141    bool                mTerminated;
142};
143