TrackBase.h revision 9cae217050aa1347d4ac5053c305754879e3f97f 
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                                int uid,
49                                bool isOut);
50    virtual             ~TrackBase();
51
52    virtual status_t    start(AudioSystem::sync_event_t event,
53                             int triggerSession) = 0;
54    virtual void        stop() = 0;
55            sp<IMemory> getCblk() const { return mCblkMemory; }
56            audio_track_cblk_t* cblk() const { return mCblk; }
57            int         sessionId() const { return mSessionId; }
58            int         uid() const { return mUid; }
59    virtual status_t    setSyncEvent(const sp<SyncEvent>& event);
60
61protected:
62                        TrackBase(const TrackBase&);
63                        TrackBase& operator = (const TrackBase&);
64
65    // AudioBufferProvider interface
66    virtual status_t getNextBuffer(AudioBufferProvider::Buffer* buffer, int64_t pts) = 0;
67    virtual void releaseBuffer(AudioBufferProvider::Buffer* buffer);
68
69    // ExtendedAudioBufferProvider interface is only needed for Track,
70    // but putting it in TrackBase avoids the complexity of virtual inheritance
71    virtual size_t  framesReady() const { return SIZE_MAX; }
72
73    audio_format_t format() const { return mFormat; }
74
75    uint32_t channelCount() const { return mChannelCount; }
76
77    audio_channel_mask_t channelMask() const { return mChannelMask; }
78
79    virtual uint32_t sampleRate() const { return mSampleRate; }
80
81    // Return a pointer to the start of a contiguous slice of the track buffer.
82    // Parameter 'offset' is the requested start position, expressed in
83    // monotonically increasing frame units relative to the track epoch.
84    // Parameter 'frames' is the requested length, also in frame units.
85    // Always returns non-NULL.  It is the caller's responsibility to
86    // verify that this will be successful; the result of calling this
87    // function with invalid 'offset' or 'frames' is undefined.
88    void* getBuffer(uint32_t offset, uint32_t frames) const;
89
90    bool isStopped() const {
91        return (mState == STOPPED || mState == FLUSHED);
92    }
93
94    // for fast tracks and offloaded tracks only
95    bool isStopping() const {
96        return mState == STOPPING_1 || mState == STOPPING_2;
97    }
98    bool isStopping_1() const {
99        return mState == STOPPING_1;
100    }
101    bool isStopping_2() const {
102        return mState == STOPPING_2;
103    }
104
105    bool isTerminated() const {
106        return mTerminated;
107    }
108
109    void terminate() {
110        mTerminated = true;
111    }
112
113    bool isOut() const { return mIsOut; }
114                                    // true for Track and TimedTrack, false for RecordTrack,
115                                    // this could be a track type if needed later
116
117    const wp<ThreadBase> mThread;
118    /*const*/ sp<Client> mClient;   // see explanation at ~TrackBase() why not const
119    sp<IMemory>         mCblkMemory;
120    audio_track_cblk_t* mCblk;
121    void*               mBuffer;    // start of track buffer, typically in shared memory
122                                    // except for OutputTrack when it is in local memory
123    // we don't really need a lock for these
124    track_state         mState;
125    const uint32_t      mSampleRate;    // initial sample rate only; for tracks which
126                        // support dynamic rates, the current value is in control block
127    const audio_format_t mFormat;
128    const audio_channel_mask_t mChannelMask;
129    const uint32_t      mChannelCount;
130    const size_t        mFrameSize; // AudioFlinger's view of frame size in shared memory,
131                                    // where for AudioTrack (but not AudioRecord),
132                                    // 8-bit PCM samples are stored as 16-bit
133    const size_t        mFrameCount;// size of track buffer given at createTrack() or
134                                    // openRecord(), and then adjusted as needed
135
136    const int           mSessionId;
137    int                 mUid;
138    Vector < sp<SyncEvent> >mSyncEvents;
139    const bool          mIsOut;
140    ServerProxy*        mServerProxy;
141    const int           mId;
142    sp<NBAIO_Sink>      mTeeSink;
143    sp<NBAIO_Source>    mTeeSource;
144    bool                mTerminated;
145};
146