FastMixerState.h revision 97b5d0d5b5ef766eb5dd680d05a5d199662d4ae0 
1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_AUDIO_FAST_MIXER_STATE_H
18#define ANDROID_AUDIO_FAST_MIXER_STATE_H
19
20#include "AudioBufferProvider.h"
21#include "NBAIO.h"
22
23namespace android {
24
25struct FastMixerDumpState;
26
27class VolumeProvider {
28public:
29    // Return the track volume in U4_12 format: left in lower half, right in upper half. The
30    // provider implementation is responsible for validating that the return value is in range.
31    virtual uint32_t getVolumeLR() = 0;
32protected:
33    VolumeProvider() { }
34    virtual ~VolumeProvider() { }
35};
36
37// Represents the state of a fast track
38struct FastTrack {
39    FastTrack();
40    /*virtual*/ ~FastTrack();
41
42    AudioBufferProvider*    mBufferProvider; // must not be NULL
43    VolumeProvider*         mVolumeProvider; // optional; if NULL then full-scale
44    int                     mGeneration;     // increment when any field is assigned
45};
46
47// Represents a single state of the fast mixer
48struct FastMixerState {
49                FastMixerState();
50    /*virtual*/ ~FastMixerState();
51
52    static const unsigned kMaxFastTracks = 8;   // must be between 2 and 32 inclusive
53
54    // all pointer fields use raw pointers; objects are owned and ref-counted by the normal mixer
55    FastTrack   mFastTracks[kMaxFastTracks];
56    int         mFastTracksGen; // increment when any mFastTracks[i].mGeneration is incremented
57    unsigned    mTrackMask;     // bit i is set if and only if mFastTracks[i] != NULL
58    NBAIO_Sink* mOutputSink;    // HAL output device, must already be negotiated
59    int         mOutputSinkGen; // increment when mOutputSink is assigned
60    size_t      mFrameCount;    // number of frames per fast mix buffer
61    enum Command {
62        INITIAL = 0,            // used only for the initial state
63        HOT_IDLE = 1,           // do nothing
64        COLD_IDLE = 2,          // wait for the futex
65        IDLE = 3,               // either HOT_IDLE or COLD_IDLE
66        EXIT = 4,               // exit from thread
67        // The following commands also process configuration changes, and can be "or"ed:
68        MIX = 0x8,              // mix tracks
69        WRITE = 0x10,           // write to output sink
70        MIX_WRITE = 0x18,       // mix tracks and write to output sink
71    } mCommand;
72    int32_t*    mColdFutexAddr; // for COLD_IDLE only, pointer to the associated futex
73    unsigned    mColdGen;       // increment when COLD_IDLE is requested so it's only performed once
74    // This might be a one-time configuration rather than per-state
75    FastMixerDumpState* mDumpState; // if non-NULL, then update dump state periodically
76};  // struct FastMixerState
77
78}   // namespace android
79
80#endif  // ANDROID_AUDIO_FAST_MIXER_STATE_H
81