FastMixerState.h revision 3ce28aa3cb5262775180a8b423cfb4a5670ebc59 
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 <system/audio.h>
21#include <media/ExtendedAudioBufferProvider.h>
22#include <media/nbaio/NBAIO.h>
23#include <media/nbaio/NBLog.h>
24
25namespace android {
26
27struct FastMixerDumpState;
28
29class VolumeProvider {
30public:
31    // Return the track volume in U4_12 format: left in lower half, right in upper half. The
32    // provider implementation is responsible for validating that the return value is in range.
33    virtual uint32_t getVolumeLR() = 0;
34protected:
35    VolumeProvider() { }
36    virtual ~VolumeProvider() { }
37};
38
39// Represents the state of a fast track
40struct FastTrack {
41    FastTrack();
42    /*virtual*/ ~FastTrack();
43
44    ExtendedAudioBufferProvider* mBufferProvider; // must be NULL if inactive, or non-NULL if active
45    VolumeProvider*         mVolumeProvider; // optional; if NULL then full-scale
46    audio_channel_mask_t    mChannelMask;    // AUDIO_CHANNEL_OUT_MONO or AUDIO_CHANNEL_OUT_STEREO
47    int                     mGeneration;     // increment when any field is assigned
48};
49
50// Represents a single state of the fast mixer
51struct FastMixerState {
52                FastMixerState();
53    /*virtual*/ ~FastMixerState();
54
55    static const unsigned kMaxFastTracks = 8;   // must be between 2 and 32 inclusive
56
57    // all pointer fields use raw pointers; objects are owned and ref-counted by the normal mixer
58    FastTrack   mFastTracks[kMaxFastTracks];
59    int         mFastTracksGen; // increment when any mFastTracks[i].mGeneration is incremented
60    unsigned    mTrackMask;     // bit i is set if and only if mFastTracks[i] is active
61    NBAIO_Sink* mOutputSink;    // HAL output device, must already be negotiated
62    int         mOutputSinkGen; // increment when mOutputSink is assigned
63    size_t      mFrameCount;    // number of frames per fast mix buffer
64    enum Command {
65        INITIAL = 0,            // used only for the initial state
66        HOT_IDLE = 1,           // do nothing
67        COLD_IDLE = 2,          // wait for the futex
68        IDLE = 3,               // either HOT_IDLE or COLD_IDLE
69        EXIT = 4,               // exit from thread
70        // The following commands also process configuration changes, and can be "or"ed:
71        MIX = 0x8,              // mix tracks
72        WRITE = 0x10,           // write to output sink
73        MIX_WRITE = 0x18,       // mix tracks and write to output sink
74    } mCommand;
75    int32_t*    mColdFutexAddr; // for COLD_IDLE only, pointer to the associated futex
76    unsigned    mColdGen;       // increment when COLD_IDLE is requested so it's only performed once
77    // This might be a one-time configuration rather than per-state
78    FastMixerDumpState* mDumpState; // if non-NULL, then update dump state periodically
79    NBAIO_Sink* mTeeSink;       // if non-NULL, then duplicate write()s to this non-blocking sink
80    NBLog::Writer* mNBLogWriter; // non-blocking logger
81};  // struct FastMixerState
82
83}   // namespace android
84
85#endif  // ANDROID_AUDIO_FAST_MIXER_STATE_H
86