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 <audio_utils/minifloat.h>
21 #include <system/audio.h>
22 #include <media/ExtendedAudioBufferProvider.h>
23 #include <media/nbaio/NBAIO.h>
24 #include <media/nbaio/NBLog.h>
25 #include "FastThreadState.h"
26 
27 namespace android {
28 
29 struct FastMixerDumpState;
30 
31 class VolumeProvider {
32 public:
33     // The provider implementation is responsible for validating that the return value is in range.
34     virtual gain_minifloat_packed_t getVolumeLR() = 0;
35 protected:
VolumeProvider()36     VolumeProvider() { }
~VolumeProvider()37     virtual ~VolumeProvider() { }
38 };
39 
40 // Represents the state of a fast track
41 struct FastTrack {
42     FastTrack();
43     /*virtual*/ ~FastTrack();
44 
45     ExtendedAudioBufferProvider* mBufferProvider; // must be NULL if inactive, or non-NULL if active
46     VolumeProvider*         mVolumeProvider; // optional; if NULL then full-scale
47     audio_channel_mask_t    mChannelMask;    // AUDIO_CHANNEL_OUT_MONO or AUDIO_CHANNEL_OUT_STEREO
48     audio_format_t          mFormat;         // track format
49     int                     mGeneration;     // increment when any field is assigned
50 };
51 
52 // Represents a single state of the fast mixer
53 struct FastMixerState : FastThreadState {
54                 FastMixerState();
55     /*virtual*/ ~FastMixerState();
56 
57     // These are the minimum, maximum, and default values for maximum number of fast tracks
58     static const unsigned kMinFastTracks = 2;
59     static const unsigned kMaxFastTracks = 32;
60     static const unsigned kDefaultFastTracks = 8;
61 
62     static unsigned sMaxFastTracks;             // Configured maximum number of fast tracks
63     static pthread_once_t sMaxFastTracksOnce;   // Protects initializer for sMaxFastTracks
64 
65     // all pointer fields use raw pointers; objects are owned and ref-counted by the normal mixer
66     FastTrack   mFastTracks[kMaxFastTracks];
67     int         mFastTracksGen; // increment when any mFastTracks[i].mGeneration is incremented
68     unsigned    mTrackMask;     // bit i is set if and only if mFastTracks[i] is active
69     NBAIO_Sink* mOutputSink;    // HAL output device, must already be negotiated
70     int         mOutputSinkGen; // increment when mOutputSink is assigned
71     size_t      mFrameCount;    // number of frames per fast mix buffer
72 
73     // Extends FastThreadState::Command
74     static const Command
75         // The following commands also process configuration changes, and can be "or"ed:
76         MIX = 0x8,              // mix tracks
77         WRITE = 0x10,           // write to output sink
78         MIX_WRITE = 0x18;       // mix tracks and write to output sink
79 
80     // This might be a one-time configuration rather than per-state
81     NBAIO_Sink* mTeeSink;       // if non-NULL, then duplicate write()s to this non-blocking sink
82 
83     // never returns NULL; asserts if command is invalid
84     static const char *commandToString(Command command);
85 
86     // initialize sMaxFastTracks
87     static void sMaxFastTracksInit();
88 
89 };  // struct FastMixerState
90 
91 }   // namespace android
92 
93 #endif  // ANDROID_AUDIO_FAST_MIXER_STATE_H
94