AudioParameter.h revision 3432e0439d3b09756f125dfa734951c654d63baf 
1/*
2 * Copyright (C) 2008-2011 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_AUDIOPARAMETER_H_
18#define ANDROID_AUDIOPARAMETER_H_
19
20#include <utils/Errors.h>
21#include <utils/KeyedVector.h>
22#include <utils/String8.h>
23
24namespace android {
25
26class AudioParameter {
27
28public:
29    AudioParameter() {}
30    AudioParameter(const String8& keyValuePairs);
31    virtual ~AudioParameter();
32
33    // reserved parameter keys for changing standard parameters with setParameters() function.
34    // Using these keys is mandatory for AudioFlinger to properly monitor audio output/input
35    // configuration changes and act accordingly.
36    //  keyRouting: to change audio routing, value is an int in audio_devices_t
37    //  keySamplingRate: to change sampling rate routing, value is an int
38    //  keyFormat: to change audio format, value is an int in audio_format_t
39    //  keyChannels: to change audio channel configuration, value is an int in audio_channels_t
40    //  keyFrameCount: to change audio output frame count, value is an int
41    //  keyInputSource: to change audio input source, value is an int in audio_source_t
42    //     (defined in media/mediarecorder.h)
43    //  keyScreenState: either "on" or "off"
44    static const char * const keyRouting;
45    static const char * const keySamplingRate;
46    static const char * const keyFormat;
47    static const char * const keyChannels;
48    static const char * const keyFrameCount;
49    static const char * const keyInputSource;
50    static const char * const keyScreenState;
51
52    //  keyBtNrec: BT SCO Noise Reduction + Echo Cancellation parameters
53    //  keyHwAvSync: get HW synchronization source identifier from a device
54    //  keyMonoOutput: Enable mono audio playback
55    //  keyStreamHwAvSync: set HW synchronization source identifier on a stream
56    static const char * const keyBtNrec;
57    static const char * const keyHwAvSync;
58    static const char * const keyMonoOutput;
59    static const char * const keyStreamHwAvSync;
60
61    //  keys for presentation selection
62    //  keyPresentationId: Audio presentation identifier
63    //  keyProgramId: Audio presentation program identifier
64    static const char * const keyPresentationId;
65    static const char * const keyProgramId;
66
67    //  keyStreamConnect / Disconnect: value is an int in audio_devices_t
68    static const char * const keyStreamConnect;
69    static const char * const keyStreamDisconnect;
70
71    // For querying stream capabilities. All the returned values are lists.
72    //   keyStreamSupportedFormats: audio_format_t
73    //   keyStreamSupportedChannels: audio_channel_mask_t
74    //   keyStreamSupportedSamplingRates: sampling rate values
75    static const char * const keyStreamSupportedFormats;
76    static const char * const keyStreamSupportedChannels;
77    static const char * const keyStreamSupportedSamplingRates;
78
79    static const char * const valueOn;
80    static const char * const valueOff;
81
82    static const char * const valueListSeparator;
83
84    // keyReconfigA2dp: Ask HwModule to reconfigure A2DP offloaded codec
85    // keyReconfigA2dpSupported: Query if HwModule supports A2DP offload codec config
86    static const char * const keyReconfigA2dp;
87    static const char * const keyReconfigA2dpSupported;
88
89    String8 toString() const { return toStringImpl(true); }
90    String8 keysToString() const { return toStringImpl(false); }
91
92    status_t add(const String8& key, const String8& value);
93    status_t addInt(const String8& key, const int value);
94    status_t addKey(const String8& key);
95    status_t addFloat(const String8& key, const float value);
96
97    status_t remove(const String8& key);
98
99    status_t get(const String8& key, String8& value) const;
100    status_t getInt(const String8& key, int& value) const;
101    status_t getFloat(const String8& key, float& value) const;
102    status_t getAt(size_t index, String8& key) const;
103    status_t getAt(size_t index, String8& key, String8& value) const;
104
105    size_t size() const { return mParameters.size(); }
106
107private:
108    String8 mKeyValuePairs;
109    KeyedVector <String8, String8> mParameters;
110
111    String8 toStringImpl(bool useValues) const;
112};
113
114};  // namespace android
115
116#endif  /*ANDROID_AUDIOPARAMETER_H_*/
117