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 
24 namespace android {
25 
26 class AudioParameter {
27 
28 public:
AudioParameter()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     //  keyAudioLanguagePreferred: Preferred audio language
68     static const char * const keyAudioLanguagePreferred;
69 
70     //  keyDeviceConnect / Disconnect: value is an int in audio_devices_t
71     static const char * const keyDeviceConnect;
72     static const char * const keyDeviceDisconnect;
73     //  Need to be here because vendors still use them.
74     static const char * const keyStreamConnect;  // Deprecated: DO NOT USE.
75     static const char * const keyStreamDisconnect;  // Deprecated: DO NOT USE.
76 
77     // For querying stream capabilities. All the returned values are lists.
78     //   keyStreamSupportedFormats: audio_format_t
79     //   keyStreamSupportedChannels: audio_channel_mask_t
80     //   keyStreamSupportedSamplingRates: sampling rate values
81     static const char * const keyStreamSupportedFormats;
82     static const char * const keyStreamSupportedChannels;
83     static const char * const keyStreamSupportedSamplingRates;
84 
85     static const char * const valueOn;
86     static const char * const valueOff;
87 
88     static const char * const valueListSeparator;
89 
90     // keyReconfigA2dp: Ask HwModule to reconfigure A2DP offloaded codec
91     // keyReconfigA2dpSupported: Query if HwModule supports A2DP offload codec config
92     static const char * const keyReconfigA2dp;
93     static const char * const keyReconfigA2dpSupported;
94 
95     // For querying device supported encapsulation capabilities. All returned values are integer,
96     // which are bit fields composed from using encapsulation capability values as position bits.
97     // Encapsulation capability values are defined in audio_encapsulation_mode_t and
98     // audio_encapsulation_metadata_type_t. For instance, if the supported encapsulation mode is
99     // AUDIO_ENCAPSULATION_MODE_ELEMENTARY_STREAM, the returned value is
100     // "supEncapsulationModes=1 << AUDIO_ENCAPSULATION_MODE_HANDLE".
101     // When querying device supported encapsulation capabilities, the key should use with device
102     // type and address so that it is able to identify the device. The device will be a key. The
103     // device type will be the value of key AUDIO_PARAMETER_STREAM_ROUTING.
104     // static const char * const keyDeviceSupportedEncapsulationModes;
105     // static const char * const keyDeviceSupportedEncapsulationMetadataTypes;
106 
107     static const char * const keyAdditionalOutputDeviceDelay;
108     static const char * const keyMaxAdditionalOutputDeviceDelay;
109 
toString()110     String8 toString() const { return toStringImpl(true); }
keysToString()111     String8 keysToString() const { return toStringImpl(false); }
112 
113     status_t add(const String8& key, const String8& value);
114     status_t addInt(const String8& key, const int value);
115     status_t addKey(const String8& key);
116     status_t addFloat(const String8& key, const float value);
117 
118     status_t remove(const String8& key);
119 
120     status_t get(const String8& key, String8& value) const;
121     status_t getInt(const String8& key, int& value) const;
122     status_t getFloat(const String8& key, float& value) const;
123     status_t getAt(size_t index, String8& key) const;
124     status_t getAt(size_t index, String8& key, String8& value) const;
125 
size()126     size_t size() const { return mParameters.size(); }
127 
128 private:
129     String8 mKeyValuePairs;
130     KeyedVector <String8, String8> mParameters;
131 
132     String8 toStringImpl(bool useValues) const;
133 };
134 
135 };  // namespace android
136 
137 #endif  /*ANDROID_AUDIOPARAMETER_H_*/
138