cpal 0.17.3

Low-level cross-platform audio I/O library in pure Rust.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

use num_derive::FromPrimitive;

use crate::{DeviceDirection, SampleFormat};

pub(crate) struct Context;

impl Context {
    pub const AUDIO_SERVICE: &'static str = "audio";
}

pub(crate) struct PackageManager;

impl PackageManager {
    pub const FEATURE_AUDIO_LOW_LATENCY: &'static str = "android.hardware.audio.low_latency";
    pub const FEATURE_AUDIO_OUTPUT: &'static str = "android.hardware.audio.output";
    pub const FEATURE_AUDIO_PRO: &'static str = "android.hardware.audio.pro";
    pub const FEATURE_MICROPHONE: &'static str = "android.hardware.microphone";
    pub const FEATURE_MIDI: &'static str = "android.software.midi";
}

pub(crate) struct AudioManager;

impl AudioManager {
    pub const PROPERTY_OUTPUT_FRAMES_PER_BUFFER: &'static str =
        "android.media.property.OUTPUT_FRAMES_PER_BUFFER";

    pub const GET_DEVICES_INPUTS: i32 = 1 << 0;
    pub const GET_DEVICES_OUTPUTS: i32 = 1 << 1;
    pub const GET_DEVICES_ALL: i32 = Self::GET_DEVICES_INPUTS | Self::GET_DEVICES_OUTPUTS;
}

/**
 * The Android audio device info
 */
#[derive(Debug, Clone)]
pub struct AudioDeviceInfo {
    /**
     * Device identifier
     */
    pub id: i32,

    /**
     * The type of device
     */
    pub device_type: AudioDeviceType,

    /**
     * The device can be used for playback and/or capture
     */
    pub direction: DeviceDirection,

    /**
     * Device address
     */
    pub address: String,

    /**
     * Device product name
     */
    pub product_name: String,

    /**
     * Available channel configurations
     */
    pub channel_counts: Vec<i32>,

    /**
     * Supported sample rates
     */
    pub sample_rates: Vec<i32>,

    /**
     * Supported audio formats
     */
    pub formats: Vec<SampleFormat>,
}

/**
 * The type of audio device
 */
#[derive(Debug, Clone, Copy, FromPrimitive)]
#[non_exhaustive]
#[repr(i32)]
pub enum AudioDeviceType {
    Unknown = 0,
    AuxLine = 19,
    BleBroadcast = 30,
    BleHeadset = 26,
    BleSpeaker = 27,
    BluetoothA2DP = 8,
    BluetoothSCO = 7,
    BuiltinEarpiece = 1,
    BuiltinMic = 15,
    BuiltinSpeaker = 2,
    BuiltinSpeakerSafe = 24,
    Bus = 21,
    Dock = 13,
    Fm = 14,
    FmTuner = 16,
    Hdmi = 9,
    HdmiArc = 10,
    HdmiEarc = 29,
    HearingAid = 23,
    Ip = 20,
    LineAnalog = 5,
    LineDigital = 6,
    RemoteSubmix = 25,
    Telephony = 18,
    TvTuner = 17,
    UsbAccessory = 12,
    UsbDevice = 11,
    UsbHeadset = 22,
    WiredHeadphones = 4,
    WiredHeadset = 3,
    Unsupported = -1,
}

/// Converts DeviceDirection to Android AudioManager device flags.
pub(super) fn android_device_flags(direction: DeviceDirection) -> i32 {
    match direction {
        DeviceDirection::Input => AudioManager::GET_DEVICES_INPUTS,
        DeviceDirection::Output => AudioManager::GET_DEVICES_OUTPUTS,
        _ => AudioManager::GET_DEVICES_ALL,
    }
}

impl SampleFormat {
    pub(crate) const ENCODING_PCM_16BIT: i32 = 2;
    //pub(crate) const ENCODING_PCM_8BIT: i32 = 3;
    pub(crate) const ENCODING_PCM_FLOAT: i32 = 4;

    pub(crate) fn from_encoding(encoding: i32) -> Option<SampleFormat> {
        match encoding {
            SampleFormat::ENCODING_PCM_16BIT => Some(SampleFormat::I16),
            SampleFormat::ENCODING_PCM_FLOAT => Some(SampleFormat::F32),
            _ => None,
        }
    }
}