1 /* 2 * Copyright (C) 2021 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 package android.media.audio.common; 18 19 /** 20 * Specifies options applicable to audio output. These can be functional 21 * requests or performance requests. These flags apply both to audio ports and 22 * audio streams. Flags specified for an audio stream are usually used to find 23 * the best matching audio port for it. 24 * 25 * {@hide} 26 */ 27 @VintfStability 28 @Backing(type="int") 29 enum AudioOutputFlags{ 30 /** 31 * Output must not be altered by the framework, it bypasses software mixers. 32 */ 33 DIRECT = 0, 34 /** 35 * When used with audio ports, indicates the "main" (primary) port. This 36 * port is opened by default and receives routing, audio mode and volume 37 * controls related to voice calls. 38 */ 39 PRIMARY = 1, 40 /** 41 * Output is optimized for decreasing audio latency. 42 */ 43 FAST = 2, 44 /** 45 * Output is optimized for having the low power consumption. 46 */ 47 DEEP_BUFFER = 3, 48 /** 49 * Output is compressed audio format, intended for hardware decoding. 50 */ 51 COMPRESS_OFFLOAD = 4, 52 /** 53 * Write operations must return as fast as possible instead of 54 * being blocked until all provided data has been consumed. 55 */ 56 NON_BLOCKING = 5, 57 /** 58 * Output stream contains AV synchronization markers embedded. 59 */ 60 HW_AV_SYNC = 6, 61 /** 62 * Used to support ultrasonic communication with beacons. 63 * Note: "TTS" here means "Transmitted Through Speaker", 64 * not "Text-to-Speech". 65 */ 66 TTS = 7, 67 /** 68 * Output stream should only have minimal signal processing applied. 69 */ 70 RAW = 8, 71 /** 72 * Output stream needs to be synchronized with an input stream. 73 */ 74 SYNC = 9, 75 /** 76 * Output stream is encoded according to IEC958. 77 */ 78 IEC958_NONAUDIO = 10, 79 /** 80 * Output must not be altered by the framework and hardware. 81 */ 82 DIRECT_PCM = 11, 83 /** 84 * Output uses MMAP no IRQ mode--direct memory mapping with the hardware. 85 */ 86 MMAP_NOIRQ = 12, 87 /** 88 * Output is used for transmitting VoIP audio. 89 */ 90 VOIP_RX = 13, 91 /** 92 * Output is used for music playback during telephony calls. 93 */ 94 INCALL_MUSIC = 14, 95 /** 96 * The rendered must ignore any empty blocks between compressed audio 97 * tracks. 98 */ 99 GAPLESS_OFFLOAD = 15, 100 /** 101 * Output is used for spatial audio. 102 */ 103 SPATIALIZER = 16, 104 /** 105 * Output is used for transmitting ultrasound audio. 106 */ 107 ULTRASOUND = 17, 108 /** 109 * Output stream is bit perfect: the implementation guarantees that PCM 110 * samples are carried untouched from audio HAL to hardware interface 111 * or DAC. The volume command need to be sent to the hardware. 112 */ 113 BIT_PERFECT = 18, 114 } 115