# War Story: Implementing solution for 4G/5G voice call verification on AOSP quickly - Wig Cheng (Mobile Technologies)

{%hackmd @mopcon/BkMIqw_76 %}

> 從這開始

## War Begining

### 講者
AOSP

講者 wig cheng

服務公司 iei the world

bsp development

### HMI human machine interface

1. first search open source project : pine phone pro
2. HAL 開發 聲卡RT5640 driver (.xml)
3. hal porting
4. linux alsa driver
5. device tree 硬體描述檔
6. linux device driver開發
7. i2s v.s. pcm
8. audacity
9. click noise -> brtual force vs latancy tradeoff!

### phone call subsystem
1. nottx os

### AOSP

android OS 總是存在我們的生活當中，點餐機，自助售票機...等

> 今天主要分享的都是android firmware

### Motivation
英國巴士上的車機
聲音需要 speaker and mic
介面有hdmi
要給司機有語音通話的功能

### Mobile phone call - Normal case I

:::info
Phone APK
Framework
- Audiopolicy service
- Audiofinger service

HAL driver
- tinyHAL
- Audio configuration

Linux Kernel
- RT5640
:::

CPU內建 audio codec

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> 講者超強！！！