鸿蒙5声波传文件工具开发实战：基于音频编码的跨设备数据传输 原创

鸿蒙5声波传文件工具开发实战

一、项目概述与架构设计

本工具基于鸿蒙5的音频处理能力实现跨设备文件传输，主要功能包括：
文件数据编码为音频信号

音频信号传输与接收

数据完整性校验

自适应传输速率控制

技术架构

┌─────────────┐ ┌─────────────┐
发送设备 │ │ 接收设备 │

┌────────┐ │ │ ┌────────┐ │

│ 编码器 │──────▶│ │ 解码器 │ │

└────────┘ │ │ └────────┘ │

└───────┬─────┘ └───────┬─────┘
│

    └─────────┬─────────┘

┌───────▼───────┐

音频处理服务 │

      └───────────────┘

二、核心代码实现
音频编码模块

// AudioEncoder.ets
export class AudioEncoder {
private readonly BASE_FREQ = 17000;
private readonly DURATION = 0.1; // 每个符号持续时间(秒)

encodeData(data: Uint8Array): number[] {
// 添加前导码和校验码
const frame = this.createFrame(data);

// 转换为频域符号
return this.dataToSymbols(frame);

private createFrame(data: Uint8Array): number[] {

const preamble = [0x55, 0xAA]; // 前导码
const checksum = this.calculateChecksum(data);
return [...preamble, ...Array.from(data), checksum];

private dataToSymbols(data: number[]): number[] {

const symbols: number[] = [];
for (const byte of data) {
  for (let i = 0; i < 8; i++) {
    const bit = (byte >> (7 - i)) & 1;
    symbols.push(bit === 1 ? this.BASE_FREQ + 500 : this.BASE_FREQ - 500);

}

return symbols;

}

音频播放控制

// AudioPlayer.ets
export class AudioPlayer {
private audioContext: audio.AudioContext;

async init() {
this.audioContext = await audio.createAudioContext();
async playSymbols(symbols: number[]) {

const sampleRate = this.audioContext.sampleRate;
const buffer = this.generateAudioBuffer(symbols, sampleRate);

await this.audioContext.decodeAudioData(buffer);
await this.audioContext.play();

private generateAudioBuffer(symbols: number[], sampleRate: number): ArrayBuffer {

const samplesPerSymbol = Math.floor(sampleRate * this.DURATION);
const buffer = new ArrayBuffer(symbols.length  samplesPerSymbol  4);
const view = new DataView(buffer);

let offset = 0;
for (const freq of symbols) {
  for (let i = 0; i < samplesPerSymbol; i++) {
    const value = Math.sin(2  Math.PI  freq  i / sampleRate)  0.5;
    view.setFloat32(offset, value, true);
    offset += 4;

}

return buffer;

}

音频接收处理

// AudioReceiver.ets
export class AudioReceiver {
private readonly SAMPLE_RATE = 44100;
private readonly SYMBOL_LENGTH = Math.floor(this.SAMPLE_RATE * 0.1);

async processAudio(data: Float32Array): Promise<Uint8Array | null> {
// 分帧处理
const frames = this.splitFrames(data);

// 解码每帧
const decodedBytes: number[] = [];
for (const frame of frames) {
  const byte = this.decodeFrame(frame);
  if (byte !== null) decodedBytes.push(byte);

return decodedBytes.length > 0 ? new Uint8Array(decodedBytes) : null;

private splitFrames(data: Float32Array): Float32Array[] {

const frameCount = Math.floor(data.length / this.SYMBOL_LENGTH);
const frames: Float32Array[] = [];

for (let i = 0; i < frameCount; i++) {
  const start = i * this.SYMBOL_LENGTH;
  frames.push(data.slice(start, start + this.SYMBOL_LENGTH));

return frames;

private decodeFrame(frame: Float32Array): number | null {

const freq = this.detectFrequency(frame);
return freq > 17250 ? 1 : (freq < 16750 ? 0 : null);

}

三、关键功能实现
文件分块传输

// FileTransfer.ets
export class FileTransfer {
private readonly CHUNK_SIZE = 512; // 512字节每块

async sendFile(file: FileData): Promise<void> {
const encoder = new AudioEncoder();
const player = new AudioPlayer();
await player.init();

// 分块处理
for (let i = 0; i < file.data.length; i += this.CHUNK_SIZE) {
  const chunk = file.data.slice(i, i + this.CHUNK_SIZE);
  const symbols = encoder.encodeData(chunk);
  await player.playSymbols(symbols);

}

数据完整性校验

// DataValidator.ets
export class DataValidator {
static verifyData(data: Uint8Array): boolean {
if (data.length < 3) return false;

// 检查前导码
if (data[0] ! 0x55 || data[1] ! 0xAA) return false;

// 检查校验和
const payload = data.slice(2, data.length - 1);
const checksum = data[data.length - 1];
return this.calculateChecksum(payload) === checksum;

private static calculateChecksum(data: Uint8Array): number {

let sum = 0;
for (const byte of data) {
  sum += byte;

return sum & 0xFF;

}

四、完整UI实现
文件发送界面

// SenderPage.ets
@Entry
@Component
struct SenderPage {
@State selectedFile: FileData | null = null;
@State progress = 0;

build() {
Column() {
// 文件选择区域
FilePicker({
onFileSelected: (file) => this.selectedFile = file
})

  // 传输控制
  Button('开始传输', { type: ButtonType.Capsule })
    .margin(20)
    .onClick(() => this.startTransfer())
    .disabled(!this.selectedFile)
  
  // 进度显示
  ProgressBar({
    value: this.progress,
    total: this.selectedFile?.data.length || 100
  })

}

private async startTransfer() {
if (!this.selectedFile) return;

const transfer = new FileTransfer();
await transfer.sendFile(this.selectedFile);

}

文件接收界面

// ReceiverPage.ets
@Entry
@Component
struct ReceiverPage {
@State receivedData: Uint8Array | null = null;
@State isReceiving = false;

private receiver = new AudioReceiver();

build() {
Column() {
// 接收状态
Text(this.isReceiving ? ‘接收中…’ : ‘准备接收’)

  // 接收控制
  Button(this.isReceiving ? '停止接收' : '开始接收', 

type: ButtonType.Capsule })

    .margin(20)
    .onClick(() => this.toggleReceiving())
  
  // 接收结果显示
  if (this.receivedData) {
    FilePreview({ data: this.receivedData })

}

private toggleReceiving() {

this.isReceiving = !this.isReceiving;

if (this.isReceiving) {
  this.startAudioProcessing();

}

private async startAudioProcessing() {
const audioContext = await audio.createAudioContext();
audioContext.onAudioProcess = (data) => {
const result = this.receiver.processAudio(data);
if (result) {
this.receivedData = result;
};

await audioContext.start();

}

五、项目部署与测试
权限配置

在module.json5中添加：

“requestPermissions”: [
“name”: “ohos.permission.MICROPHONE”

},
“name”: “ohos.permission.READ_MEDIA”

},
“name”: “ohos.permission.WRITE_MEDIA”

]

测试方案

// 编码解码测试
describe(‘AudioCodec’, () => {
it(‘should encode and decode data correctly’, () => {
const encoder = new AudioEncoder();
const testData = new Uint8Array([0x01, 0x02, 0x03]);
const encoded = encoder.encodeData(testData);

const receiver = new AudioReceiver();
const decoded = receiver.processAudio(simulateAudio(encoded));

expect(decoded).toEqual(testData);

});
});

// 文件传输测试
describe(‘FileTransfer’, () => {
it(‘should transfer small file’, async () => {
const testFile = {
name: ‘test.txt’,
data: new TextEncoder().encode(‘Hello World’)
};

const sender = new FileTransfer();
const receiver = new FileReceiver();

await sender.sendFile(testFile);
const received = await receiver.receive();

expect(received).toEqual(testFile.data);

});
});

六、总结与扩展

本方案实现了基于声波的文件传输基础功能，开发者可进一步扩展：
添加传输加密功能

实现多文件批量传输

优化抗干扰能力

开发后台传输服务

注意：实际开发中请遵守相关法律法规，确保在合法场景下使用此类技术。