#创作者激励# #跟着小白一起学鸿蒙# 制作一个视频播放器 原创

【本文正在参加2023年第一期优质创作者激励计划】

简介

媒体子系统是OpenHarmony中重要的子系统，可以提供音视频播放能力。媒体子系统为开发者提供一套简单且易于理解的接口，使得开发者能够方便接入系统并使用系统的媒体资源。媒体子系统提供以下常用功能：

• 音视频播放（AVPlayer9+），AudioPlayer6+和VideoPlayer8+整合，升级了状态机和错误码，推荐使用
• 音视频录制（AVRecorder9+），AudioRecorder6+和VideoRecorder9+整合，推荐使用
• 音频播放（AudioPlayer6+），AVPlayer9+发布后停止维护，请使用AVPlayer9+
• 视频播放（VideoPlayer8+），AVPlayer9+发布后停止维护，请使用AVPlayer9+
• 音频录制（AudioRecorder6+），AVRecorder9+发布后停止维护，请使用AVRecorder9+
• 视频录制（VideoRecorder9+），AVRecorder9+发布后停止维护，请使用AVRecorder9+

从3.2开始OpenHarmony推出了AVPlayer和AVRecorder接口，之前的VideoPlayer、AudioPlayer这些接口会停止维护，所以我们今天学习下怎么使用AVPlayer接口

导入模块

import media from '@ohos.multimedia.media';

• 创建avplayer

this.avPlayer = await media.createAVPlayer()

如上，我们使用的是promise接口，对应的接口定义为：

  /**
   * Creates an AVPlayer instance.
   * @since 9
   * @syscap SystemCapability.Multimedia.Media.AVPlayer
   * @param callback Callback used to return AVPlayer instance if the operation is successful; returns null otherwise.
   * @throws { BusinessError } 5400101 - No memory. Return by callback.
   */
   function createAVPlayer(callback: AsyncCallback<AVPlayer>): void;

  /**
   * Creates an AVPlayer instance.
   * @since 9
   * @syscap SystemCapability.Multimedia.Media.AVPlayer
   * @returns A Promise instance used to return AVPlayer instance if the operation is successful; returns null otherwise.
   * @throws { BusinessError } 5400101 - No memory. Return by promise.
   */
   function createAVPlayer() : Promise<AVPlayer>;

• 注册avplayer回调

  //注册状态变化回调，不同状态时做不同动作
  avPlayer.on('stateChange', async (state, reason) => {
  	……
  }）
  //注册时间变化回调，方便更新进度条时间
  avPlayer.on('timeUpdate', (time:number) => {
  	……
  })
  

• avplayer播放流程

graph LR
赋值avPlayer.url开始播放 --> 回调进入initialized --> 赋值avPlayer.surfaceId --> avPlayer.prepare --> 回调进入prepared --> avPlayer.play

//视频播放伪代码
async avPlayerDemo() {
    this.avPlayer.on('stateChange', async (state, reason) => {
        switch (state) {
            case 'idle': // 成功调用reset接口后触发该状态机上报
                console.info(TAG + 'state idle called')
                this.avPlayer.release() // 释放avplayer对象
                break;
            case 'initialized': // avplayer 设置播放源后触发该状态上报
                console.info(TAG + 'state initialized called ')
                this.avPlayer.surfaceId = this.surfaceID // 设置显示画面，当播放的资源为纯音频时无需设置
                this.avPlayer.prepare().then(() => {
                    console.info(TAG+ 'prepare success');
                }, (err) => {
                    console.error(TAG + 'prepare filed,error message is :' + err.message)
                })
                break;
            case 'prepared': // prepare调用成功后上报该状态机
                console.info(TAG + 'state prepared called')
                this.avPlayer.play() // 调用播放接口开始播放
                break;
            case 'playing': // play成功调用后触发该状态机上报
                console.info(TAG + 'state playing called')
                if (this.count == 0) {
                    this.avPlayer.pause() // 调用暂停播放接口
                } else {
                    this.avPlayer.seek(10000, media.SeekMode.SEEK_PREV_SYNC) // 前向seek置10秒处,触发seekDone回调函数
                }
                break;
            case 'paused': // pause成功调用后触发该状态机上报
                console.info(TAG + 'state paused called')
                if (this.count == 0) {
                    this.count++
                    this.avPlayer.play() // 继续调用播放接口开始播放
                }
                break;
            case 'completed': // 播放结束后触发该状态机上报
                console.info(TAG + 'state completed called')
                this.avPlayer.stop() //调用播放结束接口
                break;
            case 'stopped': // stop接口成功调用后触发该状态机上报
                console.info(TAG + 'state stopped called')
                this.avPlayer.reset() // 调用reset接口初始化avplayer状态
                break;
            case 'released':
                console.info(TAG + 'state released called')
                break;
            case 'error':
                console.info(TAG + 'state error called')
                break;
            default:
                console.info(TAG + 'unkown state :' + state)
                break;
        }
    })

    // 创建avPlayer实例对象
    this.avPlayer = await media.createAVPlayer()
    let fdPath = 'fd://'
    let pathDir = "/data/storage/el2/base/haps/entry/files" // pathDir在FA模型和Stage模型的获取方式不同，请参考开发步骤首行的说明，根据实际情况自行获取。
    // path路径的码流可通过"hdc file send D:\xxx\H264_AAC.mp4 /data/app/el2/100/base/ohos.acts.multimedia.media.avplayer/haps/entry/files" 命令，将其推送到设备上
    let path = pathDir  + '/H264_AAC.mp4'
    let file = await fs.open(path)
    fdPath = fdPath + '' + file.fd
    //赋值url后就会进入stateChange callback
    this.avPlayer.url = fdPath
}

• 其他播放控制接口

      /**
       * Prepare audio/video playback, it will request resource for playing.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param callback A callback instance used to return when prepare completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by callback.
       * @throws { BusinessError } 5400106 - Unsupport format. Return by callback.
       */
      prepare(callback: AsyncCallback<void>): void;
  
      /**
       * Prepare audio/video playback, it will request resource for playing.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @returns A Promise instance used to return when prepare completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by promise.
       * @throws { BusinessError } 5400106 - Unsupport format. Return by promise.
       */
      prepare(): Promise<void>;
  
      /**
       * Play audio/video playback.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param callback A callback instance used to return when play completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by callback.
       */
      play(callback: AsyncCallback<void>): void;
  
      /**
       * Play audio/video playback.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @returns A Promise instance used to return when play completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by promise.
       */
      play(): Promise<void>;
  
      /**
       * Pause audio/video playback.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param callback A callback instance used to return when pause completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by callback.
       */
      pause(callback: AsyncCallback<void>): void;
  
      /**
       * Pause audio/video playback.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @returns A Promise instance used to return when pause completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by promise.
       */
      pause(): Promise<void>;
  
      /**
       * Stop audio/video playback.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param callback A callback instance used to return when stop completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by callback.
       */
      stop(callback: AsyncCallback<void>): void;
  
       /**
        * Stop audio/video playback.
        * @since 9
        * @syscap SystemCapability.Multimedia.Media.AVPlayer
        * @returns A Promise instance used to return when stop completed.
        * @throws { BusinessError } 5400102 - Operation not allowed. Return by promise.
        */
      stop(): Promise<void>;
  
      /**
       * Reset AVPlayer, it will to idle state and can set src again.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param callback A callback instance used to return when reset completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by callback.
       */
      reset(callback: AsyncCallback<void>): void;
  
      /**
       * Reset AVPlayer, it will to idle state and can set src again.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @returns A Promise instance used to return when reset completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by promise.
       */
      reset(): Promise<void>;
  
      /**
       * Releases resources used for AVPlayer.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param callback A callback instance used to return when release completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by callback.
       */
      release(callback: AsyncCallback<void>): void;
  
      /**
       * Releases resources used for AVPlayer.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @returns A Promise instance used to return when release completed.
       * @throws { BusinessError } 5400102 - Operation not allowed. Return by promise.
       */
      release(): Promise<void>;
  
      /**
       * Jumps to the specified playback position.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param timeMs Playback position to jump, should be in [0, duration].
       * @param mode See @SeekMode .
       */
      seek(timeMs: number, mode?:SeekMode): void;
  

• 其他回调接口

  /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback stateChange event.
       */
      on(type: 'stateChange', callback: (state: AVPlayerState, reason: StateChangeReason) => void): void;
      off(type: 'stateChange'): void;
      /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback volume event.
       */
      on(type: 'volumeChange', callback: Callback<number>): void;
      off(type: 'volumeChange'): void;
      /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback end of stream
       */
      on(type: 'endOfStream', callback: Callback<void>): void;
      off(type: 'endOfStream'): void;
      /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback seekDone event.
       */
      on(type: 'seekDone', callback: Callback<number>): void;
      off(type: 'seekDone'): void;
      /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback speedDone event.
       */
      on(type: 'speedDone', callback: Callback<number>): void;
      off(type: 'speedDone'): void;
      /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback setBitrateDone event.
       */
      on(type: 'bitrateDone', callback: Callback<number>): void;
      off(type: 'bitrateDone'): void;
      /**
       * LRegister or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback timeUpdate event.
       */
      on(type: 'timeUpdate', callback: Callback<number>): void;
      off(type: 'timeUpdate'): void;
      /**
       * Register or unregister listens for media playback events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback durationUpdate event.
       */
      on(type: 'durationUpdate', callback: Callback<number>): void;
      off(type: 'durationUpdate'): void;
      /**
       * Register or unregister listens for video playback buffering events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback buffering update event to listen for.
       * @param callback Callback used to listen for the buffering update event, return BufferingInfoType and the value.
       */
      on(type: 'bufferingUpdate', callback: (infoType: BufferingInfoType, value: number) => void): void;
      off(type: 'bufferingUpdate'): void;
      /**
       * Register or unregister listens for start render video frame events.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback event return .
       */
      on(type: 'startRenderFrame', callback: Callback<void>): void;
      off(type: 'startRenderFrame'): void;
      /**
       * Register or unregister listens for video size change event.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback event return video size.
       */
      on(type: 'videoSizeChange', callback: (width: number, height: number) => void): void;
      off(type: 'videoSizeChange'): void;
      /**
       * Register or unregister listens for audio interrupt event, refer to {@link #audio.InterruptEvent}
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback event return audio interrupt info.
       */
      on(type: 'audioInterrupt', callback: (info: audio.InterruptEvent) => void): void;
      off(type: 'audioInterrupt'): void;
      /**
       * Register or unregister listens for available bitrate list collect completed events for HLS protocol stream playback.
       * This event will be reported after the {@link #prepare} called.
       * @since 9
       * @syscap SystemCapability.Multimedia.Media.AVPlayer
       * @param type Type of the playback event to listen for.
       * @param callback Callback used to listen for the playback event return available bitrate list.
       */
      on(type: 'availableBitrates', callback: (bitrates: Array<number>) => void): void;
      off(type: 'availableBitrates'): void;
  

简单样例

• 界面

  build() {
      Stack({ alignContent: Alignment.Center }) {
        if (this.isShowMenu) {
          Column() {
            //视频名称
            PlayTitle({ title: this.displayName, handleBack: this.handleBack })
            Row() {
              //播放控件
              PreVideo({ handleClick: this.handlePrevClick })
              PlayButton({ isPlaying: $isPlaying })
              NextVideo({ handleClick: this.handleNextClick })
            }
            .margin({ top: '40%' })
  
            Blank()
            //时间刻度
            Row() {
              Text(getTimeString(this.currentTime))
                .fontSize(25)
                .fontColor(Color.White)
              Blank()
              Text(this.fileAsset ? getTimeString(this.fileAsset.duration) : '00:00')
                .fontSize(25)
                .fontColor(Color.White)
            }
            .width('95%')
  		  //进度条
            Slider({ value: this.fileAsset ? this.currentTime / this.fileAsset.duration * 100 : 0 })
              .width('92%')
              .selectedColor(Color.White)
              .onChange((value: number) => {
                Logger.info(TAG, 'seek time change')
                this.currentTime = this.fileAsset.duration * value / 100
                this.videoPlayer.seek(this.currentTime)
              })
          }
          .height('100%')
          .zIndex(2)
        }
        Row() {
          XComponent({
            id: 'componentId',
            type: 'surface',
            controller: this.mxcomponentController
          })
            .onLoad(() => {
              Logger.info(TAG, 'onLoad is called')
              this.playVideo()
            })
            .width('100%')
            .aspectRatio(this.ratio)
        }
        .height('100%')
        .width('100%')
        .justifyContent(FlexAlign.Center)
      }
      .width('100%')
      .height('100%')
      .backgroundColor(Color.Black)
      .onClick(() => {
        this.isShowMenu = !this.isShowMenu
      })
    }
  

• 播放

    //根据视频文件获取视频源尺寸并生成surface
    //视频文件的路径在/storage/media/100/local/files/Videos
    async prepareVideo() {
      this.ratio = this.fileAsset.width / this.fileAsset.height
      this.mxcomponentController.setXComponentsurfaceSize({
        surfaceWidth: this.fileAsset.width,
        surfaceHeight: this.fileAsset.height
      })
      this.surfaceId = this.mxcomponentController.getXComponentsurfaceId()
      this.fd = await this.fileAsset.open('Rw')
      Logger.info(TAG, `fd://' ${this.fd} `)
      return 'fd://' + this.fd
    }
    //初始化视频文件并初始化avplayer
    async playVideo() {
      Logger.info(TAG, 'playVideo')
      try{
        await this.getMediaList()
        let fdPath = await this.prepareVideo()
        this.videoPlayer.on('timeUpdate', (time:number) => {
          console.info('timeUpdate success,and new time is :' + time)
          this.currentTime = time;
        })
        await this.videoPlayer.initVideoPlayer(fdPath, this.surfaceId)
        this.isPlaying = true
      }catch(error) {
        Logger.info(TAG, `playVideo error ${JSON.stringify(error)}`)
      }
    } 
  
  

小结

参考链接：https://gitee.com/openharmony/docs/blob/master/zh-cn/application-dev/reference/apis/js-apis-media.md#play9