If fdSrc is set, you can use ResourceManager.getRawFd to open the HAP resource file descriptor. For details, see getRawFd in the ResourceManager API. You can also access the corresponding resource through the app sandbox path (ensure the resource is available). For details, see Obtaining Application File Paths. For an introduction to the app sandbox and how to push files to it, see Application Sandbox.

import { common } from '@kit.AbilityKit';
import { media } from '@kit.MediaKit';

// Create an AVMetadataExtractor instance.
let avMetadataExtractor: media.AVMetadataExtractor = await media.createAVMetadataExtractor();
// Obtain the file descriptor of the resource file in the rawfile directory and set the fdSrc property.
// Obtain the context of the ability to which the current component belongs and obtain the application file path through the context.
let context: Context = this.getUIContext().getHostContext() as common.UIAbilityContext;
// Set fdSrc. test.mp3 is a preset resource in the rawfile directory. Replace it with the actual one.
avMetadataExtractor.fdSrc = await context.resourceManager.getRawFd('test.mp3');

To set dataSrc, set callback in dataSrc to ensure that the corresponding resource can be correctly read when the callback is invoked, and use the application sandbox directory to access the resource. For details, see Obtaining Application File Paths. For details about the application sandbox and how to push files to the application sandbox directory, see File Management.

import { fileIo, ReadOptions } from '@kit.CoreFileKit';
import { common } from '@kit.AbilityKit';
import { media } from '@kit.MediaKit';
const TAG = 'MetadataDemo';

// Create an AVMetadataExtractor instance.
let avMetadataExtractor: media.AVMetadataExtractor = await media.createAVMetadataExtractor();
let context: Context = this.getUIContext().getHostContext() as common.UIAbilityContext;
let rootPath: string = context.filesDir; // Application file directory.
let testFilename: string = '/test.mp3'; // test.mp3 is a preset resource in the application file directory. Replace it with the actual one.
// Use the fileIo system to open the sandbox address to obtain the media file address and set the dataSrc property.
// Obtain the sandbox address filesDir through UIAbilityContext. The stage model is used as an example.
let fd: number = fileIo.openSync(rootPath + testFilename).fd;
let fileSize: number = fileIo.statSync(rootPath + testFilename).size;
// Set the dataSrc descriptor, obtain resources from the file through a callback, and write the resources to the buffer.
let dataSrc: media.AVDataSrcDescriptor = {
  fileSize: fileSize,
  callback: (buffer, len, pos) => {
    if (buffer == undefined || len == undefined || pos == undefined) {
      console.error(TAG, `dataSrc callback param invalid`);
      return -1;
    }
    let options: ReadOptions = {
      offset: pos,
      length: len
    };
    let num = fileIo.readSync(fd, buffer, options);
    console.info(TAG, 'readAt end, num: ' + num);
    if (num > 0 && fileSize >= pos) {
      return num;
    }
    return -1;
  }
};
// Set the dataSrc property.
avMetadataExtractor.dataSrc = dataSrc;

// Close the fd after completing subsequent metadata retrieval or frame extraction operations.
fileIo.closeSync(fd);

If setUrlSource is used, fill in both the url and headers properties correctly to ensure that the URL is accessible.

import { media } from '@kit.MediaKit';

// Create an AVMetadataExtractor instance.
let avMetadataExtractor: media.AVMetadataExtractor = await media.createAVMetadataExtractor();
// Call setUrlSource to set the URL of the online on-demand media resource, so as to obtain online audio and video metadata and online video thumbnails.
let url: string = 'http://xx.mp4';
let headers: Record<string, string> = {
  "User-Agent" : "User-Agent-Value"
};
avMetadataExtractor.setUrlSource(url, headers);

If different AVMetadataExtractor or AVImageGenerator instances need to operate the same resource, the file descriptor needs to be opened for multiple times. Therefore, do not share a file descriptor.

import { common } from '@kit.AbilityKit';
import { fileIo } from '@kit.CoreFileKit';
import { media } from '@kit.MediaKit';

// Create an AVMetadataExtractor instance.
let avMetadataExtractor: media.AVMetadataExtractor = await media.createAVMetadataExtractor();
// Use the fileIo system to open the sandbox address to obtain the media file address and set the fdSrc property.
let context: Context = this.getUIContext().getHostContext() as common.UIAbilityContext;
let rootPath: string = context.filesDir; // Application file directory.
let testFilename: string = '/test.mp3'; // test.mp3 is a preset resource in the application file directory. Replace it with the actual one.
avMetadataExtractor.fdSrc = fileIo.openSync(rootPath + testFilename); // Set the fdSrc property.

Obtain metadata. Specifically, call fetchMetadata() to obtain an AVMetadata object. You can access its properties to obtain the metadata.

// Obtain the metadata (callback mode).
avMetadataExtractor.fetchMetadata((error, metadata) => {
  if (error) {
    console.error(TAG, `fetchMetadata callback failed, err = ${JSON.stringify(error)}`);
    return;
  }
})

// Obtain the metadata (promise mode).
let metadata = await avMetadataExtractor.fetchMetadata();

For a video resource, you can use fetchMetadata to obtain the width and height of the video resource from the metadata of the AVMetadata object.

// Obtain the width and height of the video resource.
let metadata = await avMetadataExtractor.fetchMetadata();
let width = metadata.videoWidth;
let height = metadata.videoHeight;

For an audio resource, in addition to obtaining metadata such as the title and duration of the audio resource through the AVMetadata object, you can retrieve the album cover by calling fetchAlbumCover().

import { image } from '@kit.ImageKit';
// Declare a pixelMap object, which is used for image display.
@State pixelMap: image.PixelMap | undefined = undefined;
// Obtain the album cover (callback mode).
avMetadataExtractor.fetchAlbumCover((err, pixelMap) => {
  if (err) {
    console.error(TAG, `fetchAlbumCover callback failed, err = ${JSON.stringify(err)}`);
    return;
  }
  this.pixelMap = pixelMap;
})

// Obtain the album cover (promise mode).
this.pixelMap = await avMetadataExtractor.fetchAlbumCover();

(Optional) Call fetchFrameByTime to obtain the video thumbnail.

import { image } from '@kit.ImageKit';
// Declare a pixelMap object, which is used for image display.
@State pixelMap: image.PixelMap | undefined = undefined;
// Declare the input parameters of the API.
let timeUs: number = 0;
let queryOption: media.AVImageQueryOptions = media.AVImageQueryOptions.AV_IMAGE_QUERY_PREVIOUS_SYNC;
let param: media.PixelMapParams = {
  width : 300,
  height : 300
}
// Obtain the video thumbnail (promise mode).
this.pixelMap = await avMetadataExtractor.fetchFrameByTime(timeUs, queryOption, param);

(Optional) Call fetchFramesByTimes to obtain video thumbnails in batches.

import { image } from '@kit.ImageKit';
// Declare a pixelMap object, which is used for image display.
@State pixelMap: image.PixelMap | undefined = undefined;
// Declare the input parameters of the API.
let timesUs: number[] = [0];
let queryOption: media.AVImageQueryOptions = media.AVImageQueryOptions.AV_IMAGE_QUERY_PREVIOUS_SYNC;
let param: media.PixelMapParams = {
  width : 300,
  height : 300
}
// Obtain the video thumbnail (callback mode).
avMetadataExtractor.fetchFramesByTimes(timesUs, queryOption, param, (frameInfo: media.FrameInfo, err: BusinessError) => {
  if (err) {
    console.error(TAG, `fetch frame failed, error code: ${err.code}, error message: ${err.message}`);
    return;
  }
  console.info(TAG, `fetch frame successfully.`);
  if (frameInfo !== undefined && frameInfo.image !== undefined) {
    this.pixelMap = frameInfo.image;
  }
})

// Batch thumbnail extraction may take a long time. You can call cancelAllFetchFrames to stop all thumbnail extraction tasks on the current extractor (effective only for batch extraction APIs).
avMetadataExtractor.cancelAllFetchFrames();

Call release() to release the instance.

// Release the instance (callback mode).
avMetadataExtractor.release((error) => {
  if (error) {
    console.error(TAG, `release failed, err = ${JSON.stringify(error)}`);
    return;
  }
  console.info(TAG, `release success.`);
})

// Release the instance (promise mode).
avMetadataExtractor.release();

Running the Sample Project

Refer to the sample project to obtain audio metadata and album cover.

Create a project, download the sample project, and copy its resources to the corresponding directories.

 AVMetadataExtractorArkTS
 entry/src/main/ets/
 └── pages
     └── Index.ets (metadata retrieval UI)
 entry/src/main/resources/
 ├── base
 │   ├── element
 │   │   ├── color.json
 │   │   ├── float.json
 │   │   └── string.json
 │   └── media
 │
 └── rawfile
     └── test.mp3 (audio resource)

Compile and run the project.

目录

Using AVMetadataExtractor to Extract Audio and Video Metadata (ArkTS)

How to Develop

Running the Sample Project