Flutter视频帧导出插件flutter_export_video_frames的使用

获取开始

本项目是一个新的 Flutter 插件包起点，包含针对 Android 和/或 iOS 的平台特定实现代码。

对于如何开始使用 Flutter，您可以查看官方文档，获取教程、示例、移动开发指南以及完整的 API 参考。

使用示例

以下是一个完整的示例，展示了如何使用 flutter_export_video_frames 插件来从视频中导出帧并保存到本地。

示例代码

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_export_video_frames/flutter_export_video_frames.dart';
import 'package:image_picker/image_picker.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "插件示例应用",
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(images: []),
    );
  }
}

class ImageItem extends StatelessWidget {
  ImageItem({required this.image});

  final Image image;

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Container(child: image);
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({required this.images});

  final List<Image> images;

  [@override](/user/override)
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  var _isClean = false;

  Future _getImages() async {
    // 从相册选择一个视频
    var file = await ImagePicker.platform.pickVideo(source: ImageSource.gallery);
    // 导出视频的前10帧
    var images = await ExportVideoFrame.exportImage(file!.path, 10, 0);
    // 将导出的帧转换为Image对象
    var result = images.map((file) => Image.file(file)).toList();
    // 更新UI
    setState(() {
      widget.images.addAll(result);
      _isClean = true;
    });
  }

  Future _getGifImages() async {
    // 从相册选择一个视频
    var file = await ImagePicker.platform.pickImage(source: ImageSource.gallery);
    // 导出视频的GIF图像
    var images = await ExportVideoFrame.exportGifImage(file!.path, 0);
    // 将导出的帧转换为Image对象
    var result = images.map((file) => Image.file(file)).toList();
    // 更新UI
    setState(() {
      widget.images.addAll(result);
      _isClean = true;
    });
  }

  Future _getImagesByDuration() async {
    // 从相册选择一个视频
    var file = await ImagePicker.platform.pickVideo(source: ImageSource.gallery);
    // 设置导出帧的时间间隔
    var duration = Duration(seconds: 1);
    // 导出指定时间间隔的帧
    var image = await ExportVideoFrame.exportImageBySeconds(
        file!.path, duration, pi / 2);
    // 更新UI
    setState(() {
      widget.images.add(Image.file(image));
      _isClean = true;
    });
    // 保存图像到本地
    await ExportVideoFrame.saveImage(image, "Video Export Demo",
        waterMark: "images/water_mark.png",
        alignment: Alignment.bottomLeft,
        scale: 2.0);
  }

  Future _cleanCache() async {
    // 清除缓存
    var result = await ExportVideoFrame.cleanImageCache();
    print(result);
    setState(() {
      widget.images.clear();
      _isClean = false;
    });
  }

  Future _handleClickFirst() async {
    if (_isClean) {
      await _cleanCache();
    } else {
      await _getImages();
    }
  }

  Future _handleClickSecond() async {
    if (_isClean) {
      await _cleanCache();
    } else {
      await _getImagesByDuration();
    }
  }

  Future _handleClickThird() async {
    if (_isClean) {
      await _cleanCache();
    } else {
      await _getGifImages();
    }
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("导出图像"),
      ),
      body: Container(
        padding: EdgeInsets.zero,
        child: Column(
          children: [
            Expanded(
              flex: 1,
              child: GridView.extent(
                  maxCrossAxisExtent: 400,
                  childAspectRatio: 1.0,
                  padding: const EdgeInsets.all(4),
                  mainAxisSpacing: 4,
                  crossAxisSpacing: 4,
                  children: widget.images.length > 0
                      ? widget.images
                          .map((image) => ImageItem(image: image))
                          .toList()
                      : [Container()]),
            ),
            Expanded(
              flex: 0,
              child: Center(
                child: MaterialButton(
                  padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                  height: 40,
                  minWidth: 100,
                  onPressed: () {
                    _handleClickFirst();
                  },
                  color: Colors.orange,
                  child: Text(_isClean ? "清除" : "导出图像列表"),
                ),
              ),
            ),
            Expanded(
              flex: 0,
              child: Center(
                child: MaterialButton(
                  padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                  height: 40,
                  minWidth: 150,
                  onPressed: () {
                    _handleClickSecond();
                  },
                  color: Colors.orange,
                  child: Text(_isClean ? "清除" : "导出单个图像并保存"),
                ),
              ),
            ),
            Expanded(
              flex: 0,
              child: Center(
                child: MaterialButton(
                  padding: EdgeInsets.fromLTRB(10, 10, 10, 10),
                  height: 40,
                  minWidth: 150,
                  onPressed: () {
                    _handleClickThird();
                  },
                  color: Colors.orange,
                  child: Text(_isClean ? "清除" : "导出GIF图像"),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}