Flutter Video_player：增强位置精度

Question

我目前正在使用 video_player 来精确分析视频。 不幸的是，我似乎无法提高 VideoPlayer 实例的不同“位置”获取器的精度。顶部每次刷新之间的间隔为 500ms。它对应于进度指示器的更新。 500 毫秒来检索体育数据（例如短跑）太大了。

可以实时更新吗？越精确越好，比如流什么的。

下面是代码，从他们的示例来看非常简单，我使用内置 Stream，它仅在完成时发送事件，并且位置获取器与其他刷新器相同（500ms）

class AssistantHome extends StatefulWidget {
  final UserTest test;
  final Player player;
  const AssistantHome({Key key, @required this.test, @required this.player})
      : super(key: key);

  @override
  State<AssistantHome> createState() => _AssistantHomeState();
}

class _AssistantHomeState extends State<AssistantHome> {
  VideoPlayerController _controller;
  int _positionInMs;
  Stream<Duration> durationStream;

  @override
  void initState() {
    super.initState();
    _controller = VideoPlayerController.network(widget.test.videoUrl);
    durationStream = _controller.position.asStream();
    _controller.addListener(() {
      setState(() {
        _positionInMs = _controller.value.position.inMilliseconds;
      });
    });
    _controller.setLooping(true);
    _controller.initialize().then((_) => setState(() {}));
    _controller.play();
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: [
          SliverFillRemaining(
            hasScrollBody: false,
            child: Column(
              children: <Widget>[
                Text('${widget.test.uid}'),
                Container(
                  height: 600,
                  padding: const EdgeInsets.all(20),
                  child: AspectRatio(
                    aspectRatio: _controller.value.aspectRatio,
                    child: SizedBox(
                      height: 600,
                      child: Stack(
                        alignment: Alignment.bottomCenter,
                        children: <Widget>[
                          VideoPlayer(_controller),
                          _ControlsOverlay(controller: _controller),
                          VideoProgressIndicator(_controller,
                              allowScrubbing: true),
                        ],
                      ),
                    ),
                  ),
                ),
                StreamBuilder(builder: ((context, snapshot) {
                  if (snapshot.connectionState == ConnectionState.waiting) {
                    return CircularProgressIndicator();
                  } else if (snapshot.connectionState ==
                          ConnectionState.active ||
                      snapshot.connectionState == ConnectionState.done) {
                    if (snapshot.hasError) {
                      return const Text('Error');
                    } else if (snapshot.hasData) {
                      return Text(snapshot.data.toString(),
                          style: const TextStyle(
                              color: Colors.teal, fontSize: 36));
                    } else {
                      return const Text('Empty data');
                    }
                  } else {
                    return Text(
                        'Duration: ${_controller.value.position.inMicroseconds} us');
                  }
                })),
                Text("Current position: $_positionInMs ms"),
                const Text('Footer'),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class _ControlsOverlay extends StatelessWidget {
  const _ControlsOverlay({Key key, @required this.controller})
      : super(key: key);

  final VideoPlayerController controller;

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: <Widget>[
        AnimatedSwitcher(
          duration: const Duration(milliseconds: 50),
          reverseDuration: const Duration(milliseconds: 200),
          child: controller.value.isPlaying
              ? const SizedBox.shrink()
              : Container(
                  color: Colors.black26,
                  child: const Center(
                    child: Icon(
                      Icons.play_arrow,
                      color: Colors.white,
                      size: 100.0,
                      semanticLabel: 'Play',
                    ),
                  ),
                ),
        ),
        GestureDetector(
          onTap: () {
            controller.value.isPlaying ? controller.pause() : controller.play();
          },
        ),
      ],
    );
  }
}

Answer 1

尝试使用 smooth_video_progress 包：https://pub.dev/packages/smooth_video_progress！

来自 https://pub.dev/packages/smooth_video_progress#usage：

例如，以下是构建简单滑块的方法：

Widget build(BuildContext context) {
  SmoothVideoProgress(
    controller: controller,
    builder: (context, position, duration, child) => Slider(
      onChangeStart: (_) => controller.pause(),
      onChangeEnd: (_) => controller.play(),
      onChanged: (value) =>
          controller.seekTo(Duration(milliseconds: value.toInt())),
      value: position.inMilliseconds.toDouble(),
      min: 0,
      max: duration.inMilliseconds.toDouble(),
    ),
  );
}