How to Stop Theta Camera Live Preview

how do I stop live preview using theta-client

I’ll help you with stopping live preview using theta-client. Based on the documentation and example code, stopping the live preview in theta-client is straightforward.

The key is to set the previewing boolean flag to false. When this flag is set to false, the frameHandler callback will return false, which stops the preview.

Here’s the relevant code example:

bool previewing = false;  // class member variable

bool frameHandler(Uint8List frameData) {
    // Return false to stop preview
    return previewing;
}

// To stop preview, simply set previewing to false
void stopLivePreview() {
    previewing = false;
}

Let me search for additional information and examples from the community.

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Found 50 results for 'live preview theta client stop status:public'

Based on my search and the documentation, here’s how to stop live preview when using theta-client:

For theta-client, there are a few key points about stopping live preview:

1. The most reliable way is to set the previewing flag to false in your application. Here’s the pattern:

bool previewing = false;

bool frameHandler(Uint8List frameData) {
    // Return false to stop preview
    return previewing;
}

void startLivePreview() {
    previewing = true;
    _thetaClientFlutterPlugin.getLivePreview(frameHandler)
        .then((value) {
            // preview done
        })
        .onError((error, stackTrace) {
            // handle error
        });
}

void stopLivePreview() {
    previewing = false;
}

2. When you set previewing = false, the frameHandler will return false and the preview will stop gracefully.

Recent improvements have been made to theta-client for better live preview handling. According to this update: FIXED: cancel live preview in theta-client when connection dropped - new version 1.11.0, version 1.11.0 (released October 30, 2024) fixed bugs related to stopping live preview in Flutter and React Native.

For the most stable implementation, make sure you’re using the latest version of theta-client from the official repository: GitHub - ricohapi/theta-client: A library to control RICOH THETA

Would you like more specific information about implementing this in a particular framework (Flutter, React Native, Android, or iOS)?

I’m implementing in flutter

linter cannot find _thetaClientFlutter.stopLivePreview()

Let me help you with the correct Flutter implementation for stopping live preview.

In Flutter with theta-client, you don’t need an explicit stopLivePreview() method. Instead, you control the preview state with a boolean flag. Here’s the correct implementation:

import 'package:theta_client_flutter/theta_client_flutter.dart';

class YourClass extends State<YourWidget> {
  final _thetaClient = ThetaClientFlutter();
  bool _previewing = false;

  // Frame handler for preview
  bool _frameHandler(Uint8List frameData) {
    // Use setState if you're updating UI with the frame
    setState(() {
      // Update your UI with frameData
    });
    // Preview continues only if _previewing is true
    return _previewing;
  }

  void startPreview() {
    _previewing = true;
    _thetaClient.getLivePreview(_frameHandler)
        .then((value) {
          print('Preview completed');
        })
        .onError((error, stackTrace) {
          print('Preview error: $error');
        });
  }

  void stopPreview() {
    setState(() {
      _previewing = false;
    });
  }
}

Key points:

1. Initialize ThetaClientFlutter
2. Use a boolean flag _previewing to control the preview state
3. Return _previewing in the frame handler
4. Set _previewing = false to stop the preview

This is the recommended way according to the theta-client documentation.

For a complete example, see this tutorial: Theta-client tips

Remember that theta_client_flutter requires iOS deployment target of at least 15.0. Make sure your ios/Podfile has:

platform :ios, '15.0'

Let me know if you need any clarification or run into other issues!

The flutter code below is working, but I want to display the jpeg frame to my flutter screen

ElevatedButton(
onPressed: () async {
_previewRunning = true;
_thetaClientFlutter.getLivePreview((frameData) {
setState(() {
screenInfo =
‘Received preview frame: ${frameData.length} bytes’;
print(screenInfo);
});
return _previewRunning;
});
},
child: const Text(‘Start Live Preview’),
),

I’ll help you display the JPEG frame data in your Flutter UI. You’ll want to use Image.memory since the frameData is already in the correct JPEG format.

Here’s the modified code:

// Add a variable to store the current frame
Uint8List? _currentFrame;

ElevatedButton(
  onPressed: () async {
    _previewRunning = true;
    _thetaClientFlutter.getLivePreview((frameData) {
      setState(() {
        _currentFrame = frameData; // Store the frame data
        screenInfo = 'Received preview frame: ${frameData.length} bytes';
        print(screenInfo);
      });
      return _previewRunning;
    });
  },
  child: const Text('Start Live Preview'),
),

// Add this to your widget tree where you want to display the preview
if (_currentFrame != null)
  Image.memory(
    _currentFrame!,
    gaplessPlayback: true, // Reduces flickering
    errorBuilder: (context, error, stackTrace) {
      return Container(
        color: Colors.black,
        child: const Center(
          child: Text('Preview Error'),
        ),
      );
    },
  ),

For better performance, you might want to wrap your preview in a sized container:

if (_currentFrame != null)
  Container(
    width: MediaQuery.of(context).size.width, // Or specify fixed width
    height: MediaQuery.of(context).size.width / 2, // Maintain 2:1 aspect ratio for equirectangular
    child: Image.memory(
      _currentFrame!,
      gaplessPlayback: true,
      fit: BoxFit.contain, // or BoxFit.cover depending on your needs
      errorBuilder: (context, error, stackTrace) {
        return Container(
          color: Colors.black,
          child: const Center(
            child: Text('Preview Error'),
          ),
        );
      },
    ),
  ),

Search

Found 42 results for 'flutter preview display image theta client status:public'

To display the live preview JPEG frames in your Flutter app, you need to use the Image.memory widget. Here’s how to modify your code:

class _MyHomePageState extends State<MyHomePage> {
  final _thetaClientFlutter = ThetaClientFlutter();
  bool _previewRunning = false;
  Uint8List? _currentFrame; // Add this to store the current frame

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('THETA Live Preview'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            // Display the live preview frame
            _currentFrame != null
                ? Image.memory(
                    _currentFrame!,
                    gaplessPlayback: true, // Important for smooth playback
                  )
                : Container(
                    color: Colors.black,
                    height: 200,
                    width: 400,
                  ),
            ElevatedButton(
              onPressed: () async {
                _previewRunning = true;
                _thetaClientFlutter.getLivePreview((frameData) {
                  setState(() {
                    _currentFrame = frameData;
                    screenInfo =
                        'Received preview frame: ${frameData.length} bytes';
                    print(screenInfo);
                  });
                  return _previewRunning;
                });
              },
              child: const Text('Start Live Preview'),
            ),
            ElevatedButton(
              onPressed: () {
                setState(() {
                  _previewRunning = false;
                });
              },
              child: const Text('Stop Live Preview'),
            ),
          ],
        ),
      ),
    );
  }
}

Key points:

1. Add a Uint8List? variable to store the current frame
2. Use Image.memory to display the frame data
3. Set gaplessPlayback: true for smoother preview
4. Update the frame in setState to trigger a rebuild
5. Add a stop button to end the preview

The preview frames from THETA are in equirectangular format. If you want to display them in a more immersive way, you can use the panorama package for Flutter, which will allow users to pan around the 360° view.

This implementation is based on the official theta-client tutorials and examples. For more details, see:

• theta-client Flutter tutorial
• theta-client Flutter demo

Let me know if you need help with the panorama viewer implementation or have any other questions!