Android 中使用 SurfaceTexture 的相机预览示例

Example of Camera preview using SurfaceTexture in Android

提问by AndroDev

I am trying to render camera preview using SurfaceTexture. I read the document but unable to understand how it works.

我正在尝试使用SurfaceTexture渲染相机预览。我阅读了文档，但无法理解它是如何工作的。

Can anyone provide one sample example(very basic one) or link which uses SurfaceTextureto preview camera. I googled this but not found what I am looking for.

任何人都可以提供一个示例示例（非常基本的示例）或使用SurfaceTexture预览相机的链接。我用谷歌搜索了这个，但没有找到我要找的东西。

Thanks in advance.

提前致谢。

回答by Thiago M Rocha

If you want to use the Camera with TextureSurface you can implement SurfaceTextureListenerinterface. You'll have to implement 4 methods:

如果您想将 Camera 与 TextureSurface 一起使用，您可以实现SurfaceTextureListener接口。您必须实现 4 种方法：

1) onSurfaceTextureAvailable- Here you setup your camera

1) onSurfaceTextureAvailable- 在这里你设置你的相机

2)onSurfaceTextureSizeChanged- In your case, the Android's camera will handle this method

2) onSurfaceTextureSizeChanged- 在您的情况下，Android 的相机将处理此方法

3)onSurfaceTextureDestroyed- Here you destroy all camera stuff.

3) onSurfaceTextureDestroyed- 在这里你销毁所有相机的东西。

4) onSurfaceTextureUpdated- Update your texture here when you have something to change!

4) onSurfaceTextureUpdated- 当您需要更改某些内容时，请在此处更新您的纹理！

Check the example below:

检查下面的例子：

    public class MainActivity extends Activity implements SurfaceTextureListener{

    private Camera mCamera;
    private TextureView mTextureView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mTextureView = new TextureView(this);
        mTextureView.setSurfaceTextureListener(this);

        setContentView(mTextureView);
    }

    @Override
    public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
        mCamera = Camera.open();

        Camera.Size previewSize = mCamera.getParameters().getPreviewSize();
        mTextureView.setLayoutParams(new FrameLayout.LayoutParams(
                previewSize.width, previewSize.height, Gravity.CENTER));

        try {
            mCamera.setPreviewTexture(surface);
        } catch (IOException t) {
        }

        mCamera.startPreview();

    }

    @Override
    public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
        // Ignored, the Camera does all the work for us
    }

    @Override
    public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
        mCamera.stopPreview();
        mCamera.release();
        return true;
    }

    @Override
    public void onSurfaceTextureUpdated(SurfaceTexture surface) {
        // Update your view here!
    }
}

Two more things: Don't forget to add the camera permissions in your project's manifest and the SurfaceTextureis available from API 11.

另外两件事：不要忘记在项目的清单中添加相机权限，并且SurfaceTexture可以从 API 11 获得。

回答by Kamal

public class VideoCapture extends Activity implements OnClickListener, SurfaceHolder.Callback {
MediaRecorder recorder;
SurfaceHolder holder;
boolean recording = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

recorder = new MediaRecorder();
initRecorder();

SurfaceView cameraView = new SurfaceView(this);
holder = cameraView.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

cameraView.setClickable(true);
cameraView.setOnClickListener(this);
}

private void initRecorder() {
recorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);
recorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);

CamcorderProfile cpHigh = CamcorderProfile
        .get(CamcorderProfile.QUALITY_HIGH);
recorder.setProfile(cpHigh);
recorder.setOutputFile("/sdcard/videocapture_example.mp4");
recorder.setMaxDuration(50000); // 50 seconds
recorder.setMaxFileSize(5000000); // Approximately 5 megabytes
}

private void prepareRecorder() {
recorder.setPreviewDisplay(holder.getSurface());

try {
    recorder.prepare();
} catch (IllegalStateException e) {
    e.printStackTrace();
    finish();
} catch (IOException e) {
    e.printStackTrace();
    finish();
}
}

public void onClick(View v) {
if (recording) {
    recorder.stop();
    recording = false;

    // Let's initRecorder so we can record again
    initRecorder();
    prepareRecorder();
} else {
    recording = true;
    recorder.start();
}
}

public void surfaceCreated(SurfaceHolder holder) {
prepareRecorder();
}

public void surfaceChanged(SurfaceHolder holder, int format, int width,
    int height) {
}

public void surfaceDestroyed(SurfaceHolder holder) {
if (recording) {
    recorder.stop();
    recording = false;
}
recorder.release();
finish();
}
}