CODEWITHSUNDEEP
androidcameraandroid-camera
Violet Giraffe
Violet Giraffe

Reputation: 33607

Android camera: very low preview FPS

A week ago I've started researching the Android camera API. I have successfully inited the camera and started preview, and it worked fine. Then I've found out I wasn't initializing and releasing the camera properly, so I overhauled the code somewhat, and now I have a problem that didn't occur initially: extremely low FPS. About 0.5, that's 2 seconds per frame. Interestingly enough, I get 1 frame with a delay, and then a second frame immediately after (1-15 ms), followed again by 2 seconds delay before the next frame.

This is my camera initialization code:

    m_openedCamera = Camera.open(id);
    m_surfaceHolder = new SurfaceView(MyApplication.instance().getApplicationContext()).getHolder();
    Assert.assertNotNull(m_openedCamera);

    // This is required on A500 for some reason
    Camera.Parameters params = m_openedCamera.getParameters();
    params.setPreviewFormat(ImageFormat.NV21);
    params.setPreviewSize(320, 240);
    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH)
    {
        params.setRecordingHint(true);
        params.setAutoExposureLock(true);
        params.setAutoWhiteBalanceLock(true);
    }

    m_openedCamera.setParameters(params);

    int bitsPerPx  = ImageFormat.getBitsPerPixel(ImageFormat.NV21);
    int width       = params.getPreviewSize().width;
    int height      = params.getPreviewSize().height;
    int size        = (int)(width * height * bitsPerPx / 8.0);
    m_openedCamera.addCallbackBuffer( new byte[size] );
    m_openedCamera.addCallbackBuffer( new byte[size] );
    m_openedCamera.addCallbackBuffer( new byte[size] );
    m_openedCamera.addCallbackBuffer( new byte[size] );

    m_openedCamera.setErrorCallback(this);
    m_openedCamera.setPreviewDisplay(m_surfaceHolder);
    m_openedCameraFacing = facing;
    m_openedCamera.setPreviewCallback(this);
    m_openedCamera.startPreview();

I have just added callback buffers - hasn't changed anything. In my initial code from a week ago I had no surface view, but removing it now has no effect either. This occurs on my second, much newer tablet as well, even though FPS is higher there (8-10), and there's no double frame there, the frames are spaced evenly. The FPS used to be at least 20. Light conditions haven't changed between now and then, btw.

Update: tried opening the camera in a separate thread as described here - no change.

Upvotes: 0

Views: 2622

Answers (3)

Albert Chung
Albert Chung

Reputation: 21

From your comment below "I have successfully inited the camera and started preview, and it worked fine. Then I've found out I wasn't initializing and releasing the camera properly"

I guess you was using the default camera parameters defined in camera HAL at first. Although it is not clear what "initializing" means, I think they is likely camera parameters setting.

So, I'd like to suggest you remove the code for params and then test it again. Or, you can test it one by one

  1. Remove only "params.setPreviewSize(320, 240);"
  2. Remove only "params.setPreviewFormat(ImageFormat.NV21);"
  3. Remove both 1 and 2.

Upvotes: 1

Albert Chung
Albert Chung

Reputation: 1

Please make your own previewcallbak function and then

private PreviewCallback mPreviewCallback = new PreviewCallback();

.... setPreviewCallback(mPreviewCallback);

Regarding PreviewCallback(), you can refer to CameraTest.Java in cts directory : cts/tests/tests/hawdware/src/android/hardware/cts

Upvotes: 0

Albert Chung
Albert Chung

Reputation: 21

params.setRecordingHint(true); is used to start video record starts.

Please check it again with "params.setRecordingHint(false)"

Upvotes: 1

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