SurfaceView
私の実装のサブクラスCamera.PreviewCallback
& SurfaceHolder.Callback
.
private SurfaceHolder mHolder;
private Camera mCamera;
private final FPSCounter fpscounter = new FPSCounter();
public MySurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
mHolder = getHolder();
mHolder.addCallback(this);
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
fpscounter.logFrame();
Log.d("fps", String.valueOf(fpscounter.getLastFrameCount()));
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
synchronized (this) {
mCamera.stopPreview();
Camera.Parameters parameters = mCamera.getParameters();
parameters.setRecordingHint(true);
parameters.setPreviewFormat(ImageFormat.NV21);
mCamera.setParameters(parameters);
try {
mCamera.setPreviewDisplay(holder);
mCamera.setPreviewCallback(this);
mCamera.startPreview();
} catch (IOException e) {
e.printStackTrace();
}
}
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
synchronized (this) {
setWillNotDraw(false);
mCamera = Camera.open();
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
synchronized (this) {
try {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
}
} catch (Exception e) {
Log.e("cam error", e.getMessage());
}
}
}
そしてFPSCounter
クラス
private long startTime;
private int frames, lastFrameCount;
public void logFrame() {
frames++;
if (System.nanoTime() - startTime >= 1000000000) {
lastFrameCount = frames;
frames = 0;
startTime = System.nanoTime();
}
}
public int getLastFrameCount() {
return lastFrameCount;
}
カメラのプレビューは非常にスムーズですが、このonPreviewFrame()
メソッドは 1 秒間に 5 回しか呼び出されません。フレームごとに呼び出されないのはなぜですか?