In Jelly Bean, is it possible to create a Renderscript allocation out of a SurfaceTexture filled by the camera preview ? I am building my application from within the Android source tree so I'm ok using @hide APIs such as Allocation.setSurfaceTexture(). However I would like to avoid using RS Graphics deprecated APIs. The similar question here did not get fully answered and was not JB-specific.
I have the following issues when trying the code below:
- The data getting into Renderscript is always zero
- For the onFrameAvailable callback to get repeatedly called, I have to updateTexImage() since when I call Allocation.ioReceive(), it does not get called back anymore after the first time, and there's an "invalid EGLDisplay" in the logcat. Yet I thought ioReceive() is the way to go - it internally also updateTexImage().
- Supported Allocation types include RGBA8888 but not NV21 (which is the camera preview format), how will the RS code be able to address data formatted this way ?
(I know the device I'm working with does support the requested VGA resolution).
public class SampleRSCPCActivity extends Activity implements SurfaceTexture.OnFrameAvailableListener {
final static int DO_KERNEL = 0;
private static final String TAG="SAMPLERSCP";
private static Camera mCamera;
private Camera.Parameters mParams;
private int mFrameWidth, mFrameHeight;
private static SurfaceTexture mST;
private RenderScript mRS;
private Allocation mInAllocation;
private Allocation mOutAllocation;
private ScriptC_mono mScript;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.i(TAG, "onCreate()");
createGUI();
createCamera();
createRSEnvironment();
}
public void onPause() {
Log.i(TAG, "onPause");
mCamera.stopPreview();
mCamera.release();
mCamera = null;
super.onPause();
}
private void createCamera() {
mCamera = Camera.open();
mParams = mCamera.getParameters();
mFrameWidth = 640;
mFrameHeight = 480;
mParams.setPreviewSize(mFrameWidth, mFrameHeight);
mParams.setPreviewFormat(ImageFormat.NV21);
mCamera.setParameters(mParams);
}
private void createRSEnvironment () {
mRS = RenderScript.create(this);
mScript = new ScriptC_mono(mRS, getResources(), R.raw.mono);
Type.Builder b = new Type.Builder(mRS, Element.U8(mRS));
int usage = Allocation.USAGE_SCRIPT | Allocation.USAGE_IO_INPUT;
mInAllocation = Allocation.createTyped(mRS, b.setX(mFrameWidth).setY(mFrameHeight).create(), usage);
mOutAllocation = Allocation.createTyped(mRS, b.setX(mFrameWidth).setY(mFrameHeight).create());
Log.i(TAG, "Getting SurfaceTexture from input Allocation");
mST = mInAllocation.getSurfaceTexture();
mST.setOnFrameAvailableListener(this);
try {
Log.i(TAG, "Setting SurfaceTexture for camera preview");
mCamera.setPreviewTexture(mST);
Log.i(TAG, "Starting preview");
mCamera.startPreview();
} catch (IOException e) {
Log.e(TAG, "Oops, something got wrong with setting the camera preview texture");
}
}
private void createGUI() {
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.main);
}
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (msg.what == DO_KERNEL)
Log.i(TAG, "Calling RS kernel");
mST.updateTexImage();
// mInAllocation.ioReceive();
mScript.forEach_root(mInAllocation, mOutAllocation);
Log.i(TAG, "Finishing RS");
mRS.finish();
Log.i(TAG, "Ok");
}
};
public void onFrameAvailable(SurfaceTexture st) {
Log.i(TAG, "onFrameAvailable callback");
handler.sendEmptyMessage(DO_KERNEL);
}
}
The RS code is fairly simple, just trying to detect non-null data:
void root(const uchar *v_in, uchar *v_out, uint32_t x, uint32_t y) {
if (*v_in != 0)
rsDebug("input data non null !", *v_in);
*v_out = (x / 640) * 255;
}