Improve camera open method

Signed-off-by: Leo Ma <begeekmyfriend@gmail.com>

app/src/main/java/net/ossrs/yasea/SrsCameraView.java

@@ -8,6 +8,7 @@ import android.opengl.GLES20;
 import android.opengl.GLSurfaceView;
 import android.opengl.Matrix;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.widget.Toast;
 import com.seu.magicfilter.base.gpuimage.GPUImageFilter;
@@ -219,7 +220,20 @@ public class SrsCameraView extends GLSurfaceView implements GLSurfaceView.Render
         });
         worker.start();
-        mCamera = Camera.open(mCamId);
+        Camera.CameraInfo info = new Camera.CameraInfo();
+        int numCameras = Camera.getNumberOfCameras();
+        for (int i = 0; i < numCameras; i++) {
+            Camera.getCameraInfo(i, info);
+            if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
+                mCamera = Camera.open(i);
+                mCamId = i;
+                break;
+            }
+        }
+        if (mCamera == null) {
+            mCamera = Camera.open();
+            mCamId = 0;
+        }
         Camera.Parameters params = mCamera.getParameters();
         Camera.Size size = mCamera.new Size(mPreviewWidth, mPreviewHeight);