CWAC Camera: why my SimpleCameraHost saveImage is so slow, am I doing something wrong?

问题

How to optimize this peace of code? It takes about a minute on saveImage method.

class ObrolSimpleHost extends SimpleCameraHost {
  private final String[] SCAN_TYPES = {"image/webp"};
  private Context context = null;

  public ObrolSimpleHost(Context _ctxt) {
    super(_ctxt);
    this.context = getActivity();
  }

  @Override public void saveImage(PictureTransaction xact, Bitmap bitmap) {
    File photo = getPhotoPath();
    if (photo.exists()) {
      photo.delete();
    }
    try {
      FileOutputStream fos = new FileOutputStream(photo.getPath());
      bitmap.compress(Bitmap.CompressFormat.WEBP, 70, fos);
      fos.flush();
      fos.getFD().sync();
      if (scanSavedImage()) {
        MediaScannerConnection.scanFile(context, new String[]{photo.getPath()}, SCAN_TYPES, null);
      }
    } catch (java.io.IOException e) {
      handleException(e);
    }
  }

  @Override public void saveImage(PictureTransaction xact, byte[] image) {
    // do nothing
  }
}

I am calling ObrolSimpleHost from CameraFragment:

PictureTransaction xact = new PictureTransaction(getHost());
xact.needBitmap(true);
takePicture(xact);

回答1:

Here is my own answer.

Fixed issues which CommonsWare mentioned and resize bitmap before compression by createScaledBitmap:

class ObrolSimpleHost extends SimpleCameraHost {
  private final String[] SCAN_TYPES = {"image/" + imputType};
  private Context context = null;

  public ObrolSimpleHost(Context _ctxt) {
    super(_ctxt);
    this.context = getActivity();
  }

  @Override public void saveImage(PictureTransaction xact, Bitmap bitmap) {
    File photo = getPhotoPath();
    String path = photo.getPath().replace("jpg", imputType);
    if (photo.exists()) {
      photo.delete();
    }

    /**
     * Resizing bitmap, so save some ms in compression
     * http://stackoverflow.com/questions/17839388/creating-a-scaled-bitmap-with-createscaledbitmap-in-android
     */
    final int maxSize = 960;
    int outWidth;
    int outHeight;
    int inWidth = bitmap.getWidth();
    int inHeight = bitmap.getHeight();
    if(inWidth > inHeight){
      outWidth = maxSize;
      outHeight = (inHeight * maxSize) / inWidth;
    } else {
      outHeight = maxSize;
      outWidth = (inWidth * maxSize) / inHeight;
    }
    Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, outWidth, outHeight, false);

    try {
      FileOutputStream fos = new FileOutputStream(path);
      if (imputType.equals("jpeg")) {
        resizedBitmap.compress(Bitmap.CompressFormat.JPEG, 70, fos);
      } else {
        resizedBitmap.compress(Bitmap.CompressFormat.WEBP, 70, fos);
      }
      fos.flush();
      fos.getFD().sync();
      if (scanSavedImage()) {
        MediaScannerConnection.scanFile(context, new String[]{photo.getPath()}, SCAN_TYPES, null);
      }
    } catch (java.io.IOException e) {
      handleException(e);
    }
    EventBus.getDefault().postSticky(new Events.PreparingBitmapEvent(path));
    getActivity().finish();
  }

  @Override public void saveImage(PictureTransaction xact, byte[] image) {
    // do nothing
  }
}

Instead of standard bitmap use other library which build with JNI

In my case I am going to try Roid-WebP

来源：https://stackoverflow.com/questions/25142160/cwac-camera-why-my-simplecamerahost-saveimage-is-so-slow-am-i-doing-something