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BasicRenderScript / src / com.example.android.common.media /

CameraHelper.java

       
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        /*
       
       
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        * Copyright (C) 2013 The Android Open Source Project
       
       
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        *
       
       
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        * Licensed under the Apache License, Version 2.0 (the "License");
       
       
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        * you may not use this file except in compliance with the License.
       
       
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        * You may obtain a copy of the License at
       
       
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        *
       
       
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        *      http://www.apache.org/licenses/LICENSE-2.0
       
       
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        *
       
       
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        * Unless required by applicable law or agreed to in writing, software
       
       
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        * distributed under the License is distributed on an "AS IS" BASIS,
       
       
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        * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       
       
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        * See the License for the specific language governing permissions and
       
       
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        * limitations under the License.
       
       
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        */
       
       
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        package com.example.android.common.media;
       
       
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        import android.annotation.TargetApi;
       
       
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        import android.hardware.Camera;
       
       
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        import android.os.Build;
       
       
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        import android.os.Environment;
       
       
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        import android.util.Log;
       
       
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        import java.io.File;
       
       
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        import java.text.SimpleDateFormat;
       
       
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        import java.util.Date;
       
       
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        import java.util.List;
       
       
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        /**
       
       
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        * Camera related utilities.
       
       
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        */
       
       
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        public class CameraHelper {
       
       
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        public static final int MEDIA_TYPE_IMAGE = 1;
       
       
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        public static final int MEDIA_TYPE_VIDEO = 2;
       
       
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        /**
       
       
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        * Iterate over supported camera preview sizes to see which one best fits the
       
       
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        * dimensions of the given view while maintaining the aspect ratio. If none can,
       
       
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        * be lenient with the aspect ratio.
       
       
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        *
       
       
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        * @param sizes Supported camera preview sizes.
       
       
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        * @param w The width of the view.
       
       
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        * @param h The height of the view.
       
       
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        * @return Best match camera preview size to fit in the view.
       
       
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        */
       
       
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        public static  Camera.Size getOptimalPreviewSize(List<Camera.Size> sizes, int w, int h) {
       
       
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        // Use a very small tolerance because we want an exact match.
       
       
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        final double ASPECT_TOLERANCE = 0.1;
       
       
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        double targetRatio = (double) w / h;
       
       
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        if (sizes == null)
       
       
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        return null;
       
       
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        Camera.Size optimalSize = null;
       
       
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        // Start with max value and refine as we iterate over available preview sizes. This is the
       
       
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        // minimum difference between view and camera height.
       
       
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        double minDiff = Double.MAX_VALUE;
       
       
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        // Target view height
       
       
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        int targetHeight = h;
       
       
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        // Try to find a preview size that matches aspect ratio and the target view size.
       
       
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        // Iterate over all available sizes and pick the largest size that can fit in the view and
       
       
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        // still maintain the aspect ratio.
       
       
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        for (Camera.Size size : sizes) {
       
       
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        double ratio = (double) size.width / size.height;
       
       
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        if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE)
       
       
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        continue;
       
       
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        if (Math.abs(size.height - targetHeight) < minDiff) {
       
       
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        optimalSize = size;
       
       
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        minDiff = Math.abs(size.height - targetHeight);
       
       
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        }
       
       
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        }
       
       
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        // Cannot find preview size that matches the aspect ratio, ignore the requirement
       
       
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        if (optimalSize == null) {
       
       
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        minDiff = Double.MAX_VALUE;
       
       
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        for (Camera.Size size : sizes) {
       
       
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        if (Math.abs(size.height - targetHeight) < minDiff) {
       
       
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        optimalSize = size;
       
       
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        minDiff = Math.abs(size.height - targetHeight);
       
       
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        }
       
       
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        }
       
       
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        }
       
       
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        return optimalSize;
       
       
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        }
       
       
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        /**
       
       
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        * @return the default camera on the device. Return null if there is no camera on the device.
       
       
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        */
       
       
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        public static Camera getDefaultCameraInstance() {
       
       
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        return Camera.open();
       
       
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        }
       
       
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        /**
       
       
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        * @return the default rear/back facing camera on the device. Returns null if camera is not
       
       
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        * available.
       
       
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        */
       
       
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        public static Camera getDefaultBackFacingCameraInstance() {
       
       
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        return getDefaultCamera(Camera.CameraInfo.CAMERA_FACING_BACK);
       
       
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        }
       
       
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        /**
       
       
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        * @return the default front facing camera on the device. Returns null if camera is not
       
       
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        * available.
       
       
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        */
       
       
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        public static Camera getDefaultFrontFacingCameraInstance() {
       
       
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        return getDefaultCamera(Camera.CameraInfo.CAMERA_FACING_FRONT);
       
       
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        }
       
       
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        /**
       
       
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        *
       
       
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        * @param position Physical position of the camera i.e Camera.CameraInfo.CAMERA_FACING_FRONT
       
       
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        *                 or Camera.CameraInfo.CAMERA_FACING_BACK.
       
       
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        * @return the default camera on the device. Returns null if camera is not available.
       
       
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        */
       
       
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        @TargetApi(Build.VERSION_CODES.GINGERBREAD)
       
       
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        private static Camera getDefaultCamera(int position) {
       
       
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        // Find the total number of cameras available
       
       
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        int  mNumberOfCameras = Camera.getNumberOfCameras();
       
       
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        // Find the ID of the back-facing ("default") camera
       
       
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        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
       
       
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        for (int i = 0; i < mNumberOfCameras; i++) {
       
       
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        Camera.getCameraInfo(i, cameraInfo);
       
       
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        if (cameraInfo.facing == position) {
       
       
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        return Camera.open(i);
       
       
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        }
       
       
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        }
       
       
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        return null;
       
       
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        }
       
       
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        /**
       
       
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        * Creates a media file in the {@code Environment.DIRECTORY_PICTURES} directory. The directory
       
       
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        * is persistent and available to other applications like gallery.
       
       
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        *
       
       
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        * @param type Media type. Can be video or image.
       
       
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        * @return A file object pointing to the newly created file.
       
       
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        */
       
       
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        public  static File getOutputMediaFile(int type){
       
       
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        // To be safe, you should check that the SDCard is mounted
       
       
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        // using Environment.getExternalStorageState() before doing this.
       
       
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        if (!Environment.getExternalStorageState().equalsIgnoreCase(Environment.MEDIA_MOUNTED)) {
       
       
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        return  null;
       
       
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        }
       
       
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        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
       
       
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        Environment.DIRECTORY_PICTURES), "CameraSample");
       
       
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        // This location works best if you want the created images to be shared
       
       
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        // between applications and persist after your app has been uninstalled.
       
       
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        // Create the storage directory if it does not exist
       
       
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        if (! mediaStorageDir.exists()){
       
       
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        if (! mediaStorageDir.mkdirs()) {
       
       
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        Log.d("CameraSample", "failed to create directory");
       
       
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        return null;
       
       
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        }
       
       
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        }
       
       
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        // Create a media file name
       
       
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        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
       
       
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        File mediaFile;
       
       
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        if (type == MEDIA_TYPE_IMAGE){
       
       
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        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
       
       
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        "IMG_"+ timeStamp + ".jpg");
       
       
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        } else if(type == MEDIA_TYPE_VIDEO) {
       
       
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        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
       
       
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        "VID_"+ timeStamp + ".mp4");
       
       
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        } else {
       
       
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        return null;
       
       
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        }
       
       
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        return mediaFile;
       
       
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        }
       
       
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        }