media/capture/video/android/java/src/org/chromium/media/VideoCapture.java

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

package org.chromium.media;

import android.content.Context;
import android.graphics.ImageFormat;
import android.view.Surface;
import android.view.WindowManager;

import org.chromium.base.annotations.CalledByNative;
import org.chromium.base.annotations.JNINamespace;

import java.nio.ByteBuffer;

/**
 * Video Capture Device base class, defines a set of methods that native code
 * needs to use to configure, start capture, and to be reached by callbacks and
 * provides some neccesary data type(s) with accessors.
 **/
@JNINamespace("media")
public abstract class VideoCapture {
    // The angle (0, 90, 180, 270) that the image needs to be rotated to show in
    // the display's native orientation.
    protected int mCameraNativeOrientation;
    // In some occasions we need to invert the device rotation readings, see the
    // individual implementations.
    protected boolean mInvertDeviceOrientationReadings;

    protected VideoCaptureFormat mCaptureFormat = null;
    protected final Context mContext;
    protected final int mId;
    // Native callback context variable.
    protected final long mNativeVideoCaptureDeviceAndroid;

    VideoCapture(Context context, int id, long nativeVideoCaptureDeviceAndroid) {
        mContext = context;
        mId = id;
        mNativeVideoCaptureDeviceAndroid = nativeVideoCaptureDeviceAndroid;
    }

    // Allocate necessary resources for capture.
    @CalledByNative
    public abstract boolean allocate(int width, int height, int frameRate);

    @CalledByNative
    public abstract boolean startCapture();

    @CalledByNative
    public abstract boolean stopCapture();

    @CalledByNative
    public abstract PhotoCapabilities getPhotoCapabilities();

    /**
    * @param zoom Zoom level, should be ignored if 0.
    * @param pointsOfInterest2D 2D normlized oints of interest, marshalled with
    * x coordinate first followed by the y coordinate.
    */
    @CalledByNative
    public abstract void setPhotoOptions(
            int zoom, int focusMode, int width, int height, float[] pointsOfInterest2D);

    @CalledByNative
    public abstract boolean takePhoto(final long callbackId);

    @CalledByNative
    public abstract void deallocate();

    @CalledByNative
    public final int queryWidth() {
        return mCaptureFormat.mWidth;
    }

    @CalledByNative
    public final int queryHeight() {
        return mCaptureFormat.mHeight;
    }

    @CalledByNative
    public final int queryFrameRate() {
        return mCaptureFormat.mFramerate;
    }

    @CalledByNative
    public final int getColorspace() {
        switch (mCaptureFormat.mPixelFormat) {
            case ImageFormat.YV12:
                return AndroidImageFormat.YV12;
            case ImageFormat.YUV_420_888:
                return AndroidImageFormat.YUV_420_888;
            case ImageFormat.NV21:
                return AndroidImageFormat.NV21;
            case ImageFormat.UNKNOWN:
            default:
                return AndroidImageFormat.UNKNOWN;
        }
    }

    protected final int getCameraRotation() {
        int rotation = mInvertDeviceOrientationReadings ? (360 - getDeviceRotation())
                                                        : getDeviceRotation();
        return (mCameraNativeOrientation + rotation) % 360;
    }

    protected final int getDeviceRotation() {
        if (mContext == null) return 0;
        final int orientation;
        WindowManager wm = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);
        switch (wm.getDefaultDisplay().getRotation()) {
            case Surface.ROTATION_90:
                orientation = 90;
                break;
            case Surface.ROTATION_180:
                orientation = 180;
                break;
            case Surface.ROTATION_270:
                orientation = 270;
                break;
            case Surface.ROTATION_0:
            default:
                orientation = 0;
                break;
        }
        return orientation;
    }

    // Method for VideoCapture implementations to call back native code.
    public native void nativeOnFrameAvailable(
            long nativeVideoCaptureDeviceAndroid, byte[] data, int length, int rotation);

    public native void nativeOnI420FrameAvailable(long nativeVideoCaptureDeviceAndroid,
            ByteBuffer yBuffer, int yStride, ByteBuffer uBuffer, ByteBuffer vBuffer,
            int uvRowStride, int uvPixelStride, int width, int height, int rotation);

    // Method for VideoCapture implementations to signal an asynchronous error.
    public native void nativeOnError(long nativeVideoCaptureDeviceAndroid, String message);

    // Method for VideoCapture implementations to send Photos back to.
    public native void nativeOnPhotoTaken(
            long nativeVideoCaptureDeviceAndroid, long callbackId, byte[] data);
}