Android Studio使用自定義的Android.mk文件編譯ffmpegyuv-bgr

概述

最近做項目的時候，領導安排一個任務，讓測試一下，用ffmpeg中的yuv轉bgr函數的速度。之前編譯so庫大部分都是用eclipse，本次博主花了兩天時間，在Android studio上編譯並運行，在此做一下記錄。

設置Android Studio ndk

1、打開setings->Tools->External Toos 點擊+號新建NDK分組及javah 與ndk-build項。

2、javah 及ndk-build配置如下圖


配置完畢後點擊apply->Ok，配置完畢後，在項目上點擊右鍵便能看到NDK命令組和javah 及ndk-build命令。
說明：javah 命令使用來生成頭文件，ndk-build 命令使用編譯原生代碼生成so。

新建編譯項目並配置Gradle

1、在src main下面新建jni目錄，目錄如下

2、gradle的android域中配置不使用Android studio自動生成的.mk文件

 sourceSets {
        main {
        //禁用as自動生成mk
            jni.srcDirs = []
            jniLibs.srcDirs = ['src/main/libs']
        }
    }

編譯生成so

點擊項目右鍵NDK->ndk-build （左鍵點擊）

此時便生成了so 。希望對您有所幫助！
補充：jni目錄內容
Android項目測試代碼
MainActivity.java

package cm.opengles;

import android.content.Context;
import android.content.res.Configuration;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.ImageFormat;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;

import com.interjoy.skfaceproject_zwc.utils.Utils;

import java.io.IOException;
import java.util.List;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

public class MainActivity extends AppCompatActivity implements Camera.PreviewCallback{

    private final String TAG = Main1Activity.class.getSimpleName();

    public final static int WIDTH = 1920;
    public final static int HEIGHT = 1080;
    public final static int SIZE = WIDTH * HEIGHT * 3 / 2;
    private static int CAMERA_FACING_BACK_FRONT = 0;//默認是後置camera

    private static final boolean DEBUG = false;
    public byte[] mData;

    private GLSurfaceView view;
    private Camera mCamera;

    private WakeLock wlock;
    private int wView;
    private int hView;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // 採集圖像是640*480，所以預覽窗口保證4:3
        int wScreen = Utils.getScreenWidth(this);
        int hScreen = Utils.getScreenHeight(this);
        float ratio = 1.0f * wScreen / hScreen;

        if (ratio >= 0.75f) {
            wView = wScreen;
            hView = (int) (0.75f * wScreen + 0.5f);
        } else {
            hView = hScreen;
            wView = (int) (1.25f * hScreen + 0.5f);
        }
        PowerManager pm = (PowerManager)getSystemService(Context.POWER_SERVICE);
        wlock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "fb");
        wlock.acquire();
        view = new GLSurfaceView(Main1Activity.this);
        view.setEGLContextClientVersion(2);
        view.setRenderer(new GLSurfaceView.Renderer() {

            @Override
            public void onSurfaceCreated(GL10 gl, EGLConfig config) {
                openCamera(0);
                mCamera.startPreview();
                CmOpenGLES.init(WIDTH, HEIGHT);
            }

            @Override
            public void onSurfaceChanged(GL10 gl, int width, int height) {
                //CmOpenGLES.changeLayout(width, height);
                GLES20.glViewport(0, 0,wView , hView);
            }

            @Override
            public void onDrawFrame(GL10 gl) {
                if (mData != null)
                {
                    CmOpenGLES.drawFrame(mData, SIZE);
                }
            }
        });
        setContentView(view);
    }

    /**
     * 相機初始化
     */
    private void initCamera() {
        if (mCamera != null) {
            try {
                Camera.Parameters params = mCamera.getParameters();
                params.setExposureCompensation(0);
                if (getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
                    params.set("orientation", "portrait");
                    mCamera.setDisplayOrientation(90);
                    params.setRotation(90);
                } else {
                    params.set("orientation", "landscape");
                    mCamera.setDisplayOrientation(0);
                    params.setRotation(0);
                }
                params.setPreviewSize(WIDTH, HEIGHT);
                // 實現自動對焦
                List<String> focusModes = params.getSupportedFocusModes();
                if (focusModes.contains("continuous-video")) {
                    params.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
                }
                mCamera.setParameters(params);
                mCamera.getParameters().setPreviewFormat(ImageFormat.NV21);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
    /**
     * 打開攝像頭
     */
    public void openCamera(int id) {

        int mCameraCount = Camera.getNumberOfCameras();
        int curCameraIndex;
            if (mCameraCount > 1) {
                curCameraIndex = Camera.CameraInfo.CAMERA_FACING_FRONT;
                CAMERA_FACING_BACK_FRONT = 1;
            } else {
                curCameraIndex = Camera.CameraInfo.CAMERA_FACING_BACK;
                CAMERA_FACING_BACK_FRONT = 0;
            }
            mCamera = Camera.open(curCameraIndex);
            initCamera();
            try {
                mCamera.addCallbackBuffer(mData);
                mCamera.setPreviewCallback(Main1Activity.this);
                mCamera.setPreviewTexture(new SurfaceTexture(10));
            } catch (IOException e) {
                Log.w(TAG, "setPreviewTexture error e = " + e.getMessage());
            }
    }

    @Override
    protected void onResume() {
        super.onResume();
        view.onResume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        view.onPause();
        mCamera.stopPreview();
        wlock.release();
    }
    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        if (DEBUG)
        {
            Log.i(TAG, "onPreviewFrame()");
        }
        mData = data;
        camera.addCallbackBuffer(data);
    }

}

CmOpenGLES.java

package cm.opengles;

public class CmOpenGLES {

    static {
        System.loadLibrary("CameraOpenGLES");
    }

    public static native void init(int width, int height);
    public static native void release();
    public static native void changeLayout(int width, int height);
    public static native void drawFrame(byte[] data, int size);
}