在本文中，Java创建UI和关节JNI经营层surface直接显示yuv数据（yv12）。发展环境Android 4.4，驰A23平台。

package com.example.myyuvviewer;

import java.io.File;

import java.io.FileInputStream;

import android.app.Activity;

import android.os.Bundle;

import android.os.Environment;

import android.util.Log;

import android.view.Surface;

import android.view.SurfaceHolder;

import android.view.SurfaceHolder.Callback;

import android.view.SurfaceView;

public class MainActivity extends Activity {

	final private String TAG = "MyYUVViewer";

	final private String FILE_NAME = "yuv_320_240.yuv";

	private int width = 320;

	private int height = 240;

	private int size = width * height * 3/2;

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

		nativeTest();

		SurfaceView surfaceview = (SurfaceView) findViewById(R.id.surfaceView);

		SurfaceHolder holder = surfaceview.getHolder();

		holder.addCallback(new Callback(){

			@Override

			public void surfaceCreated(SurfaceHolder holder) {

				// TODO Auto-generated method stub

				Log.d(TAG,"surfaceCreated");

				byte[]yuvArray = new byte[size];

				readYUVFile(yuvArray, FILE_NAME);

				nativeSetVideoSurface(holder.getSurface());

				nativeShowYUV(yuvArray,width,height);

			}

			@Override

			public void surfaceChanged(SurfaceHolder holder, int format,

					int width, int height) {

				// TODO Auto-generated method stub

			}

			@Override

			public void surfaceDestroyed(SurfaceHolder holder) {

				// TODO Auto-generated method stub

			}});

	}

	private boolean readYUVFile(byte[] yuvArray,String filename){

		try {

            // 假设手机插入了SD卡，并且应用程序具有訪问SD的权限

            if (Environment.getExternalStorageState().equals(

                    Environment.MEDIA_MOUNTED)) {

                // 获取SD卡相应的存储文件夹

                File sdCardDir = Environment.getExternalStorageDirectory();

                // 获取指定文件相应的输入流

                FileInputStream fis = new FileInputStream(

                        sdCardDir.getCanonicalPath() +"/" + filename);

                fis.read(yuvArray, 0, size);

                fis.close();

                return true;

            } else {

                return false;

            }

        }catch (Exception e) {

            e.printStackTrace();

            return false;

        }

	}

	private native void nativeTest();

	private native boolean nativeSetVideoSurface(Surface surface);

	private native void nativeShowYUV(byte[] yuvArray,int width,int height);

	static {

        System.loadLibrary("showYUV");

    }

}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical" >  

    <SurfaceView

        android:id="@+id/surfaceView"

        android:layout_width="fill_parent"

        android:layout_height="360dp" /> 

</LinearLayout>

JNI层。showYUV.cpp(libshowyuv.so)採用动态注冊JNI函数的方法.

#include <jni.h>

#include <android_runtime/AndroidRuntime.h>

#include <android_runtime/android_view_Surface.h>

#include <gui/Surface.h>

#include <assert.h>

#include <utils/Log.h>

#include <JNIHelp.h>

#include <media/stagefright/foundation/ADebug.h>

#include <ui/GraphicBufferMapper.h>

#include <cutils/properties.h>

using namespace android;

static sp<Surface> surface;

static int ALIGN(int x, int y) {

    // y must be a power of 2.

    return (x + y - 1) & ~(y - 1);

}

static void render(

        const void *data, size_t size, const sp<ANativeWindow> &nativeWindow,int width,int height) {

	ALOGE("[%s]%d",__FILE__,__LINE__);

    sp<ANativeWindow> mNativeWindow = nativeWindow;

    int err;

	int mCropWidth = width;

	int mCropHeight = height;

	int halFormat = HAL_PIXEL_FORMAT_YV12;//颜色空间

    int bufWidth = (mCropWidth + 1) & ~1;//按2对齐

    int bufHeight = (mCropHeight + 1) & ~1;

	CHECK_EQ(0,

            native_window_set_usage(

            mNativeWindow.get(),

            GRALLOC_USAGE_SW_READ_NEVER | GRALLOC_USAGE_SW_WRITE_OFTEN

            | GRALLOC_USAGE_HW_TEXTURE | GRALLOC_USAGE_EXTERNAL_DISP));

    CHECK_EQ(0,

            native_window_set_scaling_mode(

            mNativeWindow.get(),

            NATIVE_WINDOW_SCALING_MODE_SCALE_CROP));

    // Width must be multiple of 32??

?

	//非常重要,配置宽高和和指定颜色空间yuv420

	//假设这里不配置好，以下deque_buffer仅仅能去申请一个默认宽高的图形缓冲区

    CHECK_EQ(0, native_window_set_buffers_geometry(

                mNativeWindow.get(),

                bufWidth,

                bufHeight,

                halFormat));

	ANativeWindowBuffer *buf;//描写叙述buffer

	//申请一块空暇的图形缓冲区

    if ((err = native_window_dequeue_buffer_and_wait(mNativeWindow.get(),

            &buf)) != 0) {

        ALOGW("Surface::dequeueBuffer returned error %d", err);

        return;

    }

    GraphicBufferMapper &mapper = GraphicBufferMapper::get();

    Rect bounds(mCropWidth, mCropHeight);

    void *dst;

    CHECK_EQ(0, mapper.lock(//用来锁定一个图形缓冲区并将缓冲区映射到用户进程

                buf->handle, GRALLOC_USAGE_SW_WRITE_OFTEN, bounds, &dst));//dst就指向图形缓冲区首地址

    if (true){

        size_t dst_y_size = buf->stride * buf->height;

        size_t dst_c_stride = ALIGN(buf->stride / 2, 16);//1行v/u的大小

        size_t dst_c_size = dst_c_stride * buf->height / 2;//u/v的大小

        memcpy(dst, data, dst_y_size + dst_c_size*2);//将yuv数据copy到图形缓冲区

    }

    CHECK_EQ(0, mapper.unlock(buf->handle));

    if ((err = mNativeWindow->queueBuffer(mNativeWindow.get(), buf,

            -1)) != 0) {

        ALOGW("Surface::queueBuffer returned error %d", err);

    }

    buf = NULL;

}

static void nativeTest(){

	ALOGE("[%s]%d",__FILE__,__LINE__);

}

static jboolean

nativeSetVideoSurface(JNIEnv *env, jobject thiz, jobject jsurface){

	ALOGE("[%s]%d",__FILE__,__LINE__);

	surface = android_view_Surface_getSurface(env, jsurface);

	if(android::Surface::isValid(surface)){

		ALOGE("surface is valid ");

	}else {

		ALOGE("surface is invalid ");

		return false;

	}

	ALOGE("[%s][%d]\n",__FILE__,__LINE__);

	return true;

}

static void

nativeShowYUV(JNIEnv *env, jobject thiz,jbyteArray yuvData,jint width,jint height){

	ALOGE("width = %d,height = %d",width,height);

	jint len = env->GetArrayLength(yuvData);

	ALOGE("len = %d",len);

	jbyte *byteBuf = env->GetByteArrayElements(yuvData, 0);

	render(byteBuf,len,surface,width,height);

}

static JNINativeMethod gMethods[] = {

    {"nativeTest",       			"()V",    							(void *)nativeTest},

	{"nativeSetVideoSurface",		"(Landroid/view/Surface;)Z", 		(void *)nativeSetVideoSurface},

	{"nativeShowYUV",				"([BII)V",							(void *)nativeShowYUV},

};

static const char* const kClassPathName = "com/example/myyuvviewer/MainActivity";

// This function only registers the native methods

static int register_com_example_myyuvviewer(JNIEnv *env)

{

	ALOGE("[%s]%d",__FILE__,__LINE__);

    return AndroidRuntime::registerNativeMethods(env,

                kClassPathName, gMethods, NELEM(gMethods));

}

jint JNI_OnLoad(JavaVM* vm, void* reserved)

{

	ALOGE("[%s]%d",__FILE__,__LINE__);

    JNIEnv* env = NULL;

    jint result = -1;

    if (vm->GetEnv((void**) &env, JNI_VERSION_1_4) != JNI_OK) {

        ALOGE("ERROR: GetEnv failed\n");

        goto bail;

    }

    assert(env != NULL);

	ALOGE("[%s]%d",__FILE__,__LINE__);

   if (register_com_example_myyuvviewer(env) < 0) {

        ALOGE("ERROR: MediaPlayer native registration failed\n");

        goto bail;

    }

    /* success -- return valid version number */

    result = JNI_VERSION_1_4;

bail:

    return result;

}

Android.mk

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)

LOCAL_SRC_FILES:= \

	showYUV.cpp

LOCAL_SHARED_LIBRARIES := \

	libcutils \

	libutils \

	libbinder \

    libui \

    libgui \

	libandroid_runtime \

	libstagefright_foundation

LOCAL_MODULE:= libshowYUV

LOCAL_MODULE_TAGS := tests

include $(BUILD_SHARED_LIBRARY)

生成的so文件拷贝到Java项目里 与src并列的libs/armeabi文件夹下。没有就手动创建文件夹，

这样Eclipse会自己主动把so库打包进apk。

转载请注明出处：http://blog.csdn.net/tung214/article/details/37762487

yuvdata下载地址：点击打开链接