Android用surface直接显示yuv数据（三）

    本文用Java创建UI并联合JNI层操作surface来直接显示yuv数据（yv12），开发环境为Android 4.4，全志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 {
            // 如果手机插入了SD卡，而且应用程序具有访问SD的权限
            if (Environment.getExternalStorageState().equals(
                    Environment.MEDIA_MOUNTED)) {
                // 获取SD卡对应的存储目录
                File sdCardDir = Environment.getExternalStorageDirectory();
                // 获取指定文件对应的输入流
                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

JNI层，showYUV.cpp(libshowyuv.so)采用动态注册JNI函数的方法.

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace android;

static sp 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 &nativeWindow,int width,int height) {
	ALOGE("[%s]%d",__FILE__,__LINE__);
    sp 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???
	//很重要,配置宽高和和指定颜色空间yuv420
	//如果这里不配置好，下面deque_buffer只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;//描述buffer
	//申请一块空闲的图形缓冲区
    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文件复制到Java项目里 与src并列的libs/armeabi目录下，没有就手动创建目录，

这样Eclipse会自动把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