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<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)采用动态注册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??? //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 jbooleannativeSetVideoSurface(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 voidnativeShowYUV(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 methodsstatic 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:= libshowYUVLOCAL_MODULE_TAGS := testsinclude $(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