Android5.1显示YUV格式图片 Demo

最近需要通过surface显示YUV视频，参考了网上一些资料，发现大多是基于4.0，4.4的代码，4.0相对5.1，android的代码接口有些变化，参考示例不能直接使用，调试过程中也碰到了很多问题，故整理出来分享。

本文使用的是jni方式，应用端通过jni接口，调用C++层代码，进行YUV图像显示。应用层做了一个简单apk，jni层是在android源码里面编译的，使用so库的方式，开发环境是android5.1.



下面直接上代码（主要是测试用，很多地方写得不规范和存在问题，但整体不影响演示）。

4.1 jni层

Jni层是关键，先介绍

4.1.1 主要代码

这些代码都在一个文件里，



变量定义，库加载和jni注册

#include <stdio.h>

#include "JNIHelp.h"



#include <jni.h>

#include <stddef.h>

#include <unistd.h>

#include <limits.h>

#include "types.h"

using namespace android;

static const char *classPathName = "com/example/yuvplayer/YuvStream"; //xia

static sp<Surface> native_surface; //xia



#define CHECK_EQ(x,y) {if(x == y);}

static jobject gObject;

static JavaVM* jvm=0;



#include "debug.h"

typedef union {

JNIEnv* env;

void* venv;

} UnionJNIEnvToVoid;



jint JNI_OnLoad(JavaVM* vm, void* reserved)

{

UnionJNIEnvToVoid uenv;

uenv.venv = NULL;

jint result = -1;

JNIEnv* env = NULL;





LOGW("JNI_OnLoad 1111");



setJavaVM(vm); //xia



if (vm->GetEnv(&uenv.venv, JNI_VERSION_1_4) != JNI_OK) {

LOGD("ERROR: GetEnv failed");

goto bail;

}

env = uenv.env;



LOGW("JNI_OnLoad 2222");

if (registerNativeMethods(env, classPathName, methods, sizeof(methods) / sizeof(methods[0])) != JNI_TRUE) {

LOGD("ERROR: registerNatives failed");

goto bail;

}



result = JNI_VERSION_1_4;



bail:

return result;

}



/*

* Register several native methods for one class.

*/

static int registerNativeMethods(JNIEnv* env, const char* className,

JNINativeMethod* gMethods, int numMethods)

{

jclass clazz;



//if(className)

LOGW("registerNativeMethods: '%s',%d", className,numMethods);



clazz = env->FindClass(className);

if (clazz == NULL)

{

env->DeleteLocalRef(clazz);

return JNI_FALSE;

}



if (env->RegisterNatives(clazz, gMethods, numMethods) < 0) {

env->DeleteLocalRef(clazz);

return JNI_FALSE;

}



env->DeleteLocalRef(clazz);

return JNI_TRUE;



}









Native函数

static JNINativeMethod methods[] = {

{"NativeStartDecode", "(Landroid/view/Surface;)V", (void*)startDecode},

{"NativeStopDecode", "()V", (void*)stopDecode},

{"NativeDecode", "()I", (void*)Decode},

{"NativePutBufToDecode", "([B)I", (void*)putBufToDecode},



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

{"nativeShowYUVint", "([III)V", (void *)nativeShowYUVint},



};



static jint Decode(JNIEnv *env, jobject thiz)

{

LOGD("Decode enter ======>");

//ShowYUV();

}



static void startDecode(JNIEnv *env, jobject thiz,jobject jSurface)

{

LOGD("startDecode enter ~");

sp<Surface> mSurface;

if (jSurface != NULL) {

setSurface(env, jSurface, 9);

mSurface= native_surface;

return; //xia test

}

}



static void stopDecode(JNIEnv *env, jobject thiz)

{

}



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);



//jint *byteBuf = env->GetIntArrayElements(yuvData, 0);

//char * bufYUV = NULL;

//bufYUV = (char *)byteBuf;



//p3

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



//p4

// mDisplay->setSize(width,height);

// mDisplay->startDisplayDecode(bufYUV);



}







辅助函数

//method2

static int ALIGN(int x, int y) {

// y must be a power of 2.

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

}

static android::Surface* getNativeSurface(JNIEnv* env, jobject jsurface, jint version)

{

jclass clazz = env->FindClass("android/view/Surface");

jfieldID field_surface;

if(version <=8)

{

field_surface = env->GetFieldID(clazz, "mSurface", "I");

}

else

field_surface = env->GetFieldID(clazz, "mNativeObject", "J");



if (field_surface == NULL)

{

return NULL;

}

return (android::Surface *) env->GetLongField(jsurface, field_surface);//GetIntField GetLongField

}



int setSurface(JNIEnv *env, jobject jsurface, jint version)

{

native_surface = getNativeSurface(env, jsurface, version);



if(android::Surface::isValid(native_surface))

{

__android_log_print(ANDROID_LOG_INFO, "libjni", "native_surface is valid");

return 1;

}

else

__android_log_print(ANDROID_LOG_ERROR, "libjni", "native_surface is invalid");



return 0;

}



void ConvertYUVBuffer(uint8_t* dstbuf,const void *data,int width,int height,ANativeWindowBuffer *buf) {

int mCropWidth = width;

int mCropHeight = height;

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

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





const uint8_t *src_y = (const uint8_t *)data;

const uint8_t *src_u = (const uint8_t *)data + mWidth * mHeight;

const uint8_t *src_v = src_u + (mWidth / 2 * mHeight / 2);



uint8_t *dst_y = (uint8_t *)dstbuf;

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

size_t dst_c_stride = ALIGN(buf->stride / 2, 16);

size_t dst_c_size = dst_c_stride * buf->height / 2;

uint8_t *dst_v = dst_y + dst_y_size;

uint8_t *dst_u = dst_v + dst_c_size;



for (int y = 0; y < mCropHeight; ++y) {

memcpy(dst_y, src_y, mCropWidth);



src_y += mWidth;

dst_y += buf->stride;

}



for (int y = 0; y < (mCropHeight + 1) / 2; ++y) {

memcpy(dst_u, src_u, (mCropWidth + 1) / 2);

memcpy(dst_v, src_v, (mCropWidth + 1) / 2);



src_u += mWidth / 2;

src_v += mWidth / 2;

dst_u += dst_c_stride;

dst_v += dst_c_stride;

}

}





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;

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



CHECK_EQ(0, native_window_set_buffers_geometry(

mNativeWindow.get(),

bufWidth,

bufHeight,

halFormat));





ANativeWindowBuffer *buf;

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);



uint8_t* dst = NULL;



CHECK_EQ(0, mapper.lock(

buf->handle, GRALLOC_USAGE_SW_WRITE_OFTEN, bounds, (void**)&dst));//



//将yuv数据copy到图形缓冲区

ConvertYUVBuffer(dst,data,width,height, buf);



}



ALOGE("render buf->stride = %d",buf->stride);



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;

}







Make文件

LOCAL_PATH := $(call my-dir)



include $(CLEAR_VARS)



LOCAL_MODULE := lib YUVShow



#LOCAL_LDLIBS += -llog



LOCAL_C_INCLUDES := \

bionic \

bionic/libstdc++/include \

external/stlport/stlport \

external/libyuv/files/include \

frameworks/av/media/libstagefright \

frameworks/av/media/libstagefright/include \

frameworks/native/include/media/openmax \

frameworks/av/media/libstagefright/codecs/on2/h264dec/source \

frameworks/av/media/libstagefright/codecs/on2/h264dec/inc \

frameworks/av/include/media/stagefright \

frameworks/native/include/utils \

frameworks/native/include/gui \





LOCAL_SHARED_LIBRARIES := \

libbinder \

libui \

libgui \

libstagefright \

libutils \

libstagefright_soft_h264dec



#LOCAL_STATIC_LIBRARIES := libyuv_static

LOCAL_SRC_FILES := \

YUVShow.cpp \





LOCAL_MODULE_TAGS := optional

LOCAL_MODULE_PATH := $(TARGET_OUT_SHARED_LIBRARIES)

#LOCAL_CFLAGS += -m64



include $(BUILD_SHARED_LIBRARY)

4.2 app

4.2.1java

Java代码很多，不能写全，贴关键部分，主要是使用textureview去呈现窗口，可扩展子类，重写onSurfaceTextureAvailable等方法，当建立一个surface后surface传递给jni，



public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int width,

int height) {

…

//当SurfaceTexture被创建后，调用jni给底层设置Surface

mSavedSurface = new Surface(mSavedSurfaceTexture);

YuvStream.getInstance().setSurface(mSavedSurface);

}





做一个按钮，在触发函数里读文件，将读到的数据发给jni去播放，

final private String FILE_NAME2 = "carphone001.yuv";

private int width2 = 176;

private int height2 = 144;

private int size2 = width2 * height2 * 3/2;



private OnClickListener getOnClickListener() {

OnClickListener onClickListener = new OnClickListener() {

public void onClick(View view) {

int id = view.getId();

Log.d(this, "onClick(View " + view + ", id " + id + ")...");



switch (id) {

case R.id.btn_decode:



byte[]yuvArray = new byte[size2];

int[] mIntArray = new int[width2 * height2];



readYUVFile(yuvArray, FILE_NAME2,size2);

YuvStream.getInstance().ShowYUV(yuvArray,width2,height2);

}









读文件

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

try {

File sdCardDir = Environment.getExternalStorageDirectory();

FileInputStream fis = new FileInputStream(

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



fis.read(yuvArray, 0, len);



//test play file

fis.close();

return true;

} else {

return false;

}

}catch (Exception e) {

e.printStackTrace();

return false;

}

}

4.2.2 布局

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

android:layout_width="match_parent"

android:layout_height="match_parent">



<FrameLayout

android:layout_width="match_parent"

android:layout_height="match_parent" >



<TextureView

android:id="@+id/incomingVideo"

android:layout_gravity="center_vertical"

android:layout_width="match_parent"

android:layout_height="match_parent" />

<FrameLayout

android:id="@+id/previewVideoContainer"

android:layout_marginRight="5dp"

android:layout_marginTop="20dp"

android:layout_gravity="top|right"

android:layout_width="90dp"

android:layout_height="110dp"

android:background="#aaa" >



<TextureView

android:id="@+id/previewVideo"

android:layout_marginLeft="2dp"

android:layout_marginTop="2dp"

android:layout_width="match_parent"

android:layout_height="match_parent"

/>

</FrameLayout>



</FrameLayout>



<TextView

android:background="@android:color/transparent"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="@string/hello_world"

android:layout_marginLeft="15dp"

android:layout_marginTop="15dp" />



<TextView

android:id="@+id/btn_decode"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:drawableTop="@drawable/hello_world"

android:text="@string/hello_world" />



</FrameLayout>

4.2.3 jni接口

package com.example.yuvplayer;



import android.os.Handler;

import android.os.Message;

//import android.os.RegistrantList;

//import android.os.SystemProperties;

import android.util.Log;

import android.view.Surface;



class YuvStream {

private static final String TAG = "YuvStream";



private static native void NativeStartDecode(Surface st);

private static native int NativeDecode();

private static native void NativeStopDecode();

private static native void nativeShowYUV(byte[] frame,int w,int h);

private static native void nativeShowYUVint(int[] frame,int w,int h);



// Use a singleton

private static YuvStream mInstance;



/**

* This method returns the single instance of ImsMedia object *

*/

public static synchronized YuvStream getInstance() {

if (mInstance == null) {

mInstance = new YuvStream();

}

return mInstance;

}



static {

System.loadLibrary("YUVShow");

}



public void setSurface(Surface st) {

log("setSurface(Surface: " + st + ")");

mSurface = st;

NativeStartDecode(st);

}

public void decode() {

log("decode()");

NativeDecode();

}



public void ShowYUV(int[] frame,int w,int h) {

log("ShowYUV()");



//nativeShowYUV(frame, w, h);

nativeShowYUVint(frame, w, h);

}



public void ShowYUV(byte[] frame,int w,int h) {

log("ShowYUV()");



nativeShowYUV(frame, w, h);

}

}

4.3相关信息

YUV素材文件在http://www.cipr.rpi.edu/resource/sequences/index.html可下载。

根据代码中的文件路径，放置到手机sdcard目录下，adb remount，adb push xxx.yuv sdcard即可。



编译出的so库应该是64位的，要放置到system/lib64目录下。



需要了解YUV的基本知识，网上有很好的资料。

要了解自己的素材文件的尺寸和采样方式，代码里要匹配，否则解码会有问题。



最后的效果如图（进入apk，点击按钮出现）：