1. 移植目标
将H.264解码器移植到OPhone操作系统之上(NDK+C),并写一个测试程序(OPhoneSDK+Java)测试解码库是否正常运行,下面是解码时的截图:
OPhone的模拟器和Mobile的模拟器一样是模拟ARM指令的,不像Symbian模拟器一样执行的是本地代码,所以在模拟器上模拟出来的效率会比
真实手机上的效率要低,之前这款解码器已经优化到在nokia 6600(相当低端的一款手机,CPU主频才120Hz)上做到在线播放。
2. 面向人群
本文面向有一定的手机应用开发经验(例如:S60/Mobile/MTK)和有一定的跨手机平台移植经验的人员,帮助她们了解一个企业的核心库(C/C++)是怎么移植到OPhone之上的。
3. 假定前提
1)熟悉Java/C/C++语言;
2)熟悉Java的JNI技术;
3)有一定的跨手机平台移植经验;
4)有一套可供移植的源代码库,这里以H.264解码库为例,为了保护我们的知识版权,这里只能够公开头文件:
- #ifndef __H264DECODE_H__
- #define __H264DECODE_H__
-
- #if defined(__SYMBIAN32__) //S602rd/3rd/UIQ
- #include <e32base.h>
- #include <libc"stdio.h>
- #include <libc"stdlib.h>
- #include <libc"string.h>
- #else //Windows/Mobile/MTK/OPhone
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #endif
-
- class H264Decode
- {
- public:
- /***************************************************************************/
- /* 构造解码器 */
- /* @return H264Decode解码器实例 */
- /***************************************************************************/
- static H264Decode *H264DecodeConstruct();
- /***************************************************************************/
- /* 解码一帧 */
- /* @pInBuffer 指向H264的视频流 */
- /* @iInSize H264视频流的大小 */
- /* @pOutBuffer 解码后的视频视频 */
- /* @iOutSize 解码后的视频大小 */
- /* @return 已解码的H264视频流的尺寸 */
- /***************************************************************************/
- int DecodeOneFrame(unsigned char *pInBuffer,unsigned int iInSize,unsigned char *pOutBuffer,unsigned int &iOutSize);
- ~H264Decode();
- };
- #endif // __H264DECODE_H__
#ifndef __H264DECODE_H__
#define __H264DECODE_H__
#if defined(__SYMBIAN32__) //S602rd/3rd/UIQ
#include <e32base.h>
#include <libc"stdio.h>
#include <libc"stdlib.h>
#include <libc"string.h>
#else //Windows/Mobile/MTK/OPhone
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#endif
class H264Decode
{
public:
/***************************************************************************/
/* 构造解码器 */
/* @return H264Decode解码器实例 */
/***************************************************************************/
static H264Decode *H264DecodeConstruct();
/***************************************************************************/
/* 解码一帧 */
/* @pInBuffer 指向H264的视频流 */
/* @iInSize H264视频流的大小 */
/* @pOutBuffer 解码后的视频视频 */
/* @iOutSize 解码后的视频大小 */
/* @return 已解码的H264视频流的尺寸 */
/***************************************************************************/
int DecodeOneFrame(unsigned char *pInBuffer,unsigned int iInSize,unsigned char *pOutBuffer,unsigned int &iOutSize);
~H264Decode();
};
#endif // __H264DECODE_H__
你不用熟悉OPhone平台,一切从零开始,因为在此之前,我也不熟悉。
4. 开发环境(请参考: http://www.ophonesdn.com/documentation/)
5. 移植过程
5.1 移植流程
5.2 封装Java接口
在“假定前提”中提到了要移植的函数,接下来会编写这些 函数的Java Native Interface。
- package ophone.streaming.video.h264;
-
- import java.nio.ByteBuffer;
-
- public class H264decode {
-
- //H264解码库指针,因为Java没有指针一说,所以这里用一个32位的数来存放指针的值
- private long H264decode = 0;
-
- static{
- System.loadLibrary("H264Decode");
- }
-
- public H264decode() {
- this.H264decode = Initialize();
- }
-
- public void Cleanup() {
- Destroy(H264decode);
- }
-
- public int DecodeOneFrame(ByteBuffer pInBuffer,ByteBuffer pOutBuffer) {
- return DecodeOneFrame(H264decode, pInBuffer, pOutBuffer);
- }
-
- private native static int DecodeOneFrame(long H264decode,ByteBuffer pInBuffer,ByteBuffer pOutBuffer);
- private native static long Initialize();
- private native static void Destroy(long H264decode);
- }
package ophone.streaming.video.h264;
import java.nio.ByteBuffer;
public class H264decode {
//H264解码库指针,因为Java没有指针一说,所以这里用一个32位的数来存放指针的值
private long H264decode = 0;
static{
System.loadLibrary("H264Decode");
}
public H264decode() {
this.H264decode = Initialize();
}
public void Cleanup() {
Destroy(H264decode);
}
public int DecodeOneFrame(ByteBuffer pInBuffer,ByteBuffer pOutBuffer) {
return DecodeOneFrame(H264decode, pInBuffer, pOutBuffer);
}
private native static int DecodeOneFrame(long H264decode,ByteBuffer pInBuffer,ByteBuffer pOutBuffer);
private native static long Initialize();
private native static void Destroy(long H264decode);
}
这块没什么好说的,就是按照H264解码库的函数,封装的一层接口,如果你熟悉Java JNI,会发现原来是这么类似。这里插入一句:我一直认为技术都是相通的,底层的技术就那么几种,学懂了,其它技术都是一通百通。
5.3 使用C实现本地方法
5.3.1生成头文件
使用javah命令生成JNI头文件,这里需要注意是class路径不是源代码的路径,并且要加上包名:
这里生成了一个ophone_streaming_video_h264_H264decode.h,我们打开来看看:
- #include <jni.h>
-
- #ifndef _Included_ophone_streaming_video_h264_H264decode
- #define _Included_ophone_streaming_video_h264_H264decode
- #ifdef __cplusplus
- extern "C" {
- #endif
-
- JNIEXPORT jint JNICALL Java_ophone_streaming_video_h264_H264decode_DecodeOneFrame
- (JNIEnv *, jclass, jlong, jobject, jobject);
-
- JNIEXPORT jlong JNICALL Java_ophone_streaming_video_h264_H264decode_Initialize
- (JNIEnv *, jclass);
-
- JNIEXPORT void JNICALL Java_ophone_streaming_video_h264_H264decode_Destroy
- (JNIEnv *, jclass, jlong);
-
- #ifdef __cplusplus
- }
- #endif
- #endif
#include <jni.h>
#ifndef _Included_ophone_streaming_video_h264_H264decode
#define _Included_ophone_streaming_video_h264_H264decode
#ifdef __cplusplus
extern "C" {
#endif
JNIEXPORT jint JNICALL Java_ophone_streaming_video_h264_H264decode_DecodeOneFrame
(JNIEnv *, jclass, jlong, jobject, jobject);
JNIEXPORT jlong JNICALL Java_ophone_streaming_video_h264_H264decode_Initialize
(JNIEnv *, jclass);
JNIEXPORT void JNICALL Java_ophone_streaming_video_h264_H264decode_Destroy
(JNIEnv *, jclass, jlong);
#ifdef __cplusplus
}
#endif
#endif
5.3.2 实现本地方法
之前已经生成了JNI头文件,接下来只需要实现这个头文件的几个导出函数,这里以H264解码器的实现为例:
- #include "ophone_streaming_video_h264_H264decode.h"
- #include "H264Decode.h"
-
- JNIEXPORT jint JNICALL Java_ophone_streaming_video_h264_H264decode_DecodeOneFrame
- (JNIEnv * env, jclass obj, jlong decode, jobject pInBuffer, jobject pOutBuffer) {
-
- H264Decode *pDecode = (H264Decode *)decode;
- unsigned char *In = NULL;unsigned char *Out = NULL;
- unsigned int InPosition = 0;unsigned int InRemaining = 0;unsigned int InSize = 0;
- unsigned int OutSize = 0;
- jint DecodeSize = -1;
-
- jbyte *InJbyte = 0;
- jbyte *OutJbyte = 0;
-
- jbyteArray InByteArrary = 0;
- jbyteArray OutByteArrary = 0;
-
- //获取Input/Out ByteBuffer相关属性
- {
- //Input
- {
- jclass ByteBufferClass = env->GetObjectClass(pInBuffer);
- jmethodID PositionMethodId = env->GetMethodID(ByteBufferClass,"position","()I");
- jmethodID RemainingMethodId = env->GetMethodID(ByteBufferClass,"remaining","()I");
- jmethodID ArraryMethodId = env->GetMethodID(ByteBufferClass,"array","()[B");
-
- InPosition = env->CallIntMethod(pInBuffer,PositionMethodId);
- InRemaining = env->CallIntMethod(pInBuffer,RemainingMethodId);
- InSize = InPosition + InRemaining;
-
- InByteArrary = (jbyteArray)env->CallObjectMethod(pInBuffer,ArraryMethodId);
-
- InJbyte = env->GetByteArrayElements(InByteArrary,0);
-
- In = (unsigned char*)InJbyte + InPosition;
- }
-
- //Output
- {
- jclass ByteBufferClass = env->GetObjectClass(pOutBuffer);
- jmethodID ArraryMethodId = env->GetMethodID(ByteBufferClass,"array","()[B");
- jmethodID ClearMethodId = env->GetMethodID(ByteBufferClass,"clear","()Ljava/nio/Buffer;");
-
- //清理输出缓存区
- env->CallObjectMethod(pOutBuffer,ClearMethodId);
-
- OutByteArrary = (jbyteArray)env->CallObjectMethod(pOutBuffer,ArraryMethodId);
- OutJbyte = env->GetByteArrayElements(OutByteArrary,0);
-
- Out = (unsigned char*)OutJbyte;
- }
- }
-
- //解码
- DecodeSize = pDecode->DecodeOneFrame(In,InRemaining,Out,OutSize);
-
- //设置Input/Output ByteBuffer相关属性
- {
- //Input
- {
- jclass ByteBufferClass = env->GetObjectClass(pInBuffer);
- jmethodID SetPositionMethodId = env->GetMethodID(ByteBufferClass,"position","(I)Ljava/nio/Buffer;");
-
- //设置输入缓冲区偏移
- env->CallObjectMethod(pInBuffer,SetPositionMethodId,InPosition + DecodeSize);
- }
-
- //Output
- {
- jclass ByteBufferClass = env->GetObjectClass(pOutBuffer);
- jmethodID SetPositionMethodId = env->GetMethodID(ByteBufferClass,"position","(I)Ljava/nio/Buffer;");
-
- //设置输出缓冲区偏移
- env->CallObjectMethod(pOutBuffer,SetPositionMethodId,OutSize);
- }
- }
-
- //清理
- env->ReleaseByteArrayElements(InByteArrary,InJbyte,0);
- env->ReleaseByteArrayElements(OutByteArrary,OutJbyte,0);
-
- return DecodeSize;
- }
-
- JNIEXPORT jlong JNICALL Java_ophone_streaming_video_h264_H264decode_Initialize
- (JNIEnv * env, jclass obj) {
-
- H264Decode *pDecode = H264Decode::H264DecodeConstruct();
- return (jlong)pDecode;
- }
-
- JNIEXPORT void JNICALL Java_ophone_streaming_video_h264_H264decode_Destroy
- (JNIEnv * env, jclass obj, jlong decode) {
-
- H264Decode *pDecode = (H264Decode *)decode;
- if (pDecode)
- {
- delete pDecode;
- pDecode = NULL;
- }
- }
#include "ophone_streaming_video_h264_H264decode.h"
#include "H264Decode.h"
JNIEXPORT jint JNICALL Java_ophone_streaming_video_h264_H264decode_DecodeOneFrame
(JNIEnv * env, jclass obj, jlong decode, jobject pInBuffer, jobject pOutBuffer) {
H264Decode *pDecode = (H264Decode *)decode;
unsigned char *In = NULL;unsigned char *Out = NULL;
unsigned int InPosition = 0;unsigned int InRemaining = 0;unsigned int InSize = 0;
unsigned int OutSize = 0;
jint DecodeSize = -1;
jbyte *InJbyte = 0;
jbyte *OutJbyte = 0;
jbyteArray InByteArrary = 0;
jbyteArray OutByteArrary = 0;
//获取Input/Out ByteBuffer相关属性
{
//Input
{
jclass ByteBufferClass = env->GetObjectClass(pInBuffer);
jmethodID PositionMethodId = env->GetMethodID(ByteBufferClass,"position","()I");
jmethodID RemainingMethodId = env->GetMethodID(ByteBufferClass,"remaining","()I");
jmethodID ArraryMethodId = env->GetMethodID(ByteBufferClass,"array","()[B");
InPosition = env->CallIntMethod(pInBuffer,PositionMethodId);
InRemaining = env->CallIntMethod(pInBuffer,RemainingMethodId);
InSize = InPosition + InRemaining;
InByteArrary = (jbyteArray)env->CallObjectMethod(pInBuffer,ArraryMethodId);
InJbyte = env->GetByteArrayElements(InByteArrary,0);
In = (unsigned char*)InJbyte + InPosition;
}
//Output
{
jclass ByteBufferClass = env->GetObjectClass(pOutBuffer);
jmethodID ArraryMethodId = env->GetMethodID(ByteBufferClass,"array","()[B");
jmethodID ClearMethodId = env->GetMethodID(ByteBufferClass,"clear","()Ljava/nio/Buffer;");
//清理输出缓存区
env->CallObjectMethod(pOutBuffer,ClearMethodId);
OutByteArrary = (jbyteArray)env->CallObjectMethod(pOutBuffer,ArraryMethodId);
OutJbyte = env->GetByteArrayElements(OutByteArrary,0);
Out = (unsigned char*)OutJbyte;
}
}
//解码
DecodeSize = pDecode->DecodeOneFrame(In,InRemaining,Out,OutSize);
//设置Input/Output ByteBuffer相关属性
{
//Input
{
jclass ByteBufferClass = env->GetObjectClass(pInBuffer);
jmethodID SetPositionMethodId = env->GetMethodID(ByteBufferClass,"position","(I)Ljava/nio/Buffer;");
//设置输入缓冲区偏移
env->CallObjectMethod(pInBuffer,SetPositionMethodId,InPosition + DecodeSize);
}
//Output
{
jclass ByteBufferClass = env->GetObjectClass(pOutBuffer);
jmethodID SetPositionMethodId = env->GetMethodID(ByteBufferClass,"position","(I)Ljava/nio/Buffer;");
//设置输出缓冲区偏移
env->CallObjectMethod(pOutBuffer,SetPositionMethodId,OutSize);
}
}
//清理
env->ReleaseByteArrayElements(InByteArrary,InJbyte,0);
env->ReleaseByteArrayElements(OutByteArrary,OutJbyte,0);
return DecodeSize;
}
JNIEXPORT jlong JNICALL Java_ophone_streaming_video_h264_H264decode_Initialize
(JNIEnv * env, jclass obj) {
H264Decode *pDecode = H264Decode::H264DecodeConstruct();
return (jlong)pDecode;
}
JNIEXPORT void JNICALL Java_ophone_streaming_video_h264_H264decode_Destroy
(JNIEnv * env, jclass obj, jlong decode) {
H264Decode *pDecode = (H264Decode *)decode;
if (pDecode)
{
delete pDecode;
pDecode = NULL;
}
}
5.3.3 编译本地方法
接下来,只需要把用C实现的本地方法编译为动态链接库,如果之前你用于移植的那个库曾经移植到Symbian上过,那么编译会相当简单,因为NDK的编译器和Symbian的编译器一样,都是采用GCC做交叉编译器。
首先,需要在$NDK"apps目录下,创建一个项目目录,这里创建了一个H264Decode目录,在H264Decode目录中,创建一个Android.mk文件:
- APP_PROJECT_PATH := $(call my-dir)
- APP_MODULES := H264Decode
APP_PROJECT_PATH := $(call my-dir)
APP_MODULES := H264Decode
接下来,需要在$NDK"source目录下,创建源代码目录(这里的目录名要和上面创建的项目目录文件名相同),这里创建一个H264Decode目录,然后把之前生成的JNI头文件和你实现的本地方法相关头文件和源代码,都拷贝到 这个目录下面。
然后,我们编辑Android.mk文件:
- LOCAL_PATH := $(call my-dir)
- include $(CLEAR_VARS)
- LOCAL_MODULE := H264Decode
- LOCAL_SRC_FILES := common.c cabac.c utils.c golomb.c mpegvideo.c mem.c imgconvert.c h264decode.cpp h264.c dsputil.c ophone_streaming_video_h264_H264decode.cpp
- include $(BUILD_SHARED_LIBRARY)
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := H264Decode
LOCAL_SRC_FILES := common.c cabac.c utils.c golomb.c mpegvideo.c mem.c imgconvert.c h264decode.cpp h264.c dsputil.c ophone_streaming_video_h264_H264decode.cpp
include $(BUILD_SHARED_LIBRARY)
关于Android.mk文件中,各个字段的解释,可以参考$NDK"doc下的《OPHONE-MK.TXT》和《OVERVIEW.TXT》,里面有详细的介绍。
最后,我们启动Cygwin,开始编译:
如果你看到了Install:**,这说明你的库已经编译好了。
FAQ 2:
如果编译遇到下面错误,怎么办?
- error: redefinition of typedef 'int8_t'
需要注释掉你的代码中“typedef signed char int8_t;”,如果你的代码之前是已经移植到了Mobile/Symbian上的话,很有可能遇到这个问题。
5.4 编写库测试程序
用Eclipse创建一个OPhone工程,在入口类中输入如下代码:
- /**
- * @author ophone
- * @email 3751624@qq.com
- */
-
- package ophone.streaming.video.h264;
-
- import java.io.File;
- import java.io.FileInputStream;
- import java.io.InputStream;
- import java.nio.ByteBuffer;
- import OPhone.app.Activity;
- import OPhone.graphics.BitmapFactory;
- import OPhone.os.Bundle;
- import OPhone.os.Handler;
- import OPhone.os.Message;
- import OPhone.widget.ImageView;
- import OPhone.widget.TextView;
-
- public class H264Example extends Activity {
-
- private static final int VideoWidth = 352;
- private static final int VideoHeight = 288;
-
- private ImageView ImageLayout = null;
- private TextView FPSLayout = null;
- private H264decode Decode = null;
- private Handler H = null;
- private byte[] Buffer = null;
-
- private int DecodeCount = 0;
- private long StartTime = 0;
-
- public void onCreate(Bundle savedInstanceState) {
-
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
-
- ImageLayout = (ImageView) findViewById(R.id.ImageView);
- FPSLayout = (TextView) findViewById(R.id.TextView);
- Decode = new H264decode();
-
- StartTime = System.currentTimeMillis();
-
- new Thread(new Runnable(){
- public void run() {
- StartDecode();
- }
- }).start();
-
- H = new Handler(){
- public void handleMessage(Message msg) {
- ImageLayout.invalidate();
- ImageLayout.setImageBitmap(BitmapFactory.decodeByteArray(Buffer, 0, Buffer.length));
-
- long Time = (System.currentTimeMillis()-StartTime)/1000;
- if(Time > 0){
- FPSLayout.setText("花费时间:" + Time + "秒 解码帧数:" + DecodeCount + " FPS:" + (DecodeCount/Time) );
- }
- }
- };
- }
-
- private void StartDecode(){
-
- File h264file = new File("/tmp/Demo.264");
- InputStream h264stream = null;
- try {
-
- h264stream = new FileInputStream(h264file);
- ByteBuffer pInBuffer = ByteBuffer.allocate(51200);//分配50k的缓存
- ByteBuffer pRGBBuffer = ByteBuffer.allocate(VideoWidth*VideoHeight*3);
-
- while (h264stream.read(pInBuffer.array(), pInBuffer.position(), pInBuffer.remaining()) >= 0) {
-
- pInBuffer.position(0);
- do{
- int DecodeLength = Decode.DecodeOneFrame(pInBuffer, pRGBBuffer);
-
- //如果解码成功,把解码出来的图片显示出来
- if(DecodeLength > 0 && pRGBBuffer.position() > 0){
-
- //转换RGB字节为BMP
- BMPImage bmp = new BMPImage(pRGBBuffer.array(),VideoWidth,VideoHeight);
- Buffer = bmp.getByte();
-
- H.sendMessage(H.obtainMessage());
-
- Thread.sleep(1);
- DecodeCount ++;
- }
-
- }while(pInBuffer.remaining() > 10240);//确保缓存区里面的数据始终大于10k
-
- //清理已解码缓冲区
- int Remaining = pInBuffer.remaining();
- System.arraycopy(pInBuffer.array(), pInBuffer.position(), pInBuffer.array(), 0, Remaining);
- pInBuffer.position(Remaining);
- }
-
- } catch (Exception e1) {
- e1.printStackTrace();
- } finally {
- try{h264stream.close();} catch(Exception e){}
- }
-
- }
-
- protected void onDestroy() {
- super.onDestroy();
- Decode.Cleanup();
- }
- }
/**
* @author ophone
* @email 3751624@qq.com
*/
package ophone.streaming.video.h264;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.nio.ByteBuffer;
import OPhone.app.Activity;
import OPhone.graphics.BitmapFactory;
import OPhone.os.Bundle;
import OPhone.os.Handler;
import OPhone.os.Message;
import OPhone.widget.ImageView;
import OPhone.widget.TextView;
public class H264Example extends Activity {
private static final int VideoWidth = 352;
private static final int VideoHeight = 288;
private ImageView ImageLayout = null;
private TextView FPSLayout = null;
private H264decode Decode = null;
private Handler H = null;
private byte[] Buffer = null;
private int DecodeCount = 0;
private long StartTime = 0;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ImageLayout = (ImageView) findViewById(R.id.ImageView);
FPSLayout = (TextView) findViewById(R.id.TextView);
Decode = new H264decode();
StartTime = System.currentTimeMillis();
new Thread(new Runnable(){
public void run() {
StartDecode();
}
}).start();
H = new Handler(){
public void handleMessage(Message msg) {
ImageLayout.invalidate();
ImageLayout.setImageBitmap(BitmapFactory.decodeByteArray(Buffer, 0, Buffer.length));
long Time = (System.currentTimeMillis()-StartTime)/1000;
if(Time > 0){
FPSLayout.setText("花费时间:" + Time + "秒 解码帧数:" + DecodeCount + " FPS:" + (DecodeCount/Time) );
}
}
};
}
private void StartDecode(){
File h264file = new File("/tmp/Demo.264");
InputStream h264stream = null;
try {
h264stream = new FileInputStream(h264file);
ByteBuffer pInBuffer = ByteBuffer.allocate(51200);//分配50k的缓存
ByteBuffer pRGBBuffer = ByteBuffer.allocate(VideoWidth*VideoHeight*3);
while (h264stream.read(pInBuffer.array(), pInBuffer.position(), pInBuffer.remaining()) >= 0) {
pInBuffer.position(0);
do{
int DecodeLength = Decode.DecodeOneFrame(pInBuffer, pRGBBuffer);
//如果解码成功,把解码出来的图片显示出来
if(DecodeLength > 0 && pRGBBuffer.position() > 0){
//转换RGB字节为BMP
BMPImage bmp = new BMPImage(pRGBBuffer.array(),VideoWidth,VideoHeight);
Buffer = bmp.getByte();
H.sendMessage(H.obtainMessage());
Thread.sleep(1);
DecodeCount ++;
}
}while(pInBuffer.remaining() > 10240);//确保缓存区里面的数据始终大于10k
//清理已解码缓冲区
int Remaining = pInBuffer.remaining();
System.arraycopy(pInBuffer.array(), pInBuffer.position(), pInBuffer.array(), 0, Remaining);
pInBuffer.position(Remaining);
}
} catch (Exception e1) {
e1.printStackTrace();
} finally {
try{h264stream.close();} catch(Exception e){}
}
}
protected void onDestroy() {
super.onDestroy();
Decode.Cleanup();
}
}
BMPImage是一个工具类,主要用于把RGB序列,转换为BMP图象用于显示:
@author ophone
* @email 3751624@qq.com
*/
package ophone.streaming.video.h264;
import java.nio.ByteBuffer;
public class BMPImage {
// --- 私有常量
private final static int BITMAPFILEHEADER_SIZE = 14;
private final static int BITMAPINFOHEADER_SIZE = 40;
// --- 位图文件标头
private byte bfType[] = { 'B', 'M' };
private int bfSize = 0;
private int bfReserved1 = 0;
private int bfReserved2 = 0;
private int bfOffBits = BITMAPFILEHEADER_SIZE + BITMAPINFOHEADER_SIZE;
// --- 位图信息标头
private int biSize = BITMAPINFOHEADER_SIZE;
private int biWidth = 176;
private int biHeight = 144;
private int biPlanes = 1;
private int biBitCount = 24;
private int biCompression = 0;
private int biSizeImage = biWidth*biHeight*3;
private int biXPelsPerMeter = 0x0;
private int biYPelsPerMeter = 0x0;
private int biClrUsed = 0;
private int biClrImportant = 0;
ByteBuffer bmpBuffer = null;
public BMPImage(byte[] Data,int Width,int Height){
biWidth = Width;
biHeight = Height;
biSizeImage = biWidth*biHeight*3;
bfSize = BITMAPFILEHEADER_SIZE + BITMAPINFOHEADER_SIZE + biWidth*biHeight*3;
bmpBuffer = ByteBuffer.allocate(BITMAPFILEHEADER_SIZE + BITMAPINFOHEADER_SIZE + biWidth*biHeight*3);
writeBitmapFileHeader();
writeBitmapInfoHeader();
bmpBuffer.put(Data);
}
public byte[] getByte(){
return bmpBuffer.array();
}
private byte[] intToWord(int parValue) {
byte retValue[] = new byte[2];
retValue[0] = (byte) (parValue & 0x00FF);
retValue[1] = (byte) ((parValue >> 8) & 0x00FF);
return (retValue);
}
private byte[] intToDWord(int parValue) {
byte retValue[] = new byte[4];
retValue[0] = (byte) (parValue & 0x00FF);
retValue[1] = (byte) ((parValue >> 8) & 0x000000FF);
retValue[2] = (byte) ((parValue >> 16) & 0x000000FF);
retValue[3] = (byte) ((parValue >> 24) & 0x000000FF);
return (retValue);
}
private void writeBitmapFileHeader () {
bmpBuffer.put(bfType);
bmpBuffer.put(intToDWord (bfSize));
bmpBuffer.put(intToWord (bfReserved1));
bmpBuffer.put(intToWord (bfReserved2));
bmpBuffer.put(intToDWord (bfOffBits));
}
private void writeBitmapInfoHeader () {
bmpBuffer.put(intToDWord (biSize));
bmpBuffer.put(intToDWord (biWidth));
bmpBuffer.put(intToDWord (biHeight));
bmpBuffer.put(intToWord (biPlanes));
bmpBuffer.put(intToWord (biBitCount));
bmpBuffer.put(intToDWord (biCompression));
bmpBuffer.put(intToDWord (biSizeImage));
bmpBuffer.put(intToDWord (biXPelsPerMeter));
bmpBuffer.put(intToDWord (biYPelsPerMeter));
bmpBuffer.put(intToDWord (biClrUsed));
bmpBuffer.put(intToDWord (biClrImportant));
}
}
测试程序完整工程在此暂不提供。
5.5集成测试
集成测试有两点需要注意,在运行程序前,需要把动态库复制到模拟器的/system/lib目录下面,还需要把需要解码的视频传到模拟器的/tmp目录下。
这里要明确的是,OPhone和Symbian的模拟器都做的太不人性化了,Symbian复制一个文件到模拟器中,要进一堆很深的目录,OPhone的
更恼火,需要敲命令把文件传递到模拟器里,说实话,仅在这点上,Mobile的模拟器做的还是非常人性化的。
命令:
- PATH=D:"OPhone"OPhone SDK"tools"
- adb.exe remount
- adb.exe push D:"Eclipse"workspace"H264Example"libs"armeabi"libH264Decode.so /system/lib
- adb.exe push D:"Eclipse"workspace"H264Example"Demo.264 /tmp
- pause
PATH=D:"OPhone"OPhone SDK"tools"
adb.exe remount
adb.exe push D:"Eclipse"workspace"H264Example"libs"armeabi"libH264Decode.so /system/lib
adb.exe push D:"Eclipse"workspace"H264Example"Demo.264 /tmp
pause
这里解释一下abd push命令:
adb push <本地文件路径> <远程文件路径> - 复制文件或者目录到模拟器
在Eclipse中,启动库测试程序,得到画面如下:
FAQ 3:
模拟器黑屏怎么办?
这可能是由于模拟器启动速度比较慢所引起的,所以需要多等一会。希望下个版本能够改进。
原文地址:http://www.ophonesdn.com/article/show/45;jsessionid=306BD3BE92F43DC693BEB09B0234B036
新浪微博:http://t.sina.com.cn/androidguy 昵称:李宁_Lining