基于QT前端的mplayer播放器项目文档

基于QT前端的mplayer播放器项目文档V1.0一、项目概述Mplayer。它支持大量的多媒体文件格式，像常见的音频文件如mp3/wav/mid，常见的视频文件如avi/vcd/dvd/rm等等，各种视频编/解码方式也是应有尽有。我们项目的目标是在liunx下，用QT做一个MPlayer皮肤，能够实现播放器的常见功能，如：播放、停止、快进、快退、上/下一曲等。并把程序移植到ARM平台上。二、功能体验本节主要目的是让大家在学习具体实现过程前，先体验下播放器的功能。1、PC端功能体验将“项目代码工程代码”目录下的mplayer.tar.gz拷贝linux系统中（主机环境配置好以后，参照第四节的实现过程）。#tar xvfz mplayer.tar.gz#./mplayer2、目标平台功能体验l 将“项目代码工程镜像”文件夹中的zImage、rootfs.cramfs烧写到目标板（或者采用nfs方式）。分区情况为：Boot： 0 - 40000 size=0x40000Kernel：40000 240000 size=0x200000Rootfs： 240000 -3740000 size=0x3500000启动参数为：setenv root=1f02 init=/linuxrc rootfstype=cramfs console=ttySAC0,115200 display=sam240setenv bootcmd setenv bootcmd nand read 30008000 40000 200000 ; go 30008000l 启动系统后运行：#. ./Qtopia.sh#cd mymplayer#./mymplayer -qws三、实现原理先来考虑考虑如何为mplayer编写前端界面的问题。有两种思路，一种是把mplayer解剖，直接修改他里面的代码，这样我们做得界面就能够和mplayer一体了（当然也能够通过link mplayer用到的任何的库和.o文档，把他无缝的集成在程式里面）；第二种方法就是mplayer所谓的slave模式。mplayer /home/linux/1.mp3 -quiet -slave现在来探讨一下slave模式：所谓的slave模式，就是mplayer在运行过程中能够接收用户的输入命令行，具体支持哪些命令行，能够通过mplayer -input cmdlist这条命令来得到，在Mplayer源码的slave.txt中也有对这些命令有详细的讲解。Slave模式下工作的Mplayer可以和系统的标准输入、输出进行信息交互。我们可以用linux C编程来完成对slave模式工作的Mplayer进行控制和信息获取。如：mkfifo(“/tmp/fifo”,0777);可以使用popen()来打开MplayerFILE* mp;mp=popen(“mplyer /home/linux/1.mp3 -quiet slave input file=/tmp/fifo,”r”);可以通过管道/tmp/fifo给mplayer发送命令，通过mp获取mplay的返回数据如：system(“echo ”mute 0” /tmp/fifo”);/写命令fgets(buf,1000,mp);/读取mplay返回数据而Qt给我们提供了更方便的实现方法。通过定义一个QProcess对象调用已编译好的Mplayer。QProcess *process = new QProcess();process-setProcessChannelMode(QProcess:MergedChannels);Process-start(“mplayer ac mad xxxxx”);在命令中添加 -slave 和 -quiet就可以通过命令设置Mplayer实现相应的功能。在mplayer源码中的，slave.txt中对这些命令有详细的讲解。Process-start(“mplayer slave quiet ac mad xxxxx”);1、暂停功能通过如下代码可以设置Mplayer暂停。process-write(“pause ”);执行这段代码的时候如果是播放状态就会暂停，暂停状态时就会继续播放。2、获取播放文件的总时间和当前播放进度执行下面代码时，Mplayer将时间在标准输出显示。process-write(get_time_pos );process-write(get_time_length );通过如下代码即可读出我们需要的信息：connect(process,SIGNAL(readyReadStandardOutput(),this,SLOT(back_message_slots();process有可读取的信息时，发出信号，在槽函数back_message_slots()中读取信息。void MPlayer:back_message_slots()while(process-canReadLine()QString message(process-readLine();/message即为读取的信息我们可以根据需要取我们要的信息如/文件总时间为：ANS_LENGTH=23.00/当前时间为：ANS_TIME_POSITION=23.003、快进功能seek typeSeek to some place in the movie.0 is a relative seek of +/- seconds (default).1 is a seek to % in the movie.2 is a seek to an absolute position of seconds.下面代码即可实现快进功能：process-write(“seek * 1 ”);4、音量调节volume absIncrease/decrease volume or set it to if abs is nonzero.下面代码即可实现快进功能：Process-write(“volume -1 ”); /音量减小Process-write(“volume +1 ”); /音量增加5、静音功能mute valueToggle sound output muting or set it to value when value = 0(1 = on, 0 = off).下面代码即可实现快进功能：process-write(mute 0 ); /开启静音process-write(mute 1 ); /关闭静音6、定位视频窗口通过上面的代码基本功能实现了，可是播放视频的时候发现又弹出一个窗口。并没有出现在我们的窗口里。如下代码即可时间窗口的定位。QString common = mplayer -slave -quiet -ac mad -zoom movie/ + file_name + -wid + QString:number(widget-winId();process-start(common);红色部分实现窗口的定位。Widget是一个QWidget对象。通过winId可以获得一个数字，-wid既将视频输出定位到widget窗体部件中。注意：-wid参数只在X11、directX和OpenGL中适用。四、PC环境下的实现过程1、PC环境搭建主机环境：Red Hat Enterprise Linux 5.0交叉编译工具：gcc-3.4.5-glibc-2.3.6主机编译工具：gcc-4.1.2（1）主机端安装mplayerl 将“项目代码/mplay源码”目录下的MPlayer-1.0rc2.tar.bz2、libmad-0.15.1b.tar.gz（1个mp3解码库）拷贝到linux系统中，如：/home/linux/mplayer目录下l 安装libmad-0.15.1b.tar.gz#tar xvfz libmad-0.15.1b.tar.gz#cd libmad-0.15.1b#./configure#make#mkdir /lib/lib#mkdir /lib/include#cp mad.h /lib/include#cp .libs/libmad.a /lib/libl 安装mplayer#tar xvfj MPlayer-1.0.rc2.tar.bz2#cd MPlayer-1.0rc2#./configure -with-extraincdir=/lib/include -with-extralibdir=/lib/lib#make#make install此时可以试着播放一下mp3、avi等文件了# mplayer -ac mad 1.mp3# mplayer -ac mad 2.avi（2）安装、移植qtopia-4.2.0注：需要先按照5.2节将tslib按照好l 将“项目代码/qtopia源码”目录下的qtopia-opensource-src-4.2.0.tar.gz拷贝到linux系统中，如：/home/linux/Qtopia目录下# tar zxvf qtopia-opensource-src-4.2.0.tar.gz# mv qtopia-opensource-4.2.0 source# mkdir target /创建在source同级目录下创建目录target修改源码包# cd source# cd src/libraries/qtopiabase/# cp custom-linux-cassiopeia-g+.h custom-linux-arm-g+.h# cp custom-linux-cassiopeia-g+.cpp custom-linux-arm-g+.cpp修改时区信息# vi src/libraries/qtopia/qtimezone.cpp将114行的 /usr/share/zoneinfo/ 改为/Qtipia/zoneinfo/ ,保存退出。# vi src/settings/systemtime/settime.cpp将318行的 /usr/share/zoneinfo/ 改为/Qtipia/zoneinfo/ ,保存退出。l 裁减Qtopia core的库(下列操作后在屏幕上会出现一个光标，否则没有光标。根据需求配置)# vi qtopiacore/qconfig-qpe.h首先注释掉关于鼠标光标的宏定义，让程序运行时，触摸屏中央有光标出现：/ Qtopia Core/*#ifndef QT_NO_QWS_CURSOR# define QT_NO_QWS_CURSOR#endif*/*#ifndef QT_NO_QWS_MOUSE# define QT_NO_QWS_MOUSE#endif#ifndef QT_NO_QWS_MOUSE_AUTO# define QT_NO_QWS_MOUSE_AUTO#endif*/其它宏定义根据需要进行注释。保存后将qconfig-qpe.h拷贝到global目录。# cp qtopiacore/qconfig-qpe.h qtopiacore/qt/src/corelib/global/qconfig-qpe.h (必须进行的操作)注释掉其他文件里的QT_NO_QWS_CURSOR的定义# vi qtopiacore/qt/src/corelib/global/qfeatures.h注释掉如下内容：/*#if !defined(QT_NO_QWS_CURSOR) & (defined(QT_NO_CURSOR)#define QT_NO_QWS_CURSOR#endif*/保存退出。# vi qtopiacore/qt/src/corelib/global/qglobal.h注释掉以下内容：/# define QT_NO_QWS_CURSOR#vim qtopiacore/qt/tools/qvfb/qvfbshmem.cpp注释掉asm/page.h/#include #vim qtopiacore/qt/tools/qvfb/qvfbmmap.cpp注释掉asm/page.h/#include 并修改如下内容unsigned char *data;uint data_offset_value = sizeof(QVFbHeader);if (data_offset_value % PAGE_SIZE)data_offset_value += PAGE_SIZE - (data_offset_value % PAGE_SIZE);为：unsigned char *data;uint data_offset_value = sizeof(QVFbHeader);const int page_size = getpagesize();if (data_offset_value % page_size)data_offset_value += page_size - (data_offset_value % page_size);# vim src/libraries/qtopiabase/qmemoryfile_unix.cpp +128修改f = :open(tmpFile.toLatin1(), O_CREAT | O_WRONLY);为：f = :open(tmpFile.toLatin1(), O_CREAT | O_WRONLY ，0777);l 修改交叉工具#vim qtopiacore/qt/mkspecs/qws/linux-arm-g+/qmake.conf将文件中的arm-linux-*全部修改为arm-softfloat-linux-gnu-*这样做的前提是我的交叉工具链是arm-softfloat-linux-gnu，如果你的是arm-linux就不用改了。l 生成Makefile#cd ./target /为了不破坏源码，选择在此目录下配置、编译源码#./source/configure -release -image /Qtopia -prefix /Qtopia -xplatform linux-arm-g+ -arch arm -no-qvfb -displaysize 320x240 -no-modem -extra-qtopiacore-config -release -xplatform qws/linux-arm-g+ -embedded arm -qconfig qpe -depths 4,8,16,32 -qt-sql-sqlite -no-mouse-linuxtp -qt-mouse-tslib -I/home/linux/tslib/include -L/home/linux/tslib/lib 2./configureERR.txt注意：这里/Qtopia是最后Qtopia的安装路径，安装到主机的某个路径下，最终这个路径和目标板上的路径必须一致。主要配置选项说明如下：-xplatform linux-arm-g+ -arch arm目标平台为arm-linux,体系结构为arm。-no-qvfb目标平台已支持framebuffer,因而不使用虚拟帧缓冲。-extra-qtopiacore-config为Qtopia core 配置选项。-xplatform qws/linux-arm-g+ -embedded arm目标平台编译配置文件使用qtopiacore/qt/mkspecs/qws/linux-arm-g+目录下的配置文件，嵌入式平台为arm。-qconfig qpe使用配置文件qconfig-qpe.h，若使用qconfig-large.h配置文件，则使用-qconfig large选项。-qt-sql-sqlite数据库支持Sqlite。-qt-kbd-usb键盘支持usb协议。-no-mouse-linuxtp -qt-mouse-tslib-I/home/linux/tslib/include -L/home/linux/tslib/lib触摸屏协议不支持linuxtp，支持tslib，并在后面添加上刚才编译的tslib的头文件和库。2./qtopiaconfigureERR.txt最后将配置过程中的错误输出到qtopiaconfigureERR.txt文件中。l 编译#make#make installl 将安装和的目录考到nfsroot目录下#cp /Qtopia /rootfs -a（3）熟悉主机开发环境l 提供给PC端的开发工具上面的qtopia编译安装完成后，会在咱们前面创建的target目录下生成很多开发工具。先看一下供主机端使用的工具rootlocalhost bin# pwd/home/linux/Qtopia/target/qtopiacore/host/binrootlocalhost bin# lsassistant linguist lupdate qmake rcc uicdesigner lrelease moc qvfb templates uic3如果系统以前有其它qt开发工具，把环境变量修改一下，保证它们不要和我们这几个工具冲突。下面可以试一下你的designer了。#./designer2、在PC端实现基于qt前端的mplayer播放器创建工程目录/home/linux/mplayer（1）搭建ui界面利用前面安装的designer搭建ui界面，并将其保存至/home/linux/mplayer/mplayer.ui#./designer圆角矩形标注: 加了一个widget，留作mplayer的播放区（2）编写程序在/home/linux/mymplayer/下创建mplayer.cpp、mplayer.h、main.cpp 、image.qrcMain.cpp/*main.cpp*/#include #include mplayer.hint main(int argc, char *argv)QApplication app(argc, argv);MPlayer player; /实例最终的MPlayer类player.show(); /显示界面return app.exec(); /运行程序mplayer.h#ifndef _MPLAYER_H#define _MPLAYER_H#include #include #include #include #include #include #include #include ui_mplayer.hclass MPlayer:public QDialog,private Ui_DialogQ_OBJECTpublic:MPlayer(QWidget *parent = 0);public:QTime int_to_time(int);public slots: void play_pause_slots(); /暂停void stop_slots(); /停止void previous_slots(); /上一曲void next_slots(); /下一曲void seek_slots(int);void get_time_slots(); /得到播放时间void set_volume_slots(int); /设置音量void set_sound_slots(); /静音void playerReward_slots(); /快退void playerForward_slots(); /快进void back_message_slots(); /更新显示信息private:QProcess *process;QStringList files;QDir directory;int file_count;QString file_name;bool isPlay;bool isSound;bool isStop;QTimer *timer;int file_length;int curr_time;#endifmplayer.cpp/*mplayer.cpp */#include mplayer.h#include #include MPlayer:MPlayer(QWidget *parent):QDialog(parent)setupUi(this); /初始化界面isPlay = true;isSound = true;isStop = false;/*为按键添加图标*/playQIcon icon_play;icon_play.addPixmap(QPixmap(QString:fromUtf8(images/pause_enabled.png), QIcon:Normal, QIcon:Off);pushButton_2-setIcon(icon_play);/stopQIcon icon_stop;icon_stop.addPixmap(QPixmap(QString:fromUtf8(images/stop_enabled.png), QIcon:Normal, QIcon:Off);pushButton_3-setIcon(icon_stop);/rewardQIcon icon_reward;icon_reward.addPixmap(QPixmap(QString:fromUtf8(images/reward_enabled.png), QIcon:Normal, QIcon:Off);pushButton_4-setIcon(icon_reward);/forwardQIcon icon_forward;icon_forward.addPixmap(QPixmap(QString:fromUtf8(images/forward_enabled.png), QIcon:Normal, QIcon:Off);pushButton_5-setIcon(icon_forward);/soundQIcon icon_sound;icon_sound.addPixmap(QPixmap(QString:fromUtf8(images/sound_enabled.png), QIcon:Normal, QIcon:Off);pushButton-setIcon(icon_sound);QIcon icon_previous;icon_previous.addPixmap(QPixmap(QString:fromUtf8(images/previous_disabled.png), QIcon:Normal, QIcon:Off);pushButton_6-setIcon(icon_previous);QIcon icon_next;icon_next.addPixmap(QPixmap(QString:fromUtf8(images/next_enabled.png), QIcon:Normal, QIcon:Off);pushButton_7-setIcon(icon_next);/*设置按钮无边框*/pushButton-setFlat(true);pushButton_2-setFlat(true);pushButton_3-setFlat(true);pushButton_4-setFlat(true);pushButton_5-setFlat(true);pushButton_6-setFlat(true);pushButton_7-setFlat(true);/*获得播放列表*/directory.setPath(./movie);files = directory.entryList(QDir:AllEntries,QDir:Time);file_name = files2; /文件0和1为 ”.” ”.”，所以从文件2开始播放file_count = 2;label_3-setText(files2);/*初始化进度条及QProcess类*/horizontalSlider-setPageStep(1);process = new QProcess(this);process-setProcessChannelMode(QProcess:MergedChannels);/*初始化信号、槽*/connect(pushButton_2,SIGNAL(clicked(),this,SLOT(play_pause_slots();connect(pushButton_3,SIGNAL(clicked(),this,SLOT(stop_slots();connect(pushButton_4,SIGNAL(clicked(),this,SLOT(playerReward_slots();connect(pushButton_5,SIGNAL(clicked(),this,SLOT(playerForward_slots();connect(pushButton_6,SIGNAL(clicked(),this,SLOT(previous_slots();connect(pushButton_7,SIGNAL(clicked(),this,SLOT(next_slots();/connect(horizontalSlider,SIGNAL(valueChanged(int),this,SLOT(seek_slots(int);connect(spinBox,SIGNAL(valueChanged(int),this,SLOT(set_volume_slots(int);connect(pushButton,SIGNAL(clicked(),this,SLOT(set_sound_slots();connect(process,SIGNAL(readyReadStandardOutput(),this,SLOT(back_message_slots();/当process可以读到Mplayer的返回信息时，产生readyReadStandardOutput()信号/process-start(mplayer -slave -quiet -ac mad 2.avi);/add -wid QWidget-winId();QString common = mplayer -slave -quiet -ac mad -zoom movie/ + file_name + -wid + QString:number(widget-winId(); /这里的widget是ui中MPlayer的显示区process-start(common); /开始运行程序spinBox-setValue(40); timer = new QTimer(this);connect(timer,SIGNAL(timeout(),this,SLOT(get_time_slots();/定时获取MPlayer的时间信息timer-start(1000); /启动定时器 1秒timeout 1次void MPlayer:play_pause_slots()if(!isPlay)if(isStop)file_name = filesfile_count;QString common = mplayer -slave -quiet -ac mad -zoom movie/ + file_name + -wid + QString:number(widget-winId();process-start(common);QIcon icon_stop;icon_stop.addPixmap(QPixmap(QString:fromUtf8(images/stop_enabled.png), QIcon:Normal, QIcon:Off);pushButton_3-setIcon(icon_stop);isStop = false;elseprocess-write(pause );QIcon icon_play;icon_play.addPixmap(QPixmap(QString:fromUtf8(images/pause_enabled.png), QIcon:Normal, QIcon:Off);pushButton_2-setIcon(icon_play);isPlay = true;elseQIcon icon_pause;icon_pause.addPixmap(QPixmap(QString:fromUtf8(images/play_enabled.png), QIcon:Normal, QIcon:Off);pushButton_2-setIcon(icon_pause);isPlay = false;process-write(pause );void MPlayer:stop_slots()if(!isStop)process-write(quit );QIcon icon_pause;icon_pause.addPixmap(QPixmap(QString:fromUtf8(images/play_enabled.png), QIcon:Normal, QIcon:Off);pushButton_2-setIcon(icon_pause);isPlay = false;QIcon icon_stop;icon_stop.addPixmap(QPixmap(QString:fromUtf8(images/stop_disabled.png), QIcon:Normal, QIcon:Off);pushButton_3-setIcon(icon_stop);isStop = true;label-setText(00:00:00);label_2-setText(00:00:00);void MPlayer:previous_slots()if(file_count 2)if(file_count = (files.size()-1)QIcon icon_next;icon_next.addPixmap(QPixmap(QString:fromUtf8(images/next_enabled.png), QIcon:Normal, QIcon:Off);pushButton_7-setIcon(icon_next);process-write(quit );process = new QProcess(this);connect(process,SIGNAL(readyReadStandardOutput(),this,SLOT(back_message_slots();file_count-;if(!isStop)file_name = filesfile_count;QString common = mplayer -slave -quiet -ac mad -zoom movie/ + file_name + -wid + QString:number(widget-winId();process-start(common);if(file_count = 2)QIcon icon_previous;icon_previous.addPixmap(QPixmap(QString:fromUtf8(images/previous_disabled.png), QIcon:Normal, QIcon:Off);pushButton_6-setIcon(icon_previous);label_3-setText(filesfile_count);void MPlayer:next_slots()if(file_count setIcon(icon_previous);process-write(quit ); process = new QProcess(this);connect(process,SIGNAL(readyReadStandardOutput(),this,SLOT(back_message_slots();file_count+;if(!isStop)file_name = filesfile_count;QString common = mplayer -slave -quiet -ac mad -zoom movie/ + file_name + -wid + QString:number(widget-winId();process-start(common);if(file_count = (files.size()-1) QIcon icon_next;icon_next.addPixmap(QPixmap(QString:fromUtf8(images/next_disabled.png), QIcon:Normal, QIcon:Off);pushButton_7-setIcon(icon_next);label_3-setText(filesfile_count);void MPlayer:seek_slots(int seek_num)qDebug()state() = QProcess:Running )process-write(QString(seek + QString:number(qMin(seek_num,100) + 1 ).toAscii();void MPlayer:get_time_slots()if(isPlay)process-write(get_time_pos );process-write(get_time_length );void MPlayer:set_volume_slots(int volume)qDebug()write(QString(volume + + QString:number(volume) + ).toAscii();/process-write(QString(volume +1 ).toAscii();void MPlayer:set_sound_slots()if(isSound)process-write(mute 1 );QIcon icon_sound;icon_sound.addPixmap(QPixmap(QString:fromUtf8(images/nosound_enabled.png), QIcon:Normal, QIcon:Off);pushButton-setIcon(icon_sound);isSound = false;elseprocess-write(mute 0 );QIcon icon_sound;icon_sound.addPixmap(QPixmap(QString:fromUtf8(images/sound_enabled.png), QIcon:Normal, QIcon:Off);pushButton-setIcon(icon_sound);isSound = true;void MPlayer:playerReward_slots()/bool ok;/int m=moviePosition.toInt(&ok);if (process & process-state()=QProcess:Running & !isPlay)/QString cmd=seek +QString:number(qMax(m-10,0)+ 1 ;/process-write(cmd.toAscii();qDebug()setVisible(false);/bool ok;/int m=moviePosition.t