在某个项目中需要在树莓派上播放广告视频，由于QT默认的QMultimedia播放视频性能堪忧（也可能没有用好！），于是想到了omxplayer这个性能一流的的播放器。
# 第1步，安装ffmpeg
###配置C++编译开发环境
~~~
$ sudo apt-get install build-essential
~~~
安装automake
~~~
$ sudo apt-get install automake1.11
~~~
如果是windows环境，还要安装yasm
~~~
$ sudo apt-get install yasm
~~~
通过git下载ffmpeg源码
~~~
$sudo git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg
~~~
生成makefile，编译
~~~
./configure
make
make install
~~~
在树莓派下默认安装是在/usr/local
头文件在/usr/local/include
库文件在/usr/local/lib
# 第2步，安装omxplayer
可通过git下载源码安装
~~~
https://github.com/popcornmix/omxplayer
~~~
也可apt-get直接安装编译好的包
~~~
$ sudo apt-get install omxplayer
~~~
现在可通过命令行输入播放视频了
~~~
$ omxplayer /home/pi/myVideo.mp4 --win '100,100,500,300'
在100,100处播放myVideo.mp4,视频大小设定为500 × 300
~~~
# 第3步，python使用dbus调用omxplayer
找到一个pytho的调用omxplayer的程序，哈哈
https://github.com/willprice/python-omxplayer-wrapper/
下载安装
~~~
$ git clone https://github.com/willprice/python-omxplayer-wrapper python-omxplayer-wrapper
~~~
确保python-dbus已经安装了
~~~
$ sudo apt-get install python-dbus
~~~
进入python-omxplayer-wrapper目录安装
~~~
$ python setup.py install
~~~
然后就是照着例子写个Hello程序吧
```
from omxplayer import OMXPlayer
from time import sleep
player = OMXPlayer('/home/pi/myVideo.mp4', args=['--win','100,100,500,300'])
player.play()
sleep(5)
player.pause()
player.quit()
```
# 第4步，使用QT调用omxplayer
在树莓派上，使用QT5.3编译
~~~
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QStringList>
#include <QtCore/QCoreApplication>
#include <QtDBus/QtDBus>
MainWindow::MainWindow(QWidget *parent):
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
QString prog = "/usr/bin/omxplayer";
QStringList args;
args <<"/home/pi/myVideo.mp4"<<"--win"<<"100,100,500,300";
QProcess *omxplayer = new QProcess();
omxplayer->startDetached(prog, args);
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::on_pushButtonPause_clicked()
{
QString prog = "/root/omxplayer/dbuscontrol.sh";
QStringList args;
args << "pause";
QProcess *pause = new QProcess();
pause->startDetached(prog,args);
}
~~~
