欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  移动技术

Android提高之MediaPlayer播放网络视频的实现方法

程序员文章站 2022-04-30 22:57:45
前面讲解了mediaplayer播放网络音频,主要介绍了mediaplayer关于网络音频的缓冲和进度条控制的方法,本文再来讲解一下mediaplayer播放网络视频的方法...

前面讲解了mediaplayer播放网络音频,主要介绍了mediaplayer关于网络音频的缓冲和进度条控制的方法,本文再来讲解一下mediaplayer播放网络视频的方法。播放网络视频比播放网络音频需要多一个surfaceview而已,在已经熟悉了mediaplayer播放网络音频之后,相信大家对本文所述的播放网络视频也能很快地掌握。

先来看看本文程序运行截图,如下所示:

Android提高之MediaPlayer播放网络视频的实现方法

本文程序的视频来自http://daily3gp.com,大家可以替换程序中的视频链接,试试其他影片。

main.xml的源码如下:

<?xml version="1.0" encoding="utf-8"?>
<framelayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_height="fill_parent" android:layout_width="fill_parent">
 <surfaceview android:id="@+id/surfaceview1"
 android:layout_height="fill_parent" android:layout_width="fill_parent"></surfaceview>
 <linearlayout android:layout_height="wrap_content"
 android:layout_width="fill_parent" android:layout_gravity="bottom"
 android:orientation="vertical">
 <linearlayout android:orientation="horizontal"
  android:layout_gravity="center_horizontal" android:layout_margintop="4.0dip"
  android:layout_height="wrap_content" android:layout_width="wrap_content">
  <button android:layout_width="wrap_content"
  android:layout_height="wrap_content" android:id="@+id/btnplayurl"
  android:text="播放网络视频"></button>
  <button android:layout_height="wrap_content" android:id="@+id/btnpause"
  android:text="暂停" android:layout_width="80dip"></button>
  <button android:layout_height="wrap_content"
  android:layout_width="80dip" android:text="停止" android:id="@+id/btnstop"></button>
 </linearlayout>
 <linearlayout android:orientation="horizontal"
  android:layout_width="fill_parent" android:layout_height="wrap_content"
  android:layout_marginbottom="20dip">
  <seekbar android:paddingright="10dip" android:layout_gravity="center_vertical"
  android:paddingleft="10dip" android:layout_weight="1.0"
  android:layout_height="wrap_content" android:layout_width="wrap_content"
  android:id="@+id/skbprogress" android:max="100"></seekbar>
 </linearlayout>
 </linearlayout>
</framelayout>

player.java是本文的核心,player.java实现了“进度条更新”、“数据缓冲”、“surfaceholder生命周期”等功能,其中“surfaceholder生命周期”是视频与音频播放的最大区别,通过surfacecreated()、surfacedestroyed()、surfacechanged()可以创建/释放某些资源。下面这个地方需要注意一下:

videowidth = mediaplayer.getvideowidth();
videoheight = mediaplayer.getvideoheight();
if (videoheight != 0 && videowidth != 0) {
 arg0.start();
}

有些视频是android播放器不能播放的,不能播放时videoheight=0,videowidth=0,以此来判断是否播放视频。

player.java源码如下:

package com.videoplayer;
import java.io.ioexception;
import java.util.timer;
import java.util.timertask;
import android.media.audiomanager;
import android.media.mediaplayer;
import android.media.mediaplayer.onbufferingupdatelistener;
import android.media.mediaplayer.oncompletionlistener;
import android.os.handler;
import android.os.message;
import android.util.log;
import android.view.surfaceholder;
import android.view.surfaceview;
import android.widget.seekbar;
public class player implements onbufferingupdatelistener,
 oncompletionlistener, mediaplayer.onpreparedlistener,
 surfaceholder.callback {
 private int videowidth;
 private int videoheight;
 public mediaplayer mediaplayer;
 private surfaceholder surfaceholder;
 private seekbar skbprogress;
 private timer mtimer=new timer();
 public player(surfaceview surfaceview,seekbar skbprogress)
 {
 this.skbprogress=skbprogress;
 surfaceholder=surfaceview.getholder();
 surfaceholder.addcallback(this);
 surfaceholder.settype(surfaceholder.surface_type_push_buffers);
 mtimer.schedule(mtimertask, 0, 1000);
 }
 /*******************************************************
 * 通过定时器和handler来更新进度条
 ******************************************************/
 timertask mtimertask = new timertask() {
 @override
 public void run() {
  if(mediaplayer==null)
  return;
  if (mediaplayer.isplaying() && skbprogress.ispressed() == false) {
  handleprogress.sendemptymessage(0);
  }
 }
 };
 handler handleprogress = new handler() {
 public void handlemessage(message msg) {
  int position = mediaplayer.getcurrentposition();
  int duration = mediaplayer.getduration();
  
  if (duration > 0) {
  long pos = skbprogress.getmax() * position / duration;
  skbprogress.setprogress((int) pos);
  }
 };
 };
 //*****************************************************
 public void play()
 {
 mediaplayer.start();
 }
 public void playurl(string videourl)
 {
 try {
  mediaplayer.reset();
  mediaplayer.setdatasource(videourl);
  mediaplayer.prepare();//prepare之后自动播放
  //mediaplayer.start();
 } catch (illegalargumentexception e) {
  // todo auto-generated catch block
  e.printstacktrace();
 } catch (illegalstateexception e) {
  // todo auto-generated catch block
  e.printstacktrace();
 } catch (ioexception e) {
  // todo auto-generated catch block
  e.printstacktrace();
 }
 }
 public void pause()
 {
 mediaplayer.pause();
 }
 public void stop()
 {
 if (mediaplayer != null) { 
  mediaplayer.stop();
      mediaplayer.release(); 
      mediaplayer = null; 
    } 
 }
 @override
 public void surfacechanged(surfaceholder arg0, int arg1, int arg2, int arg3) {
 log.e("mediaplayer", "surface changed");
 }
 @override
 public void surfacecreated(surfaceholder arg0) {
 try {
  mediaplayer = new mediaplayer();
  mediaplayer.setdisplay(surfaceholder);
  mediaplayer.setaudiostreamtype(audiomanager.stream_music);
  mediaplayer.setonbufferingupdatelistener(this);
  mediaplayer.setonpreparedlistener(this);
 } catch (exception e) {
  log.e("mediaplayer", "error", e);
 }
 log.e("mediaplayer", "surface created");
 }
 @override
 public void surfacedestroyed(surfaceholder arg0) {
 log.e("mediaplayer", "surface destroyed");
 }
 @override
 /**
 * 通过onprepared播放
 */
 public void onprepared(mediaplayer arg0) {
 videowidth = mediaplayer.getvideowidth();
 videoheight = mediaplayer.getvideoheight();
 if (videoheight != 0 && videowidth != 0) {
  arg0.start();
 }
 log.e("mediaplayer", "onprepared");
 }

 @override
 public void oncompletion(mediaplayer arg0) {
 // todo auto-generated method stub
 }
 @override
 public void onbufferingupdate(mediaplayer arg0, int bufferingprogress) {
 skbprogress.setsecondaryprogress(bufferingprogress);
 int currentprogress=skbprogress.getmax()*mediaplayer.getcurrentposition()/mediaplayer.getduration();
 log.e(currentprogress+"% play", bufferingprogress + "% buffer");
 }
}

test_videoplayer.java是主程序,负责调用player类,其中关键部分是seekbarchangeevent这个seekbar拖动的事件:seekbar的progress是0~seekbar.getmax()之内的数,而mediaplayer.seekto()的参数是0~mediaplayer.getduration()之内数,所以mediaplayer.seekto()的参数是(progress/seekbar.getmax())*mediaplayer.getduration()。

test_videoplayer.java源码如下:

package com.videoplayer;
import android.app.activity;
import android.content.pm.activityinfo;
import android.net.uri;
import android.os.bundle;
import android.util.log;
import android.view.surfaceview;
import android.view.view;
import android.view.view.onclicklistener;
import android.widget.button;
import android.widget.seekbar;
public class test_videoplayer extends activity {
 private surfaceview surfaceview;
 private button btnpause, btnplayurl, btnstop;
 private seekbar skbprogress;
 private player player;
 /** called when the activity is first created. */
 @override
 public void oncreate(bundle savedinstancestate) {
 super.oncreate(savedinstancestate);
 setcontentview(r.layout.main);
 setrequestedorientation(activityinfo.screen_orientation_landscape);
 surfaceview = (surfaceview) this.findviewbyid(r.id.surfaceview1);

 btnplayurl = (button) this.findviewbyid(r.id.btnplayurl);
 btnplayurl.setonclicklistener(new clickevent());

 btnpause = (button) this.findviewbyid(r.id.btnpause);
 btnpause.setonclicklistener(new clickevent());

 btnstop = (button) this.findviewbyid(r.id.btnstop);
 btnstop.setonclicklistener(new clickevent());

 skbprogress = (seekbar) this.findviewbyid(r.id.skbprogress);
 skbprogress.setonseekbarchangelistener(new seekbarchangeevent());
 player = new player(surfaceview, skbprogress);
 }
 class clickevent implements onclicklistener {
 @override
 public void onclick(view arg0) {
  if (arg0 == btnpause) {
  player.pause();
  } else if (arg0 == btnplayurl) {
  string url="http://daily3gp.com/vids/family_guy_penis_car.3gp";
  player.playurl(url);
  } else if (arg0 == btnstop) {
  player.stop();
  }
 }
 }
 class seekbarchangeevent implements seekbar.onseekbarchangelistener {
 int progress;
 @override
 public void onprogresschanged(seekbar seekbar, int progress,
  boolean fromuser) {
  // 原本是(progress/seekbar.getmax())*player.mediaplayer.getduration()
  this.progress = progress * player.mediaplayer.getduration()
   / seekbar.getmax();
 }
 @override
 public void onstarttrackingtouch(seekbar seekbar) {

 }
 @override
 public void onstoptrackingtouch(seekbar seekbar) {
  // seekto()的参数是相对与影片时间的数字,而不是与seekbar.getmax()相对的数字
  player.mediaplayer.seekto(progress);
 }
 }
}

感兴趣的读者可以自己动手测试一下本文实例代码,相信对大家进行android程序开发有一定的借鉴作用。