如何用IPbulishProvider API发布直播流?
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IPublishingProvider API是一个底层的流发布接口,它可以在直播源中混合入VOD的点播文件。Stream类是它的上层API. 这个底层的API没有提供节目编排表和播放列表功能。www.wowza.cn 它只提供了最基本的流发布能力。

下面是一个例子,它利用这个API创建到了一个名字为publishstream的流,并将其发布到live应用。 这个类在后台启动了一个线程,每隔10秒钟在VOD文件sample.mp4的片段和直播流myStream之间切换直播流的信号源。

package com.wowza.wms.plugin.test.integration;

import com.wowza.wms.stream.publish.*;
import com.wowza.wms.vhost.*;
import com.wowza.wms.logging.*;

public class ServerPublisherWorker extends Thread
{
	private long sleepTime = 75;
	private boolean running = true;
	private Object lock = new Object();
	
	private String applicationName = "live";
	private String vodStreamName = "mp4:sample.mp4";
	private String liveStreamName = "myStream";
	private String publishStreamName = "publishstream";
	private int cycleTime = 10000;
	
	public synchronized void quit()
	{
		synchronized(lock)
		{
			running = false;
		}
	}

	public void run()
	{
		WMSLoggerFactory.getLogger(ServerPublisherWorker.class).info("ServerPublisherWorker.run: START");

		long startTime = System.currentTimeMillis();
		long playStartTime = startTime;

		try
		{
			IVHost vhost = VHostSingleton.getInstance(VHost.VHOST_DEFAULT);
			Publisher publisher = Publisher.createInstance(vhost, applicationName);
			
			publisher.publish(publishStreamName);

			long nextSwitch = playStartTime + cycleTime;
			long nextType = 0;
			IPublishingProvider provider = new PublishingProviderMediaReader(publisher, playStartTime, vodStreamName);
			//provider.seek(20000);
			provider.setRealTimeStartTime(startTime);

			WMSLoggerFactory.getLogger(ServerPublisherWorker.class).info("ServerPublisherWorker.run: Start with vod stream: "+vodStreamName);
			
			while(true)
			{
				boolean moreInFile = provider!=null?provider.play(publisher):false;
				
				long currentTime = System.currentTimeMillis();
				if (!moreInFile || currentTime > nextSwitch)
				{
					if (provider != null)
						provider.close();
					provider = null;
					
					if ((nextType % 2) == 0)
					{
						provider = new PublishingProviderLive(publisher, publisher.getMaxTimecode(), liveStreamName);
						//((PublishingProviderLive)provider).setStartOnPreviousKeyFrame(false);
						provider.setRealTimeStartTime(currentTime);

						WMSLoggerFactory.getLogger(ServerPublisherWorker.class).info("ServerPublisherWorker.run: Switch to live stream: "+liveStreamName);
					}
					else
					{
						provider = new PublishingProviderMediaReader(publisher, publisher.getMaxTimecode(), vodStreamName);
						//provider.seek(20000);
						provider.setRealTimeStartTime(currentTime);

						WMSLoggerFactory.getLogger(ServerPublisherWorker.class).info("ServerPublisherWorker.run: Switch to vod stream: "+vodStreamName);
					}
					
					nextSwitch = currentTime + cycleTime;
					nextType++;
					
					if (nextType == 100)
						break;
				}
				else
					sleep(sleepTime);
				
				synchronized(lock)
				{
					if (!running)
						break;
				}
			}
			
			provider.close();
			
			publisher.publish(null);
			
			synchronized(lock)
			{
				running = false;
			}
		}
		catch (Exception e)
		{
			WMSLoggerFactory.getLogger(ServerPublisherWorker.class).error("ServerPublisherWorker.run: "+e.toString());
			e.printStackTrace();
		}
		
		WMSLoggerFactory.getLogger(ServerPublisherWorker.class).info("ServerPublisherWorker.run: STOP");
	}
}
www.wowza.cn
To see this example in action, create a server side listener that is invoked on server startup and stopped on server shutdown. Here is an example:

package com.wowza.wms.plugin.test.integration;

import com.wowza.wms.server.*;

public class ServerPublisherServerListener implements IServerNotify
{
	ServerPublisherWorker worker = null;
	
	public void onServerCreate(IServer server)
	{
	}

	public void onServerInit(IServer server)
	{
		worker = new ServerPublisherWorker();
		worker.start();
	}

	public void onServerShutdownComplete(IServer server)
	{
	}

	public void onServerShutdownStart(IServer server)
	{
		if (worker != null)
			worker.quit();
		worker = null;
	}

}
之后,将这个server listener 添加到[install-dir]/conf/Server.xml文件的<ServerListeners>列表中:

<ServerListener>
	<BaseClass>com.wowza.wms.plugin.test.integration.ServerPublisherServerListener</BaseClass>
</ServerListener>
在启动后,发布一个名为myStream的直播流到live应用中。 www.wowza.cn 开始测试后,你可以播放名为publishstream的直播流,你将会看到每隔10秒钟直播流都会发生一次变化,它会在点播文件和直播信号之间做切换。