采集rtsp流摄像头到浏览器实时播放方案

本文旨在实现使用摄像头采集视频，并且可以在网页实时显示，主要参考的两篇博文为： 
1.  视频实时显示的三种方案  
2.  使用WebSockets进行HTML5视频直播  
我们使用博文1介绍的第三种方案，将摄像头采集到的视频流使用ffmpeg进行编码，并且将其推送给远程服务器，在远程服务器使用stream-server.js处理视频流并且在网页上显示出来。由于原博文介绍详尽，本处不再赘述。 
注意 ： 
1. 客户端电脑中需要预先安装ffmpeg，安装方案谷歌即可。 

2. 博文1中第三种方案安装nodejs过程中sudo apt-get install node-legacy 应该改为sudo apt-get install nodejs-legacy。

最近在做一个流媒体的项目，项目中需要采集摄像头的视频流到网页界面实时播放，一般ip摄像头的流格式都是rtsp的，虽然可以通过vlc实时播放，但是不如浏览器观看给用户的体验简单。

根据查找的资料和实际的实践，目前发现的切实可行的方案有以下几种（因为项目是采用java开发，因此下面的代码也主要使用java实现）：

1. 使用xuggle库直接解码rtsp流，将解码的一帧帧图片发送给浏览器，使用html5的video播放mjpeg格式，即图片的不断刷新；

2. 使用xuggle库直接解码rtsp流，解码结果直接发送给rtmp服务器，然后浏览器使用flash直接播放rtmp的视频流；

3. ffmpeg直接解码rtsp流，将解码结果使用http发送到nodejs服务器，nodejs服务器使用websocket发送给客户端，客户端使用canvas实时绘制图像；

下面详细介绍这几种方案。

FFmpeg和Xuggle的简介

FFmpeg是一个自由软件，可以运行音频和视频多种格式的录影、转换、流功能，包含了libavcodec——这是一个用于多个项目中音频和视频的解码器库，以及libavformat——一个音频与视频格式转换库。
FFmpeg的安装请参考：ubuntu上安装ffmpeg

xuggle官网是一个开源的资源库，能够让开发者更好的去对视频和音频文件进行解码、编码、以及录制等功能。xuggle是对ffmepg的封装，是一套基于ffmpeg的开发库。 使用非常方便。 在java中使用时，请在eclipse中导入其jar包。 xuggle-5.4-jar包下载

方案一的具体实现

xuggle读取rtsp摄像头的代码如下：
import包如下：

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import com . xuggle . mediatool . IMediaReader ; import com . xuggle . mediatool . MediaListenerAdapter ; import com . xuggle . mediatool . ToolFactory ; import com . xuggle . mediatool . event . IVideoPictureEvent ;

其中：streamLocation是需要读取的rtsp地址

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mediaReader = ToolFactory . makeReader ( streamLocation ) ; mediaReader . setBufferedImageTypeToGenerate ( BufferedImage . TYPE_3BYTE _BGR） ; mediaReader . addListener ( this ) ; while ( mediaReader . readPacket ( ) == null && running ) ; mediaReader . close ( ) ;

上面这段代码实现了rtsp的持续读取，那么读取到的数据怎么获取，很简单，实现以下的帧回调函数onVideoPicture即可。

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/** * Gets called when FFMPEG transcoded a frame */ public void onVideoPicture ( IVideoPictureEvent event ) {      BufferedImage frame = event . getImage ( ) ;      //stream是用户自定义的rtsp视频流的id，例如;streamId = this.hashcode()即可      images . put ( streamId , frame ) ;      frameNr ++ ; }

以上的images是使用guava库的Cache建立的代码如下：

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import com . google . common . cache . Cache ; import com . google . common . cache . CacheBuilder ;   private static Cache < String , BufferedImage > images = null ;

使用html5 video标签+javax.ws.rs实现的网页显示代码如下：

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import java . awt . image . BufferedImage ; import java . io . ByteArrayOutputStream ; import java . io . IOException ; import java . io . OutputStream ; import java . util . HashSet ; import java . util . Set ;   import javax . imageio . ImageIO ; import javax . ws . rs . DefaultValue ; import javax . ws . rs . GET ; import javax . ws . rs . Path ; import javax . ws . rs . PathParam ; import javax . ws . rs . Produces ; import javax . ws . rs . QueryParam ; import javax . ws . rs . WebApplicationException ; import javax . ws . rs . core . Application ; import javax . ws . rs . core . Response ; import javax . ws . rs . core . StreamingOutput ;   import org . slf4j . Logger ; import org . slf4j . LoggerFactory ;   import com . google . common . cache . Cache ; import com . sun . jersey . api . container . httpserver . HttpServerFactory ; import com . sun . jersey . api . core . ApplicationAdapter ; import com . sun . net . httpserver . HttpServer ;   /** * A simple webservice used to view results MJPEG streams. * The webservice supports a number of calls different calls: * * http://IP:PORT/streaming/streams : lists the available JPG and MJPEG urls * * http://IP:PORT/streaming/picture/{streamid}.jpg : url to grab jpg * pictures * http://IP:PORT/streaming/tiles : provides a visual overview of all the * streams available at this service. Clicking an image will open the mjpeg * stream * http://IP:PORT/streaming/mjpeg/{streamid}.mjpeg : provides a possibly * never ending mjpeg formatted stream * * * The service runs on port 8558 by default but this can be changed by using the * port(int) method. * * @author Corne Versloot * */   @ Path ( "/streaming" ) public class MjpegStreamingOp extends Application {        private static Cache < String , BufferedImage > images = null ;      private Logger logger = LoggerFactory . getLogger ( getClass ( ) ) ;      private HttpServer server ;      private int port = 8558 ;      private int frameRate = 20 ;    // this parameter decide the sleep time        public MjpegStreamingOp port ( int nr ) {          this . port = nr ;          return this ;      }        public MjpegStreamingOp framerate ( int nr ) {          this . frameRate = nr ;          return this ;      }        public void prepare ( ) throws IllegalArgumentException , IOException {          //此处需要修改为从rtsp读进来的images存放的类          images = TCPClient . getImages ( ) ;          ApplicationAdapter connector = new ApplicationAdapter (                  new MjpegStreamingOp ( ) ) ;          server = HttpServerFactory . create ( "http://localhost:" + port + "/" ,                  connector ) ;          server . start ( ) ;      }        /**      * Sets the classes to be used as resources for this application      */      public Set < Class >> getClasses ( ) {          Set < Class > > s = new HashSet < Class < ? >> ( ) ;          s . add ( MjpegStreamingOp . class ) ;          return s ;      }        public void deactivate ( ) {          server . stop ( 0 ) ;          images . invalidateAll ( ) ;          images . cleanUp ( ) ;      }        @ GET      @ Path ( "/streams" )      @ Produces ( "text/plain" )      public String getStreamIds ( ) throws IOException {          String result = new String ( ) ;          for ( String id : images . asMap ( ) . keySet ( ) ) {              result += "/streaming/picture/" + id + ".jpeg\r\n" ;          }          System . out . println ( "\r\n" ) ;          for ( String id : images . asMap ( ) . keySet ( ) ) {              result += "/streaming/mjpeg/" + id + ".mjpeg\r\n" ;          }          return result ;      }        @ GET      @ Path ( "/picture/{streamid}.jpeg" )      @ Produces ( "image/jpg" )      public Response jpeg ( @ PathParam ( "streamid" ) final String streamId ) {          BufferedImage image = null ;          if ( ( image = images . getIfPresent ( streamId ) ) != null ) {              ByteArrayOutputStream baos = new ByteArrayOutputStream ( ) ;              try {                  ImageIO . write ( image , "jpg" , baos ) ;                  byte [ ] imageData = baos . toByteArray ( ) ;                  return Response . ok ( imageData ) . build ( ) ; // non streaming                  // return Response.ok(new                  // ByteArrayInputStream(imageDAta)).build(); // streaming              } catch ( IOException ioe ) {                  logger . warn ( "Unable to write image to output" , ioe ) ;                  return Response . serverError ( ) . build ( ) ;              }          } else {              return Response . noContent ( ) . build ( ) ;          }      }        @ GET      @ Path ( "/playmultiple" )      @ Produces ( "text/html" )      public String showPlayers ( @ DefaultValue ( "3" ) @ QueryParam ( "cols" ) int cols ,              @ DefaultValue ( "0" ) @ QueryParam ( "offset" ) int offset ,              @ DefaultValue ( "6" ) @ QueryParam ( "number" ) int number )              throws IOException {          // number = Math.min(6, number);          String result = "" ;          result += "Streams: " + images . size ( )                  + " (showing " + offset + " - "                  + Math . min ( images . size ( ) , offset + number ) + ") " ;          result += "                    border-collapse: collapse;\"> ";          int videoNr = 0 ;          for ( String id : images . asMap ( ) . keySet ( ) ) {              if ( videoNr < offset ) {                  videoNr ++ ;                  continue ;              }              if ( videoNr - offset > 0 && ( videoNr - offset ) % cols == 0 ) {                  result += " ";              }              result += " ";              // result +=              // " ";              if ( videoNr > offset + number )                  break ;              videoNr ++ ;          }          result += "                              + ":" + port + "/streaming/mjpeg/" + id + ".mjpeg\"> " ;          return result ;      }        @ GET      @ Path ( "/play" )      @ Produces ( "text/html" )      public String showPlayers ( @ QueryParam ( "streamid" ) String streamId )              throws IOException {          String result = "" ;          result += "Back " ;          result += "";          result += "                  + "Your browser does not support the video tag." ;          return result ;      }        @ GET      @ Path ( "/tiles" )      @ Produces ( "text/html" )      public String showTiles ( @ DefaultValue ( "3" ) @ QueryParam ( "cols" ) int cols ,              @ DefaultValue ( "-1" ) @ QueryParam ( "width" ) float width )              throws IOException {          String result = "" ;          result += "" ;            result += " ";          int videoNr = 0 ;          for ( String id : images . asMap ( ) . keySet ( ) ) {              if ( videoNr > 0 && videoNr % cols == 0 ) {                  result += " ";              }              result += " + id                      + "\"> + id + ".jpeg\" "                      + ( width > 0 ? "width=\"" + width + "\"" : "" ) + "/>" ;              videoNr ++ ;          }          result += " " ;          return result ;      }        @ GET      @ Path ( "/mjpeg/{streamid}.mjpeg" )      @ Produces ( "multipart/x-mixed-replace; boundary=--BoundaryString\r\n" )      public Response mjpeg ( @ PathParam ( "streamid" ) final String streamId ) {          StreamingOutput output = new StreamingOutput ( ) {              private BufferedImage prevImage = null ;              private int sleep = 1000 / frameRate ;                @ Override              public void write ( OutputStream outputStream ) throws IOException ,                      WebApplicationException {                  BufferedImage image = null ;                  try {                      while ( ( image = images . getIfPresent ( streamId ) ) != null )                          if ( prevImage == null || ! image . equals ( prevImage ) ) {                              ByteArrayOutputStream baos = new ByteArrayOutputStream ( ) ;                              ImageIO . write ( image , "jpg" , baos ) ;                              byte [ ] imageData = baos . toByteArray ( ) ;                              outputStream                                      . write ( ( "--BoundaryString\r\n"                                              + "Content-type: image/jpeg\r\n"                                              + "Content-Length: "                                              + imageData . length + "\r\n\r\n" )                                              . getBytes ( ) ) ;                              outputStream . write ( imageData ) ;                              outputStream . write ( "\r\n\r\n" . getBytes ( ) ) ;                              outputStream . flush ( ) ;                          }                          Thread . sleep ( sleep ) ;                      }                      outputStream . flush ( ) ;                      outputStream . close ( ) ;                  } catch ( IOException ioe ) {                      logger . info ( "Steam for [" + streamId                              + "] closed by client!" ) ;                  } catch ( InterruptedException e ) {                      e . printStackTrace ( ) ;                  }              }          } ;          return Response . ok ( output ) . header ( "Connection" , "close" )                  . header ( "Max-Age" , "0" ) . header ( "Expires" , "0" )                  . header ( "Cache-Control" , "no-cache, private" )                  . header ( "Pragma" , "no-cache" ) . build ( ) ;      } }

以上代码参考自github上stormcv项目，项目地址为：https://github.com/sensorstorm/StormCV, 感谢原作者。

至此，打开网页 http://localhost:8558/streaming/tiles 即可查看到实时视频。

方案二的具体实现

xuggle库转rtsp为rtmp

rtsp的reader：

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import org . slf4j . Logger ; import org . slf4j . LoggerFactory ; import com . xuggle . mediatool . IMediaReader ; import com . xuggle . mediatool . MediaListenerAdapter ; import com . xuggle . mediatool . ToolFactory ; import com . xuggle . mediatool . event . IVideoPictureEvent ; import com . xuggle . xuggler . ICodec ; import com . xuggle . xuggler . IContainer ; import com . xuggle . xuggler . IVideoPicture ;   /** * This class reads a video stream or file, decodes frames and transcode to rtmp stream * @author jkyan */ public class RTSPReader extends MediaListenerAdapter implements Runnable {      private Logger logger = LoggerFactory . getLogger ( RTSPReader . class ) ;      private IMediaReader mediaReader ;      private int frameSkip ;      private int groupSize ;      private long frameNr ; // number of the frame read so far      private boolean running = false ;      // used to determine if the EOF was reached if Xuggler does not detect it      private long lastRead = - 1 ;      private int sleepTime = 0 ;        private String streamName ;      private String streamLocation = null ;      private RTMPWriter rtmpWriter = null ;      Double frameRate = 0.0 ;        // frameskip和groupsize决定了需要读取的帧的数目，即采样率，      // 例如，1,1时代表每一帧都需要读取，10,5时代表只需要[0 1 2 3 4] [10 11 12 13 14] ...      public RTSPReader ( String streamName , String streamLocation ,          int frameSkip , int groupSize , int sleepTime ) {          this . streamLocation = streamLocation ;          this . frameSkip = Math . max ( 1 , frameSkip ) ;          this . groupSize = Math . max ( 1 , groupSize ) ;          this . sleepTime = sleepTime ;          this . streamName = streamName ;          lastRead = System . currentTimeMillis ( ) + 10000 ;      }        /**      * Start reading the provided URL      */      public void run ( ) {          running = true ;          while ( running ) {              try {                  // if a url was provided read it                  if ( streamLocation != null ) {                      logger . info ( "Start reading stream: " + streamLocation ) ;                      mediaReader = ToolFactory . makeReader ( streamLocation ) ;                      lastRead = System . currentTimeMillis ( ) + 10000 ;                      frameNr = 0 ;                      rtmpWriter = new RTMPWriter ( 576 , 704 , 30.0 , streamName ) ;                      mediaReader . addListener ( this ) ;                      while ( mediaReader . readPacket ( ) == null && running ) ;                      // reset internal state                      rtmpWriter . setFinish ( ) ;                      mediaReader . close ( ) ;                  } else {                      logger . error ( "No stream provided, nothing to read" ) ;                      break ;                  }              } catch ( Exception e ) {                  logger . warn ( "Stream closed unexpectatly: " + e . getMessage ( ) , e ) ;                  // sleep a minute and try to read the stream again                  sleep ( 60 * 1000 ) ;              }          }          running = false ;