Android下通過Mediarecorder擷取H.263視訊框架並通過RTP簡單發送

功能如題。參考了此文：

http://blog.csdn.net/zblue78/article/details/6083374

 

本人覺得上文中的代碼還有些bug，而且不是針對H.263，所以自己編寫了一個。本工程除了截取H263視訊框架外的代碼仍不完善，待以後有時間的時候繼續修改。還有就是代碼中實現了RTP的包頭編寫，但payload部分並不是按照RFC2190來組織，少了一個payload header的實現。

 

完整的Android工程在此下載：

http://download.csdn.net/detail/qwertyuj/3865413

 

下面是實現視訊框架截取的主要代碼：

    public void run() {          final int READ_SIZE = 1024;//bytes count for every reading from 'inputStreamForReceive'        final int BUFFER_SIZE_RECEIVE = READ_SIZE * 128;        final int BUFFER_SIZE_RTP = READ_SIZE * 20;        stateMachineOfFrameReceiving STM_Recv = stateMachineOfFrameReceiving.FRAMEHEAD_NOTFOUND;        int i;        byte[] PSC_checkArr = new byte[3];        byte[] RTP_pocket_buffer = new byte[BUFFER_SIZE_RTP];        byte[] bufferForReceive = new byte[BUFFER_SIZE_RECEIVE]; //64K        int num = 0;          InputStream inputStreamForReceive = null;        //udp        final int RTP_PORT_SENDING = 8000;        final int RTP_PORT_DEST = 8000;        DatagramSocket socketSendRPT = null;        DatagramPacket RtpPocket = null;        InetAddress PC_IpAddress = null;        try {         PC_IpAddress = InetAddress.getByName("192.168.1.100");        }         catch (UnknownHostException e){        e.printStackTrace();        }                 try{        socketSendRPT = new DatagramSocket(RTP_PORT_SENDING);        }        catch (SocketException e){        e.printStackTrace();        }                       //get the data stream from mediaRecorder        try {              inputStreamForReceive = receiver.getInputStream();        } catch (IOException e1) {              return;          }                 //create a media file to store captured video data        try {              File file = new File("/sdcard/stream02.h263");              Log.d(TAG, "File created!");             if (file.exists())                  file.delete();//delete old file            raf = new RandomAccessFile(file, "rw");          } catch (Exception ex) {              Log.v("System.out", ex.toString());          }                        int offsetInBufferForReceive = 0;         m_timer.schedule(m_timerTask, 1000, 1000);//timer for statistics               STM_Recv = stateMachineOfFrameReceiving.FRAMEHEAD_NOTFOUND;         PSC_checkArr[0] = (byte)0xFF;PSC_checkArr[1] = (byte)0xFF;PSC_checkArr[2] = (byte)0xFF;         while (true && !threadCanStop) {         //1. read data from receive stream until to the end         offsetInBufferForReceive = 0;        do {              try {                  num = inputStreamForReceive.read(bufferForReceive, offsetInBufferForReceive, READ_SIZE);//copy data to buffer                if(num < 0){// there's nothing in there                //wait for a while        try {              Thread.currentThread().sleep(5);         } catch (InterruptedException e1) {          e1.printStackTrace();          }        break;                }                                offsetInBufferForReceive += num; //offsetInBufferForReceive points to next position can be wrote                if (num < READ_SIZE || offsetInBufferForReceive == BUFFER_SIZE_RECEIVE) {  //indicating the end of this reading                    break;   // or bufferForReceive is full                }              } catch (IOException e) {                  break;              }          }while(false);//do                //2. find Picture Start Code (PSC) (22 bits) in bufferForReceive        for(i=0; i< offsetInBufferForReceive; i++){        PSC_checkArr[0] = PSC_checkArr[1];        PSC_checkArr[1] = PSC_checkArr[2];        PSC_checkArr[2] = bufferForReceive[i];                //see if got the PSC        if(PSC_checkArr[0] == 0 && PSC_checkArr[1] == 0 && (PSC_checkArr[2] & (byte)0xFC) == (byte)0x80)        {        //found the PSC        if(STM_Recv == stateMachineOfFrameReceiving.FRAMEHEAD_NOTFOUND)        {        STM_Recv = stateMachineOfFrameReceiving.FRAMEHEAD_FOUND;        //copy current byte to packet buffer        intializeRTP_PocketBuffer(RTP_pocket_buffer);        RTP_pocket_buffer[offsetInRTP_pocket_buffer] = bufferForReceive[i];        offsetInRTP_pocket_buffer++;        }        else if(STM_Recv == stateMachineOfFrameReceiving.FRAMEHEAD_FOUND)        {        //delete two zeros in the end of the buffer        offsetInRTP_pocket_buffer -= 2;        //TODO:3. send the packet, and reset the buffer        RtpPocket = new DatagramPacket(RTP_pocket_buffer, offsetInRTP_pocket_buffer, PC_IpAddress, RTP_PORT_DEST);          try {        socketSendRPT.send(RtpPocket);        Log.v(TAG, "Sent bytes: " + String.valueOf(offsetInRTP_pocket_buffer));          } catch (IOException e) {        e.printStackTrace();}                /*        try {         raf.write(RTP_pocket_buffer, 0, offsetInRTP_pocket_buffer);          //raf.close();        } catch (IOException e1) {              e1.printStackTrace();          }        */                intCapturedFrameCount++;//for statistics        //copy current byte to packet buffer        intializeRTP_PocketBuffer(RTP_pocket_buffer);        RTP_pocket_buffer[offsetInRTP_pocket_buffer] = bufferForReceive[i];        offsetInRTP_pocket_buffer++;                }        }        else//if NOT got the PSC        {        if(STM_Recv == stateMachineOfFrameReceiving.FRAMEHEAD_NOTFOUND)        {        continue;        }        else if(STM_Recv == stateMachineOfFrameReceiving.FRAMEHEAD_FOUND)        {        //copy current byte to packet buffer        RTP_pocket_buffer[offsetInRTP_pocket_buffer] = bufferForReceive[i];        offsetInRTP_pocket_buffer++;        }        }//if(PSC_checkArr[0] == 0 && PSC_checkArr[1] == 0 && (PSC_checkArr[2] & (byte)0xFC) == (byte)0x80)                //4. if RTP_pocket_buffer is full then discard all the bytes in it        if(offsetInRTP_pocket_buffer >= BUFFER_SIZE_RTP)        {        STM_Recv = stateMachineOfFrameReceiving.FRAMEHEAD_NOTFOUND;        offsetInRTP_pocket_buffer = 0;        }                }//for(i=0; i< offsetInBufferForReceive; i++)                        }// while (true && !threadCanStop)                  m_timer.cancel();                releaseMediaRecorder();            }  })