採用live555 轉發音視頻複合流

  live555是採用c++寫的輕量級流媒體庫，我這裏僅採用此庫處理RTSP請求，發送音視頻流在庫外部做。

視頻RTP組包代碼

u_int8_t frame_header[4];

	if (m_init == 0) {
		srandom(time(NULL));
		m_seq_no = (u_int16_t)random();
		m_ssrc = (u_int32_t)random();

		m_init = 1;
	}

		int data_len = 0;

        frame_header[0] = '$';
        frame_header[1] = 0;
        frame_header[2] = (u_int8_t)(((segm_len + 12) & 0xFF00) >> 8);
        frame_header[3] = (u_int8_t)((segm_len + 12) & 0xFF);

        memcpy(pData, frame_header, 4);
        data_len += 4;

        u_int32_t n_rtp_header;
        u_int32_t rtp_header = 0x80000000;
		if (streamHead.nStreamDataLen<1444)
		{
		    rtp_header |= (224 << 16);       // marker  1
		}
		else
		{
		   rtp_header |= (96 << 16); 
		}
        
        rtp_header |= m_seq_no;

        n_rtp_header = htonl(rtp_header);
        memcpy(pData + data_len, &n_rtp_header, 4);
        data_len += 4;

        u_int32_t n_send_time;
        u_int32_t send_time = 90000 * pack_tv.tv_sec;
        send_time += (u_int32_t)(90000 * (pack_tv.tv_usec / 1000000.0) + 0.5);
        n_send_time = htonl(send_time);
        memcpy(pData + data_len, &n_send_time, 4);
        data_len += 4;

        u_int32_t n_ssrc;
        n_ssrc = htonl(m_ssrc);
        memcpy(pData + data_len, &n_ssrc, 4);
        data_len += 4;  
		if (65535==m_seq_no)
		{
		    m_seq_no=0;
		}
		else
		{
		    m_seq_no++;
		}		

音頻 RTP 組包 

pData[0] = '$';
	pData[1] = 2;
	pData[2] = (u_int8_t)(((streamHead.nStreamDataLen+ 12) & 0xFF00) >> 8);
	pData[3] = (u_int8_t)((streamHead.nStreamDataLen + 12) & 0xFF);	

	
    RTP_FIXED_HEADER* rtp_hdr =(RTP_FIXED_HEADER*)&pData[4]; 
	memset(rtp_hdr,0,sizeof(RTP_FIXED_HEADER));           // this is very important
	rtp_hdr->payload     = 0;  
	rtp_hdr->version     = 2;  
	rtp_hdr->extension   = 0;

    rtp_hdr->marker    = 1; 
    rtp_hdr->ssrc        = htonl(10);  // it's unique in a rtp session,  set 10 here   
	if (65535==m_audioSeqNum)
	{
	    rtp_hdr->seq_no = htons(m_audioSeqNum);
		m_audioSeqNum=0;
	}
	else
	{
	    rtp_hdr->seq_no = htons(m_audioSeqNum ++);
	}     

	

	m_audioTsCurrent= m_audioTsCurrent+m_audioTimestamp_increse;
	
    rtp_hdr->timestamp=htonl(m_audioTsCurrent);