public void WriteFlvHead()
{
//2. Write FLV header
Bw.Write(Encoding.ASCII.GetBytes("FLV"));
//3. Write FLV version
Bw.Write((byte)1);
//4. Write FLV flags
Bw.Write((byte)5);
//5. Write FLV offset
Bw.Write(9);
//前一个tag长度,第一个tag永远是0
Bw.Write(0);
//6. Write first dummy audio
WriteFlvTag(null, 0, true);
//7. Write first dummy video
WriteFlvTag(null, 0, false);
}