public bool TryDecode()
{
int skip = 4;
switch (adaptation_field_control)
{
case 0x0: // reserved for future use by ISO/IEC
return(false);
case 0x1: // 无调整字段，仅含有效负载
skip = 4 + payload_unit_start_indicator;
break;
case 0x2: // 仅含调整字段，无有效负载
skip = SrcBuffer.Length;
break;
case 0x3: // 调整字段后含有效负载
AdaptationField = new AdaptationInfo();
AdaptationField.SetBytes(SrcBuffer);
skip = 4 + AdaptationField.adaptation_field_length + 1;
break;
default:
break;
}
return(true);
}
public static byte[] MediaFrame2TSData(MediaFrame frame, TSProgramManage pm)
{
var msOutput = new MemoryStream();
var pes = PESPacket.MediaFrame2PES(frame);
var pes_buffer = pes.GetBytes();
var msInput = new MemoryStream(pes_buffer);
int PID = frame.nIsAudio == 1 ? 257 : 258;
bool isFirstPack = true;
do
{
var payload_unit_start_indicator = 0;
var size = (int)(msInput.Length - msInput.Position);
var max_data_len = 188 - 4;//4B为包头长度
var data_len = 0;
AdaptationInfo ai = null;
if ((isFirstPack || size < max_data_len))
{
if (isFirstPack && (frame.nIsAudio == 0 || true))
{
max_data_len = 188 - 4 - 8; //5B为包头长度 8B为adaptation长度
data_len = Math.Min(max_data_len, size);
var adaptation_field_length = 188 - 4 - data_len - 1; //1B为adaptation的头，这1B不算在adaptation_field_length中
var pcr_bas = (frame.nTimetick - pm.FirstFrameTimeTick) * 90; //这里为什么是*45我也不知道，
ai = new AdaptationInfo()
{
adaptation_field_length = (byte)adaptation_field_length,
random_access_indicator = 1,
PCR_flag = 1,
PCR_base = pcr_bas,
};
payload_unit_start_indicator = 1;
}
else
{
max_data_len = 188 - 4 - 1;//4B为包头长度 8B为adaptation长度
if (size < max_data_len)
{
data_len = Math.Min(max_data_len, size);
var adaptation_field_length = 188 - 4 - data_len - 1;
ai = new AdaptationInfo();
ai.adaptation_field_length = (byte)adaptation_field_length;
}
else
{
payload_unit_start_indicator = 0;
data_len = size;
}
}
}
else
{
data_len = max_data_len;
}
byte[] data = new byte[data_len];
msInput.Read(data, 0, data.Length);
TSPacket pack_pat = new TSPacket()
{
sync_byte = 0x47,
transport_error_indicator = 0,
payload_unit_start_indicator = (byte)payload_unit_start_indicator,//一帧第一个packet或者这个packet需要fill字节时
transport_priority = 0,
PID = (ushort)PID,
transport_scrambling_control = 0,
adaptation_field_control = (byte)(ai != null ? 3 : 1),
continuity_counter = pm.GetCounter(PID),
AdaptationField = ai,
data = data
};
var buf = pack_pat.GetBytes();
msOutput.Write(buf, 0, buf.Length);
isFirstPack = false;
} while (msInput.Position < msInput.Length);
var result = msOutput.ToArray();
return(result);
}
public void Decode()
{
//以下是整个程序的逻辑主要是以解析为主，实际应用可能要优化下方式以提高性能
var buffer = SrcBuffer;
int skip = 4;
switch (adaptation_field_control)
{
case 0x0: // reserved for future use by ISO/IEC
throw new Exception();
case 0x1: // 无调整字段，仅含有效负载
skip = 4 + payload_unit_start_indicator;
skip = 4; //
break;
case 0x2: // 仅含调整字段，无有效负载
skip = SrcBuffer.Length;
break;
case 0x3: // 调整字段后含有效负载
AdaptationField = new AdaptationInfo();
AdaptationField.SetBytes(SrcBuffer);
skip = 4 + AdaptationField.adaptation_field_length + 1;
break;
default:
break;
}
data = new byte[SrcBuffer.Length - skip];
if (data.Length > 0)
{
Array.Copy(SrcBuffer, skip, data, 0, data.Length);
}
if (PID == 0x00)
{
PacketType = TSPacketType.PAT;
var pat = new TS_PAT();
pat.SetBytes(data);
foreach (var p in pat.PATProgramList)
{
ProgramManage.AddProgram(p);
}
_pat = pat;
}
else
{
if (ProgramManage.IsPMT_PID(PID))
{
//PMT
PacketType = TSPacketType.PMT;
var pmt = new TS_PMT();
pmt.SetBytes(data);
foreach (var p in pmt.PMTStreamList)
{
ProgramManage.AddStream(p);
}
_pmt = pmt;
}
else if (ProgramManage.IsTSTable(PID))
{
PacketType = TSPacketType.OTHER;
//其他表示，这里先不作处理
}
else if (ProgramManage.IsData(PID))
{
//这里一般为 媒体数据
PacketType = TSPacketType.DATA;
}
}
}
