psi: added a std template PSI struct for pmt with time and gps descriptors to make things easier

stream/mts/psi/std.go

@@ -26,8 +26,9 @@ LICENSE
 
 package psi
 
-// Std PSI in struct form without descriptor
+// Some common manifestations of PSI
 var (
+	// PSI struct to represent basic pat
 	stdPat = PSI{
 		Pf:  0x00,
 		Tid: 0x00,
@@ -47,6 +48,7 @@ var (
 		},
 	}
 
+	// PSI struct to represent basic pmt without descriptors for time and gps
 	stdPmt = PSI{
 		Pf:  0x00,
 		Tid: 0x02,
@@ -69,6 +71,42 @@ var (
 			},
 		},
 	}
+
+	// Std pmt with time and gps descriptors, time and gps fields are zerod out
+	stdPmtTimeGps = PSI{
+		Pf:  0x00,
+		Tid: 0x02,
+		Ssi: true,
+		Sl:  uint16(0x12),
+		Tss: &TSS{
+			Tide: uint16(0x01),
+			V:    0,
+			Cni:  true,
+			Sn:   0,
+			Lsn:  0,
+			Sd: &PMT{
+				Pcrpid: 0x0100, // wrong
+				Pil:    10,
+				Pd: []Desc{
+					Desc{
+						Dt: byte(timeDescTag),
+						Dl: byte(timeDataSize),
+						Dd: make([]byte, timeDataSize),
+					},
+					Desc{
+						Dt: byte(gpsDescTag),
+						Dl: byte(gpsDataSize),
+						Dd: make([]byte, gpsDataSize),
+					},
+				},
+				Essd: &ESSD{
+					St:   0x1b,
+					Epid: 0x0100,
+					Esil: 0x00,
+				},
+			},
+		},
+	}
 )
 
 // Std PSI in bytes form