streaming

commit b93d0c2e5b69b49940dc51d9ad13ae286366a0d8
parent 0d150658248fae47a082e21d7233c0ef8af80ff6
Author: Oliver Lowe <o@olowe.co>
Date:   Mon, 10 Jun 2024 13:06:16 +1000

mpegts: pack PID in the header correctly

While here add validation for PacketID.

Diffstat:
M
mpegts/codec.go
 | 
7
++++++-
M
mpegts/mpegts.go
 | 
4
++--

2 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/mpegts/codec.go b/mpegts/codec.go
@@ -135,7 +135,12 @@ func Encode(w io.Writer, p *Packet) error {
 	if p.Priority {
 		buf[1] |= 0x20
 	}
-	binary.BigEndian.PutUint16(buf[1:3], uint16(p.PID))
+	if p.PID > PacketNull {
+		return fmt.Errorf("packet id %s greater than max %s", p.PID, PacketNull)
+	}
+	buf[1] |= byte(p.PID >> 8)
+	buf[2] = byte(p.PID)
+
 	buf[3] |= byte(p.Scrambling)
 	if p.Adaptation != nil || p.emptyAdaptation {
 		buf[3] |= 0x20
diff --git a/mpegts/mpegts.go b/mpegts/mpegts.go
@@ -41,8 +41,8 @@ const (
 	CAT                  // Conditional access table
 	TSDT                 // Transport stream description table
 	IPMP
-	_          // reserved through to
-	PacketNull = 8191
+	_                          // reserved through to
+	PacketNull PacketID = 8191 // max 13-bit integer
 )
 
 func (id PacketID) String() string {