/
NetInput.go
87 lines (77 loc) · 1.69 KB
/
NetInput.go
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package main
import (
"log"
"net"
)
type NetInput struct {
addr net.UDPAddr
conn *net.UDPConn
TsNode
}
//register with global AvailableNodes map
func init() {
AvailableNodes.Register("NetInput", NewNetInput)
}
func NewNetInput(address string, port int) (*NetInput, error) {
var err error
var conn *net.UDPConn
n := &NetInput{}
n.addr = net.UDPAddr{
Port: port,
IP: net.ParseIP(address),
}
n.input = nil
// the stream may be unicast or multicast, so choose appropriately
if n.addr.IP.IsMulticast() {
conn, err = net.ListenMulticastUDP("udp", nil, &n.addr)
} else {
conn, err = net.ListenUDP("udp", &n.addr)
}
if err != nil {
conn.Close()
return nil, err
}
n.conn = conn
go n.process()
return n, nil
}
func (node *NetInput) process() {
defer node.closeDown()
var packetsize int
packet := make([]byte, 4096)
for {
m := 0
n, _, err := node.conn.ReadFromUDP(packet)
if err != nil {
log.Printf("TS capture error: %s", err)
continue
}
// log.Printf("got %d bytes", n)
if (packet[0] & 192) == 128 {
// this is RTP, skip the header
m += 12 + (4 * (int(packet[0]) & 15))
}
// check packetsize (188/204)
if ((n - m) % 188) == 0 {
packetsize = 188
} else if ((n - m) % 204) == 0 {
// 204 bytes pkts
packetsize = 204
} else {
panic("Unknown TS packet size!!")
}
// log.Printf("packetsize is %d bytes", packetsize)
// split into TS packets
for i := m; i < n; i += packetsize {
pkt := NewTsPacket(packet[i : i+packetsize])
node.PktsIn++
node.Send(pkt)
}
}
}
func (node *NetInput) closeDown() {
node.Active = false
log.Printf("Closing down NetInput on %s@%d", node.addr.IP, node.addr.Port)
node.conn.Close()
node.output.Close()
}