av/protocol/rtcp/parse.go

27 lines
679 B
Go

package rtcp
import (
"encoding/binary"
"errors"
)
// Timestamp gets the timestamp from a receiver report and returns as the most
// significant word, and the least significant word. If the given bytes do not
// represent a valid receiver report, and error is returned.
func Timestamp(buf []byte) (msw, lsw uint32, err error) {
// First check version of rtcp
if (buf[0] & 0xc0 >> 6) != 2 {
return 0, 0, errors.New("incompatible RTCP version")
}
// Check type of packet
if buf[1] != typeSenderReport {
return 0, 0, errors.New("rtcp packet is not of sender report type")
}
msw = binary.BigEndian.Uint32(buf[8:])
lsw = binary.BigEndian.Uint32(buf[12:])
return
}