mirror of https://github.com/jech/galene.git
65 lines
1.7 KiB
Go
65 lines
1.7 KiB
Go
// Package rtptime manipulates RTP and NTP time
|
|
package rtptime
|
|
|
|
import (
|
|
"time"
|
|
)
|
|
|
|
// epoch is the origin of NTP time
|
|
var epoch = time.Now()
|
|
|
|
// FromDuration converts a time.Duration into units of 1/hz.
|
|
func FromDuration(d time.Duration, hz uint32) uint64 {
|
|
return uint64(d) * uint64(hz) / uint64(time.Second)
|
|
}
|
|
|
|
// ToDuration converts units of 1/hz into a time.Duration.
|
|
func ToDuration(tm uint64, hz uint32) time.Duration {
|
|
return time.Duration(tm * uint64(time.Second) / uint64(hz))
|
|
}
|
|
|
|
// Now returns the current time in units of 1/hz from an arbitrary origin.
|
|
func Now(hz uint32) uint64 {
|
|
return FromDuration(time.Since(epoch), hz)
|
|
}
|
|
|
|
// Microseconds is like Now, but uses microseconds.
|
|
func Microseconds() uint64 {
|
|
return Now(1000000)
|
|
}
|
|
|
|
// JiffiesPerSec is the number of jiffies in a second. This is the LCM of
|
|
// 48000, 96000 and 65536.
|
|
const JiffiesPerSec = 24576000
|
|
|
|
// Jiffies returns the current time in jiffies.
|
|
func Jiffies() uint64 {
|
|
return Now(JiffiesPerSec)
|
|
}
|
|
|
|
// TimeToJiffies converts a time.Time into jiffies.
|
|
func TimeToJiffies(tm time.Time) uint64 {
|
|
return FromDuration(tm.Sub(epoch), JiffiesPerSec)
|
|
}
|
|
|
|
// The origin of NTP time.
|
|
var ntpEpoch = time.Date(1900, 1, 1, 0, 0, 0, 0, time.UTC)
|
|
|
|
// NTPToTime converts an NTP time into a time.Time.
|
|
func NTPToTime(ntp uint64) time.Time {
|
|
sec := uint32(ntp >> 32)
|
|
frac := uint32(ntp & 0xFFFFFFFF)
|
|
return ntpEpoch.Add(
|
|
time.Duration(sec)*time.Second +
|
|
((time.Duration(frac) * time.Second) >> 32),
|
|
)
|
|
}
|
|
|
|
// TimeToNTP converts a time.Time into an NTP time.
|
|
func TimeToNTP(tm time.Time) uint64 {
|
|
d := tm.Sub(ntpEpoch)
|
|
sec := uint32(d / time.Second)
|
|
frac := uint32(d % time.Second)
|
|
return (uint64(sec) << 32) + (uint64(frac)<<32)/uint64(time.Second)
|
|
}
|