Make duration functions work with negative values.

rtpconn/rtpstats.go

@@ -57,7 +57,7 @@ func (c *webClient) GetStats() *stats.Client {
 			maxTid := layer.maxTid
 			rate, _ := t.rate.Estimate()
 			maxRate, _, _ := t.GetMaxBitrate()
-			rtt := rtptime.ToDuration(t.getRTT(),
+			rtt := rtptime.ToDuration(int64(t.getRTT()),
 				rtptime.JiffiesPerSec)
 			loss, jitter := t.stats.Get(jiffies)
 			j := time.Duration(jitter) * time.Second /

rtpconn/rtpwriter.go

@@ -138,7 +138,7 @@ func (wp *rtpWriterPool) write(seqno uint16, index uint16, delay uint32, isvideo
 			// audio, try again with a delay
 			d := delay / uint32(2*len(wp.writers))
 			timer := time.NewTimer(rtptime.ToDuration(
-				uint64(d), rtptime.JiffiesPerSec,
+				int64(d), rtptime.JiffiesPerSec,
 			))
 
 			select {