decode RTP time globally

pkg/rtptime/global_decoder_test.go

@@ -0,0 +1,140 @@
+package rtptime
+
+import (
+	"testing"
+	"time"
+
+	"github.com/pion/rtp"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDecoderNegativeDiff(t *testing.T) {
+	i := uint32(0)
+	d := newGlobalDecoderTrackData(0, 90000, i)
+
+	i += 90000 * 2
+	pts := d.decode(i)
+	require.Equal(t, 2*time.Second, pts)
+
+	i -= 90000 * 1
+	pts = d.decode(i)
+	require.Equal(t, 1*time.Second, pts)
+
+	i += 90000 * 2
+	pts = d.decode(i)
+	require.Equal(t, 3*time.Second, pts)
+}
+
+func TestDecoderOverflow(t *testing.T) {
+	secs := time.Duration(0)
+	i := uint32(0xFFFFFFFF - 90000 + 1)
+	d := newGlobalDecoderTrackData(0, 90000, i)
+
+	const stride = 1500
+	lim := uint32(uint64(0xFFFFFFFF + 1 - (stride * 90000)))
+
+	for n := 0; n < 100; n++ {
+		// overflow
+		i += 90000 * stride
+		secs += stride
+		pts := d.decode(i)
+		require.Equal(t, secs*time.Second, pts)
+
+		// reach 2^32 slowly
+		secs += stride
+		i += 90000 * stride
+		for ; i < lim; i += 90000 * stride {
+			pts = d.decode(i)
+			require.Equal(t, secs*time.Second, pts)
+			secs += stride
+		}
+	}
+}
+
+func TestDecoderOverflowAndBack(t *testing.T) {
+	d := newGlobalDecoderTrackData(0, 90000, 0xFFFFFFFF-90000+1)
+
+	pts := d.decode(90000)
+	require.Equal(t, 2*time.Second, pts)
+
+	pts = d.decode(0xFFFFFFFF - 90000 + 1)
+	require.Equal(t, time.Duration(0), pts)
+
+	pts = d.decode(0xFFFFFFFF - 90000 + 1 - 90000)
+	require.Equal(t, -1*time.Second, pts)
+
+	pts = d.decode(0xFFFFFFFF - 90000 + 1)
+	require.Equal(t, time.Duration(0), pts)
+
+	pts = d.decode(90000)
+	require.Equal(t, 2*time.Second, pts)
+}
+
+func BenchmarkDecoder(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		func() {
+			n := uint32(0)
+			d := newGlobalDecoderTrackData(0, 90000, n)
+			for j := 0; j < 200; j++ {
+				if (j % 2) == 0 {
+					n += 90000
+				} else {
+					n -= 45000
+				}
+				d.decode(n)
+			}
+		}()
+	}
+}
+
+type dummyTrack struct {
+	clockRate    int
+	ptsEqualsDTS bool
+}
+
+func (t *dummyTrack) ClockRate() int {
+	return t.clockRate
+}
+
+func (t *dummyTrack) PTSEqualsDTS(*rtp.Packet) bool {
+	return t.ptsEqualsDTS
+}
+
+func TestGlobalDecoder(t *testing.T) {
+	g := NewGlobalDecoder()
+
+	t1 := &dummyTrack{clockRate: 90000}
+	t2 := &dummyTrack{clockRate: 48000, ptsEqualsDTS: true}
+
+	timeNow = func() time.Time {
+		return time.Date(2008, 0o5, 20, 22, 15, 20, 0, time.UTC)
+	}
+
+	_, ok := g.Decode(t1, &rtp.Packet{})
+	require.Equal(t, false, ok)
+
+	t1.ptsEqualsDTS = true
+	pts, ok := g.Decode(t1, &rtp.Packet{Header: rtp.Header{Timestamp: 22500}})
+	require.Equal(t, true, ok)
+	require.Equal(t, time.Duration(0), pts)
+
+	timeNow = func() time.Time {
+		return time.Date(2008, 0o5, 20, 22, 15, 21, 0, time.UTC)
+	}
+
+	pts, ok = g.Decode(t1, &rtp.Packet{Header: rtp.Header{Timestamp: 22500 + 90000}})
+	require.Equal(t, true, ok)
+	require.Equal(t, 1*time.Second, pts)
+
+	timeNow = func() time.Time {
+		return time.Date(2008, 0o5, 20, 22, 15, 25, 0, time.UTC)
+	}
+
+	pts, ok = g.Decode(t2, &rtp.Packet{Header: rtp.Header{Timestamp: 33100}})
+	require.Equal(t, true, ok)
+	require.Equal(t, 5*time.Second, pts)
+
+	pts, ok = g.Decode(t2, &rtp.Packet{Header: rtp.Header{Timestamp: 33100 + 48000}})
+	require.Equal(t, true, ok)
+	require.Equal(t, 6*time.Second, pts)
+}