Add GetMediaStats to StatsReport

Add an API to get basic stats around media.

Relates to #610

mend

mediaengine.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/pion/rtp"
 	"github.com/pion/rtp/codecs"
@@ -340,6 +341,7 @@ type RTPCodec struct {
 	Name        string
 	PayloadType uint8
 	Payloader   rtp.Payloader
+	statsID     string
 }
 
 // NewRTPCodec is used to define a new codec
@@ -363,6 +365,7 @@ func NewRTPCodec(
 		Payloader:   payloader,
 		Type:        codecType,
 		Name:        name,
+		statsID:     fmt.Sprintf("RTPCodec-%d", time.Now().UnixNano()),
 	}
 }
 
@@ -411,3 +414,22 @@ type RTPCapabilities struct {
 	Codecs           []RTPCodecCapability
 	HeaderExtensions []RTPHeaderExtensionCapability
 }
+
+func (m *MediaEngine) collectStats(collector *statsReportCollector) {
+
+	for _, codec := range m.codecs {
+		collector.Collecting()
+		stats := CodecStats{
+			Timestamp:   statsTimestampFrom(time.Now()),
+			Type:        StatsTypeCodec,
+			ID:          codec.statsID,
+			PayloadType: codec.PayloadType,
+			MimeType:    codec.MimeType,
+			ClockRate:   codec.ClockRate,
+			Channels:    uint8(codec.Channels),
+			SDPFmtpLine: codec.SDPFmtpLine,
+		}
+
+		collector.Collect(stats.ID, stats)
+	}
+}

peerconnection.go

@@ -1958,6 +1958,8 @@ func (pc *PeerConnection) GetStats() StatsReport {
 	}
 	pc.mu.Unlock()
 
+	pc.api.mediaEngine.collectStats(statsCollector)
+
 	return statsCollector.Ready()
 }
 

stats.go

@@ -153,7 +153,7 @@ type CodecStats struct {
 	ID string `json:"id"`
 
 	// PayloadType as used in RTP encoding or decoding
-	PayloadType uint32 `json:"payloadType"`
+	PayloadType uint8 `json:"payloadType"`
 
 	// CodecType of this CodecStats
 	CodecType CodecType `json:"codecType"`
@@ -169,7 +169,7 @@ type CodecStats struct {
 	ClockRate uint32 `json:"clockRate"`
 
 	// Channels is 2 for stereo, missing for most other cases.
-	Channels uint32 `json:"channels"`
+	Channels uint8 `json:"channels"`
 
 	// SDPFmtpLine is the a=fmtp line in the SDP corresponding to the codec,
 	// i.e., after the colon following the PT.

stats_go.go

@@ -75,4 +75,20 @@ func (r StatsReport) GetCertificateStats(c *Certificate) (CertificateStats, bool
 		return CertificateStats{}, false
 	}
 	return certificateStats, true
+
+}
+
+// GetCodecStats is a helper method to return the associated stats for a given Codec
+func (r StatsReport) GetCodecStats(c *RTPCodec) (CodecStats, bool) {
+	statsID := c.statsID
+	stats, ok := r[statsID]
+	if !ok {
+		return CodecStats{}, false
+	}
+
+	codecStats, ok := stats.(CodecStats)
+	if !ok {
+		return CodecStats{}, false
+	}
+	return codecStats, true
 }

stats_go_test.go

@@ -5,6 +5,8 @@ package webrtc
 import (
 	"encoding/json"
 	"fmt"
+	"github.com/stretchr/testify/require"
+	"math/rand"
 	"sync"
 	"testing"
 	"time"
@@ -98,6 +100,13 @@ func getDataChannelStats(t *testing.T, report StatsReport, dc *DataChannel) Data
 	return stats
 }
 
+func getCodecStats(t *testing.T, report StatsReport, c *RTPCodec) CodecStats {
+	stats, ok := report.GetCodecStats(c)
+	assert.True(t, ok)
+	assert.Equal(t, stats.Type, StatsTypeCodec)
+	return stats
+}
+
 func getTransportStats(t *testing.T, report StatsReport, statsID string) TransportStats {
 	stats, ok := report[statsID]
 	assert.True(t, ok)
@@ -194,6 +203,12 @@ func TestPeerConnection_GetStats(t *testing.T) {
 	offerPC, answerPC, err := newPair()
 	assert.NoError(t, err)
 
+	track1, err := offerPC.NewTrack(DefaultPayloadTypeVP8, rand.Uint32(), "video", "pion1")
+	require.NoError(t, err)
+
+	_, err = offerPC.AddTrack(track1)
+	require.NoError(t, err)
+
 	baseLineReportPCOffer := offerPC.GetStats()
 	baseLineReportPCAnswer := answerPC.GetStats()
 
@@ -262,6 +277,11 @@ func TestPeerConnection_GetStats(t *testing.T) {
 	assert.NotEmpty(t, findLocalCandidateStats(reportPCAnswer))
 	assert.NotEmpty(t, findRemoteCandidateStats(reportPCAnswer))
 	assert.NotEmpty(t, findCandidatePairStats(t, reportPCAnswer))
+	assert.NoError(t, err)
+	for _, codec := range offerPC.api.mediaEngine.codecs {
+		codecStat := getCodecStats(t, reportPCOffer, codec)
+		assert.NotEmpty(t, codecStat)
+	}
 
 	// Close answer DC now
 	dcWait = sync.WaitGroup{}