Cache H264/H265 GOPs in order to allow readers to decode frames immediately

apidocs/openapi.yaml

@@ -71,6 +71,8 @@ components:
           type: boolean
         runOnDisconnect:
           type: string
+        gopCache:
+          type: boolean
 
         # Authentication
         authMethod:

internal/conf/conf.go

@@ -169,6 +169,7 @@ type Conf struct {
 	RunOnConnect        string          `json:"runOnConnect"`
 	RunOnConnectRestart bool            `json:"runOnConnectRestart"`
 	RunOnDisconnect     string          `json:"runOnDisconnect"`
+	GopCache            bool            `json:"gopCache"`
 
 	// Authentication
 	AuthMethod                AuthMethod                  `json:"authMethod"`

internal/core/core.go

@@ -360,6 +360,7 @@ func (p *Core) createResources(initial bool) error {
 			pathConfs:         p.conf.Paths,
 			externalCmdPool:   p.externalCmdPool,
 			parent:            p,
+			gopCache:          p.conf.GopCache,
 		}
 		p.pathManager.initialize()
 
@@ -715,6 +716,7 @@ func (p *Core) closeResources(newConf *conf.Conf, calledByAPI bool) {
 		newConf.WriteTimeout != p.conf.WriteTimeout ||
 		newConf.WriteQueueSize != p.conf.WriteQueueSize ||
 		newConf.UDPMaxPayloadSize != p.conf.UDPMaxPayloadSize ||
+		newConf.GopCache != p.conf.GopCache ||
 		closeMetrics ||
 		closeAuthManager ||
 		closeLogger

internal/core/path.go

@@ -75,6 +75,7 @@ type path struct {
 	wg                *sync.WaitGroup
 	externalCmdPool   *externalcmd.Pool
 	parent            pathParent
+	gopCache          bool
 
 	ctx                            context.Context
 	ctxCancel                      func()
@@ -701,6 +702,7 @@ func (pa *path) setReady(desc *description.Session, allocateEncoder bool) error
 		Desc:               desc,
 		GenerateRTPPackets: allocateEncoder,
 		DecodeErrLogger:    logger.NewLimitedLogger(pa.source),
+		GopCache:           pa.gopCache,
 	}
 	err := pa.stream.Initialize()
 	if err != nil {

internal/core/path_manager.go

@@ -59,6 +59,7 @@ type pathManager struct {
 	pathConfs         map[string]*conf.Path
 	externalCmdPool   *externalcmd.Pool
 	parent            pathManagerParent
+	gopCache          bool
 
 	ctx         context.Context
 	ctxCancel   func()
@@ -352,6 +353,7 @@ func (pm *pathManager) createPath(
 		wg:                &pm.wg,
 		externalCmdPool:   pm.externalCmdPool,
 		parent:            pm,
+		gopCache:          pm.gopCache,
 	}
 	pa.initialize()
 

internal/servers/rtsp/session.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/bluenviron/gortsplib/v4"
 	"github.com/bluenviron/gortsplib/v4/pkg/base"
+	"github.com/bluenviron/gortsplib/v4/pkg/description"
 	"github.com/google/uuid"
 	"github.com/pion/rtp"
 
@@ -250,6 +251,27 @@ func (s *session) onPlay(_ *gortsplib.ServerHandlerOnPlayCtx) (*base.Response, e
 		s.state = gortsplib.ServerSessionStatePlay
 		s.transport = s.rsession.SetuppedTransport()
 		s.mutex.Unlock()
+
+		if len(s.stream.CachedUnits) > 0 {
+			lastCachedUnits := s.stream.CachedUnits[len(s.stream.CachedUnits)-1]
+			rtpPackets := lastCachedUnits.GetRTPPackets()
+			if len(rtpPackets) > 0 {
+				lastTimestamp := rtpPackets[0].Timestamp
+				for _, medi := range s.stream.Desc.Medias {
+					if medi.Type == description.MediaTypeVideo {
+						for _, u := range s.stream.CachedUnits {
+							for _, pkt := range u.GetRTPPackets() {
+								pkt.Timestamp = lastTimestamp
+								err := s.rsession.WritePacketRTP(medi, pkt)
+								if err != nil {
+									break
+								}
+							}
+						}
+					}
+				}
+			}
+		}
 	}
 
 	return &base.Response{