From b4a8028c042fd7a6bcb86481f2fcb9b997967f98 Mon Sep 17 00:00:00 2001
From: Cedric Verstraeten <cedric@verstraeten.io>
Date: Tue, 14 Feb 2023 08:57:55 +0100
Subject: [PATCH] better way of doing prerecording + matching timestamp with
 prerecord time

---
 machinery/src/capture/IPCamera.go    | 54 ++++++++++++++++++++++++++++
 machinery/src/capture/main.go        |  8 ++++-
 machinery/src/components/Kerberos.go |  6 ++--
 3 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/machinery/src/capture/IPCamera.go b/machinery/src/capture/IPCamera.go
index bfb6d59..527d180 100644
--- a/machinery/src/capture/IPCamera.go
+++ b/machinery/src/capture/IPCamera.go
@@ -46,6 +46,60 @@ func DecodeImage(frame *ffmpeg.VideoFrame, pkt av.Packet, decoder *ffmpeg.VideoD
 	return img, err
 }
 
+func GetStreamInsights(infile av.DemuxCloser, streams []av.CodecData) (int, int, int, int) {
+	var width, height, fps, gopsize int
+	for _, stream := range streams {
+		if stream.Type().IsAudio() {
+			//astream := stream.(av.AudioCodecData)
+		} else if stream.Type().IsVideo() {
+			vstream := stream.(av.VideoCodecData)
+			width = vstream.Width()
+			height = vstream.Height()
+		}
+	}
+
+loop:
+	for timeout := time.After(1 * time.Second); ; {
+		var err error
+		if _, err = infile.ReadPacket(); err != nil { // sometimes this throws an end of file..
+			log.Log.Error("HandleStream: " + err.Error())
+		}
+		fps++
+		select {
+		case <-timeout:
+			break loop
+		default:
+		}
+	}
+
+	gopCounter := 0
+	start := false
+	for {
+		var pkt av.Packet
+		var err error
+		if pkt, err = infile.ReadPacket(); err != nil { // sometimes this throws an end of file..
+			log.Log.Error("HandleStream: " + err.Error())
+		}
+		// Could be that a decode is throwing errors.
+		if len(pkt.Data) > 0 {
+			if start {
+				gopCounter = gopCounter + 1
+			}
+
+			if pkt.IsKeyFrame {
+				if start == false {
+					start = true
+				} else {
+					gopsize = gopCounter
+					break
+				}
+			}
+		}
+	}
+
+	return width, height, fps, gopsize
+}
+
 func HandleStream(infile av.DemuxCloser, queue *pubsub.Queue, communication *models.Communication) { //, wg *sync.WaitGroup) {
 
 	log.Log.Debug("HandleStream: started")
diff --git a/machinery/src/capture/main.go b/machinery/src/capture/main.go
index 839e79a..eb688e4 100644
--- a/machinery/src/capture/main.go
+++ b/machinery/src/capture/main.go
@@ -278,6 +278,12 @@ func HandleRecordStream(queue *pubsub.Queue, configuration *models.Configuration
 				startRecording = time.Now().Unix() // we mark the current time when the record started.
 				numberOfChanges := motion.NumberOfChanges
 
+				// If we have prerecording we will substract the number of seconds.
+				// Taking into account FPS = GOP size (Keyfram interval)
+				if config.Capture.PreRecording > 0 {
+					startRecording = startRecording - int64(config.Capture.PreRecording) + 1
+				}
+
 				// timestamp_microseconds_instanceName_regionCoordinates_numberOfChanges_token
 				// 1564859471_6-474162_oprit_577-283-727-375_1153_27.mp4
 				// - Timestamp
@@ -318,7 +324,7 @@ func HandleRecordStream(queue *pubsub.Queue, configuration *models.Configuration
 				var cursorError error
 				var pkt av.Packet
 				var nextPkt av.Packet
-				recordingCursor := queue.Oldest()
+				recordingCursor := queue.DelayedGopCount(int(config.Capture.PreRecording))
 
 				if cursorError == nil {
 					pkt, cursorError = recordingCursor.ReadPacket()
diff --git a/machinery/src/components/Kerberos.go b/machinery/src/components/Kerberos.go
index cb74685..4e50b42 100644
--- a/machinery/src/components/Kerberos.go
+++ b/machinery/src/components/Kerberos.go
@@ -131,14 +131,14 @@ func RunAgent(configuration *models.Configuration, communication *models.Communi
 		// processed by the different consumers: motion detection, recording, etc.
 		queue = pubsub.NewQueue()
 		communication.Queue = queue
-		queue.SetMaxGopCount(int(config.Capture.PreRecording)) // GOP time frame is set to prerecording.
-		log.Log.Info("RunAgent: SetMaxGopCount was set with: " + strconv.Itoa(int(config.Capture.PreRecording)))
+		queue.SetMaxGopCount(int(config.Capture.PreRecording) + 1) // GOP time frame is set to prerecording (we'll add 2 gops to leave some room).
+		log.Log.Info("RunAgent: SetMaxGopCount was set with: " + strconv.Itoa(int(config.Capture.PreRecording)+1))
 		queue.WriteHeader(streams)
 
 		// We might have a substream, if so we'll create a seperate queue.
 		var subQueue *pubsub.Queue
 		if subStreamEnabled {
-			log.Log.Info("RunAgent: Creating sub stream queue with SetMaxGopCount set to " + strconv.Itoa(int(config.Capture.PreRecording)))
+			log.Log.Info("RunAgent: Creating sub stream queue with SetMaxGopCount set to " + strconv.Itoa(int(1)))
 			subQueue = pubsub.NewQueue()
 			subQueue.SetMaxGopCount(1)
 			subQueue.WriteHeader(subStreams)