From 52cef01dcac487fac5b350f82a984869721976f1 Mon Sep 17 00:00:00 2001
From: Varun Patil <varunpatil@ucla.edu>
Date: Sun, 14 May 2023 18:38:50 -0700
Subject: [PATCH] manager: read rotation from side data

---
 manager.go | 40 ++++++++++++++++++++++------------------
 stream.go  |  6 +++---
 2 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/manager.go b/manager.go
index a3c3b29c..7eaf98c3 100644
--- a/manager.go
+++ b/manager.go
@@ -234,10 +234,8 @@ func (m *Manager) ffprobe() error {
 		// Hide debug information
 		"-v", "error",
 
-		// video
-		"-show_entries", "format=duration",
-		"-show_entries", "stream=duration,width,height,avg_frame_rate,codec_name,bit_rate",
-		"-show_entries", "stream_tags=rotate",
+		// Show everything
+		"-show_entries", "stream",
 		"-select_streams", "v", // Video stream only, we're not interested in audio
 
 		"-of", "json",
@@ -259,22 +257,26 @@ func (m *Manager) ffprobe() error {
 
 	out := struct {
 		Streams []struct {
-			Width     int    `json:"width"`
-			Height    int    `json:"height"`
-			Duration  string `json:"duration"`
-			FrameRate string `json:"avg_frame_rate"`
-			CodecName string `json:"codec_name"`
-			BitRate   string `json:"bit_rate"`
-			Tags      struct {
-				Rotate string `json:"rotate"`
-			} `json:"tags"`
+			Width        int    `json:"width"`
+			Height       int    `json:"height"`
+			Duration     string `json:"duration"`
+			FrameRate    string `json:"avg_frame_rate"`
+			CodecName    string `json:"codec_name"`
+			BitRate      string `json:"bit_rate"`
+			SideDataList []struct {
+				SideDataType string `json:"side_data_type"`
+				Rotation     int    `json:"rotation"`
+			} `json:"side_data_list"`
 		} `json:"streams"`
 		Format struct {
 			Duration string `json:"duration"`
 		} `json:"format"`
 	}{}
 
-	if err := json.Unmarshal(stdout.Bytes(), &out); err != nil {
+	byts := stdout.Bytes()
+	log.Println(string(byts))
+
+	if err := json.Unmarshal(byts, &out); err != nil {
 		return err
 	}
 
@@ -315,10 +317,12 @@ func (m *Manager) ffprobe() error {
 		bitRate = 5000000
 	}
 
-	// Rotation is a string
-	rotation, err := strconv.Atoi(out.Streams[0].Tags.Rotate)
-	if err != nil {
-		rotation = 0
+	// Get rotation from side data
+	rotation := 0
+	for _, sideData := range out.Streams[0].SideDataList {
+		if sideData.SideDataType == "Display Matrix" {
+			rotation = sideData.Rotation
+		}
 	}
 
 	m.probe = &ProbeVideoData{
diff --git a/stream.go b/stream.go
index 1228a547..f8b658c1 100644
--- a/stream.go
+++ b/stream.go
@@ -415,11 +415,11 @@ func (s *Stream) transcodeArgs(startAt float64) []string {
 		} else if CV == ENCODER_NVENC {
 			transposer = "transpose_npp"
 		}
-		if s.m.probe.Rotation == 90 {
+		if s.m.probe.Rotation == -90 {
 			filter = fmt.Sprintf("%s,%s=1", filter, transposer)
-		} else if s.m.probe.Rotation == 270 {
+		} else if s.m.probe.Rotation == 90 {
 			filter = fmt.Sprintf("%s,%s=2", filter, transposer)
-		} else if s.m.probe.Rotation == 180 {
+		} else if s.m.probe.Rotation == 180 || s.m.probe.Rotation == -180 {
 			filter = fmt.Sprintf("%s,%s=1,%s=1", filter, transposer, transposer)
 		}