Allow negative MP4 rotations

drewnoakes · drewnoakes · commit bd419963901e · 2021-04-16T22:47:04.000+10:00
diff --git a/MetadataExtractor/Formats/QuickTime/QuickTimeMetadataReader.cs b/MetadataExtractor/Formats/QuickTime/QuickTimeMetadataReader.cs
@@ -89,11 +89,11 @@ static void SetRotation(QuickTimeTrackHeaderDirectory directory)
                     var x = matrix[1] + matrix[4];
                     var y = matrix[0] + matrix[3];
                     var theta = Math.Atan2(x, y);
-                    var degree = ((180 / Math.PI) * theta) - 45;
-                    if (degree < 0)
-                        degree += 360;
+                    var degree = RadiansToDegrees(theta) - 45;
 
                     directory.Set(QuickTimeTrackHeaderDirectory.TagRotation, degree);
+
+                    static double RadiansToDegrees(double radians) => (180 / Math.PI) * radians;
                 }
             }
 

Original file line number	Diff line number	Diff line change
`@@ -89,11 +89,11 @@ static void SetRotation(QuickTimeTrackHeaderDirectory directory)`
`89`	`89`	`var x = matrix[1] + matrix[4];`
`90`	`90`	`var y = matrix[0] + matrix[3];`
`91`	`91`	`var theta = Math.Atan2(x, y);`
`92`		`- var degree = ((180 / Math.PI) * theta) - 45;`
`93`		`- if (degree < 0)`
`94`		`- degree += 360;`
	`92`	`+ var degree = RadiansToDegrees(theta) - 45;`
`95`	`93`
`96`	`94`	`directory.Set(QuickTimeTrackHeaderDirectory.TagRotation, degree);`
	`95`	`+`
	`96`	`+ static double RadiansToDegrees(double radians) => (180 / Math.PI) * radians;`
`97`	`97`	`}`
`98`	`98`	`}`
`99`	`99`