Preserve display aspect ratio for videos with rectangular samples

1 files changed, 35 insertions, 15 deletions

diff --git a/activestorage/lib/active_storage/analyzer/video_analyzer.rb b/activestorage/lib/active_storage/analyzer/video_analyzer.rb
index aa532da201..f0d9baa199 100644
--- a/activestorage/lib/active_storage/analyzer/video_analyzer.rb
+++ b/activestorage/lib/active_storage/analyzer/video_analyzer.rb
@@ -9,12 +9,12 @@ module ActiveStorage
   # * Height (pixels)
   # * Duration (seconds)
   # * Angle (degrees)
-  # * Aspect ratio
+  # * Display aspect ratio
   #
   # Example:
   #
   #   ActiveStorage::VideoAnalyzer.new(blob).metadata
-  #   # => { width: 640, height: 480, duration: 5.0, angle: 0, aspect_ratio: [4, 3] }
+  #   # => { width: 640.0, height: 480.0, duration: 5.0, angle: 0, display_aspect_ratio: [4, 3] }
   #
   # When a video's angle is 90 or 270 degrees, its width and height are automatically swapped for convenience.
   #
@@ -25,24 +25,24 @@ module ActiveStorage
     end
 
     def metadata
-      { width: width, height: height, duration: duration, angle: angle, aspect_ratio: aspect_ratio }.compact
+      { width: width, height: height, duration: duration, angle: angle, display_aspect_ratio: display_aspect_ratio }.compact
     end
 
     private
       def width
-        rotated? ? raw_height : raw_width
+        if rotated?
+          computed_height || encoded_height
+        else
+          encoded_width
+        end
       end
 
       def height
-        rotated? ? raw_width : raw_height
-      end
-
-      def raw_width
-        Integer(video_stream["width"]) if video_stream["width"]
-      end
-
-      def raw_height
-        Integer(video_stream["height"]) if video_stream["height"]
+        if rotated?
+          encoded_width
+        else
+          computed_height || encoded_height
+        end
       end
 
       def duration
@@ -53,16 +53,36 @@ module ActiveStorage
         Integer(tags["rotate"]) if tags["rotate"]
       end
 
-      def aspect_ratio
+      def display_aspect_ratio
         if descriptor = video_stream["display_aspect_ratio"]
-          descriptor.split(":", 2).collect(&:to_i)
+          terms = descriptor.split(":", 2).collect(&:to_i)
+          terms if terms.count == 2 && terms.min >= 0
         end
       end
 
+
       def rotated?
         angle == 90 || angle == 270
       end
 
+      def computed_height
+        if encoded_width && display_height_scale
+          encoded_width * display_height_scale
+        end
+      end
+
+      def encoded_width
+        @encoded_width ||= Float(video_stream["width"]) if video_stream["width"]
+      end
+
+      def encoded_height
+        @encoded_height ||= Float(video_stream["height"]) if video_stream["height"]
+      end
+
+      def display_height_scale
+        @display_height_scale ||= Float(display_aspect_ratio.last) / display_aspect_ratio.first if display_aspect_ratio
+      end
+
 
       def tags
         @tags ||= video_stream["tags"] || {}