Update param computation (#87)

* import sorter config

* organize video types

* ignore import sort for proto files

* equality for video types

* impl

* adjust defaults

* max

lib/src/types/video_dimensions.dart

@@ -40,6 +40,12 @@ class VideoDimensions {
 }
 
 extension VideoDimensionsHelpers on VideoDimensions {
+  // aspect ratios
+  static const aspect169 = 16.0 / 9.0;
+  static const aspect43 = 4.0 / 3.0;
+
+  double aspect() => width > height ? width / height : height / width;
+
   /// Returns the larger value
   int max() => math.max(width, height);
 

lib/src/types/video_parameters.dart

@@ -56,6 +56,18 @@ class VideoParameters implements Comparable<VideoParameters> {
 }
 
 extension VideoParametersPresets on VideoParameters {
+  // 16:9 default
+  static final List<VideoParameters> defaultSimulcast169 = [
+    h180_169,
+    h360_169,
+  ];
+
+  // 4:3 default
+  static final List<VideoParameters> defaultSimulcast43 = [
+    h180_43,
+    h360_43,
+  ];
+
   // all 16:9 presets
   static final List<VideoParameters> all169 = [
     h90_169,