fix(FEC-11402): preview doesn't work in video ratio different than 16…

…:9 (#466)

Preview image height should be calculated according to video ratio and not used from constant as video ratio can be different than 16:9

src/common/thumbnail-manager.js

@@ -38,7 +38,7 @@ class ThumbnailManager {
   _convertKalturaThumbnailToThumbnailInfo = (time: number): ?ThumbnailInfo => {
     if (this._thumbnailConfig) {
       const {thumbsSprite, thumbsWidth, thumbsSlices} = this._thumbnailConfig;
-      const {thumbsHeight} = DefaultThumbnailConfig;
+      const thumbsHeight = Math.floor(thumbsWidth * (this._player.videoHeight / this._player.videoWidth));
       const duration = this._player.duration / thumbsSlices;
       const thumbnailInfo = {
         x: Math.floor(time / duration) * thumbsWidth,

test/src/common/thumbnail-manager.spec.js

@@ -100,6 +100,17 @@ describe('ThumbnailManager', () => {
     spy.should.calledOnce;
   });
 
+  it('should return thumbnail height from core player with video ratio 4:3', () => {
+    fakeMediaConfig.sources.poster = null;
+    fakePlayer.config.ui.components.seekbar.thumbsSprite = thumbsSprite;
+    thumbnailManager = new ThumbnailManager(fakePlayer, fakePlayer.config.ui, fakeMediaConfig);
+    fakePlayer.duration = 1000;
+    fakePlayer.videoHeight = 480;
+    fakePlayer.videoWidth = 640;
+    const thumbInfo = thumbnailManager.getThumbnail(100);
+    thumbInfo.height.should.equal(thumbInfo.width * (fakePlayer.videoHeight / fakePlayer.videoWidth));
+  });
+
   it('should set the configured thumbs sprite with default sizes', () => {
     fakePlayer.config.ui.components.seekbar.thumbsSprite = thumbsSprite;
     thumbnailManager = new ThumbnailManager(fakePlayer, fakePlayer.config.ui, fakeMediaConfig);