Paella 8 on mobile: broken on landscape mode

[miesgre]

Reported by @lkiesow

If you launch the new Paella 8 in portrait mode on a smartphone, you just get a blank page.

See polimediaupv/paella-player#26

• The default preview images are not installed on demo page
• Opencast does not generate a portrait preview image. Should we use the one generated in landscape? We need to test it to see how it would look.

[miesgre]

Opencast does not generate a vertical preview image, we can use the same one as for landscape, but by default Paella will show you the image centered in the video container with empty space above and below:

We can modify Opencast's CSS to fit the image to the container by cropping the image:

The CSS to add would be something like this:

/* Preview image styles */
.preview-container>.preview-image-container {
  width: 100%;
  height: 100%;
}
.preview-container>.preview-image-container>.preview-image-landscape,
.preview-container>.preview-image-container>.preview-image-portrait {
  width: 100%;
  height: 100%;
  object-fit: cover;
  overflow: hidden;
}

@lkiesow? @turro? , do you have a preference? Which one seems like the best option to you?