Projector usecase: configurable subtitles size & brightness, and auto-positioning of image and subtitles

[nekohayo]

I would like to be able to use this video player with a projector, on a big wall, which creates a 10' diagonal display… where subtitles can be overwhelmingly big and bright.

To be useful for this type of usecase,

• The app should automagically position the video image and regular (non-ASS) subtitles to avoid overlap:
  when a video has subtitles and the viewport/fullscreen is taller than the video for the current aspect ratio (ex: 16:9 projector showing a wide cinema aspect ratio video fullscreen), the image should be positioned at the top and subtitles should be positioned below the image as much as possible, essentially, making the letterbox have only one black band (below) instead of one at the top and one at the bottom.
• Subtitles would need to have a dimmable color: I would want to be able to set the subtitles' to 30-50% brightness (i.e. gray instead of pure white) to avoid glare (which would be difficult on the eyes in dark scenes, and introduce light bleed for the projector).
• The maximum font size should be configurable: on large screens (such as a whole wall), when sitting close to it, large subtitles are hard to read because they make your eye dart across the whole room, so I would need to be able to limit their size. However, this is very dependent on the screen size and viewing distance, so it's not like we can have a one-size-fits-all hardcoded value here.

[philn]

First one is a GStreamer issue imho.

Second one, GstPlay color-balance control API, so we could use it. There's already an issue about that.

Third one is a missing feature in GstPlay before we can do anything here.

[philn]

First one is a GStreamer issue imho.

Well, we could do as in WebKit too, deferring rendering to some third-party UI component (a widget in this case).