@jimunderscorep It means that Chromium browser must be installed to get proprietary codecs support in Opera. I think Opera should provide these codecs support by default (because a lot of websites use these proprietary codecs). Otherwise, people will switch to a different browser.

I am currently using Opera 53.0 in Kali Linux 2018.2. Opera is not running videos and GIFs from websites like Twitter, Coursera, etc. This is because H.264 and H.265 multimedia codecs are not supported. YouTube Live Stream is also not working. I did an HTML5test of Opera. In that test, Opera scored 524 out of 555 points. It showed that a lot of things are not supported, like

VIDEO

• Audio track selection
• Video track selection
• Video codecs
  • MPEG-4 ASP support
  • H.264 support
  • H.265 support

AUDIO

• Advanced
  • Speech Recognition
  • Speech Synthesis
• Audio codecs
  • AAC support
  • Dolby Digital support
  • Dolby Digital Plus support

STREAMING

• Adaptive bit rate

  • Dynamic Adaptive Streaming / MPEG-DASH
  • HTTP Live Streaming / HLS

• Codecs

  • Video codecs
    • MP4 with H.264 support
    • MP4 with H.265 support
    • TS with H.264 support
    • TS with H.265 support
  • Audio codecs
    • MP4 with AAC support
    • MP4 with Dolby Digital support
    • MP4 with Dolby Digital Plus support
    • TS with AAC support
    • TS with Dolby Digital support
    • TS with Dolby Digital Plus support

If you want to know more about it, HTML5test of my browser is : https://html5te.st/62e18c3dfde7c450

So, how do I get Streaming and Codecs (Audio & Video) support in Opera 53?