feat: deprecate smoothQualityChange

[gesinger]

Description

smoothQualityChange was used during certain user interactions: selecting a new rendition via the representations API (when set to true), and when going fullscreen. The method served to keep the content in the buffer but overlay new content on top, allowing playback to continue at the current rendition without the interruption of a loading screen. However, in these user interactions, it is generally expected behavior that the quality change should be immediate, and a short loading period is not an unexpected interruption.

As such, smoothQualityChange is deprecated as an option and will call fastQualityChange until it is removed in the next major version.

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[codecov]

Codecov Report

Merging #1074 (2029b0e) into main (3124fbc) will decrease coverage by 0.02%.
The diff coverage is 40.00%.

@@            Coverage Diff             @@
##             main    #1074      +/-   ##
==========================================
- Coverage   86.43%   86.41%   -0.03%     
==========================================
  Files          39       39              
  Lines        9465     9465              
  Branches     2182     2182              
==========================================
- Hits         8181     8179       -2     
- Misses       1284     1286       +2     

Impacted Files	Coverage Δ
src/videojs-http-streaming.js	90.30% <25.00%> (-0.40%)	⬇️
src/master-playlist-controller.js	94.45% <100.00%> (-0.03%)	⬇️

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[benesva4]

Why exactly was this feature deprecated? The main point is correct - this behaviour is expected generally and it certainly is behaviour that I would expect and want. But it seems kind of strange to remove useful and already working feature. The feature could be used for example in applications where the amount of data is somewhat important factor.

[gkatsev]

@benesva4 actual smooth quality change isn't deprecated. We still change smoothly during normal playback. We've only deprecated the feature for when a user changes quality levels because it has caused some bugs for us but also because users almost always want fast switching when they select a different rendition.