DRAFT: Migrate video player from video.js to shaka-player

Pull Request Type

• Bugfix
• Feature Implementation

Related issue

• closes 'Back to video player' doesnt work when not on video page #624
• closes Option to start Live videos from 0:00 and ability to rewind live videos #661
• closes Videos that aren't 16:9 are cut off by the bottom of the screen. #959
• closes Title not visible on white background videos #1348
• closes [Feature Request]: 1440p and 2160p qualities when using the local API #2013
• closes [Bug]: you cant exit out of fullwindowmode when there is a network error and the video stops working #2098
• closes [Bug]: Video starts playing from the beginning when the format is changed #2365
• closes Keybindings for the videoplayer are not successfully overriden #637
• closes [Bug]: Picture in Picture - Background Continue to Play Unable to Stop #4039
• closes [Bug]: Rewinding, entering/exiting Full Window/Fullscreen mode, and turning CC on/off reduces the captions font size #3920
• closes [Bug]: Screen tearing when switching qualities #3560
• closes [Bug]: SponsorBlock segment isnt skipped #3534
• closes [Bug]: Clicking fast through video qualities creates visual bug #3163
• closes [Bug]: Problem with subtitle centering with local language option #2931
• closes [Bug]: Attempting to pause a video in a popout window only pauses the main window - the popout window cannot be paused anymore #2455
• closes Long videos causes some problems #845
• closes Resolution qualities appear twice in quality selector #1344
• closes [Feature Request] Hide Progress Bar / Old Progress Bar Option #920
• closes [Feature Request]: hard to select between the timeline bar and video options buttons #3049
• closes Move Auto from top to bottom in player quality menu #1803
• closes [Bug]: Video is shifted and cropped when pausing in full screen after controls disappear #4983
• partially adresses (only some VR videos are supported) 360゜Camera Video Support #1460

Description

After almost a years worth of work, here is the shaka-player migration.

Significant improvements and new features

• vp9 and opus during DASH playback. vp9 only works on the local API due to Invidious limitations
• The video player will now match the users display language when possible (41/45 locales) and custom player elements added by FreeTube are now translatable. shaka-player doesn't support Estonian et (eesti keel), Basque eu (Euskera), Galician gl (galego) and Icelandic is (Íslenska), for those languages it will use English (US) instead.
• Stats are now supported for all 3 Media Formats, not just DASH.
• Switching formats with keep your playback rate, selected subtitle, audio language and video quality settings and the player will no longer flash while switching.
• The player should be a lot more usuable on mobile screens, as player elements get moved into an overflow menu when they don't fit.
• Seeking on live streams when the uploader hasn't disabled it (4 hours back for normal ones, 2 hours on low latency live streams). Not supported when video proxying is enabled, as Invidious doesn't support proxying DASH live streams.
• You can now watch just finished live streams (Post-Live-DVR) from the start with the local API and you'll get thumbnails on the seek bar when they are available (the thumbnails seem to be missing on about 50% of Post-Live-DVR streams).
• The video player will pick up most settings changes without having to leave the watch page, such as changing the display language or the playback rate interval.
• Subtitles will now work on live streams that have them (very rare but they do exist), local API only.
• Support for VR videos that use equirectangular projection, shaka-player doesn't support YouTube's other projection types yet, local API only (The ANDROID_TESTSUITE client that Invidious uses, claims that all video streams use normal rectangular projection, so we don't have a way to identify VR videos through Invidious).

Significant bug fixes

• The subtitle translation feature now works on all videos, not just ones that are in English.
• Starting at a certain timestamp from the video URL or resuming a partially watched video, should now work all the time, instead of just randomly.
• Long videos start straigh away and no longer freeze FreeTube for almost a minute.

Missing/Removed features

• shaka-player doesn't have any subtitle settings. Maybe in the future we could implement our own ones, but it's not-trivial to implement, so creating a replacement is out-of-scope for this pull request.
• I removed the ability to seek into sponsor block segments that are set to skip, as it was causing the skipping to not work properly, due to the existing implementation being fundamentally flawed. If someone would like to add something like that back in the future, it should require a specific user-interaction to unskip the segment, e.g. a button in the skip message, instead of allowing users to manually seek into the segment.

Known issues

• The error handling for fatal errors isn't finished yet, it gets logged to the console but it doesn't show the message in the UI yet.
• Invidious' video proxy doesn't support live or post live DVR DASH, so we have to keep using the HLS manifests when the "Proxy Videos Through Invidious" setting is enabled, which means you can't seek in them or use the captions if there are any.
• Invidious' DASH manifests don't include the vp9 or opus streams and the API doesn't return enough information on the vp9 streams for us to be able to generate our own DASH manifest for them (height and width are missing), so vp9 playback is only supported on the local API, when "Proxy Videos Through Invidious" is disabled. Return actual height, width and fps for streams in /api/v1/videos iv-org/invidious#4586
• Focus is not restored properly from exiting video player menus using keyboard navigation (will not be addressed in this pull request).

Screenshots

Testing

• HDR: https://youtu.be/njX2bu-_Vw4
• Dubbed and descriptive audio tracks: https://youtu.be/Kn56bMZ9OE8
• Audio and subtitle tracks in multiple languages: https://youtu.be/pU9sHwNKc2c
• Live: https://youtu.be/jfKfPfyJRdk
• 21:9 aspect ratio: https://youtu.be/Ttl8Gg-P-Ao
• YouTube short: https://youtu.be/hxQwWEOOyU8
• Chapters: https://youtu.be/Rb0k9vUCEno
• 100 hours long (has no seek bar thumbnails): https://youtu.be/56lkofpjOAs
• Subtitle formatting and colors: https://youtu.be/OwQwz07-DFc (The video stream has some burned in subtitles too, which we can't do anything about.)
• Non-seekable live stream: https://youtu.be/HQtFR3mhzOY
• Live streams with subtitles: https://www.youtube.com/@NBCNews/streams
• VR video that uses equirectangular projection: https://youtu.be/H9r8CTsSf4U

Desktop

• OS: Windows
• OS Version: 10
• FreeTube version: 0.20.0