Linus Tech Tips Discussion

 Youtube quietly pulled the plug on custom subtitle tracks (.ytt /.srv3) support, removing it from videos that had it without notice Summary   If you ever watched a YT video with subtitle format that are seemingly custom, with different color style, font style, custom positioning and even vertical text, or if you are active viewer of Tom Scott and Hololive, chances are you didn't realize it's a thing that Youtube has the support for. Yes, Youtube has advanced subtitle formatting that enabled videos like that to be on their platform. What's behind it is called SRV3, or commonly known through Youtube community as YTT, which is basically a very customized but sort of YT proprietary subtitle format. It's not really that documented, however it sees massive usage on certain channels and again, one of which is Hololive, VTuber group with videos reaching tens of millions, sometimes over a hundred million views. All officially translated Hololive videos (which is a lot) uses SRV3 subtitle format in order to achieve the subtitle style they need for their videos.   However, it seems that Google/ Youtube are preparing the Google guillotine once more. Some Youtube and Hololive community members discovered that the custom subtitle outright not appearing on the video they published despite the SRV3 file being successfully uploaded to the video they intend to put the SRV3 subtitle into. Google once made an update to support JSON3 without breaking the SRV3 upload for the custom subtitle feature, however even now, if you try to upload JSON3 files for custom subtitle, Youtube will reject the file for being unrecognized format. This silent deprecation threatens videos and creators that rely on this custom subtitle feature, one of which is VTuber community, which can sometimes even spend extra budget to have subtitling team that relies on SRV3.   Examples of how SRV3 subtitle look like can be viewed on the first quote.   Quotes Quote If you want to add manually-created subtitles to a video, you have two options: enter them in the online subtitle editor that's built into YouTube Studio, or upload a file. YouTube supports a good number of file formats with varying capabilities: bold, italic, sometimes even color. What's less known, however, is that it also accepts a proprietary format called "SRV3" (also known in the community as "YTT"). It's similar to TTML, and it used to be YouTube's internal, unified format for sending subtitles to the video player. (They switched to "JSON3" a few years back, but SRV3 kept working for uploads.)   This hidden format has a wealth of styling options, most of which aren't possible with any of the officially supported ones: Bold/italic/underline Cu