: These "Premium" or high-bitrate itags (like 616 and 617) are part of YouTube's efforts to provide enhanced quality for certain viewers or devices [26, 30].
: Users of yt-dlp and similar tools may see this ID when listing available formats for a video [18].
In the context of YouTube's internal format identifiers (itags), is a specific MP4 video format code. Format Details Video Format : MP4 (H.264/AVC) [26].
: Primarily associated with 1080p (Full HD) video streams [18, 23].
: Typically a "video-only" stream, meaning it must be combined (muxed) with a separate audio stream (like itag 140 or 251) for full playback [28]. Usage and Issues
: Some users have reported significantly slower download speeds when requesting the 617 format compared to other high-definition streams like itag 399 [28].
