Jam Session Music Block for Svelte

A buffer of N samples at 48 kHz lasts N divided by 48 thousandths of a second, so 128 samples is 2.7 ms. A player's one-way delay is half their ping plus that buffer, kept in tenths of a millisecond so no rounding error shows: a ping of 86 ms with a 64 sample buffer is 43.0 plus 1.3, or 44.3 ms. The grade follows from the number: up to 30 ms Playable, up to 45 ms Tolerable, past that Too slow.

It looks only at the slowest player. At 30 ms or under it says everyone is playable, at 45 or under it says playable with care, and past that it counts the players over 45 ms. Change the buffer and the bars, the words and the verdict all move together, and the status line speaks the new buffer with the verdict.

Each grade has a glyph and a word, and the bars differ by weight: Playable is solid, Tolerable is a lighter fill and Too slow is hatched with an outline. Only the Too slow glyph takes the destructive colour. The two ticks at 30 and 45 ms give the bars a scale you can read in greyscale.

Yes: it writes the room code to the clipboard and the status line says so. The code is invented. Join session connects to nothing and says so; to make it real, open your own audio session from the join handler and replace the typed pings with measurements from your relay.

Everything: the five players and their pings are typed example figures, the buffer choice lives in the page and nothing is measured, connected or played. Latency in a real session also depends on the network path and the audio interface, which this demo does not model.

The code and the Copy button sit on one line with the buffer group below, each player's bar drops under their name and city, and the verdict and the foot follow. The foot status wraps in a reserved two-line slot, so the Join button never moves.