ADR-0030: One Piece of Music Can Have a Look of Its Own, Shown Whatever Plays It, and the Stand Learns to Scan

Context

Its owner wants the stand to do what the front of KITT does while the theme from Knight Rider is playing: one red light, going from side to side.

Three things are in the way.

No effect does it. sweep and chase go around, and come back in at the other end. A scanner turns around.

Looks belong to albums (ADR-0019). The theme is one track, on a soundtrack whose other tracks are not it, and on any number of compilations of television themes.

The stand is lit for records only (ADR-0028), and the theme is as likely to be played from iTunes.

Options considered

For the effect: send frames. Ruled out for every effect, long ago (ADR-0001).

For the effect: chase with a black ground and one red accent. It laps; it does not turn around, and has no tail.

For the effect: a parameter on sweep. A bounce and a tail are not what sweep is, and the scene descriptor would grow a field one effect reads.

For the effect: a new one, scanner. A reflash of the stand, which is the cost every effect has had.

For the match: the album. Lights the whole soundtrack, and misses every compilation.

For the match: the recording - an identifier from a catalog. Exact, and there are dozens of recordings of it, and the turntable’s recognizer gives a title and an artist and no identifier.

For the match: the title alone.

For iTunes: leave it dark, as decided that morning. Consistent, and the thing asked for would then be seen only by someone who owns the record.

For iTunes: let any look through. The Dark Side of the Moon from iTunes would light the stand again, which ADR-0028 chose against by name.

For iTunes: say, look by look, which are for any source.

Decision

A track whose title is a known piece of music has that piece’s look, before any look its album has. A look can be marked as being for any source, and then a dark source’s cover is published with it and not with dark. The one such piece is the theme from Knight Rider, whose look is scanner: the firmware’s new effect of that name, in red.

The match, in nowplayd

• By title, and by nothing else. The artist is not asked: it is the same piece whoever recorded it.
• The title has to be the piece’s and no more. Lower case, without what is in parentheses, without punctuation, and without the words that only say it is a theme - theme, from, main, title, tv, the, original, version, opening, music - what is left must be exactly knight rider. “Theme from Knight Rider”, “Knight Rider (Main Title)” and “KNIGHT RIDER: TV THEME” are it. “KITT Jumps”, on the same soundtrack, is not, and nor is “My Knight Rider”.
• The look follows the track, on a cover that does not change. The look is published again when the next track has a different one, with the same cover’s hash, and lightd relights from the pair. A soundtrack on the turntable scans for the theme and goes back to its sleeve’s colors.
• Any source: looks.AnySource says which looks are, and the publisher asks it before giving a dark source’s cover the look dark. Everything else from a dark source is as dark as it was.

The look, in lightd

• scanner is a scene like spectrum: effect scanner, one color, 255, 0, 0.
• Its speed and brightness are its own, 0.9 and 1, where spectrum takes the stand’s. It is there and back in a second and a half, which is the thing itself, and it is one point of light with a dark strip around it.
• lightd knows a name and a red light. It does not know a car.

The effect, in the firmware

• scanner: one eye of the dominant color, going from one end of the strip to the other and back in one cycle, with what it has just passed fading behind it, and the rest of the strip dark. It uses the first color of the palette and no other.
• The eye is a fifth of the strip wide, soft-edged, three or four LEDs of eighteen. The tail is the eye’s own last eight positions, each dimmer.
• A stand that does not know scanner shows it as solid, as with any name it does not know: a red strip. So the stand is flashed first.
• The console’s port (effects.js) has it too, held to the firmware’s pixels like the others.

Consequences

• With the turntable off and the theme played from iTunes, the stand comes on, scans, and goes off again: dark to lit is the opening of ADR-0029, and lit to dark its closing. Nothing has to be switched on.
• With the turntable on, iTunes is not current (ADR-0023), and the theme played from it is not seen. From a record, it is.
• A look needs a cover to travel with. A track for which no cover is found has no look. The catalogs find one for nearly everything.
• The turntable has to name the track to scan for it: thirty seconds or so into a theme that lasts about a minute, unless it follows a gap (ADR-0026).
• Some other track called exactly “Knight Rider” will scan. Accepted: the title is not a common one.
• “Records only” has an exception, and a place where the next is written. One line in internal/looks, and a decision each time.
• Six effects. Each one is a reflash, a port to the console, and a row in the reference. That is still few.
• Spotify is unchanged. It publishes no cover (ADR-0016), so it has no look.

What would settle it

Tested: the titles that are the theme and the ones that are not; a dark source’s cover published with scanner, and with dark for the track after; lightd’s scene for the name; the effect on the host, as where the eye is over a cycle, its tail, and the dark around it; the console’s port against pixels printed from the firmware’s own code.

Not yet shown:

• The theme from iTunes, turntable off: the opening, the scanner, the closing.
• Whether a second and a half, and three or four LEDs, look like the thing. Both are constants.
• The theme from a record.