Vinyl record player

Vinyl record player

One shot, looking straight down at a turntable in a pool of light on black. The tonearm swings in from off the frame, lowers onto the lead-in groove (its shadow tightens under it as it touches), then the platter spins up: the strobe dots on the rim smear into a blur and the label starts turning. The sound starts on the touch. It's an intro or a bridge for music, a podcast or an audio clip: its own clip, or b-roll over a few seconds of the video. Builds on tella-motion-design.

Ask once

Work out without asking: the label's words (the video's title, the episode or song name, the speaker's name in the transcript), whether the video has speech or music to play (get_transcript, get_timeline), its beats if a track plays (get_music_beats), and attachments on the message. Then one ask_form, every field prefilled, so the user can just submit:

Skipped form: use the prefilled values. Media can't go in a form:

• Label artwork: if the message has a square image attached (cover art, logo), use it as the label in place of label.png, masked to the label circle, and leave the text fields empty (untested). Don't ask for artwork that isn't there.
• Your own photo (Deck = My own photo): if none is attached, ask_question for "one photo taken straight down over the spindle, phone flat and level, the tonearm parked on its rest off the record, even light, no glare on the label; any turntable". Cover any brand marks before use. No photo: use Tella's deck.
• The clip's own audio on its own clip: the stretch to play, from the transcript or the user's message as from <word/time> to <word/time>; ask with ask_question only when the video has several candidates.

Timing

D is the needle drop. Key everything from it, on the document's clock:

On b-roll, put D on the first downbeat of a song (get_music_beats) or on the word that introduces it, and start the graphic D−3.6 s before.

The look

Grant's example: 1920×1080, 10 s, D = 3.6 s. Every layer's file, position, size, anchor and keys are in references/tella-deck.md; follow it exactly.

• Black fill, the static deck photo (record, platter, plinth) full frame, the spindle at (960, 536).
• The rim is two layers over it: strobe dots that spin for 1.2 s, then a ready-blurred ring that never rotates.
• The label (label.png, a plain white paper label with a small hand-drawn smiley) is a disc of radius 163 px on (960.5, 536.5); it and anything on it turn about that point. The spindle sits on top, still.
• The tonearm's pivot is off the top right at (1632, 230): it starts out of frame and only its headshell and the end of the arm swing in.
• Spotlight on top: fx.vignette amount 1, size 0.19, softness 0.475, black. It hides the plinth and the corners.
• Label text: the title in Inter 700 27 px #16161A, box (840.5, 568) 240 wide, centred; the second line in Inter 600 17 px, tracked 0.18, #6B675E, box (840.5, 608). Both below the spindle, clear of the smiley. Give them the label's anchor and rotation keys and paint them just above it.
• Motion blur (shutter 180°) on the label, its text, the dots and the arm. The record's light sheen is in the static photo and never turns.

Building it

1. Get the files. Tella's deck: $HOME/.agents/skills/vinyl-record-player/assets/, else /workspace/skills/vinyl-record-player/assets/; outside the editor, get_community_skill vinyl-record-player gives a download url for each file. For each PNG: create_source kind: 'image' with its width and height, PUT the bytes (Content-Type: image/png) to uploadUrl. Eight uploads.
2. New 1920×1080 document (no videoId for its own clip; with videoId for b-roll), canvas = Length. addMedia each sourceId in the table's order, then node.patch each destination (addMedia lands with fit: contain), setProperty anchorX/anchorY, setKeyframes, setMotionBlur, and the spotlight last: a #00000000 full-frame shape with addEffect fx.vignette, backdrop: true.
3. Label text: addTitle both lines, node.move them to just above label (parent: "", index), then the label's anchor and rotation keys.
4. Generated or My own photo: references/deck-prompts.md (a generate_image prompt and a decompose_image split into a plate and a tonearm layer; the plate's rim is masked out and spun, the label drawn).
5. Its own clip: create_clip type: 'motion' with the documentId (a new video, or videoId to append). B-roll: add_layout with media: {type: 'motion', documentId} inside one clip. A layout can't span clips: split a range at clip boundaries, one document per clip.

Sound in the result

A Tella Motion clip is silent until you give it sound:

• Tella track (tested): list_library scope: 'default', type: 'music' gives the track's url. Download it, create_source kind: 'audio' with its duration, PUT the bytes, then add_sound_effect on the motion clip with that sourceId, starting at D minus the track's leading silence, until the clip's end. Vinyl Memories has 2.82 s of silence. Measure it (ffmpeg -af silencedetect=n=-50dB). add_sound_effect refuses a music presetId, and set_background_music loops the whole video from 0, so it can't start on the drop.
• The clip's own audio on its own clip (untested): addMedia the clip's source into the document at D, node.patch sourceIn to the range start and common.hidden: true (it keeps playing).
• B-roll: the clip's own audio plays on under it; nothing to add.
• A soft touch: curated press at D−0.55, volume 0.5.

Check

get_filmstrip of the document at 0, D−1.9 (mid-swing), D−0.3 (shadow closing), D, D+0.7 (dots smearing), D+3 and the end. Look for: the stylus on the lead-in, not on the label; the arm turning about its pivot, not drifting; the label text readable at D+3 and turning with the label; no seam between the dots and the blurred rim. Then get_video_preview the result and confirm it isn't silent and the sound starts within 0.1 s of D (ffmpeg volumedetect in 0.25 s windows). The first preview right after an upload can be silent while the source processes: render it again a minute later.

Gotchas

• get_motion_frame needs startTimeMs. inspect_motion_node_properties takes path, not node.
• A new title paints on top of everything, the spotlight included, until you node.move it.
• Anchors are canvas pixels, not the layer's own: without them every layer turns about (960, 540) and the arm flies off.
• Generated decks sometimes add a logo or lettering; regenerate (or mask it) rather than use one.

Variations

• 45 rpm for an upbeat intro; a slower 0.9 s swing for a calm one.
• Behind an audiogram or captions: build it as b-roll and put the text on top.