Having troubles writing position in Premiere

Premiere Pro
1

Writing a Position (or any PointF-typed) keyframe value through the UXP scripting API silently corrupts the value to 32767, 32767 (INT16_MAX — a classic uninitialized-memory sentinel) instead of storing what was requested. No error is thrown. The API’s own immediate readback even reports a plausible-looking {value: [x, y]} shape — the corruption only becomes visible when you look at Effect Controls. This blocks any workflow that needs to programmatically write animated 2D-point parameters (Position, Anchor Point, and likely Scale).

Minimal repro

js

const project = await require('premierepro').Project.getActiveProject();
const sequence = await project.getActiveSequence();
const clip = (await (await sequence.getSelection()).getTrackItems())[0];
const chain = await clip.getComponentChain();
// find the intrinsic Motion component (matchName "AE.ADBE Motion")
const posParam = await motionComponent.getParam(0); // "Position"

await project.lockedAccess(() => {
  project.executeTransaction((ca) => {
    ca.addAction(posParam.createSetTimeVaryingAction(true));
  }, "enable time-varying");
});

await project.lockedAccess(() => {
  project.executeTransaction((ca) => {
    const pt = new ppro.PointF(200, 200);   // also tried: new PointF() + pt.x=200; pt.y=200 — identical result
    const kf = posParam.createKeyframe(pt); // documented signature: createKeyframe(inValue: PointF)
    kf.position = ppro.TickTime.createWithTicks(someTicksString);
    ca.addAction(posParam.createAddKeyframeAction(kf));
  }, "write test keyframe");
});
// getValueAtTime() afterward reports {value: [x, y]} — looks fine via API.
// Effect Controls shows 32767, 32767 — not 200, 200.

Environment: Premiere Pro 26.5.1, manifest v5, tested via UDT debug session.

  1. Where does the corruption happen — the JS↔native marshaling layer, or inside the parameter engine after receiving a correctly-formed PointF? (We tested two different construction patterns — constructor args vs. property assignment — both produced the identical 32767 sentinel, which points away from a JS-side construction mistake.)
  2. Is there a different, currently-undocumented correct pattern for writing point-type keyframe values? We followed the documented createKeyframe(inValue: PointF) signature exactly.
  3. Does this affect all PointF-typed params, or specifically Position?
2

Hey @MoisesNavarroSolera,

Thanks for the detailed report! This is less a “corruption” issue and more a documentation (or lack thereof) one. PointF-based keyframes work based on normalized values rather than pixel-based values: if you get the initial value for the Position param, you’ll get something like:

const project = await require('premierepro').Project.getActiveProject();
const sequence = await project.getActiveSequence();
const clip = (await (await sequence.getSelection()).getTrackItems())[0];
const chain = await clip.getComponentChain();
// find the intrinsic Motion component (matchName "AE.ADBE Motion")
const posParam = await motionComponent.getParam(0); // "Position"

const value = await posParam.getStartValue();
console.log(value.value);  // [0.5, 0.5]

That [0.5, 0.5] refers to frame center. If you wanted to adjust the “Motion > Position” param specifically you can do so by normalizing against the sequence’s frame rect first, e.g.:

const sequence = await project.getActiveSequence();
const sequenceSettings = await sequence.getSettings();
const videoFrameRect = await sequenceSettings.getVideoFrameRect();

project.lockedAccess(() => {
  // Normalize the x, y values by dividing the
  // pixel value by frame width/height
  const pt = new ppro.PointF(
    200 / videoFrameRect.width,
    200 / videoFrameRect.height
  );
  const kf = posParam.createKeyframe(pt);
  kf.position = ppro.TickTime.createWithTicks(someTicksString);

  project.executeTransaction((ca) => {
    ca.addAction(posParam.createAddKeyframeAction(kf));
  }, "write test keyframe");
});

Can you see if doing that gets you closer to what you’re expecting?

2 Likes
# [PPro UXP 26] How do I write a PointKeyframe value? (Motion / Transform Position)
3

Thank you Cameron! Yes, this solve my issue.

can temporal bezier handles be read or written?

We’re building a panel that copies keyframed animations between clips. With Keyframe.temporalInterpolationMode and createSetInterpolationAtKeyframeAction we can read and set Linear, Hold and Bezier, but a Bezier keyframe always comes back with default handles.

  1. Is there any API to read or write the temporal handles (influence and speed, or in/out tangents) of a keyframe?
  2. The same question for spatial handles on Position.
  3. If not, is there a planned API? And is getValueAtTime intended to be accurate enough to reconstruct the curve by sampling?
  4. Are there limits on how many keyframes one transaction can add?
4

Right now there isn’t any support for temporal ease or spatial handles yet, but we can certainly look to adding these sorts of features in the future. I’ve created DVAPR-4268138 on our side to track this more.

To answer your questions:

  1. Not yet
  2. Not yet
  3. getValueAtTime should be accurate enough.
  4. None as far as I’m aware, but I’d love to know if you find one!
1 Like