# Skill: effect/speed-ramp — "ספיד ראמפ" (Speed ramp)

Fast, then slow-motion on the moment, then fast again — inside the span, which keeps its length.
מהיר, ואז הילוך איטי על הרגע, ושוב מהיר — בתוך הקטע, שנשאר באותו אורך.

Category: Speed & time · מהירות וזמן · a real preview: https://media.gpt.org.il/lookbook/effects/speed-ramp.mp4?v=mv19exzc
Price: **60 credits per finished minute**: the render itself — 1 credit per second of 1080p output. Combined with captions, a hook or other effects: still one render, nothing more for combining.

Base URL: `https://apihub.co.il` · Auth: `Authorization: Bearer <API key>` · Docs: `/docs` (group "Video Effects")
Send `X-Tag: <job name>` on every call of one video; `GET /v1/usage?tag=<job name>` returns what it cost.
**Files are kept 24 hours** — download the finished video.

---

## 1. On its own — one call

```jsonc
POST /v1/effects/speed-ramp             // x-wait-ms: 110000
{
  "video_url": "https://media.gpt.org.il/samples/sample-he.mp4",
  "start": 0.6,
  "duration": 2.8
}
```

A normal render: `status: processing` → poll `GET /v1/executions/{id}` until `completed`, then read `output.url`.

When it plays: a stretch: `start` + `duration` (seconds of the finished video), or `at` (a word id) + `duration`, or `during` { from, to } (word ids).

## 2. With captions, a hook and other effects — the same render

```jsonc
POST /v1/studio/edit               // x-wait-ms: 110000
{
  "video_url": "<the video>",
  "language_code": "he",
  "captions": {
    "style": "classic"
  },
  "effects": [
    {
      "id": "speed-ramp",
      "start": 0.6,
      "duration": 2.8
    }
  ],
  "audio": {
    "normalize": true
  },
  "output": {
    "aspect_ratio": "9:16",
    "resolution": "1080",
    "fit": "crop",
    "quality": "high"
  }
}
```

`effects` is a list: add more entries for more effects. The engine applies them by pipeline stage (cuts and time →
camera → grade and looks → overlays → text and captions → sound), never by their order in the list. An edit has one
`transition`, one `color` grade, one `music` bed, one `speed` and one caption style: two effects that set the same
one are refused with a message that names them.

## 3. Params

| param | default | range / options | what it does |
|---|---|---|---|
| `slow` | `0.35` | 0.2–0.9 | The slow-motion speed (0.35 = about a third) |
| `slow_share` | `0.4` | 0.15–0.7 | How much of the span is in slow motion |
| `slow_at` | `"middle"` | `middle` · `start` · `end` | Where the slow motion sits in the span |
| `smooth` | `true` | boolean | Blend frames in the slow part (smoother) instead of repeating them |

GET `/v1/effects/speed-ramp` returns the same as JSON (with the full body schema). Every field has a default; numbers
outside their range are refused with the field's name.