FFmpeg Trim Video
Trim Video cuts one window out of a finished clip: state where the cut starts and where it ends, and the result is a new, shorter clip.
assembly · model trim-video · catalog model-catalog@2026-10-06.v5 · pricing customer-pricing@2026-11-05.v15.Endpoint
POST https://api.roasos.com/v1/assembly/trim-videoSend your API key as a bearer token. The key needs the scope api:write. Every paid request also needs an Idempotency-Key header.
The envelope fields quote_only, quote_id, webhook_url and wait_timeout_seconds behave the same on each model endpoint. Refer to Jobs and Quotes and credits.
Good at
Cut a long source down before an operation with a length ceiling — a recast source must be 15 seconds or shorter, and this door is the trim primitive that gets it there. Also good for pulling one usable segment out of a long take.
The price is one credit, flat.
Pricing
The unit is one operation. Pricing key: trim-video.
| Request | Credits |
|---|---|
per_operation | 1 |
The credits come from the roasOS pricing table. No other field changes the price. To get the exact price of your request, send it with quote_only: true first.
Modes
trim-video
Provider endpoints: fal-ai/workflow-utilities/trim-video.
Request fields
| Field | Type | Required | Default | Rule |
|---|---|---|---|---|
duration_seconds | number | no | — | 0.1–180 |
end_time_seconds | number | no | — | 0–180 |
quote_id | string | no | — | UUID |
quote_only | boolean | no | false | — |
start_time_seconds | number | yes | — | 0–180 |
video_url | string | yes | — | https URL; ≤ 4,096 characters |
wait_timeout_seconds | integer | no | 0 | 0–60 |
webhook_url | string | no | — | https URL; ≤ 4,096 characters |
The schema is strict. A field that is not in this table gets 400 unsupported_option. The field names are the roasOS role names. One role has one name in every family.
Media
This endpoint accepts these media roles:
video_url— the source video
| Role | Items | Maximum size | Content types | Duration |
|---|---|---|---|---|
video_url | ≤ 1 | 100 MB | video/mp4 | 0–180 s |
Every other role is refused: avatar_id, elements, product_id, product_images, references, reference_images, image_url, end_image_url, scene_id, scene_image, video_urls, audio_urls, audio_url, voice_id. A refused role gets 400 unsupported_option.
https://cdn.roasos.com that your workspace owns. Any other URL gets 400 reference_media_not_workspace_owned. Refer to Reference media and uploads to learn how to put a file there.Prompt
None. This operation takes no prompt.
All three numbers are seconds. start_time_seconds is required, and 0 means "from the top" — there is no default, because the provider would otherwise start the cut at 1 second on its own. State exactly one of end_time_seconds (an absolute point, which must be past the start) or duration_seconds (a length measured from the start). The provider ignores duration when end_time is present, so sending both is refused rather than half-honoured.
Not exposed
These catalog entries describe omitted inputs, pinned values and source constraints. They do not imply that the provider accepts every listed field.
start_time— pinned tofal defaults it to 1; this door requires an explicit value (0 is allowed) and always sends it.duration— pinned tofal defaults it to 2 and ignores it beside end_time; this door requires exactly one of end_time/duration and sends only that one.
Result
The result kind is video. Always present: url.
{
"data": {
"id": "gen_…",
"kind": "video",
"model": "trim-video",
"status": "completed",
"result": {
"url": "https://cdn.roasos.com/workspaces/ws_01/result"
}
}
}The files are immutable objects on https://cdn.roasos.com. A result URL is a valid media input for your next request.
Example
The three steps are always the same: quote, run, poll.
# 1. Quote. Nothing is spent.
curl -X POST https://api.roasos.com/v1/assembly/trim-video \
-H "Authorization: Bearer roasos_sk_live_..." \
-H "Idempotency-Key: 0f1c9e2a-trim-video-0001" \
-H "Content-Type: application/json" \
-d '{"quote_only":true,"start_time_seconds":0,"video_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"}'
# 200 { "data": { "kind": "quote", "quote_id": "q_7Hk...", "credits": 1, "expires_at": "...",
# "confirmation": { "model": "trim-video", "example": "per_operation" } } }
# 2. Run. Same body, same Idempotency-Key, quote_id in place of quote_only.
curl -X POST https://api.roasos.com/v1/assembly/trim-video \
-H "Authorization: Bearer roasos_sk_live_..." \
-H "Idempotency-Key: 0f1c9e2a-trim-video-0001" \
-H "Content-Type: application/json" \
-d '{"quote_id":"q_7Hk...","start_time_seconds":0,"video_url":"https://cdn.roasos.com/workspaces/ws_01/uploads/video_url.mp4"}'
# 201 { "data": { "id": "gen_...", "status": "queued", "credits_reserved": 1 } }
# 3. Poll, then read the result.
curl https://api.roasos.com/v1/jobs/gen_.../status -H "Authorization: Bearer roasos_sk_live_..."
curl https://api.roasos.com/v1/jobs/gen_.../result -H "Authorization: Bearer roasos_sk_live_..."Today
The endpoint is POST /v1/assembly/trim-video.
It is live.
See also
llms.txtfor this model — the same facts as one plain-text file for an agent.GET https://api.roasos.com/v1/catalog/trim-video— the machine-readable form: enums, defaults, limits and prices. Refer to the API reference.- Jobs — how to poll a job and read its result.
- Provider endpoints:
fal-ai/workflow-utilities/trim-video.
Text Overlay
Text Overlay puts one line of copy on a finished clip. The copy shows as white text in a dark, rounded card. You set the position and the time window. The clip keeps its own sound.
Auto Subtitle
Auto Subtitle transcribes a clip and burns word-timed captions into it. It is the only caption model that also returns word-level timings and a transcript.