> ## Documentation Index
> Fetch the complete documentation index at: https://docs.omniall.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Subtitle / Watermark Removal API

> OmniAll self-developed subtitle and watermark removal guide: auto mode, region boxes, and per-second billing.

# Subtitle / Watermark Removal API

Pass a public source video URL and poll for a clip with hard subtitles or fixed watermarks removed.

| Action | Method | Path |
| - | - | - |
| Create | `POST` | `/v1/video/generations` (also `/v1/videos`) |
| Fetch | `GET` | `/v1/video/generations/{task_id}` |

**Host:** `https://api.omniall.ai` · Auth `Authorization: Bearer sk-...` · Model: `omniall-desub-1`

| Item | Notes |
| - | - |
| Auto mode | Omit `videoName` |
| Region / watermark | `videoName`: `x1_y1_x2_y2` (true video pixels) |
| `duration` / `seconds` | 1–600s; strongly recommended; default billing 10s |
| `prompt` | Required; e.g. `"remove subtitles"` |

```bash theme={null}
curl -X POST "https://api.omniall.ai/v1/video/generations" \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "omniall-desub-1",
    "prompt": "remove subtitles",
    "video_url": "https://cdn.example.com/input.mp4",
    "duration": 16
  }'
```

Full fields: **API Reference → Platform → Subtitle / Watermark Removal**.

## Capabilities and limits

| Item | Notes |
| - | - |
| Removes | Hard-burned subtitles / on-screen text, static corner marks / channel bugs / logo watermarks |
| Not suitable | Moving watermarks, full-frame translucent overlays (only fixed regions can be erased) |
| Input | Public http/https direct video URL; upload local files first |
| Format | Server **auto-converts to standard mp4** before processing; mp4 / mov / CapCut exports and similar are fine |
| Duration | 1–600 seconds (within 10 minutes) |
| File size | Upload API suggests ≤ 60MB; compress or split if larger |
| Output | Same resolution and duration as source, original audio kept |

## FAQ

| Symptom / error | Cause | Fix |
| - | - | - |
| `prompt is required` | Missing `prompt` | Pass any non-empty string, e.g. `"remove subtitles"` |
| Needs a public video URL | `video_url` is not public http/https | Upload first, or use a directly downloadable link |
| Subtitles still there after region mode | Box missed the text, or coordinates used preview pixels | Use **true video pixels**, pad the box; if unsure, try auto mode first |
| Erased area looks blurry | Inpainting fills from surrounding pixels; larger boxes show more artifacts | Keep the box tight around the subtitle / watermark |
| Both subtitles and watermark | One region per request | Submit twice; reuse the first `result_url` as input |
| Desub service balance insufficient | Temporary upstream unavailability | Contact us; charges are refunded |
| Stuck processing | Long video | Keep polling; if unfinished after 30 minutes, contact us with `task_id` |


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