# LTX Video-0.9.7 13B Distilled · Extend API

> 使用 0.9.7 distilled 13B 模型和文字提示詞延伸現有影片

延續 `video` 中的片段，並由必要的 `prompt` 引導。輸出為 480p 或 720p，`aspect_ratio` 可為 auto、9:16、1:1 或 16:9，`num_frames` 為 9 到 1441。`constant_rate_factor`（0 到 51）控制輸入壓縮，`loras` 接受自訂權重。

- Model id: `ltx-video-13b-distilled/extend`
- Made by: Lightricks
- Category: Video to Video
- Output: video
- Price: $0.04 / video (cheapest run $0.04 (40 API credits))
- Run: `POST https://api.doitong.ru/v1/run/ltx-video-13b-distilled/extend`
- Quote: `POST https://api.doitong.ru/v1/quote/ltx-video-13b-distilled/extend`
- Docs page: https://doitong.com/zh-TW/developers/models/ltx-video-13b-distilled/extend

## Pricing

Price: **$0.04 / video**. Billed once per generated video.

The full example input below costs $0.04 = 40 API credits (1 video × 40 API credits).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.ru/v1/quote/ltx-video-13b-distilled/extend` with the same JSON body returns the exact price for that input; the quote is exactly what a run charges. Invalid input is never charged and failed or canceled requests are refunded automatically.

## Input parameters

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `prompt` |  | string | yes |  |  | 引導生成的文字指示。 |
| `negative_prompt` |  | string | no | `worst quality, inconsistent motion, blurry, jittery, distorted` |  | 生成用的負面文字指示。 |
| `loras` |  | array of object {path, weight_name, scale} | no | `[]` |  | 生成期間套用的 LoRA 權重。 |
| `loras[].path` |  | string | yes |  |  | LoRA 權重的位置，以 URL 或路徑提供。 |
| `loras[].weight_name` |  | string \| null | no |  |  | 用於在 HuggingFace 儲存庫的多個權重中選取權重的 LoRA 權重名稱；只有包含多個權重的儲存庫需要此項。除非 `path` 指向 HuggingFace 儲存庫，否則此設定不會生效。 |
| `loras[].scale` |  | number | no | `1` | 0 – 4 | 載入 LoRA 權重時用於縮放權重的乘數。 |
| `resolution` |  | enum (string) | no | `720p` | `480p`, `720p` | 輸出影片的解析度。 |
| `aspect_ratio` |  | enum (string) | no | `auto` | `9:16`, `1:1`, `16:9`, `auto` | 影片長寬比。 |
| `seed` |  | integer \| null | no |  |  | 控制生成期間隨機性的種子。 |
| `num_frames` |  | integer | no | `121` | 9 – 1,441 | 影片的總影格數。 |
| `first_pass_num_inference_steps` |  | integer | no | `8` | 2 – 12 | 第一遍的推論步驟數。 |
| `second_pass_num_inference_steps` |  | integer | no | `8` | 2 – 12 | 第二遍的推論步驟數。 |
| `second_pass_skip_initial_steps` |  | integer | no | `5` | 1 – 11 | 第二遍省略的初始推論步驟數，使該遍偏向細節處理，而非大幅變更。 |
| `frame_rate` |  | integer | no | `24` | 1 – 60 | 影片的影格率。 |
| `expand_prompt` |  | boolean | no | `false` |  | 透過語言模型擴展提示詞。 |
| `reverse_video` |  | boolean | no | `false` |  | 反轉影片播放順序。 |
| `enable_safety_checker` |  | boolean | no | `true` |  | 安全檢查開關；關閉設定僅對已授權帳戶有效。所有未獲該授權的請求都會進行安全檢查。 |
| `enable_detail_pass` |  | boolean | no | `false` |  | 啟用後改善影片細節的選用第二精修遍。 |
| `temporal_adain_factor` |  | number | no | `0.5` | 0 – 1 | 自適應實例正規化（AdaIN）強度；較高值平衡色彩一致性，較低值允許更大的色彩變化。它會作用於第一個以外的生成區塊，在整部影片中正規化色彩分布，以協助抑制飽和度或對比度逐步升高。 |
| `tone_map_compression_ratio` |  | number | no | `0` | 0 – 1 | 色調映射壓縮程度，範圍從 0.0 的不壓縮到 1.0 的最大壓縮。以此方式壓縮影片動態範圍可提升視覺品質。 |
| `constant_rate_factor` |  | integer | no | `29` | 0 – 51 | 用於輸入壓縮的固定速率因子（CRF），可能透過使提供的媒體更接近模型訓練資料來改善動態品質。 |
| `video` |  | object {video_url, start_frame_num, strength, limit_num_frames, max_num_frames, resample_fps, target_fps, reverse_video} | yes |  |  | 用於延長的來源影片。 |
| `video.video_url` |  | string (video URL) | yes |  |  | 透過 URL 提供的條件影片。 |
| `video.start_frame_num` |  | integer | no | `0` | 0 – 1,440 | 影片中的條件起始位置，以可被 8 整除的影格編號指定。 |
| `video.strength` |  | number | no | `1` | 0 – 1 | 條件強度：0.0 停用條件，1.0 完全套用。 |
| `video.limit_num_frames` |  | boolean | no | `false` |  | 影片影格上限開關：啟用後，`max_num_frames` 會限制從影片取用的影格數。 |
| `video.max_num_frames` |  | integer | no | `1441` | 1 – 1,441 | 影片影格使用上限；None 表示選取整部影片，而非限制影格數。 |
| `video.resample_fps` |  | boolean | no | `false` |  | 影片影格率轉換開關：啟用後，會以 `target_fps` 指定的速率重新取樣影片。 |
| `video.target_fps` |  | integer | no | `24` | 1 – 60 | 重新取樣影格率（FPS），僅在啟用 `resample_fps` 時適用。 |
| `video.reverse_video` |  | boolean | no | `false` |  | 影片順序反轉，適用於需要條件內容依反向影格順序排列的工作。 |

## Example input

Required parameters only:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "video": {
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }
}
```

A fuller example:

```json
{
  "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
  "video": {
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  }
}
```

## Run it

Set `DOITONG_API_KEY` to a key from https://doitong.com/developers/dashboard#keys. `?wait=20` returns the finished request in the same call when it is ready within 20 seconds; otherwise poll `GET /requests/{id}` (it also accepts `?wait=`), or pass `webhook_url`.

### curl

```bash
# Run the model; wait up to 20 s for the finished result in the same call
curl -X POST "https://api.doitong.ru/v1/run/ltx-video-13b-distilled/extend?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video": {
      "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
    }
  }'

# Still "queued" or "running"? Poll with the id from the response:
curl "https://api.doitong.ru/v1/requests/REQUEST_ID?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY"
```

### JavaScript

```javascript
const API = "https://api.doitong.ru/v1";
const headers = {
  "Authorization": "Bearer " + process.env.DOITONG_API_KEY,
  "Content-Type": "application/json",
};

// Run the model; wait up to 20 s for the finished result in the same call
let res = await fetch(API + "/run/ltx-video-13b-distilled/extend?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video": {
      "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
    }
  }),
});
let request = await res.json();
if (!res.ok) throw new Error(request.error.code + ": " + request.error.message);

// Not finished yet: long-poll until it is
while (request.status === "queued" || request.status === "running") {
  res = await fetch(API + "/requests/" + request.id + "?wait=20", { headers });
  request = await res.json();
}
if (request.status !== "succeeded") throw new Error(JSON.stringify(request.error));
console.log(request.outputs.map((o) => o.url), request.cost.credits + " API credits ($" + request.cost.usd + ")");
```

### Python

```python
import os
import requests

API = "https://api.doitong.ru/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video": {
        "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4",
    },
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ltx-video-13b-distilled/extend", params={"wait": 20}, json=payload, headers=headers)
request = r.json()
if not r.ok:
    raise RuntimeError(request["error"]["code"] + ": " + request["error"]["message"])

# Not finished yet: long-poll until it is
while request["status"] in ("queued", "running"):
    request = requests.get(API + "/requests/" + request["id"], params={"wait": 20}, headers=headers).json()
if request["status"] != "succeeded":
    raise RuntimeError(request["error"])
print([o["url"] for o in request["outputs"]], request["cost"]["credits"], "API credits", "$" + request["cost"]["usd"])
```

### MCP

The MCP server at `https://api.doitong.ru/v1/mcp` exposes the tools `search_models`, `get_model`, `quote`, `run`, `get_request`, `cancel_request`, `list_requests`, `create_upload` and `get_account`. A `run` call for this model:

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "run",
    "arguments": {
      "model_id": "ltx-video-13b-distilled/extend",
      "input": {
        "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
        "video": {
          "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
        }
      },
      "wait_seconds": 20
    }
  }
}
```

## Response

Every call returns a request object. `status` is one of `queued`, `running`, `succeeded`, `failed`, `canceled`. `outputs` lists the generated files with URLs on our storage (kept forever, or 7 days with `?storage=temporary`; `storage` says which); `output` is the model's own result object with the same URLs.

```json
{
  "id": "req_8k2m4q7x1z9c3v5b6n0p2r4t",
  "object": "request",
  "model": "ltx-video-13b-distilled/extend",
  "status": "succeeded",
  "created_at": "2026-10-20T12:00:00Z",
  "started_at": "2026-10-20T12:00:02Z",
  "completed_at": "2026-10-20T12:00:09Z",
  "queue_position": null,
  "cost": {
    "credits": 40,
    "usd": "0.04",
    "charged": 40,
    "refunded": 0
  },
  "input": {
    "prompt": "A red fox trots through fresh snow at sunrise, soft golden light, shallow depth of field",
    "video": {
      "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
    }
  },
  "output": {
    "video": {
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_name": "0-output.mp4",
      "file_size": 1843200
    },
    "prompt": "Woman walking on a street in Tokyo",
    "seed": 42
  },
  "outputs": [
    {
      "type": "video",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp4",
      "content_type": "video/mp4",
      "file_size": 1843200,
      "width": 1280,
      "height": 720,
      "duration": 5,
      "stored": true
    }
  ],
  "error": null,
  "metrics": {
    "inference_seconds": 6.8
  },
  "urls": {
    "self": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.ru/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `video` | object {url, content_type, file_name, file_size} | 生成產生的影片檔案。 |
| `prompt` | string | 用於生成輸出的提示詞。 |
| `seed` | integer | 生成期間套用的種子值。 |

## Related models

- [LTX Video-0.9.7 13B Distilled](https://doitong.com/developers/models/ltx-video-13b-distilled.md) (`ltx-video-13b-distilled`): from $0.04 / second of output video
- [LTX Video-0.9.7 13B Distilled · Image to Video](https://doitong.com/developers/models/ltx-video-13b-distilled/image-to-video.md) (`ltx-video-13b-distilled/image-to-video`): from $0.04 / second of output video
- [LTX Video-0.9.7 13B Distilled · Multiconditioning](https://doitong.com/developers/models/ltx-video-13b-distilled/multiconditioning.md) (`ltx-video-13b-distilled/multiconditioning`): from $0.04 / second of output video
- [Ltx 2.3](https://doitong.com/developers/models/ltx-2.3/reframe.md) (`ltx-2.3/reframe`): from $0.10 / second of input video
- [LTX 2.3 22B](https://doitong.com/developers/models/ltx-2.3-22b/reference-video-to-video/lora.md) (`ltx-2.3-22b/reference-video-to-video/lora`): $0.00181 / megapixel of output video
- [Ltx 2.3 Quality · Clean Plate](https://doitong.com/developers/models/ltx-2.3-quality/clean-plate.md) (`ltx-2.3-quality/clean-plate`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Colorization](https://doitong.com/developers/models/ltx-2.3-quality/colorization.md) (`ltx-2.3-quality/colorization`): $0.00241 / megapixel of output video
- [Ltx 2.3 Quality · Cross Eyed](https://doitong.com/developers/models/ltx-2.3-quality/cross-eyed.md) (`ltx-2.3-quality/cross-eyed`): $0.00241 / megapixel of output video

## Links

- HTML page: https://doitong.com/developers/models/ltx-video-13b-distilled/extend
- All models and guides for AI agents: https://doitong.com/developers/llms.txt
- OpenAPI 3.1 with this model's typed request body: https://doitong.com/developers/openapi.json?model=ltx-video-13b-distilled/extend
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/ltx-video-13b-distilled/extend