# LTX 2.3 Video Pro · Audio to Video API

> 오디오 파일에서 클립을 생성하고 선택적으로 첫 프레임 이미지에 맞출 수 있는 프로 오디오-동영상 모델

오디오 파일을 따라가는 비디오를 생성하며, `image_url`로 시작 이미지를 선택적으로 제공할 수 있습니다. 이미지가 없으면 최대 5000자로 된 `prompt`가 필요합니다. 오디오는 2 to 20초여야 하며 Pro 모델에서는 최대 10초입니다. `aspect_ratio`는 auto, 16:9 또는 9:16이고, `guidance_scale`의 범위는 1 to 50입니다.

- Model id: `ltx-2.3/audio-to-video`
- Made by: Lightricks
- Category: Lipsync & Avatars
- Output: video
- Price per second of your input audio: $0.10 / second of input audio (cheapest run $0.10 (100 API credits))
- Run: `POST https://api.doitong.com/v1/run/ltx-2.3/audio-to-video`
- Quote: `POST https://api.doitong.com/v1/quote/ltx-2.3/audio-to-video`
- Docs page: https://doitong.com/ko/developers/models/ltx-2.3/audio-to-video

## Pricing

Price: **$0.10 / second of input audio**. Price per second of your input audio: the input files are measured before the run (length, resolution, frame rate). The quote measures the same files and is exactly what the run charges.

The full example input below costs $1.00 = 1000 API credits (10 s input audio × $0.10).

Prices are the upstream price in USD, paid from the API balance in API credits (1000 API credits = 1 USD). `POST https://api.doitong.com/v1/quote/ltx-2.3/audio-to-video` 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

Send either the canonical name or the native field name (not both). Canonical names are the same across models.

| Parameter | Canonical name | Type | Required | Default | Allowed values / range | Description |
|---|---|---|---|---|---|---|
| `audio_url` | `audio` | string (audio URL) | yes |  |  | 동영상 생성의 소스로 사용되는 오디오 파일 URL입니다. 공개적으로 접근 가능한 URL 또는 base64 data URI를 제공해야 합니다. 오디오 길이는 2–20초여야 하며, pro 모델은 10초로 제한됩니다. |
| `image_url` | `image` | string (image URL) \| null | no |  |  | 시작 프레임 이미지 URL입니다. 생략하면 프롬프트가 필수입니다. |
| `prompt` |  | string \| null | no |  | 1 – 5000 characters | `image_url`에 따라 역할이 달라지는 동영상 지시문입니다. 이미지가 있으면 해당 이미지의 애니메이션을 지정하고, 없으면 생성할 동영상을 설명해야 합니다. |
| `guidance_scale` |  | number \| null | no |  | 1 – 50 | 동영상 생성 시 프롬프트 준수 강도입니다. 이미지 사용 시 기본값은 9, 텍스트-동영상 사용 시 5입니다. 프롬프트와 더 가깝게 일치시키려면 값을 높입니다. |
| `aspect_ratio` |  | enum (string) | no | `auto` | `auto`, `16:9`, `9:16` | 동영상 화면비입니다. 'auto'는 입력 이미지가 제공되면 이미지에서 비율을 추출하고, 그렇지 않으면 16:9를 선택합니다. |
| `enable_safety_checker` |  | boolean | no | `true` |  | 호출자에게 권한이 있으면 false로 설정해 검사를 완화할 수 있습니다. |

File parameters (`audio`, `image`) take a public `https://` URL, a `data:` URI up to 10 MB, or the `file_url` of an upload from `POST /files`.

## Example input

Required parameters only:

```json
{
  "audio": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

A fuller example:

```json
{
  "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
}
```

## 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.com/v1/run/ltx-2.3/audio-to-video?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }'

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

### JavaScript

```javascript
const API = "https://api.doitong.com/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-2.3/audio-to-video?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  }),
});
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.com/v1"
headers = {"Authorization": "Bearer " + os.environ["DOITONG_API_KEY"]}

payload = {
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3",
}

# Run the model; wait up to 20 s for the finished result in the same call
r = requests.post(API + "/run/ltx-2.3/audio-to-video", 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.com/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-2.3/audio-to-video",
      "input": {
        "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
      },
      "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-2.3/audio-to-video",
  "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": 1000,
    "usd": "1.00",
    "charged": 1000,
    "refunded": 0
  },
  "input": {
    "audio_url": "https://content.doitong.com/audio/showcase/v3/tools/dub_es.mp3"
  },
  "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,
      "width": 1024,
      "height": 768,
      "fps": 1.0,
      "duration": 5,
      "num_frames": 1
    }
  },
  "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.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t",
    "cancel": "https://api.doitong.com/v1/requests/req_8k2m4q7x1z9c3v5b6n0p2r4t/cancel"
  }
}
```

### Output fields (`output`)

| Field | Type | Description |
|---|---|---|
| `video` | object {url, content_type, file_name, file_size, width, height, fps, duration, num_frames} | 결과 동영상 파일입니다. |

## Related models

- [LTX 2.3 Video Fast · Text to Video](https://doitong.com/developers/models/ltx-2.3/text-to-video/fast.md) (`ltx-2.3/text-to-video/fast`): from $0.06 / second
- [LTX Video 2.3 Pro · Text to Video](https://doitong.com/developers/models/ltx-2.3/text-to-video.md) (`ltx-2.3/text-to-video`): from $0.08 / second
- [LTX 2.3 Video Fast · Image to Video](https://doitong.com/developers/models/ltx-2.3/image-to-video/fast.md) (`ltx-2.3/image-to-video/fast`): from $0.06 / second
- [LTX 2.3 Video Pro · Image to Video](https://doitong.com/developers/models/ltx-2.3/image-to-video.md) (`ltx-2.3/image-to-video`): from $0.08 / second
- [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 Video 2.3 Pro · Extend Video](https://doitong.com/developers/models/ltx-2.3/extend-video.md) (`ltx-2.3/extend-video`): $0.10 / second
- [LTX Video 2.3 Pro · Retake Video](https://doitong.com/developers/models/ltx-2.3/retake-video.md) (`ltx-2.3/retake-video`): $0.10 / second
- [Kling AI Avatar 2.0 Pro](https://doitong.com/developers/models/kling-video/ai-avatar/v2/pro.md) (`kling-video/ai-avatar/v2/pro`): $0.115 / second of input audio

## Links

- HTML page: https://doitong.com/developers/models/ltx-2.3/audio-to-video
- 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-2.3/audio-to-video
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.com/v1/models/ltx-2.3/audio-to-video