# Mirelo SFX2.0 · Video to Audio API

> 入力動画のサウンドトラックを作成し、別個の音声ファイルとして返す

`video_url`で指定したクリップに音声を追加し、動画なしで音声ファイルを返します。`text_prompt`と`negative_prompt`で結果を制御し、`preserve_speech`で既存の音声を残しながら他の音を生成できます。`duration`は1～600秒で、動画の長さを超える場合は動画長に制限されます。`num_samples`は1～4種類のバリエーションを生成します。形式はwav、mp3、aac、flacです。

- Model id: `mirelo-ai/sfx2.0/video-to-audio`
- Made by: Mirelo AI
- Category: Video to Audio
- Output: audio
- Price per second of your output audio: $0.01 / second of output audio (cheapest run $0.01 (10 API credits))
- Run: `POST https://api.doitong.ru/v1/run/mirelo-ai/sfx2.0/video-to-audio`
- Quote: `POST https://api.doitong.ru/v1/quote/mirelo-ai/sfx2.0/video-to-audio`
- Docs page: https://doitong.com/ja/developers/models/mirelo-ai/sfx2.0/video-to-audio

## Pricing

Price: **$0.01 / second of output audio**. Price per second of your output 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 $0.20 = 200 API credits (20 s output audio × $0.01).

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/mirelo-ai/sfx2.0/video-to-audio` 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 |
|---|---|---|---|---|---|---|
| `video_url` | `video` | string (video URL) | yes |  |  | 音声を付加する動画のURL。 |
| `text_prompt` |  | string \| null | no |  | ≤ 2000 characters | 生成を誘導する任意のテキスト指示。 |
| `negative_prompt` |  | string \| null | no |  | ≤ 1000 characters | 音の簡潔な除外リスト。項目はカンマで区切ります。 |
| `preserve_speech` |  | boolean | no | `true` |  | 生成されたサウンドトラックの音声処理。false にすると音声を抑制し、効果音のみを生成します。有効にすると入力音声をそのまま残し、その周囲のサウンドトラックを生成します。 |
| `duration` |  | number | no | `10` | 1 – 600 | リクエストする音声の長さ（秒単位）。1 s 未満の動画は400を返します。指定長は少なくとも1 sで、動画の長さを上限とします。長さが10 sを超える場合、生成は10 sのウィンドウに分割されます。 |
| `num_samples` |  | integer | no | `2` | 1 – 4 | 生成するバリエーション数。 |
| `seed` |  | integer \| null | no |  | -1 – 18,446,744,073,709,552,000 | 生成シード。-1 または None を選択するとランダム値が使用されます。 |
| `upload_audio_format` |  | enum (string) | no | `wav` | `wav`, `mp3`, `aac`, `flac` | 各音声ファイルに使用する形式。 |
| `upload_audio_bitrate_kbps` |  | integer \| null | no |  | 32 – 320 | kbps単位のアップロードビットレート上書き。upload_audio_format が可逆形式の場合は拒否されます。未設定にすると、mp3ではLAME V0 VBR、aacでは256 kbpsの目標値が維持されます。mp3では32、40、48、56、64、80、96、112、128、160、192、224、256、320から正確な固定レートを選択します。aacでは32～256の値は保証レートではなくエンコーダーの目標値を指定するため、モノラルまたは疎な音声ではそれを下回る場合があります。 |

File parameters (`video`) 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
{
  "video": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
}
```

A fuller example:

```json
{
  "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/mirelo-ai/sfx2.0/video-to-audio?wait=20" \
  -H "Authorization: Bearer $DOITONG_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "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/mirelo-ai/sfx2.0/video-to-audio?wait=20", {
  method: "POST",
  headers,
  body: JSON.stringify({
    "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 = {
    "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/mirelo-ai/sfx2.0/video-to-audio", 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": "mirelo-ai/sfx2.0/video-to-audio",
      "input": {
        "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": "mirelo-ai/sfx2.0/video-to-audio",
  "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": 200,
    "usd": "0.20",
    "charged": 200,
    "refunded": 0
  },
  "input": {
    "video_url": "https://content.doitong.com/video/showcase/v3/gen_fox_cartoon.mp4"
  },
  "output": {
    "model": "sfx-2.0",
    "audio": [
      {
        "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp3",
        "content_type": "audio/mpeg",
        "file_name": "0-output.mp3",
        "file_size": 1843200
      }
    ]
  },
  "outputs": [
    {
      "type": "audio",
      "url": "https://content.doitong.com/dev-api/2026/10/20/req_8k2m4q7x1z9c3v5b6n0p2r4t/0-output.mp3",
      "content_type": "audio/mpeg",
      "file_size": 1843200,
      "duration": 12,
      "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 |
|---|---|---|
| `model` | string | 出力の生成に使用するSFXモデルのリリース。 |
| `audio` | array of object {url, content_type, file_name, file_size} | 生成されたサウンドトラックの音声ファイル。動画は含まれません。 |

## Related models

- [Mirelo SFX2.0 · Video to Video](https://doitong.com/developers/models/mirelo-ai/sfx2.0/video-to-video.md) (`mirelo-ai/sfx2.0/video-to-video`): $0.01 / second of output audio
- [Mirelo SFX2.0 · Text to Audio](https://doitong.com/developers/models/mirelo-ai/sfx2.0/text-to-audio.md) (`mirelo-ai/sfx2.0/text-to-audio`): $0.01 / second of output audio
- [Hunyuan Video Foley](https://doitong.com/developers/models/hunyuan-video-foley.md) (`hunyuan-video-foley`): $0.10 / 10 seconds of input video
- [Kling Video · Video to Audio](https://doitong.com/developers/models/kling-video/video-to-audio.md) (`kling-video/video-to-audio`): $0.035 / video
- [PixVerse Sound Effects](https://doitong.com/developers/models/pixverse/sound-effects.md) (`pixverse/sound-effects`): $0.10 / 5 seconds of input video
- [Sam Audio · Visual Separate](https://doitong.com/developers/models/sam-audio/visual-separate.md) (`sam-audio/visual-separate`): from $0.05 / 30 seconds of input video
- [Sonilo V1.1](https://doitong.com/developers/models/sonilo/v1.1/video-to-music.md) (`sonilo/v1.1/video-to-music`): $0.009 / second of output audio
- [Sonilo V1.1 Video to Sound Effects](https://doitong.com/developers/models/sonilo/v1.1/video-to-sound-effects.md) (`sonilo/v1.1/video-to-sound-effects`): $0.009 / second of input video

## Links

- HTML page: https://doitong.com/developers/models/mirelo-ai/sfx2.0/video-to-audio
- 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=mirelo-ai/sfx2.0/video-to-audio
- Errors: https://doitong.com/developers/docs/errors
- Model details as JSON: https://api.doitong.ru/v1/models/mirelo-ai/sfx2.0/video-to-audio