# Mirelo SFX2.0 · Video to Audio API

> Creates a soundtrack for an input video and returns it as separate audio files

Adds sound to a clip given in `video_url`, returning audio files without the video. `text_prompt` and `negative_prompt` guide the result, and `preserve_speech` keeps existing speech while generating the rest. `duration` is 1 to 600 seconds, clamped to the video length, and `num_samples` gives 1 to 4 variations. Formats are wav, mp3, aac or flac.

- 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/en-US/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 |  |  | URL of the video that will receive sound. |
| `text_prompt` |  | string \| null | no |  | ≤ 2000 characters | Optional text instructions to guide generation. |
| `negative_prompt` |  | string \| null | no |  | ≤ 1000 characters | Brief exclusion list for sounds, with commas between entries. |
| `preserve_speech` |  | boolean | no | `true` |  | Speech handling for the generated soundtrack: false suppresses speech and produces sound effects only. When enabled, input speech remains intact and the rest of the soundtrack is generated around it. |
| `duration` |  | number | no | `10` | 1 – 600 | Sound duration requested in seconds; videos below 1 s return 400. The requested length must be at least 1 s and is capped at the video's duration, with generation split into 10 s windows when the duration exceeds 10 s. |
| `num_samples` |  | integer | no | `2` | 1 – 4 | Count of variations to produce. |
| `seed` |  | integer \| null | no |  | -1 – 18,446,744,073,709,552,000 | Generation seed; choosing -1 or None uses a random value. |
| `upload_audio_format` |  | enum (string) | no | `wav` | `wav`, `mp3`, `aac`, `flac` | Format used for each audio file. |
| `upload_audio_bitrate_kbps` |  | integer \| null | no |  | 32 – 320 | Upload bitrate override in kbps, rejected when upload_audio_format is lossless; leaving it unset preserves LAME V0 VBR for mp3 or a 256 kbps target for aac. For mp3, choose an exact constant rate from 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320. For aac, values from 32 to 256 specify an encoder target rather than a guaranteed rate, so mono or sparse audio may fall below it. |

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 | SFX model release used to produce the output. |
| `audio` | array of object {url, content_type, file_name, file_size} | Audio files for the generated soundtracks, with the video excluded. |

## 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