# Ltx 2.3 Quality

> Generate high-quality video with audio from images using LTX-2.3


## Overview

- **Endpoint**: `https://fal.run/fal-ai/ltx-2.3-quality/image-to-video`
- **Model ID**: `fal-ai/ltx-2.3-quality/image-to-video`
- **Category**: image-to-video
- **Kind**: inference
**Tags**: image-to-video



## Pricing

Your request will cost $0.0024075 per megapixel of generated video data (width × height × frames), rounded up. For example, if you generate a video that is 121 frames long at 1280 × 720, your total generated video is ≈112 MP, and your request will cost $0.270.

For more details, see [fal.ai pricing](https://fal.ai/pricing).

## API Information

This model can be used via our HTTP API or more conveniently via our client libraries.
See the input and output schema below, as well as the usage examples.


### Input Schema

The API accepts the following input parameters:


- **`prompt`** (`string`, _required_):
  The prompt to guide the video generation.
  - Examples: "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence."

- **`image_url`** (`string`, _required_):
  The URL of the starting image.
  - Examples: "https://storage.googleapis.com/falserverless/example_inputs/ltxv-2-i2v-input.jpg"

- **`num_frames`** (`integer`, _optional_):
  The number of frames to generate. Default value: `121`
  - Default: `121`
  - Range: `9` to `481`

- **`resolution`** (`ImageSize | Enum`, _optional_):
  The size of the generated video. 'auto' derives the size from the input image aspect ratio. Default value: `auto`
  - Default: `"auto"`
  - One of: ImageSize | Enum

- **`frames_per_second`** (`float`, _optional_):
  Frames per second of the generated video. Default value: `24`
  - Default: `24`
  - Range: `1` to `60`

- **`num_inference_steps`** (`integer`, _optional_):
  Number of inference steps. Defaults to 15 for this distilled ComfyUI workflow and can be increased up to 30. Default value: `15`
  - Default: `15`
  - Range: `8` to `30`

- **`guidance_scale`** (`float`, _optional_):
  Classifier-free guidance scale. The default follows the distilled LTX-2.3 workflow. Default value: `1`
  - Default: `1`
  - Range: `1` to `20`

- **`generate_audio`** (`boolean`, _optional_):
  Whether to include audio in the returned video. When disabled, the final MP4 is returned without an audio track. Default value: `true`
  - Default: `true`

- **`image_strength`** (`float`, _optional_):
  Conditioning strength on the start image. 1.0 = exact first-frame match, lower = more freedom for the model. Default value: `0.7`
  - Default: `0.7`
  - Range: `0` to `1`

- **`negative_prompt`** (`string`, _optional_):
  The negative prompt to steer generation away from. Default value: `"color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards"`
  - Default: `"color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards"`

- **`seed`** (`integer`, _optional_):
  Random seed for reproducibility. If None, a random seed is chosen.

- **`enable_prompt_expansion`** (`boolean`, _optional_):
  Whether to enable prompt expansion. Default value: `true`
  - Default: `true`

- **`enable_safety_checker`** (`boolean`, _optional_):
  Whether to enable the safety checker. Default value: `true`
  - Default: `true`

- **`video_quality`** (`VideoQualityEnum`, _optional_):
  The quality preset of the generated video. Default value: `"high"`
  - Default: `"high"`
  - Options: `"low"`, `"medium"`, `"high"`, `"maximum"`

- **`video_write_mode`** (`VideoWriteModeEnum`, _optional_):
  The write mode of the generated video. Default value: `"balanced"`
  - Default: `"balanced"`
  - Options: `"fast"`, `"balanced"`, `"small"`

- **`sync_mode`** (`boolean`, _optional_):
  If True, the media is returned as a data URI inline in the response. Useful for short-lived requests and tests.
  - Default: `false`



**Required Parameters Example**:

```json
{
  "prompt": "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence.",
  "image_url": "https://storage.googleapis.com/falserverless/example_inputs/ltxv-2-i2v-input.jpg"
}
```

**Full Example**:

```json
{
  "prompt": "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence.",
  "image_url": "https://storage.googleapis.com/falserverless/example_inputs/ltxv-2-i2v-input.jpg",
  "num_frames": 121,
  "resolution": "auto",
  "frames_per_second": 24,
  "num_inference_steps": 15,
  "guidance_scale": 1,
  "generate_audio": true,
  "image_strength": 0.7,
  "negative_prompt": "color distortion, overexposure, static, blurry details, subtitles, style, artwork, painting, frame, still, dim overall tone, worst quality, low quality, JPEG compression artifacts, ugly, mutilated, extra fingers, poorly drawn hands, poorly drawn face, deformed, disfigured, malformed limbs, fused fingers, motionless frame, cluttered background, three legs, crowded background, walking backwards",
  "enable_prompt_expansion": true,
  "enable_safety_checker": true,
  "video_quality": "high",
  "video_write_mode": "balanced"
}
```


### Output Schema

The API returns the following output format:

- **`video`** (`File`, _required_):
  The generated video.

- **`seed`** (`integer`, _required_):
  The seed actually used for generation.

- **`prompt`** (`string`, _required_):
  The prompt used for generation (after any expansion).



**Example Response**:

```json
{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  },
  "prompt": ""
}
```


## Usage Examples

### cURL

```bash
curl --request POST \
  --url https://fal.run/fal-ai/ltx-2.3-quality/image-to-video \
  --header "Authorization: Key $FAL_KEY" \
  --header "Content-Type: application/json" \
  --data '{
     "prompt": "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence.",
     "image_url": "https://storage.googleapis.com/falserverless/example_inputs/ltxv-2-i2v-input.jpg"
   }'
```

### Python

Ensure you have the Python client installed:

```bash
pip install fal-client
```

Then use the API client to make requests:

```python
import fal_client

def on_queue_update(update):
    if isinstance(update, fal_client.InProgress):
        for log in update.logs:
           print(log["message"])

result = fal_client.subscribe(
    "fal-ai/ltx-2.3-quality/image-to-video",
    arguments={
        "prompt": "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence.",
        "image_url": "https://storage.googleapis.com/falserverless/example_inputs/ltxv-2-i2v-input.jpg"
    },
    with_logs=True,
    on_queue_update=on_queue_update,
)
print(result)
```

### JavaScript

Ensure you have the JavaScript client installed:

```bash
npm install --save @fal-ai/client
```

Then use the API client to make requests:

```javascript
import { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/ltx-2.3-quality/image-to-video", {
  input: {
    prompt: "A woman stands still amid a busy neon-lit street at night. The camera slowly dollies in toward her face as people blur past, their motion emphasizing her calm presence.",
    image_url: "https://storage.googleapis.com/falserverless/example_inputs/ltxv-2-i2v-input.jpg"
  },
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") {
      update.logs.map((log) => log.message).forEach(console.log);
    }
  },
});
console.log(result.data);
console.log(result.requestId);
```


## Additional Resources

### Documentation

- [Model Playground](https://fal.ai/models/fal-ai/ltx-2.3-quality/image-to-video)
- [API Documentation](https://fal.ai/models/fal-ai/ltx-2.3-quality/image-to-video/api)
- [OpenAPI Schema](https://fal.ai/api/openapi/queue/openapi.json?endpoint_id=fal-ai/ltx-2.3-quality/image-to-video)

### fal.ai Platform

- [Platform Documentation](https://docs.fal.ai)
- [Python Client](https://docs.fal.ai/clients/python)
- [JavaScript Client](https://docs.fal.ai/clients/javascript)