GET
/v1/schemas/fal/video/fal-ai/ltx-2.3-quality/extend-video
Accept:
| field | recorded source |
|---|---|
| schema | Source linked above.Source trace89d8ad3fc0d3479e23a3500712e40a9848b87aee416f53a84038962ac274886f{
"fetchedAt": 1783573357,
"extractorVersion": "1",
"verifiedAt": null
} |
Request body
21 properties · 2 required · 1 $defs| property | type | description | constraints |
|---|---|---|---|
| video_url* | string | The URL of the video to extend. | |
| prompt* | string | The prompt describing how the video should continue. | |
| match_input_fps | boolean | When enabled, the output FPS matches the source video's FPS (rounded to an integer and clamped to the supported range) instead of frames_per_second. | default: true |
| video_quality | enum | The quality preset of the generated video. | low | medium | high | maximum · default: "high" |
| num_inference_steps | integer | Number of inference steps. Defaults to 15 and can be increased up to 30. | 8 ≤ n ≤ 30 · default: 15 |
| end_image_strength | number | Conditioning strength of the optional end keyframe. 1.0 = exact match, lower = more freedom for the model. | 0 ≤ n ≤ 1 · default: 1 |
| generate_audio | boolean | Whether to generate new audio for the extension segment (crossfaded with the source audio at the seam). When disabled, the source video's own audio track is preserved and the extension stays silent. | default: true |
| sync_mode | boolean | If True, the media is returned as a data URI inline in the response. Useful for short-lived requests and tests. | default: false |
| enable_prompt_expansion | boolean | Whether to enable prompt expansion. | default: true |
| num_context_frames | integer | The number of source frames used as context/overlap for the extension. Snapped down to the LTX temporal grid (8k+1) and clamped to the frames available in the source video. | 9 ≤ n ≤ 121 · default: 25 |
| negative_prompt | string | The negative prompt to steer generation away from. | default: "color distortion, overexposure,… |
| frames_per_second | number | Frames per second of the generated video. | 1 ≤ n ≤ 60 · default: 24 |
| guidance_scale | number | Classifier-free guidance scale. The default is tuned for fast, high-quality generation. | 1 ≤ n ≤ 20 · default: 1 |
| seed | integer | Random seed for reproducibility. If None, a random seed is chosen. | nullable |
| enable_safety_checker | boolean | Whether to enable the safety checker. | default: true |
| resolution | ImageSize | enum | The size of the generated video. 'auto' follows the source video size/aspect up to the LTX limits; the source is scaled to the final size in the stitched output. Sizes are 32px-aligned (e.g. 1920x1080 is delivered as 1888x1056). Higher resolutions reduce the m… | default: "auto" |
| video_strength | number | Conditioning strength of the source context frames. 1.0 keeps the overlap locked to the source for a seamless transition; lower values give the model more freedom. | 0 ≤ n ≤ 1 · default: 1 |
| video_write_mode | enum | The write mode of the generated video. | fast | balanced | small · default: "balanced" |
| num_frames | integer | The number of frames to generate for the extension segment, including num_context_frames of overlap with the source video. The new content adds approximately (num_frames - num_context_frames) / frames_per_second seconds. The stable generation budget caps the r… | 9 ≤ n ≤ 481 · default: 121 |
| end_image_url | string | Optional keyframe image for the far end of the extension: the final frame for forward extension, or the new first frame for backward extension. | nullable |
| extend_direction | enum | Direction to extend the video. 'forward' continues from the end of the video, 'backward' generates a new beginning. | forward | backward · default: "forward" |
Types
1 $defsImageSizeobject
| width | integer | The width of the generated image. | 0 < n ≤ 14142 · default: 512 |
| height | integer | The height of the generated image. | 0 < n ≤ 14142 · default: 512 |
Validate a payload
before you spend tokensshell
$ curl -X POST https://modelschemas.com/v1/validate \
-d '{"provider":"fal","endpointId":"fal-ai/ltx-2.3-quality/extend-video","payload":{…}}'
→ {"valid": false, "errors": [{"path": "#", "keyword": "required", …}]}