
LTX 2.5 Pro Audio-to-Video API by LTX
LTX-2.5 Pro audio-to-video (Lightricks LTX-2 native API): generate video synchronized to a driving audio track (dialogue/music/ambient); the audio sets the length. Up to 4K at 24/48 fps.
LTX 2.5 Pro Audio-to-Video is developed by a third-party provider. Atlas Cloud (operated by Atlas Cloud AI LLC) provides access to it and does not own it. All trademarks belong to their respective owners.
1. Introduction
LTX-2.5 Pro Audio-to-Video is served through the native Lightricks LTX-2 API (api.ltx.io). This README covers a single API model identifier:
ltx/ltx-2.5-pro/audio-to-video
Audio-to-video generates visuals synchronized to a driving audio track — dialogue, music, or ambient sound. The audio sets the length of the generated video. Optionally condition on a first-frame image for visual direction, a last frame for interpolation, and a camera-motion directive. Requests are processed asynchronously (submit + poll) and delivered as a finished MP4 on AtlasCloud storage.
2. Key Features
- Audio-Driven Generation: Visuals are synchronized to the supplied
audio; the audio also sets the output length. - Optional Image Conditioning: Provide
image(first frame) for visual direction, andlast_imageto interpolate first→last. If no image is given,promptdrives the content. - Up to 4K, 24/48 fps: 720p / 1080p / 1440p / 4K in landscape (16:9) or portrait (9:16).
- Camera Control: Optional
camera_motiondirective (dolly, jib, focus shift, static). - Billed by Input Audio: Charged per second of the input audio (which equals the output length).
3. Support Matrix
| Resolution | Landscape | Portrait | Max input audio |
|---|---|---|---|
| 720p | 1280x720 | 720x1280 | 10s |
| 1080p | 1920x1080 | 1080x1920 | 10s |
| 1440p | 2560x1440 | 1440x2560 | 10s |
| 4K | 3840x2160 | 2160x3840 | 10s |
Either prompt or image must be provided. The input audio duration must not exceed the maximum shown for the chosen resolution.
4. Parameters
The request body matches this model's schema exactly:
| Parameter | Type | Required | Default | Notes |
|---|---|---|---|---|
audio | string | Yes | Driving audio track: URL, Base64, or asset reference (asset://<ASSET_ID>). The audio sets the generated video length; it must not exceed the model's maximum at the chosen resolution. | |
image | string | No | Optional first-frame image (URL / Base64 / asset://) for visual direction. Required if prompt is empty. | |
last_image | string | No | Optional last-frame image (URL / Base64 / asset://); requires image. When set, the clip interpolates from the first frame to this frame. | |
prompt | string | No | A person speaking to camera, natural expression, cinematic lighting. | Text prompt. Required if image is not provided; when image is set, describes how the image should be animated (may be empty). |
resolution | string | No | 1080p | One of: 720p, 1080p, 1440p, 4k. Output resolution tier. Combined with aspect_ratio to select the exact frame size (720p→1280x720, 1080p→1920x1080, 1440p→2560x1440, 4k→3840x2160; portrait 9:16 swaps width/height). If omitted, LTX derives it from the input image. |
aspect_ratio | string | No | 16:9 | One of: 16:9, 9:16. Frame orientation: 16:9 landscape or 9:16 portrait. |
fps | integer | No | 24 | One of: 24, 48. Frames per second. Defaults to 24. |
camera_motion | string | No | One of: dolly_in, dolly_out, dolly_left, dolly_right, jib_up, jib_down, static, focus_shift. Optional camera movement directive applied to the shot. |
5. Intended Use & Applications
- Talking-Head & Dialogue Video: Drive a speaking character from a voice track, optionally starting from a portrait image.
- Music-Driven Clips: Generate visuals timed to a music track.
- Lip-Sync & Performance: Sync facial/character motion to supplied speech.
- Social & Vertical Content: Native 9:16 portrait output for short-form platforms.


















