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Use this recipe to generate a video whose timing and performance follow an existing audio track. This is useful for dialogue, narration, music, and other audio-led scenes; it does not transcribe the audio or create a talking avatar by itself.

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1. Choose an audio-capable model

Audio-to-video is available on these LTX routes:
  • ltx-2-5-fast
  • ltx-2-5-pro
  • ltx-2-3-pro
  • ltx-2-pro until its published retirement date
Check GET /v1/videos/models before production requests because model status and supported parameters can change.

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2. Send the audio input

Provide exactly one audio_url reference with the source role. Set input_audio_duration to the source audio length in seconds so Phaseo can validate it against the model’s supported range. Because LTX does not return authoritative duration or usage, LTX audio-to-video jobs are currently reserved and settled at the 20-second input ceiling.
The source must be a publicly reachable HTTPS URL. LTX audio inputs must be between 2 and 20 seconds.

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3. Optionally provide a first frame

Add one image_url reference with the first_frame role when you want to set the opening appearance. Do not add a last frame to an LTX audio-driven request.

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4. Poll or subscribe for completion

The create call returns an async video job. Poll its status URL, or add a webhook configuration to receive lifecycle events. Download the output only after the job reaches completed.
Last modified on August 12, 2026