MiniMax H3 Max reference audio needs an image or video on Sume

You cannot send reference audio on its own to MiniMax H3 Max reference-to-video, and Sume has the same rule: reference_audio_urls requires at least one reference image or video. Krea's September 1 changelog adds one limit Sume's video page does not name: up to 7 reference videos, 15 seconds combined, reported with reference_video_seconds.

Krea facts are from its changelog (preview feature); Sume facts are from the video input fields and video generation docs, read 2026-10-01.

What does Krea say about H3 Max references?

MiniMax H3 Max supports reference-to-video in preview. You pass image, video, and audio references together to keep characters, motion, and voice consistent. Krea states the video limit as up to 7 clips, 15 seconds combined, and says audio references cannot be sent alone.

How do the reference limits compare?

The counts differ, so do not copy a payload from one API to the other.

Which Sume models take audio and video references?

The video generation docs say only models whose supported_input_references lists a type accept it. Audio and video references are honored by the Seedance 2.x models, Wan 3.0, MiniMax H3, and MiniMax H3 Max. Check GET /v1/models for the model you intend to use before you submit.

For a related limit on another vendor, see Kling 4.0: five reference videos.

What do I do if I only have a voice track?

Add at least one reference image or video of the subject, then pass the audio next to it. A lone reference_audio_urls array fails the rule above.