Wan 3.0 says 30 fps MP4: check your Sume download with ffprobe

Alibaba's Wan 3.0 guide says the output is 30 fps MP4 with native dialogue, music and sound effects. The Sume video docs do not state a frame rate for wan-3.0, so treat 30 fps as the vendor's claim and measure the file you download. ffprobe gives fps, size, length and whether an audio stream exists in one call.

What does the vendor page claim?

The Alibaba guide states these output properties.

How do you probe a download?

Download with GET /v1/videos/{id}/content?index=0 and your API key, then run this. It needs ffprobe on your PATH.

import json, subprocess

def probe(path):
    out = subprocess.run(
        ["ffprobe", "-v", "error", "-print_format", "json", "-show_streams", "-show_format", path],
        capture_output=True, text=True, check=True).stdout
    d = json.loads(out)
    v = next(s for s in d["streams"] if s["codec_type"] == "video")
    n, m = map(int, v["avg_frame_rate"].split("/"))
    return {
        "container": d["format"]["format_name"],
        "fps": n / m,
        "size": (v["width"], v["height"]),
        "seconds": float(d["format"]["duration"]),
        "audio": any(s["codec_type"] == "audio" for s in d["streams"]),
    }

print(probe("output.mp4"))

Why does the frame rate matter?

Mixed frame rates cause resampling when you join clips. Sume's Timeline warns about it when sources differ, so probe each model once and record the result next to the model id. Do not assume it from another vendor's page.