Cutdown batch for Cyber Monday: check trim rows before posting

Before you post a batch of Cyber Monday cutdowns to Sume POST /v1/video-trim, run each row through a local check for the rules that return a refusal: a media.sume.com URL, a start of 0 or more, exactly one of end or duration, a range that is not empty, and no output with precision: "keyframe". Each trim costs $0.02, so a row that would be refused is a call you can skip.

The rules and refusal codes are from Video trim (read 2026-10-06). The script below holds them in one function and prints a verdict for each row. It makes no network call, so it runs on a laptop with nothing but Python.

Which rules does a trim request have?

The API also rejects any ffmpeg field such as vf or crf with ffmpeg_fields_rejected, so a row must hold only the trim fields.

What does the check look like?

Pipe a JSON list of rows into it. Three cutdown rows of a 45-second master, cut at 6, 15, and 30 seconds, all pass. A row that sends both end and duration, or a URL on another host, is flagged.

import json, sys

def check(row):
    errors = []
    url = str(row.get("video_url", ""))
    if not url.startswith("https://media.sume.com/"):
        errors.append("unsupported_media_source")
    start = row.get("start")
    if not isinstance(start, (int, float)) or start < 0:
        errors.append("start must be a number of 0 or more")
    end, dur = row.get("end"), row.get("duration")
    if (end is None) == (dur is None):
        errors.append("send exactly one of end or duration")
    elif end is not None and isinstance(start, (int, float)) and end <= start:
        errors.append("video_trim_range_empty")
    elif dur is not None and not 0.2 <= dur <= 900:
        errors.append("duration must be 0.2 to 900")
    if row.get("precision") == "keyframe" and "output" in row:
        errors.append("output needs precision exact")
    return errors

rows = json.load(sys.stdin)
for i, row in enumerate(rows):
    print(i, check(row) or "ok")

What do I do with the verdicts?

Fix the flagged rows, then post the clean ones with one Idempotency-Key each. The check does not look at the file, so a dead link still returns source_not_found from the API, and a source longer than 1800 seconds returns source_duration_exceeded.

• Import each master first with POST /v1/media-imports, since the API does not fetch from the open internet.
• Three cutdowns of one master cost $0.06 in trims.
• The cut starts at start and runs for duration, so all three of 6, 15, and 30 seconds can start at 0 and share the hook.