Build an Adaptive Bitrate Ladder

Why this matters

Adaptive streaming needs multiple renditions — the player picks the one that fits the connection. A well-built ladder balances quality at each rung and total storage cost.

Encoding each rung separately is error-prone and slow; one API call with a ladder spec produces all renditions consistently.

How it works

Define resolution/bitrate pairs (1080p/5M, 720p/2.8M, 480p/1.4M, 360p/800k), submit once, and get per-rung MP4s plus HLS/DASH manifests.

Submit a job with an input URL (S3, GCS or HTTPS), poll the job URL, and download the rendered output. No GPU, no queues, no ffmpeg builds to babysit.

Code

import requests, time

API = "https://api.mlslabs.io/v1/encode/jobs"
headers = {"X-API-Key": "YOUR_API_KEY"}
payload = {"input": "s3://bucket/master.mp4", "codec": "h264", "ladder": [[1920, 5000000], [1280, 2800000], [854, 1400000], [640, 800000]]}

resp = requests.post(API, json=payload, headers=headers)
job = resp.json()
while job["status"] not in ("succeeded", "failed"):
    time.sleep(3)
    job = requests.get(job["url"], headers=headers).json()

print("Output:", job["output_url"])

Pro tips

• Don't waste rungs: 4–5 well-spaced renditions cover nearly all connections.
• Anchor the top rung to your source quality; encode the bottom rung for 2G connections.
• Use keyframe alignment — the API aligns segment boundaries across rungs automatically.

Run the ABR ladder example in Postman.