Documentation Index
Fetch the complete documentation index at: https://rendi.dev/docs/llms.txt
Use this file to discover all available pages before exploring further.
Scale a video to a target resolution (e.g., 1280×720 or 1920×1080) and letterbox where needed to preserve the source aspect ratio.
Code
const API_KEY = process.env.RENDI_API_KEY;
const submit = await fetch("https://api.rendi.dev/v1/run-ffmpeg-command", {
method: "POST",
headers: {
"Content-Type": "application/json",
"X-API-KEY": API_KEY,
},
body: JSON.stringify({
input_files: {
in_1: "https://storage.rendi.dev/sample/sample.avi",
},
output_files: {
out_1: "resized-720p.mp4",
},
ffmpeg_command:
'-i {{in_1}} -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -c:a copy {{out_1}}',
}),
});
const { command_id } = await submit.json();
while (true) {
const res = await fetch(`https://api.rendi.dev/v1/commands/${command_id}`, {
headers: { "X-API-KEY": API_KEY },
});
const data = await res.json();
if (data.status === "SUCCESS") {
console.log("Resized URL:", data.output_files.out_1.storage_url);
break;
}
if (data.status === "FAILED") throw new Error("Command failed");
await new Promise((r) => setTimeout(r, 2000));
}
import os
import time
import requests
API_KEY = os.environ["RENDI_API_KEY"]
BASE = "https://api.rendi.dev/v1"
headers = {"X-API-KEY": API_KEY}
submit = requests.post(
f"{BASE}/run-ffmpeg-command",
headers=headers,
json={
"input_files": {"in_1": "https://storage.rendi.dev/sample/sample.avi"},
"output_files": {"out_1": "resized-720p.mp4"},
"ffmpeg_command": '-i {{in_1}} -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -c:a copy {{out_1}}',
},
)
command_id = submit.json()["command_id"]
while True:
res = requests.get(f"{BASE}/commands/{command_id}", headers=headers).json()
if res["status"] == "SUCCESS":
print("Resized URL:", res["output_files"]["out_1"]["storage_url"])
break
if res["status"] == "FAILED":
raise RuntimeError("Command failed")
time.sleep(2)
curl --request POST \
--url https://api.rendi.dev/v1/run-ffmpeg-command \
--header 'Content-Type: application/json' \
--header 'X-API-KEY: <api-key>' \
--data '{
"input_files": {"in_1": "https://storage.rendi.dev/sample/sample.avi"},
"output_files": {"out_1": "resized-720p.mp4"},
"ffmpeg_command": "-i {{in_1}} -vf \"scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2\" -c:v libx264 -c:a copy {{out_1}}"
}'
curl --request GET \
--url https://api.rendi.dev/v1/commands/<command_id> \
--header 'X-API-KEY: <api-key>'
How the FFmpeg command works
scale=1280:720:force_original_aspect_ratio=decrease — fit inside 1280×720, keep aspect ratiopad=1280:720:(ow-iw)/2:(oh-ih)/2 — letterbox with black bars centered-c:v libx264 — re-encode video with H.264 (required after scaling)-c:a copy — pass audio through unchanged (faster than re-encoding){{out_1}} — output file
For stretch-to-fit without letterbox, drop the pad filter. For crop-to-fit, change decrease to increase and add crop=1280:720.
Response
{
"output_files": {
"out_1": {
"file_id": "a8b2f3c4-...",
"size_mbytes": 22.4,
"duration": 596.459,
"file_type": "video",
"file_format": "mp4",
"storage_url": "https://storage.rendi.dev/temp_files/.../resized-720p.mp4",
"width": 1280,
"height": 720,
"codec": "h264"
}
},
"status": "SUCCESS",
"command_type": "FFMPEG_COMMAND"
}
