Ambassador Video Output Recommendations i.e. file limit, file type, orientation

Before you export: get the shape right

Ambassador clips play inside a square bubble. Vepple doesn’t crop or zoom your footage to fit, so whatever shape you export is exactly what students see.

This is the single most important thing to get right. If you export a square video it fills the bubble perfectly. If you export a landscape (widescreen) video, it sits inside the square with black bars above and below it. It’s also why you might notice one ambassador looking great while others have black bars: the good one was exported square, and the others were left in their original landscape shape.

Note - there is no setting to remove black bars after a video has been uploaded. The shape is fixed inside the video file itself, so the fix is always to re-export the clip as a square video and upload it again.

Filmed in portrait or landscape on a phone? That’s fine - it just needs cropping to a square before upload. The FFmpeg scripts further down do this for you automatically, cropping to a square framed slightly above centre so heads and shoulders sit nicely.

Ambassador Video Output Recommendations

You’ll need to export a separate video file for each Ambassador clip.

Here are the recommended specifications for the files:

MP4

WebM

Helpful Scripts for Video Processing (Using FFmpeg)

Below, you’ll find scripts that are pre-configured to take a portrait input video (for example shot on a mobile phone) and turn it into a web-optimised square video for use in Ambassador bubbles.

FFmpeg is a free, open-source command-line tool used to process video and audio. It's widely supported, highly flexible, and ideal for automating tasks like cropping, resizing, compressing, and converting videos into web-optimized formats.

What You Need

1. Download FFmpeg and install it (available for macOS, Windows, and Linux)
2. Open your terminal (or command prompt)
3. Run the commands below by replacing input.mp4 with your actual file name

Script 1: Export Square MP4 (H.264) with Audio for Web

On Mac/Linux: 

ffmpeg -i input.mp4 \
-filter:v "crop=in_w:in_w:0:in_h/5,scale=512:512" \
-c:v libx264 -preset slow -crf 30 \
-c:a aac -b:a 96k \
-movflags +faststart \
output-512x512.mp4

On Windows: 

ffmpeg -i input.mp4 -filter:v "crop=in_w:in_w:0:in_h/5,scale=512:512" -c:v libx264 -preset slow -crf 30 -c:a aac -b:a 96k -movflags +faststart output-512x512.mp4

What it does:

• Crops to a square, starting just above the vertical center - (in_h/5) starts cropping one-fifth of the way down the video — this places the square slightly above vertical center, which often frames a person more naturally (e.g. head and shoulders)
• Resizes to 512×512
• Compresses video using H.264 at high quality (CRF 30)
• Keeps clear speech with AAC audio at 96 kbps
• Enables fast web playback with +faststart

Script 2: Export Square WebM (VP9 + Opus) with Audio for Web

Mac/Linux:

ffmpeg -i input.mp4 \

-filter:v "crop=in_w:in_w:0:in_h/5,scale=512:512" \

-c:v libvpx-vp9 -crf 32 -b:v 0 -row-mt 1 -threads 4 \

-c:a libopus -b:a 96k \

output-512x512.webm

Windows:

ffmpeg -i input.mp4 -filter:v "crop=in_w:in_w:0:in_h/5,scale=512:512" -c:v libvpx-vp9 -crf 32 -b:v 0 -row-mt 1 -threads 4 -c:a libopus -b:a 96k output-512x512.webm

What it does:

• Same crop & resize as the MP4 version
• Uses the VP9 codec for better compression at smaller sizes
• Includes Opus audio, designed for high-quality speech
• -crf 32 provides a great balance of quality and file size (~1–1.5MB for 30s)