#!/bin/bash

# Each source is rendered as 60 FPS. Change as needed.
# Change output bitrate as needed.
ffmpeg -r 60 -f image2 -i camera_0_%010d.png \
       -r 60 -f image2 -i camera_1_%010d.png \
       -r 60 -f image2 -i camera_2_%010d.png \
       -r 60 -f image2 -i camera_3_%010d.png \
       -filter_complex '[0:v][1:v]hstack[top];[2:v][3:v]hstack[bot];[top][bot]vstack[vid]' \
       -map [vid] -vcodec mpeg4 -b:v 10000k out.mp4