# switch containers from MKV to MP4 (does not re-encode)
ffmpeg -i HCC\ DataCenterCollapse.mkv -codec copy HCC\ DataCenterCollapse.mp4 

# crop (re-encodes)   crop=w:h:x:y
ffmpeg -i /Users/nfisher/DATA_XFER/www/hcc/DataCenter\ shelf\ collapse/HCC\ DataCenterCollapse.mp4  -filter:v "crop=500:360:485:0" /Users/nfisher/DATA_XFER/www/hcc/DataCenter\ shelf\ collapse/HCC\ DataCenterCollapse\ cropped.mp4