resizer.rb

OutDir = 'out'
Scale = '640:-1'
AllowedExtenstions = ['avi', 'mp4']

def convert(filename, ext)
	command = "ffmpeg -i #{filename}.#{ext} -vf scale=#{Scale} -strict -2 #{OutDir}/#{filename}_small.#{ext}"
	p command
	`#{command}`
end

Dir["./*.{#{AllowedExtenstions.join(",")}}"].map{ |f|
	ext = AllowedExtenstions.find {|ext| f.end_with? ext }
	base = File.basename(f, ".#{ext}") 
	[base, ext]
}.each{ |basename, ext|
	convert(basename, ext)
	# p [basename, ext]
}

# ffmpeg -i VID_20150407_220615_TU3.mp4 -vf scale=640:-1 -strict -2  VID_20150407_220615_TU3_small.mp4