conv.lua

#!/usr/bin/lua
---
-- Created 2014 by Jacob Hacker <jacobhacker@outlook.com>
-- Licensed under the MIT license: http://opensource.org/licenses/MIT
---
-- Install: sudo apt-get install lua5.2 libav-tools googlecl python-pip && sudo pip install megacl googlecl

--(------------)--
--(--- Util ---)--
--(------------)--

local cli = {}
function cli.run(command, args)
	local handle = io.popen(command, args)
	local result = handle:read("*a")
	handle:close()
	
	return result
end

function fileExists(n)
	local f = io.open(n, "r");
	if f ~= nil then
		io.close(f)
		return true
	else
		return false
	end
end

function getAudioDuration(audioFilename)
	local out = cli.run("avconv -i '" .. audioFilename .. "' 2>&1")
	local audioLen = out:match("Duration: (%d%d:%d%d:%d%d%.%d%d)")
	if audioLen == nil then
		print("Failed to extract audio length")
		print("Program out: " .. out)
		os.exit()
	end

	return audioLen
end

function cli.packageInstalled(package)
	local out = cli.run("dpkg -l | grep -E '^ii' | grep '^ii\\s*" .. package .. "\\s'")
	return out ~= ''
end

--(-----------------------)--
--(-- Program Functions --)--
--(-----------------------)--

function mp3ToMkv(audioFilename, thumbnailFilename, audioLen)
	local outFilename = audioFilename:match("(.*)%.")
	local cmd = "avconv -loop 1 -r 1 -i '" .. thumbnailFilename .. "' " ..
		" -i '" .. audioFilename .."' -c:a copy -preset medium -threads 2" ..
		" -t " .. audioLen .. " -c:v libx264 '".. outFilename..".mkv' -y"

	print("<<" .. cmd .. ">>")
	cli.run(cmd)
end

function getThumbnail(thumbnailFilename)
	if thumbnailFilename == nil then
		cli.run("wget 'https://i.imgur.com/XYTACtb.jpg' -O 'video-thumb.jpg'")
	end

	if not fileExists(thumbnailFilename) then
		print("Thumbnail file '" .. thumbnailFilename .. "' not found.")
		os.exit()
	end

	return thumbnailFilename
end

local ansiColor = {
	red = "\27[31m",
	green = "\27[32m",
	clear = "\27[0m",
}

function checkPackages(packages)
	local toInstall = {}
	for i=1, #packages do
		--io.write(packages[i])
		if not cli.packageInstalled(packages[i]) then
			io.write(packages[i] .. ansiColor.red .. " [Not Installed]\n" .. ansiColor.clear)
			toInstall[#toInstall+1] = packages[i]
		end
		--io.write("\n")
	end

	if #toInstall ~= 0 then
		io.write("sudo apt-get install")
		for i=1, #toInstall do
			io.write(" " .. toInstall[i])
		end
		io.write("\n")
	end
end

--(-------------)--
--(-- Program --)--
--(-------------)--

local audioFilename = arg[1]
if audioFilename == nil then
	print("You must pass the audio file's location.")
	os.exit()
end

if not fileExists(audioFilename) then
	print("Audio file '" .. audioFilename .. "' not found.")
	os.exit()
end

local thumbnailFilename = getThumbnail(arg[2] or "./video-thumb.jpg")

if string.find(audioFilename, ".+%.mp3", 1) == nil then
	local outFilename = audioFilename:match("(.*)%.") .. ".mp3"
	cli.run("avconv -i '" .. audioFilename .. "' -b 128k '" .. outFilename .. "'")
	audioFilename = outFilename
end

local audioLen = getAudioDuration(audioFilename)
mp3ToMkv(audioFilename, thumbnailFilename, audioLen)