Recursively encode any ffmpeg-supported audio tracks to Ogg Vorbis

rogg.lua

#!/usr/bin/env lua
-- Recursively encode any ffmpeg-supported audio tracks to Ogg Vorbis
local lfs = require("lfs") -- LuaFileSystem
local exec = os.execute

local function is_directory(fullname)
	return lfs.attributes(fullname, "mode") == "directory"
end

local function recurse(path, target)
	if not lfs.attributes(target..path:sub(2)) then -- if the target directory doesn't have this folder,
		lfs.mkdir(target..path:sub(2)) -- create it
	end
	for name in lfs.dir(path) do -- for every file in the directory
		if not (name == "." or name == "..") then
		local fullname = path.."/"..name
		if is_directory(fullname) then -- if a directory
			if name:lower() ~= "scans" then -- and it's not useless
				recurse(fullname, target) -- recurse that
			end
		else -- if not a directory
			local outname = target..fullname:sub(2):match("(.+/[^.]+)")..".ogg" -- determine our filename
			exec(("ffmpeg -i %q -map_metadata 0:0 -acodec libvorbis -ab %dk -threads 2 %q"):format(fullname, BITRATE or 64, outname)) -- re-encode
		end
	end end
end

if select("#", ...) < 2 then
	print("usage: rogg.lua from-directory to-directory [bitrate k]")
	os.exit()
end

if select(3, ...) then
	BITRATE = tonumber(select(3, ...))
end

recurse(...)

rogg.py

#!/usr/bin/env python3
# Recursively encode any ffmpeg-supported audio tracks to Ogg Vorbis
import argparse, os, subprocess
from sys import exit

parser = argparse.ArgumentParser(description='Recursively encode any ffmpeg-supported audio tracks to Ogg Vorbis')
parser.add_argument('-v', '--verbose', action='store_true', help='print out actions as they are happening')
parser.add_argument('--dry-run', action='store_true', help='don\'t actually do anything')
parser.add_argument('-b', '--bitrate', default=64, type=int, help='bitrate in kilobits per second')
parser.add_argument('fromd', metavar='from-directory', help='original directory to recurse')
parser.add_argument('tod', metavar='to-directory', help='directory to place converted file tree')

verbose = False
dry_run = False
bitrate = None
devnull = open(os.devnull, "w")

def recurse(path, target, indent=0):
    full_target = os.path.join(target, os.path.basename(path))
    ind = " " * indent
    if not os.access(full_target, os.F_OK):
        if verbose: print("%screating `%s'" % (ind, full_target))
        if not dry_run: os.mkdir(full_target)
    for file in os.listdir(path):
        if os.path.isfile(os.path.join(path, file)):
            new_file = os.path.splitext(file)[0] + ".ogg"
            full_newfile = os.path.join(full_target, new_file)
            if os.access(full_newfile, os.F_OK):
                print("`%s' already exists" % new_file)
                continue
            if verbose: print("%sconverting `%s' -> `%s'" % (ind, file, new_file))
            if not dry_run:
                popen = subprocess.Popen(["ffmpeg", "-i", os.path.join(path, file), "-map_metadata", "0:0", "-acodec", "libvorbis", "-ab", "%dk" % bitrate, os.path.join(full_target, new_file)], stdout=devnull, stderr=devnull)
                popen.wait()
                if popen.returncode != 0:
                    print("error while converting, stopping")
                    exit(1)
        else:
            if verbose: print("%sentering `%s'" % (ind, file))
            recurse(os.path.join(path, file), full_target, indent=indent + 1)
            if verbose: print("%sleaving `%s'" % (ind, file))

def main():
    options = parser.parse_args()
    if options.verbose:
        global verbose
        verbose = True
    if options.dry_run:
        global dry_run
        dry_run = True
    global bitrate
    bitrate = options.bitrate
    if not os.access(os.path.abspath(options.fromd), os.X_OK):
        exit()
    recurse(os.path.abspath(options.fromd), os.path.abspath(options.tod))
if __name__ == "__main__":
    main()