gistfile1.lua

local pack = vpk.Open(steam.GetInstallPath() .. "/steamapps/common/GarrysMod/sourceengine/hl2_sound_vo_english_dir.vpk")

vfs.Mount({
	id = "test", 
	root = "",
	callback = function(type, path, ...)  
		if type == "find" then
			
			path = path:sub(2) 
			path = path .. "/"

			return pack:Find(path)
		elseif type == "open" then
			path = path:sub(2) 

			local file = vfs.CreateDummyFile()
			local done = false
			
			function file:OnRead(type, bytes)
				if type == "all" or true --[[wip]] then
					if not done then
						done = true
						return ffi.string(pack:Read(path))
					end
				end
			end 
			
			return file
		else
			print(type, path, ...)
		end
	end 
}) 
  
local snd = Sound("sound/vo/breencast/br_overwatch08.wav")

snd:Play()

table.print(snd.decode_info)