[vlc] / share / lua / README.txt

Instructions to code your own VLC Lua scripts.
$Id$

1 - About Lua
=============

Lua documenation is available on http://www.lua.org . The reference manual
is very usefull: http://www.lua.org/manual/5.1/ .
VLC uses Lua 5.1
All the Lua standard libraries are available.

2 - Lua in VLC
==============

3 types of VLC Lua scripts can currently be coded:
 * Playlist (see playlist/README.txt)
 * Art fetcher (see meta/README.txt)
 * Interface (see intf/README.txt)

Lua scripts are tried in alphabetical order in the user's VLC config
directory lua/{playlist,meta,intf}/ subdirectory on Windows and Mac OS X or
in the user's local share directory (~/.local/share/vlc/lua/... on linux),
then in the global VLC lua/{playlist,meta,intf}/ directory.

3 - VLC specific Lua modules
============================

All VLC specifc modules are in the "vlc" object. For example, if you want
to use the "info" function of the "msg" VLC specific Lua module:
vlc.msg.info( "This is an info message and will be displayed in the console" )

Note: availability of the different VLC specific Lua modules depends on
the type of VLC Lua script your are in.

Access lists
------------
local a = vlc.acl(true) -> new ACL with default set to allow
a:check("10.0.0.1") -> 0 == allow, 1 == deny, -1 == error
a("10.0.0.1") -> same as a:check("10.0.0.1")
a:duplicate() -> duplicate ACL object
a:add_host("10.0.0.1",true) -> allow 10.0.0.1
a:add_net("10.0.0.0",24,true) -> allow 10.0.0.0/24 (not sure)
a:load_file("/path/to/acl") -> load ACL from file

Configuration
-------------
config.get( name ): Get the VLC configuration option "name"'s value.
config.set( name, value ): Set the VLC configuration option "name"'s value.

HTTPd
-----
http( host, port, [cert, key, ca, crl]): create a new HTTP (SSL) daemon.

local h = vlc.httpd( "localhost", 8080 )
h:handler( url, user, password, acl, callback, data ) -- add a handler for given url. If user and password are non nil, they will be used to authenticate connecting clients. If acl is non nil, it will be used to restrict access. callback will be called to handle connections. The callback function takes 7 arguments: data, url, request, type, in, addr, host. It returns the reply as a string.
h:file( url, mime, user, password, acl, callback, data ) -- add a file for given url with given mime type. If user and password are non nil, they will be used to authenticate connecting clients. If acl is non nil, it will be used to restrict access. callback will be called to handle connections. The callback function takes 2 arguments: data and request. It returns the reply as a string.
h:redirect( url_dst, url_src ): Redirect all connections from url_src to url_dst.

Input
-----
input.info(): Get the current input's info. Return value is a table of tables. Keys of the top level table are info category labels.
input.is_playing(): Return true if input exists.
input.get_title(): Get the input's name.
input.stats(): Get statistics about the input. This is a table with the following fields:
    .read_bytes
    .input_bitrate
    .demux_read_bytes
    .demux_bitrate
    .decoded_video
    .displayed_pictures
    .lost_pictures
    .decoded_audio
    .played_abuffers
    .lost_abuffers
    .sent_packets
    .sent_bytes
    .send_bitrate

Messages
--------
msg.dbg( [str1, [str2, [...]]] ): Output debug messages (-vv).
msg.warn( [str1, [str2, [...]]] ): Output warning messages (-v).
msg.err( [str1, [str2, [...]]] ): Output error messages.
msg.info( [str1, [str2, [...]]] ): Output info messages.

Misc
----
misc.version(): Get the VLC version string.
misc.copyright(): Get the VLC copyright statement.
misc.license(): Get the VLC license.

misc.datadir(): Get the VLC data directory.
misc.userdatadir(): Get the user's VLC data directory.
misc.homedir(): Get the user's home directory.
misc.configdir(): Get the user's VLC config directory.
misc.cachedir(): Get the user's VLC cache directory.

misc.datadir_list( name ): FIXME: write description ... or ditch function if it isn't usefull anymore, we have datadir and userdatadir :)

misc.mdate(): Get the current date (in milliseconds).
misc.mwait(): Wait for the given date (in milliseconds).

misc.lock_and_wait(): Lock our object thread and wait for a wake up signal.
misc.signal(): Wake up our object thread.

misc.should_die(): Returns true if the interface should quit.
misc.quit(): Quit VLC.

Net
---
net.url_parse( url, [option delimiter] ): Parse URL. Returns a table with
  fields "protocol", "username", "password", "host", "port", path" and
  "option".
net.listen_tcp( host, port ): Listen to TCP connections. This returns an
  object with an accept method. This method takes an optional timeout
  argument (in milliseconds). For example:
local l = vlc.net.listen_tcp( "localhost", 1234 )
while true do
  local fd = l:accept( 500 )
  if fd >= 0 do
    net.send( fd, "blabla" )
    net.close( fd )
  end
end
net.close( fd ): Close file descriptor.
net.send( fd, string, [length] ): Send data on fd.
net.recv( fd, [max length] ): Receive data from fd.
net.select( nfds, fds_read, fds_write, timeout ): Monitor a bunch of file descriptors. Returns number of fds to handle and the amount of time not slept. See "man select".
net.fd_set_new(): Create a new fd_set.
local fds = vlc.net.fd_set_new()
fds:clr( fd ) -- remove fd from set
fds:isset( fd ) -- check if fd is set
fds:set( fd ) -- add fd to set
fds:zero() -- clear the set
net.fd_read( fd, [max length] ): Read data from fd.
net.fd_write( fd, string, [length] ): Write data to fd.
net.stat( path ): Stat a file. Returns a table with the following fields:
    .type
    .mode
    .uid
    .gid
    .size
    .access_time
    .modification_time
    .creation_time
net.opendir( path ): List a directory's contents.

Objects
-------
object.input(): Get the current input object.
object.playlist(): Get the playlist object.
object.libvlc(): Get the libvlc object.

object.find( object, type, mode ): Find an object of given type. mode can
  be any of "parent", "child" and "anywhere". If set to "parent", it will
  look in "object"'s parent objects. If set to "child" it will look in
  "object"'s children. If set to "anywhere", it will look in all the
  objects. If object is unset, the current module's object will be used.
  Type can be: "libvlc", "module", "intf", "playlist", "input", "decoder",
  "vout", "aout", "packetizer", "encoder", "dialogs", "announce", "demux",
  "access", "stream", "opengl", "filter", "osdmenu", "httpd_host",
  "interaction", "generic". This function is slow and should be avoided.
object.find_name( object, name, mode ): Same as above except that it matches
  on the object's name and not type. This function is also slow and should
  be avoided if possible.

OSD
---
osd.icon( type, [id] ): Display an icon on the given OSD channel. Uses the
  default channel is none is given. Icon types are: "pause", "play",
  "speaker" and "mute".
osd.message( string, [id] ): Display text message on the given OSD channel.
osd.slider( position, type, [id] ): Display slider. Position is an integer
  from 0 to 100. Type can be "horizontal" or "vertical".
osd.channel_register(): Register a new OSD channel. Returns the channel id.
osd.channel_clear( id ): Clear OSD channel.

Playlist
--------
playlist.prev(): Play previous track.
playlist.next(): Play next track.
playlist.skip( n ): Skip n tracs.
playlist.play(): Play.
playlist.pause(): Pause.
playlist.stop(): Stop.
playlist.clear(): Clear the playlist.
playlist.repeat( [status] ): Toggle item repeat or set to specified value.
playlist.loop( [status] ): Toggle playlist loop or set to specified value.
playlist.random( [status] ): Toggle playlsit random or set to specified value.
playlist.goto( id ): Go to specified track.
playlist.add( ... ): Add a bunch of items to the playlist.
  The playlist is a table of playlist objects.
  A playlist object has the following members:
      .path: the item's full path / URL
      .name: the item's name in playlist (OPTIONAL)
      .title: the item's Title (OPTIONAL, meta data)
      .artist: the item's Artist (OPTIONAL, meta data)
      .genre: the item's Genre (OPTIONAL, meta data)
      .copyright: the item's Copyright (OPTIONAL, meta data)
      .album: the item's Album (OPTIONAL, meta data)
      .tracknum: the item's Tracknum (OPTIONAL, meta data)
      .description: the item's Description (OPTIONAL, meta data)
      .rating: the item's Rating (OPTIONAL, meta data)
      .date: the item's Date (OPTIONAL, meta data)
      .setting: the item's Setting (OPTIONAL, meta data)
      .url: the item's URL (OPTIONAL, meta data)
      .language: the item's Language (OPTIONAL, meta data)
      .nowplaying: the item's NowPlaying (OPTIONAL, meta data)
      .publisher: the item's Publisher (OPTIONAL, meta data)
      .encodedby: the item's EncodedBy (OPTIONAL, meta data)
      .arturl: the item's ArtURL (OPTIONAL, meta data)
      .trackid: the item's TrackID (OPTIONAL, meta data)
      .options: a list of VLC options (OPTIONAL)
                example: .options = { "fullscreen" }
      .duration: stream duration in seconds (OPTIONAL)
      .meta: custom meta data (OPTIONAL, meta data)
             A .meta field is a table of custom meta categories which
             each have custom meta properties.
             example: .meta = { ["Google video"] = { ["docid"] = "-5784010886294950089"; ["GVP version"] = "1.1" }; ["misc"] = { "Hello" = "World!" } }
  Invalid playlist items will be discarded by VLC.
playlist.enqueue( ... ): like playlist.add() except that track isn't played.
playlist.get( [what, [tree]] ): Get the playist.
  If "what" is a number, then this will return the corresponding playlist
  item's playlist hierarchy. If it is "normal" or "playlist", it will
  return the normal playlist. If it is "ml" or "media library", it will
  return the media library. If it is "root" it will return the full playlist.
  If it is a service discovery module's name, it will return that service
  discovery's playlist. If it is any other string, it won't return anything.
  Else it will return the fullplaylist.
  The second argument, "tree", is optional. If set to true or unset, the
  playlist will be returned in a tree layout. If set to false, the playlist
  will be returned using the flat layout.
  Each playlist item returned will have the following members:
      .id: The item's id.
      .flags: a table with the following members if the corresponing flag is
              set:
          .save
          .skip
          .disabled
          .ro
          .remove
          .expanded
      .name:
      .path:
      .duration: (-1 if unknown)
      .nb_played:
      .children: A table of children playlist items.

FIXME: add methods to get an item's meta, options, es ...

SD
--
sd.get_services_names(): Get a table of all available service discovery
  modules. The module name is used as key, the long name is used as value.
sd.add( name ): Add service discovery.
sd.remove( name ): Remove service discovery.
sd.is_loaded( name ): Check if service discovery is loaded.

Stream
------
stream( url ): Instantiate a stream object for specific url.

s = vlc.stream( "http://www.videolan.org/" )
s:read( 128 ) -- read up to 128 characters. Return 0 if no more data is available (FIXME?).
s:readline() -- read a line. Return nil if EOF was reached.

Strings
-------
strings.decode_uri( [uri1, [uri2, [...]]] ): Decode a list of URIs. This
  function returns as many variables as it had arguments.
strings.encode_uri_component( [uri1, [uri2, [...]]] ): Encode a list of URI
  components. This function returns as many variables as it had arguments.
strings.resolve_xml_special_chars( [str1, [str2, [...]]] ): Resolve XML
  special characters in a list of strings. This function returns as many
  variables as it had arguments.
strings.convert_xml_special_chars( [str1, [str2, [...]]] ): Do the inverse
  operation.

Variables
---------
var.get( object, name ): Get the object's variable "name"'s value.
var.set( object, name, value ): Set the object's variable "name" to "value".
var.get_list( object, name ): Get the object's variable "name"'s value list.
  1st return value is the value list, 2nd return value is the text list.
var.create( object, name, value ): Create and set the object's variable "name"
  to "value". Created vars can be of type float, string or bool.

var.add_callback( object, name, function, data ): Add a callback to the
  object's "name" variable. Callback functions take 4 arguments: the
  variable name, the old value, the new value and data.
var.del_callback( object, name, function, data ): Delete a callback to
  the object's "name" variable. "function" and "data" must be the same as
  when add_callback() was called.

var.command( object name, name, argument ): Issue "object name"'s "name"
  command with argument "argument".
var.libvlc_command( name, arguement ): Issue libvlc's "name" command with
  argument "argument".

Video
-----
video.fullscreen( [status] ):
 * toggle fullscreen if no arguments are given
 * switch to fullscreen 1st argument is true
 * disable fullscreen if 1st argument is false

VLM
---
vlm(): Instanciate a VLM object.

v = vlc.vlm()
v:execute_command( "new test broadcast" ) -- execute given VLM command

Note: if the VLM object is deleted and you were the last person to hold
a reference to it, all VLM items will be deleted.

Volume
------
volume.set( level ): Set volume to an absolute level between 0 and 1024.
volume.get(): Get volume.
volume.up( [n] ): Increment volume by n steps of 32. n defaults to 1.
volume.down( [n] ): Decrement volume by n steps of 32. n defaults to 1.