vlc/projects/activex

== ACTIVEX Control for VLC ==

The VLC ActiveX Control has been primary designed to work with Internet Explorer.
however it may also work with Visual Basic and/or .NET
Please note, that this code does not rely upon Microsoft MFC/ATL code,
hence good compatibility is not guaranteed. 

I. Compiling

The ActiveX Control should compile without any glitches as long as you have the latest
version of mingw gcc and headers. However, In order to script the ActiveX Control
on Internet Explorer, a type library is required.

This type library is usually generated from an IDL file using Microsoft MIDL compiler.
Therefore, for convenience I have checked in the output of the MIDL compiler in the
repository so that you will only need the MIDL compiler if you change axvlc.idl.
the generated files are as follow:

axvlc_idl.c
axvlc_idl.h
axvlc.tlb

To use the MIDL compiler on cygwin, you will need to set some environment variables
before configuring vlc. If you have a copy of 'Microsoft Visual C++ 6.0' installed,
the following settings are correct:

export PATH=$PATH:"/cygdrive/c/Program Files/Microsoft Visual Studio/COMMON/MSDev98/Bin":"/cygdrive/c/Program Files/Microsoft Visual Studio/VC98/Bin"
export INCLUDE='C:\Program Files\Microsoft Visual Studio\VC98\Include'
export MIDL="midl"

If you are cross-compiling on Linux, you can use 'widl' which is part of
the WINE project (http://www.winehq.com). At leat wine-dev-0.9.57 works,
the comand line to compile IDL should looks like the following :

widl -I/usr/include/wine/windows/ \
     -h -H axvlc_idl.h -t -T axvlc.tlb -u -U axvlc_idl.c \
     axvlc.idl
NOTE: widl breaks compatibility with Visual Basic. If that is important to you then use midl.

II. Debugging

the ActiveX control is compiled with verbose output by default. However you will
need to launch Internet Explorer from a Cygwin shell to see the output.
Alternatively, the plugin will also use the VLC preferences, hence if you enable
the file logging interface through the player and save the preferences, the
control will automatically log its verbose output into the designated file.

Debugging the ActiveX control DLL with GNU GDB can be difficult. Fortunately,
the ActiveX control can also be compiled as an executable rather than a DLL.
In ActiveX terms, this is called a local server.
The advantage of a local server is that it will never crash its client,
i.e Internet Explorer, if itself is crashing.
The build system does not currently allow to create an executable version of
the ActiveX control, you will need to manually define the BUILD_LOCALSERVER
pre-processor variable and modify the Makefile to exclude the '-shared' option
at the linking stage. Once this is done, you just need to launch axvlc.exe to
have a working Activex control. Please note, that executable version of the
ActiveX control will override any settings required for the DLL version, which
will no longer work until you (re)register it as shown in the following section

III. Local Install

The VLC NSIS installer will install the ActiveX Control without requiring any
further manual intervention, but for people who like to live on the edge, here
are the steps you need to perform once you have built the ActiveX Control.

The ActiveX control DLL file may be copied anywhere on the target machine,
but before you can use the control, you will need to register it with Windows
by using the REGSVR32 command, as per following example:

REGSVR32 C:\WINDOWS\AXVLC.DLL

If the control needs to use external VLC plugins (i.e other than built-in ones),
make sure that the plugin path is set in the registry as per following example:

[HKEY_LOCAL_MACHINE\Software\VideoLAN\VLC]
InstallDir="C:\Program Files\VideoLAN\VLC"

The InstallDir must be the parent directory of the 'plugins' directory.

WARNING: Both control and plugins must come from the same build source tree.
Otherwise, at best, the control will not play any content, at worse
it may crash Internet Explorer while attempting to load incompatible plugins.

IV. Internet Install

The activex control may be installed from a remote through Internet Installer if
it is packaged up in a CAB file. The following link explains how to achieve this

http://msdn.microsoft.com/workshop/components/activex/packaging.asp

For convenience, I have provided a sample axvlc.INF file, which assumes that the VLC
NSIS Installer has been packaged up a CAB file called AXVLC.CAB.

The ActiveX Control DLL file can also be distributed by itself if it has been
compiled with built-in VLC plugins; check developer information for more
information on built-in plugins.

V. Controlling the plugin

1) Properties

the following public properties can be used to control the plugin from HTML,
the property panel of Visual Basic and most ActiveX aware applications.

+==========+=========+===================================+===============+
| Name:    | Type:   |   Description:                    | Alias:        |
+==========+=========+===================================+===============+
| autoplay | boolean | play when control is activated    | autostart     |
+----------+---------+-----------------------------------+---------------+
| autoloop | boolean | loop the playlist                 | loop          |
+----------+---------+-----------------------------------+---------------+
| mrl      | string  | initial MRL in playlist           | src, filename |
+----------+---------+-----------------------------------+---------------+
| mute     | boolean | mute audio volume                 |               |
+----------+---------+-----------------------------------+---------------+
| visible  | boolean | show/hide control viewport        | showdisplay   |
+----------+---------+-----------------------------------+---------------+
| volume   | integer | set/get audio volume              |               |
+----------+---------+-----------------------------------+---------------+
| toolbar  | boolean | set/get visibility of the toolbar |               |
+----------+---------+-----------------------------------+---------------+

the alias column allows to specify an alternative <PARAM name> for the
property in internet explorer, which is useful to maintain compatibility
with HTML pages already leveraging Windows Media Player

2) Programming APIs

the MRL, Autoplay and Autoloop properties are only used to configure the initial
state of the ActiveX control,i.e before its activation; they are ignored afterward.
Therefore, if some runtime control is required, the following APIs should be used
within your programming environment:

Variables:

+==========+=========+=========+=======================================+
| Name:    | Type:   | Access: | Description:                          |
+==========+=========+=========+=======================================+
| Playing  | boolean |   RO    | Returns whether some MRL is playing   |
+----------+---------+---------+---------------------------------------+
| Time     | integer |   RW    | Time elapsed in seconds playing       |
|          |         |         | current MRL                           |
|          |         |         | NOTE: live feeds returns 0            |
+----------+---------+---------+---------------------------------------+
| Position | real    |   RW    | Playback position within current MRL  |
|          |         |         | in a scale from 0.0 to 1.0            |
|          |         |         | NOTE: live feeds returns 0.0          |
+----------+---------+---------+---------------------------------------+
| Length   | integer |   RO    | Total length in seconds of current MRL|
|          |         |         | NOTE: live feeds returns 0            |
+----------+---------+---------+---------------------------------------+
| Volume   | integer |   RW    | Current volume from 0 to 100          |
+----------+---------+---------+---------------------------------------+
| Visible  | boolean |   RW    | Indicates whether control is visible  |
+----------+---------+---------+---------------------------------------+

Methods:

  *** current interface (0.8.6+) ***
UUID : 9BE31822-FDAD-461B-AD51-BE1D1C159921
defined in axvlc.idl as "coclass VLCPlugin2", "interface IVLCControl2"

This interface organize API with several object (like .audio.mute)
It is currently documented on videolan wiki (may change) at
http://wiki.videolan.org/Documentation:Play_HowTo/Advanced_Use_of_VLC


  ***  old interface (deprecated)  ***
UUID : E23FE9C6-778E-49D4-B537-38FCDE4887D8
defined in axvlc.idl as "coclass VLCPlugin", "interface IVLCControl"

play()
    Play current item the playlist

pause()
    Pause current item in the playlist

stop()
    Stop playing current item in playlist

shuttle(Seconds as integer)
    Advance/backtrack playback by specified amount (which is negative for
    backtracking). This is also called relative seeking.
    This method does not work for live streams.

fullscreen()
    Switch between normal and full screen video

playFaster()
    Increase play back speed by 2X, 4X, 8X

playSlower()
    Decrease play back speed by 2X, 4X, 8X

toggleMute()
    mute/unmute sound output

addTarget(MRL As String, Options as array of strings, Mode as enumeration, Position as integer)
    Add MRL into the default playlist, you can also specify a list of playlist Options to attach
    to this MRL or Null for no options. mode indicates the action taken by the playlist on MRL
    which is one the following:
        VLCPlayListInsert       =  1 (Insert MRL into playlist at Position)
        VLCPlayListInsertAndGo  =  9 (Insert MRL into playlist at Position and play it immediately)
        VLCPlayListReplace      =  2 (Replace MRL in playlist at Position)
        VLCPlayListReplaceAndGo = 10 (Replace MRL in playlist at Position and play it immediately)
        VLCPlayListAppend       =  4 (Append MRL in playlist after Position)
        VLCPlayListAppendAndGo  = 12 (Append MRL in playlist after Position and play it immediately)
        VLCPlayListCheckInsert  = 16 (Verify if MRL is in playlist) 
    Position can take the value of -666 as wildcard for the last element in playlist


setVariable(Name as string, Value as object);
    Set a value into a VLC variables

getVariable( Name as string) as object
    Retrieve the value of a VLC variable.

Regards,
    Damien Fouilleul <Damien dot Fouilleul at laposte dot net>