As mentioned in 
http://valentin.dasdeck.com/xtras/avmedia_xtra/win/readme.txt
playing media with the LAV filters via DirectShow in Win 7/8/10 requires 2 steps:

STEP 1: registering the LAV filters in the system
STEP 2: deactivating/replacing the default MS decoders


Concerning STEP 1:
==================

DirectShow Xtra can register those 3 filters (LAVAudio.ax, LAVVideo.ax,
LAVSplitter.ax) via function 'ds_register_filter'.

But in Win 7+ this requires that the projector calling this function has
admin rights. There are 2 ways to achieve this:

a) Run the Projector by selecting "Run as adminstrator" from the
Explorer's contect menu

b) Using a projector that contains the word "install" in its name, which then
automatically has admin rights.


Here a full standalone demo (including the LAV filters) for approach a):
http://valentin.dasdeck.com/xtras/avmedia_xtra/win/lav_filters/LAV_filters_register.zip

Unpack, then run "lav_register.exe" (or "lav_unregister.exe") as admin,
as shown in this screenshot:
http://valentin.dasdeck.com/xtras/avmedia_xtra/win/lav_filters/register_lav.png


And here a standalone demo (including the LAV filters) for approach b):
http://valentin.dasdeck.com/xtras/avmedia_xtra/win/lav_filters/LAV_filters_install.zip

Unpack, then run "lav_install.exe" (or "lav_uninstall.exe") by a normal
double click in Explorer.


Both approaches work fine and succesfully register/unregister the
filters, but in my Win 8 test system, approach b) results in a Windows
dialog asking if the application worked fine or not after it was
quit. It DID work fine, but this might confuse users...

Note: those 2 standalone projects are just D11 projectors, but based on
my LSW framework. To quit them, type "q" (+RETURN) into the message
window. The relevant lingo code is found in files:
- lav_register.lsw / lav_unregister.lsw
- lav_install.lsw / lav_uninstall.lsw


Concerning STEP 2:
==================

As far as I can see, deactivating the MS decoders is a little tricky.
The "Win7DSFilterTweaker" tool seems to rename
  C:\Windows\System32\mspeg2adec.dll
  C:\Windows\System32\mspeg2vdec.dll
to
  C:\Windows\System32\mspeg2adec.dll.bak
  C:\Windows\System32\mspeg2vdec.dll.bak

and it also changes some registry keys.

There is no doubt that the same thing could be done by a projecctor run
with admin rights (see 2 approaches described above) - and you could also
run "Win7DSFilterTweaker-6.0.exe" from your Director projector, either
using Director's "open" command or Shell Xtra.

BUT actually you don't have to!

Once you succesfully registered the LAV filters (see above), you can use
the following function to FORCE playback of media via LAV filters:


----------------------------------------
-- requires LAV filters to be registered
----------------------------------------
on playMediaWithLAVFilters (mediaFile)

  props = [:]

  -- create filter graph
  props["filterlist"] = [:]
  props["filterlist"]["filters"] = []
  props["filterlist"]["filters"].add(["source": mediaFile]) -- 1
  props["filterlist"]["filters"].add(["guid":\
    "{171252A0-8820-4AFE-9DF8-5C92B2D66B04}"]) -- 2 = LAV Splitter
  props["filterlist"]["filters"].add(["guid":\
   "{EE30215D-164F-4A92-A4EB-9D4C13390F9F}"]) -- 3 = LAV Video Decoder
  props["filterlist"]["filters"].add(["guid":\
    "{E8E73B6B-4CB3-44A4-BE99-4F7BCB96E491}"]) -- 4 = LAV Audio Decoder

  props["filterlist"]["connections"] = []
  props["filterlist"]["connections"].add([1,2])
  props["filterlist"]["connections"].add([2,3])
  props["filterlist"]["connections"].add([2,4])

  -- render LAV decoders with system default renderers
  props["filterlist"]["render"] = [3,4]

  -- play the filter graph
  hr = $.directshow.ds_open(props)

  -- not needed, since autostart is activated by default
  -- (otherwise set property "paused" to 1 in ds_open)
  -- $.directshow.ds_play()

end

Here a standalone D11 demo based on this approach:
http://valentin.dasdeck.com/xtras/avmedia_xtra/win/lav_filters/LAV_play_media.zip

Unpack, then run "lav_play_media.exe", and playback of the demo AVC/AAC
video should start. Again, this only works AFTER the LAV filters were
registered.