Re: Automatic Gain Conrtol in WMENC 9

On Thu, 26 Apr 2007 07:40:18 GMT, "Rüdiger Faust" <r.faust@xxxxxx>
wrote:

i need an Plug In that makes an ACG Function bevor the Stream is encoded.

Do you mean "AGC", automatic gain control - to keep the level of your
audio near to constant ?

Yes, sorry, i mean ACG.


Then I don't know what ACG is. Wikipedia lists these possibilities :
http://en.wikipedia.org/wiki/ACG which I don't know to choose.


This process usually done by using a compressor / limiter, physical
(analog) hardware to keep the audio INPUT at a stable volume.

That's the best way, i know. But we must handle 16 Channels, so we have 16 x
1 HE Processing Boxes, an half Rack. :-) We want to test with a plug in
before we buy external hardware.


But you could afford 1x compressor/limiter right ? Even basic musical
ones used in home studios are only about $50, which would be enough to
discover if it's working as desired. A high end manufacturer may loan
you equipment for a few days if you have a large rack to purchase.

It's much better than expecting the encoder to do this, which will
only introduce digital noise and give poor encoding.


I repeat : Limit the INPUT, otherwise the encoder will encode noise
and digital clipping, which is not what you want in the output as it
sounds terrible. Garbage-In = Garbage-Out no matter which plugins you
may be able to find.


OK. Is an Plug-In Existing for WME? I want to test the Quality, than i can
think about to buy the hardware.


Some Audio plugins are registered by default (and others may be
registered with Directshow by audio or video processing programs).

Each system may have different software installed, so some filters may
be available on some machines but not others.

On my encoder, going to the Plug-Ins tab, selecting Audio, then
selecting Register... shows a list of installed plugins.

I have one labelled as "Compressor" there. Tick the box, choose
Apply, then select it in the left panel. Move it to the Right panel
using the >> button. Now the button "Configure" becomes available.


In your saved WME profile, you'll now see a new section, similar to
this, which indicates the compressor settings chosen. You should be
able to apply that to the other encoder profiles in Notepad, if
required

<StreamTransformPlugins >
<TransformPlugin Source="Compressor"
Scheme="pluginwrapperfordmo" >
<UserData >
<WMENC_BLOB Name="BinaryProperty" >

<![CDATA[791f01ef00406d4087afbffb3fc39d5700000000000000000000000000000000333353411904d24200e044449a9901c2713db641cdcc4c40]]>
</WMENC_BLOB>

</UserData>

</TransformPlugin>

</StreamTransformPlugins>

As noted prebiously, do not expect good results if your audio is
clipping at the input (analog sound source). There's no way to recover
data above the clipping threshold, it is totally lost (aas well as
sounding awful)

Cheers - Neil
------------------------------------------------
Digital Media MVP : 2004-2007
http://mvp.support.microsoft.com/mvpfaqs
.