ffdshow is an open source DirectShow and VFW codec for
decoding/encoding many video and audio formats, including DivX and XviD
movies using libavcodec, xvid and other open source libraries with a
rich set of postprocessing filters. It can also be used to imprint graphic
overlays onto NSV video streams.
If everything is installed correctly your start menu should have these things
under Start> All Programs> ffdshow.
You want to select the bottom one - Video Decoder Configuration.
When you open ffdshow, a large window opens.
The first place you want to visit is the codecs section. You can pretty much tell
everything to use libavcodec, but for this guide, we are going to select DVSD.
Next go to the tray section, make sure show tray icon is checked.
(This will let you know that ffdshow is working when you launch NSVenc. )
This is how I have the overlay section setup.
This is the bitmap overlay section
(You can make adjustments once NSVenc is running.)
Next, run NSVenc.
Once NSVenc is running, and
you're capturing from your DVSD source, you will notice a little ffdshow icon in
your system tray.
Double clicking the ffdshow icon will bring up the ffdshow dialog.
In the dialog box, you can tweak ffdshow configurations on a live stream.
You can add filters, change picture properties, psuedo zoom (digital)
change overlays and other things.
The bitmap overlays that I have used are bitmaps, not jpg,png,gif,etc.
Black is a transparent color, if you use the lighten mode.
Enabling settings per application is useful if ffdshow is used for more that
Additional ffdshow features.
ffdshow allows you to include screen announcements overlaid on the live
broadcast screen. In the same way you made your
logo bitmap for logo overlay, you can make announcement bitmaps.
ffdshow lets you save a profile for each one -- load the announcement bitmap for
overlay, you'll see it appear on the live screen. Then go to the "image
settings" part of ffdshow config and save it as a profile to use whenever you
want to overlay the announcement. You can make as many different bitmap profiles
as you need.
Overlaying a profiled announcement live is simply a matter of loading the
profile for it -- takes about 5 to 10 seconds to appear on the live screen, but
the time delay is an unavoidable result of encoding to a remote Shoutcast server.
In addition, outdoor live broadcast tests have presented a variety of
environments -- bright sun, overcast, and so on. With ffdshow as helper, you can
correct the image appearance in real time to suit the situation. You can also
save the adjustments in a profile to use later in a similar situation.