VDR (VirtualDub) are created and used by VirtualDub, a program primarily used for editing
AVI movie clips.
Such files are also called VirtualDub Signpost file or VirtualDub link handler.
The signpost file, which normally uses the .vdr filename extension, is used as input to the AVI capable client application and contains the frameserver name and video name. This video is then converted and offered by VirtualDub Frameserver to the client.
VDR files use the RIFF container format.
.VDR files start with ASCII "
RIFF", have "
VDRM" at offset 8, and
PATH at offset 12.
At offset 20 the name of the used video is stored and at offset 16 the length of that name is stored.