If it is fine for you to do the batch job of transforming a bunch of x3d into x3dv in classic vrml format (or the tool allows you to transform to vrml97 format, just in case you are interested in knowing), you can do it with your own batch file. I say your own batch file because the batch file you seem to have downloaded and in hand is quite out-dated and was written in a fashion which can confuse users quite a bit. For instance vorlon is practically out of the sceen... checking syntax with xmlint is usually unnecessary if the users already know what they are doing and simply want to get the x3dv file output..., hence you don't even bother to have xmlint downloaded etc.
One thing you need to have is an xslt engine. The said batch file use saxon which is a good choice (but you can use Apache's up-to-date version of xalan. no problem). But it uses some dated info and therefore you need to rewrite that part despite all. If you keep that suggestion of using saxon, you must download it and the free version works just fine. I happen to have saxon9 on my box and know it quite well. If you go to their site, you might find a new version and it is in general recommended to use a more updated version. Just download its -j (java) and -n (dot net) variants. To use it for batch (or powershell), you can stick to the dotnet version. The executable is now called transform.exe (rather than saxon.exe as written in that dated batch file).
You can write a greatly simplified bat, something like this.
I will transform it to ClassicVRML encoding output named after the input x3d. If it is HelloWorld.x3d, it would output HelloWorldClassicVRML.x3dv etc... (The naming is actually quite free. If you want it differently named, just edit your requirement into the batch file.) The xslt file is having an extension xslt. I most of the time use xsl then just edit the line set xsltext=xslt to set xsltext=xsl.
Since you use X3dToX3dvClassicVrmlEncoding.xslt, you don't even need to set the parameter fileEncoding, as it is defaulted to ClassicVRML. I still put there just for in case you read the downloaded bat and find it there.
For example, now if you call:
You will transform a HelloWorld.x3d (or something you put there for
testing...) to HelloWorldClassicVRML.x3dv.
If you do this:
It will transform an x3d file 2d.x3d to output a 2dClassicVRML.x3dv. That's all it does.