Use Format Factory to convert the WMV clips to something more Vegas-freindly.

Format Factory is free and can be downloaded from http://www.formatoz.com/

Windows Media Encoder (Free From MS) has a custom mode that lets you batch encode (combine) from multiple files. Don't know how slow it is though.

UPDATE: Oh, I re-read your post and this won't help. You don't want to just stitch, you want to apply transitions too.

Also, your bitrate is WAY too high. Cut it down to 1000, or even 500. Just try it with a small selection area first, and see how long it takes.

I don't know where Sony gets this "WMV 11" from, AFAIK WMV9 is still the latest release. Perhaps it's referring to VC-1 advanced profile, but anyway it still has to re-encode to render the transitions, there's no way around it.

Way to high for what? 3840Kbps is about as low as i'd want to go for DVD-quality SD clips.

The latest version of Super by Erightsoft has a wmv stitcher.
This is just information -- I haven't tried it.

For the WMVHD (AKA VC-1). source files, they're 720p, 4 times larger resolution than DVD resolution. That's why it's taking so long.

OK thanks for all the tips. I'll check out a couple of the stitching tools and see how it goes and I'll drop the transitions. Wouldn't a simple 'copy base video template' also be an option in Vegas - to copy a video file on a hard drive only takes a few seconds!

Well, a couple things.

1. You aren't copying the file. You are using an encoder to re-encode the file. And you are HOPING that it's smart enough to realize that nothing has changed.

2. Microsoft make an encoding application that is excellent. It gives access to more professional tools and results, and its a free download from their Windows media site. It has both a 32 and a 64bit version. It can encode live streams or files.

3. Get used to the idea of using helper programs for your video work. Yes, Vegas Pro costs a few hundred dollars, but it can't do everything. No NLE can. Sometimes there are other VERY valuable tools out there to do specific tasks.

OK, a change of tacks. What about if I just want to trim a file to extract the part of the timeline that I want from each clip. In other words copy a segment of a file, or alternatively copy the whole video file and then chop off the bits I don't want. Is there any software that does this - perhaps something from Vasst? Sounds easy and quick without the need to render a new file frame by frame but maybe it isn't?

the problem that you are having, is that you are thinking of video as though it were a discrete set of frames. You want to remove a certain number of frames, slide the rest into place, and just put it all back together. Well, in many professional codecs, this is exactly how it works. They are called INTRA -Frame codecs, because each frame is compressed completely separate from any other.

However, consumer based, or highly compressed codecs like WMV, AVCHD, Mpeg2, etc. aren't done this way. They rely on the frames around them for information. Remove a frame, and things begin to fall down. This is why they have to be re-encoded. To recalculate that missing information. It's like the links in a chain. If you have a chain 100 links long, and you remove link 12, link 55, link 71, and link 98, you aren't going to be doing much with that chain any more! It must be reconstructed.

So no, this isn't as simple as it might seem on the surface. Cutting the ends off or attaching two videos together can work. Just like with a chain. But as soon as you split it, integrity is lost.

Maybe I'm not following this thread as I should, but wouldn't simply rendering the raw .WMV files to suitable lossless (or if space allows, even uncompressed) .AVI ones in Vegas -- and then use the AVI versions in-project for editing solve the whole dealing-with-WMV thing?

Once something is in AVI many more options open up, including exporting/rendering out the final render. But then I'm not an expert on the nano-topography of formats and codecs either, so my suggestion may or may not be naive.