Like Edge said do this in console:
host_framerate 30; startmovie namehere; playdemo filename
This will create a bunch of TGA files and a wav file in your hl2dm folder.
Now use
VirtualDub to open the first TGA. This will actually open the entire series of TGA files. Under the Video menu set Frame Rate to 30 fps. Under the Audio menu select Audio From Other File and find the wav file that was create in your hl2dm folder and change the mode to full Processing Mode. Now go to File and select Save As AVI.
Basically you are following step 4 in this guide:
http://www.hl2dm-university.com/forum/p ... f=13&t=917
From here if you are wanting free tools to assemble the DVD you could try the following this guide:
http://www.afterdawn.com/guides/archive ... vi2dvd.cfm
It makes use of
AVI2DVD which is free.
You could also just author the dvd in something like Premiere (Elements) or any one of the Sony Vegas products. All you would really be doing is dropping the avi on the timeline and then selecting Render to DVD.
That will get you a VIEDO_TS folder that you can then burn onto the DVD using anything like Nero or Roxio or whatever.