Trying to edit video with AviSynth, but process is tedious

I'm going through my RBR footage from the CNY and trying to put it together and make it look nice, but I'm not pleased with the time it takes to put out a final product. My current process is this:

• Use AviSynth to string together videos, add fades to the beginning and end of the string, and perform a dissolve transition between certain videos.
• Open AviSynth script in VirtualDubMod and save as .avi.
• Open .avi file in Windows Live Movie Maker and save movie for high-definition display.
• Upload video.

The reason I don't like how this works is because VDM generates a file in .avi format that is four times the size of the source materials. Because I don't want to tie up my computer for a whole day uploading a single video to YouTube, I toss this .avi file into Movie Maker, and it spits out a file that's an eighth of the size of the source material, and looks decent enough to watch. I was hoping that I'd just be able to run the AviSynth script in Movie Maker and save it from there, but the script isn't compatible.

What I'd like to know is if there's a way to cut down on this process of having to save the file in VDM to put everything together and then save it again in Movie Maker to cut down on the size. If there's something that can run AviSynth scripts that would save to a file whose size is in the ballpark of what Movie Maker does, that would be ideal. Whatever it ends up being, I hope I won't have to cease using AviSynth, because it does a fantastic job of what I want it to do (transitions and splicing).

You should be able to skip the encoding step in VDubMod by using a frameserver. VDubMod also has a frameserver, but I can't get it working(may be user error). I'm trying to figure this process out myself, and I'll update if/when I have a working method.

Basically I'm trying to do something similar: open an .avs script and encode for upload, but I prefer to use AviDemux(so I can encode to .x264 and AAC in .mp4 container) rather than Windows Movie Maker. I'm pretty sure I don't have all the required plugins in the AviSynth folder.

Do you use a GUI for all the editing and transitions in AviSynth, and if so, can you link it?

Maybe I can get around the problem by frameserving with VDub. Anyway, guide for VDub frameserving is here:
http://www.videohelp.com/oldguides/virtualdubframeserve
Steps are the same for VDubMod, since that's not been updated. I don't know if WLMM will recognize the file since I don't use it.

I don't use a GUI to create scripts with AviSynth. I just manually write them up in Notepad.

I will look into the frameserver when I have a chance and see if that works for me.

I found an easier solution if you don't mind using an all-in-one tool. Despite the name, XVid4PSP natively supports AviSynth input, and can encode to MP4, which is YouTube's preferred format. Select the PS3/X360 or MP4 format, and adjust settings as needed. File size can be controlled with video encoding settings.

I'm unable to give specific recommendations for the settings without additional information, namely: resolution, aspect ratio, duration of video(s), approximate file size desired, quality desired, encoding time desired, and if quality of encode or speed is preferable. In general, you can select x264 Q16 Turbo(Check if resolution and aspect ratio are correct.(Video -> Resolution/Aspect)) and AAC-LC ABR 128k(Make sure sample rate is 48,000 Hz.(Click Configure button after selecting audio encoding.)) for stereo audio. You can try a sample encode(say, 10 seconds) of a high action scene to see if this produces acceptable results.

YouTube - Simple encoding tips
Encoding Video For YouTube: Advanced Specifications

Sounds good, I'll download that tonight and see if it can do good things with some of my shorter clips.