Converting vfr clips to VfW AVI-containered cfr lips

[turk690]

In the Adobe scheme of things, variable frame rate clips such as those shot with devices whose names starts with "i" or downloaded from YouTube (WebM) are categorized under best-left-where-found. In cases where these clips have to be included in a Premiere timeline, one is left to transcoding them with handbrake, for one, to an amenable constant frame rate before importing them. But though handbrake does it respectably (preserving AV sync), in the latest versions only two (container) formats (MP4 and MKV) are offered as output. Staxrip still offers AVI (not clear if any other codec apart from xvid is available under that), but introducing any avisynth FPS filter (convert & change; assume makes it hang) makes AV in the resulting cfr file gradually drift out of sync with each other. Short of using Vegas, is it possible to tweak handbrake or staxrip into transcoding such vfr clips into driftless cfr AVI-containered clips (using system installed VfW codecs like Ut or MagicYUV)?

[sneaker]

Use AviSynth with e.g. ffms2 (adding "fpsnum" and "fpsden" parameters for vfr->cfr conversion) and then use e.g. VirtualDub or ffmpeg to encode to a lossless avi with the codec (or uncompressed) of your choice or use the avisynth virtual file system (avfs) to directly load the script in any software that can open avis.