FFmpegSource("location of vid", atrack=-2, timecodes="TIMECODES.TXT", vcache=true, seekmode=-1)
# try seekmode=1 if you want, that's faster, and isn't linear access only, but seekmode=-1 is the "safest".

#Linear access, stick filters here, but no filters here that needs to backtrack or seek, otherwise bad stuff happens

If you aren't going to do any filtering, trimming, and stuff like that, then encode the final directly.

If you do want to use more filtering (that can't be done on previous step), then use the above to encode an intermediate (use high quantizer, or lossless), then write new avs.

DirectShowSource("location of intermediate", fps=whatever, audio=false)
#or AVISource if your thing is avi

#Stick all your filters and stuff here

Use that to encode final video.


Encode audio separately.


Use MKVMerge on video and audio. Your previous encode/s should have spit out a file called "TIMECODES.TXT". Click on your video track, under general track options, stick in your timecodes, mux.

You should end up with a VFR MKV file.