The –threads switch is optional: it only shortens processing time if you have a multi-core CPU (a value of zero means that the optimum number of threads is automatically chosen for you). Useful values for crf fall between 15 and 28.

The crf (constant rate factor) controls the quality: a lower crf value gives better quality at the expense of a higher video bitrate. The preset is concerned with encoding speed and compression efficiency. The nearest other valid switches are -preset slow and – preset fast. Note that AVStoMKV.bat assumes you’re using a recent version of ffmpeg that recognises a ‘medium’ preset for x264 encoding.

The frame rate will match the source and be 25fps, 29.970fps or 30fps. Expect it to work for AviSynth scripts based on either AVCHD Lite files or AVI files derived from MOV. This will produce an x264 compressed video with AC3 sound in an MKV container. Place AVStoMKV.bat within the same folder as the source video files and the AviSynth script then double click the batch file. Copy and paste the following text into Notepad and save it as AVStoMKV.batįor %%a in ('*.avs') do ffmpeg -i '%%a' -vcodec libx264 -preset medium -crf 19 -acodec ac3 -threads 0 '%%~na.mkv' A simple way to do it is to call ffmpeg from within a batch file. You can use ffmpeg to process the output from a 720p AviSynth script into an MKV file with x264 compression.

Convert avs to mp4