AviSynth mp4 Not Supported (Total beginner) Trying to process an MP4 file using an AviSynth script, as follows:
    DirectShowSource(inputFile, fps=25, convertfps=true, logfile=logFile)

Error message: "DirectShowSource: couldn't open file SomeFile.mp4. Cannot play back the file. The format is not supported."

The file is valid, i.e. it can be played in a video player.

Using Windows 10 64-bit, and AviSynth 2.60

How can I process this file using AviSynth?
In the end, I made it work just as posted above, by installing the Haali Media Splitter. I have seen posts by people who say that this software is needed to process MP4 files.