(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?

2 Answers 2


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.


You'll have to use another source filter, such as FFMS2 or LSMASHSource

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