Using the GUI, I can successfully encode a video by selecting "M-JPEG" from the Video drop down. I'd like to now create a batch script to do this. How do I figure out the corresponding name that I should give to --video-codec when calling avidemux from the command line? I've tried "mjpeg", "m-jpeg" with various capitalizations. I've also tried all of those preceded by "avcodec:" and none work. Every time it says "Mmmm Select codec by name failed...". Maybe this is relevant, but after that it always lists a bunch of names but they are garbled like e.g.: "Copy:�9H�" Thanks.
I saved several Tinpy Project with the options I wanted to be scripted and use them as a draft to create custom ones by bash script. Finally, I run the newly created project file from commandline.
Not a straight answer to your question but a proposal with which I worked around similar problems you raised.