Avidemux keeps telling me Muxer cannot open, then doesn't save the file.

[Anfiles]

Anybody know what can cause this?

These are my settings, and I also pasted, below the red line in the picture, the error I get.

https://i.imgur.com/bvKwPm8.png

[Alwyn]

I just tried with a MOV from an iphone using your basic settings and it worked OK.

Try a different Output format, say the MP4 Muxer. If that fails as well, you might have a file that has issues. You could also try Handbrake.

[DB83]

Same here. I just did a quick test and the muxer certainly opened and proceeded to encode.

Not sure if avidemux retains the settings of the audio/video codecs from previous use and since we can not see these we can not comment on them.

[davexnet]

The file info would help, perhaps a mediainfo report (text view)

[Anfiles]

I just tried with a MOV from an iphone using your basic settings and it worked OK.

Try a different Output format, say the MP4 Muxer. If that fails as well, you might have a file that has issues. You could also try Handbrake.

Only output format that works is avi muxer, which says "bad idea."

I have noticed all these videos with this problem come from another iphone I recently purchased But I can't figure whatsetting on that iphone could be causing this.

Handbrake is not a good option for me because doesn't seem to allow me to trim the video visually, the way I can with Avidemux.

[Anfiles]

The file info would help, perhaps a mediainfo report (text view)

I downloaded it but not sure how to use it.

[Alwyn]

With AVIDemux, try saving the audio as AAC. I'm not sure that MP4 with AVC/H264 likes having MP3 as the audio.

Re MediaInfo: just open your video file in it, then go to View>Text (MediaInfo should also be available from the right-click context menu). You'll get a comprehensive readout of the details. Then copy all that text and paste it here.