Converting video but keeping original AC-3 audio

[pooksahib]

Hi. I've indexed my file using MeGUI and it's demuxed the AC-3 track for me. For the encode, I've ticked the box for "add additional content" but it gives me no options. Doing the same thing when the audio is AAC is a breeze...

Why is AC-3 different and what do I need to do so that I end up with a recoded vid and the original audio? Many thanks.

[ProWo]

Mux the videostream and the ac3 with mkvtoolnix to mkv. If you prefer mp4 output you can use my clever Ffmpeg-GUI for muxing.

[pooksahib]

Yes, I did consider using mkvtoolnix after the encode but it's so wasteful - you've created two video files. I'd love to have a one-step solution if possible.

[LigH.de]

MeGUI contains "Muxer" dialogs for its "Queue" in its "Tools" menu. No need to run external tools manually, instead you can add a multiplexing job to the queue after the video encoding job is done.

The encoders used in MeGUI (like x264) will usually ignore audio and create only the video track, anyway. Having a mute intermediate result to multiplex the audio into may be inevitable.

I only know the manual mode of MeGUI, adding jobs to the queue. It is possible that One Click or Auto Encode can handle converting the video and passing the original audio stream conveniently, but I have no experience with these tools in MeGUI.

[pooksahib]

Danke, LigH.de. I found this thread:
https://forum.videohelp.com/threads/288774-How-do-I-add-AC3-and-AAC-to-my-video-files-...ed-using-meGUI
and the message seems to be: Don't use AC-3.

[LigH.de]

Well, it's from 2008, that's 12 years ago. In the meantime, AC-3 is very well supported in MP4, using MP4Box (by MeGUI's muxer job).