Appending Audio Always Fails

[shley]

Hi all! I'm having some trouble getting avidemux to append audio files to a video. It pulls in my video just fine, but when I try to insert an audio file (either through the file menu or drag and drop), it tells me "Attempt to open [File] failed" and "Something failed when appending." This applies to a bunch of different file formats (tried mp4, m4a, aac with an mp4 video). I'm on MacOS Monterey on a Pro with avidimux version 2.8.0. Any tips?

[eumagga0x2a]

This is not supposed to work this way (or any way, actually). Only videos can be appended, with preferably fully matching audio tracks.

For external audio tracks, which should always be multiplexed into video to become internal ones as the first step prior to any further editing, only raw streams (ADTS encapsulated streams in case of AAC as AAC absolutely requires so-called extradata = instructions for audio decoder how to interpret compressed data) are supported, no containers like MP4 (m4a is an MP4 container without a video track).

That said, you need to prepare a video matching the first loaded video at least in dimensions and frame rate with an internal audio track you wanted to append which needs to match the audio track of the first video in number of channels, sampling rate and the codec and codec settings. Then you should be able to append this video.

[eumagga0x2a]

Unrelated to your question, I strongly recommend updating to the latest 2.8.1 nightly build for macOS due to important fixes including those for crashes found in 2.8.0 shortly after the release was out.

[shley]

Ah, okay! Sorry, I'm not super familiar with all of this, I thought I'd be able to use it to add a new audio track over my silent video like a dub. Thanks for your help! I'll keep working with those files and see what I can do.

[eumagga0x2a]

Adding (Audio --> Select audio track --> "Add file" from dropdown menu) an audio track from an external file is possible, but not appending and not mixing an external track into existing (non-silent) internal track.

[shley]

Ah, I think I found my problem. I thought the video didn't have an audio track, turns out it does, but I had the option turned off when I viewed the tracks in Quicktime.

That makes more sense now. I'll mess with those clips more when I get off work. Thanks again!