Re-encode audio only

[umbala]

I recently started re-encoding some of my high bit rate videos to save space. The problem is that I may have set the audio quality a bit too low. I went from 6 channel FLAC to 6 channel AAC at 384 kbps. I regret doing this, but now I have no way to re-encode only the audio portion using Handbrake. I'm sure I'm not the first person to make this mistake and I'm hoping I could get some suggestions on how to proceed.

I think a better choice would have been to go with AAC at 1536 kbps or maybe even DTS at that bit rate? Is there some way to re-encode only the audio portion using Handbrake that I don't know about? What do others do in this situation?

I'm no audiophile, but I want to keep my audio high quality without paying for expensive software to do it. Another thing I'm worried about is the audio being out of sync if I use a separate program to encode it and then mux it with the video. I normally use mkvmerge for muxing and it's been pretty reliable. Any suggestions regarding this would be greatly appreciated.

[mduell]

Not using HB. Other tools like ffmpeg, etc can do video copy, and have their own set of features and limitations.

[Woodstock]

Also, unless you start with the FLAC source, you are building in an additional layer of compression loss. Even encoding at a higher bit rate is NOT going to magically regain the fidelity.

[mduell]

Also, unless you start with the FLAC source, you are building in an additional layer of compression loss. Even encoding at a higher bit rate is NOT going to magically regain the fidelity.

I assumed OP wanted to mux the already-encoded video with new audio (original or a new encode from original)... surely they're not pants-on-head retarded going to work from the 384k AAC audio...

[umbala]

So no one's encountered a similar situation and has any suggestions on how to proceed then? I'm not going to use something like ffmpeg and [Censored] around on the command line with dozens of audio files.

[WhatZit]

So no one's encountered a similar situation and has any suggestions on how to proceed then?

Try this: viewtopic.php?f=6&t=37043&p=174739#p174739

The source in Step 1 is the original source with FLAC.
The source in Step 7 is your original HB encode (384 AAC)
The encode in Step 9 is the one from Step 6.

Be aware that you actually need to set your framerate options in Step 3 to suit whatever you used to originally encode your videos (to keep the new audio track the same length as the old video). If that wasn't SameAsSource+Constant, expect to lose sync.

[rollin_eng]

Or rather than messing around trying to encode/re-encode/mux things together just re-encode from your source with the correct settings

That way you don't have to worry about synch issues, plus you get any encoder/filter updates.

Longer to run, Yes. Less complicated, HELL YES.