MeGUI Converting to FLAC

[VideoFanatic]

I've got an AAC MKV. I'm re-encoding the video and audio in MeGUI. I need to re-encode the audio to FLAC. There's no FLAC options to choose apart from the speed of the encode. The AAC is 16 bit but for some reason MeGUI is converting it to 24 bit. Is there a "Custom command line" I can use to keep it as 16 bit?

[sneaker]

AAC is not 16 bit. AAC doesn't have an inherent bitdepth. You can even decode it at 64 bit. So MeGUI dithers down to 24 bit to make the file size not too big (humans can't hear difference). I don't know if it is possible to set MeGUI to convert to 16 bit (unless you write your own AviSynth script).

Why do you want to convert AAC to FLAC? It will only make file size bigger, quality will not get better.

[VideoFanatic]

Because I'm combining the video with a another video which has bad audio so I'm converting the bad audio to FLAC for cleanup.

I hover over the AAC file and a dbPoweramp popup says it's 16-bit.

[hardy]

eac3to

[sneaker]

Opening AAC MKV with eac3to is kinda complicated as it requires some old, deprecated Nero filters. If anything I'd use ffmpeg.

[hello_hello]

I've got an AAC MKV. I'm re-encoding the video and audio in MeGUI. I need to re-encode the audio to FLAC. There's no FLAC options to choose apart from the speed of the encode. The AAC is 16 bit but for some reason MeGUI is converting it to 24 bit. Is there a "Custom command line" I can use to keep it as 16 bit?

If you're not sure where MeGUI keeps it's files, drag and drop your MKV onto MeGUI's audio section (reset the flac encoder configuration to the defaults) and run a short encode so you can get the correct information from MeGUI's log file. You'll find something like this:

[Information] [21/01/18 5:33:14 PM] AviSynth script
-[NoImage] LoadPlugin("C:\Program Files\MeGUI\tools\lsmash\LSMASHSource.dll")
-[NoImage] LWLibavAudioSource("E:\Some Video.mkv")
-[NoImage] # detected channels: 2
-[NoImage] # detected channel positions: 2/0/0
-[NoImage] AudioBits(last)>24?ConvertAudioTo24bit(last):last
-[NoImage] return last

Open notepad, copy and paste the info from the log file, then edit it down to the following (with the correct file path for your PC), and make the last line - ConvertAudioTo16bit()

LoadPlugin("C:\Program Files\MeGUI\tools\lsmash\LSMASHSource.dll")
LWLibavAudioSource("E:\Some Video.mkv")
ConvertAudioTo16bit()

Save that to your hard drive, but with an avs extension instead of txt.

Drag and drop the script you created onto MeGUI's audio section. It might appear to hang while the MKV is indexed, so just wait a bit if need be. Once it's ready you can encode the script and you'll end up with a 16 bit flac file.

Mind you if you're converting the audio to flac to clean it up, why not leave it as 24bit and when you've edited the flac file, or cleaned it up with whatever program you're using, convert it to 16bit when you're done?