what is Mixdown?

[brakenwagen]

In handbrake’s audio section there is something called a Mixdown, what exactly does this do/mean? Also when I select Mixdown none the bitrate is grayed out. I’m on Handbrack 0.10.5.0-64bit.

[rollin_eng]

https://handbrake.fr/docs/en/1.0.0/adva ... sound.html

[brakenwagen]

Ok that makes things a little more clear but how does this apply when the format you select is not surround sound. I use AAC witch from my understanding is stereo only (I use this to keep file size down) so how does that effect Mixdown. Also what happens to the bit rat if your on AAC and choose none for Mixdown.

[mduell]

I use AAC witch from my understanding is stereo only

You are wrong.

[brakenwagen]

Then how come when I choose AAC its always comes out as stereo.

[BradleyS]

Because mixdowns like DPL2 are matrixed stereo, meaning the surround channels are hidden in the stereo track in a sense. This allows you to have both stereo sound for all devices and surround for devices supporting modes like DPL2.

[brakenwagen]

Oooo that explains a lot. So then what is happening if you select Mixdown None vs Dolby Pro Logic II vs Stereo, why is the bitrate grayed out (correction more like outlined in red) when None is selected? Also if the surround sound is hidden in a stereo track why does vlc show up as stereo does it not have the capabilities to read hidden surround sound? How would you tell the difference between regular stereo track and a stereo track with extra surround sound?

[BradleyS]

Not sure about the red outline situation off the top of my head.

Typically, DPL2 is something supported by home theater amps/receivers. There's no easy test other than playing audio with receiver set to the appropriate mode and listening to the audio image change. There is essentially no drawback to using DPL2 all the time, with or without compatible hardware.