Passthru audio using two different codecs

[willman42]

If I have an AC3 source audio track, HB apparently allows me to use the passthru options for other codecs (DTS, AAC, etc.). In my research, "passthru" means HB passes through the source audio without altering it to preserve the original quality. So how can it pass through an AC3 source to an output that doesn't match, like DTS or AAC?

My goal is to make a preset that outputs everything to AC3 at original quality, so my thinking is I'd set default behavior to AC3 Passthru. But then if the source isn't AC3, how does this work and is it beneficial at all?

HandBrake version 1.3.3

[rollin_eng]

https://handbrake.fr/docs/en/1.3.0/adva ... aults.html

[willman42]

https://handbrake.fr/docs/en/1.3.0/adva ... aults.html

I understand I can tell HB to automatically passthru an AC3 source to AC3 output. My question is why am I allowed to "pass through" an AC3 source to a DTS output if the source was not DTS?

And would passing thru one source codec to another codec, if even possible, make any sense or be in any way advantageous?

[willman42]

d'oh....

When you have a passthru encoder selected, if the source track format does not match this format, HandBrake will automatically re-encode the track. The fallback encoder is the default encoder it will fallback to.

[rollin_eng]

d'oh....

When you have a passthru encoder selected, if the source track format does not match this format, HandBrake will automatically re-encode the track. The fallback encoder is the default encoder it will fallback to.

[mduell]

You can make a preset that allows for multiple different types of input streams be passedthrough. Allows you to have one preset handle most movies without having to care which audio codec the studio picked. Any non-allowed audio codec will encoded using the selected fallback encoder.