Add override for Record and Broadcast inputs

[Jonathan Bastnagel]

I'm currently using a Digital Vinyl System setup in Mixxx, this means I'm individually routing each Deck from Mixxx to two seperate channels on my external mixer which works as expected. The the master/rec output from my Mixer is then routed back to my computer. However, Mixxx doesn't support overriding the master output.

This would be extremely useful, because as it stands I have no way to utilize the broadcast/record features since the Master channel can not be manually set.

Audio routing solutions such as JACK do not help with this solution since there is no way to override the Mixxx master.

[Owen Williams (ywwg)]

What do you want to do with the master audio stream? It's already being mixed by your mixer, so what else does Mixxx have that you want to do with it?

[Jonathan Bastnagel (jonthebagel)]

Perhaps I wasn't clear enough, in Mixxx I have my outputs for each Deck individually set in the outputs panel see: http://mixxx.org/manual/latest/_images/Mixxx-111-Preferences-Soundhardware.png

These outputs are individually routed to my analog mixer so I can cross-fade, etc using my analog mixer (DJM 600). My mixer has a master output of it's own, independent on Mixxx's. I can route the output of my analog mixer back to my computer very easily.

I'd like to be able to use the built in recording and broadcasting functionality built into Mixxx, however I can't because the Master within Mixxx doesn't really correspond to the Master from my analog hardware mixer. There's no way for me to tell Mixxx, "record and broadcast from this input."

I think the simplest way to solve this problem, without necessarily overriding Mixxx's master output, is to let the user pick the input device they want to record/broadcast from. This would be an extra set of drop-downs in the Sound Hardware -> Preferences -> Input view.

[Jonathan Bastnagel (jonthebagel)]

I'm not actually utilizing Mixxx's master output stream since I'm using the individual outputs from each Deck.

[Owen Williams (ywwg)]

We are unlikely to add this feature soon due to the difficulty synchronizing all of the audio sources. But keep in mind that Mixxx doesn't do the broadcasting itself, it just interfaces with icecast. If you look at the documentation for icecast, you'll find a simpler way to route the input from your mixer directly into the broadcast server.

[Owen Williams (ywwg)]

(for instance, I take the output from my own mixer and record it with Audacity or Ardour -- it's very straightforward)

[Daniel Schürmann (daschuer)]

Isn't it the same like route an external effect into the Mixxx chain? In this case it is a hardware Mixxer effect :-)
Bug #876140 is slightly similar.

But Own is right, we must first fix the sync issue when using different audio Hardware. Do you refere Bug #1203249

[Jonathan Bastnagel (jonthebagel)]

I'm sorry, I don't quite understand why it's necessary to sync all the audio sources for this feature.

I'm only recording/broadcasting from one source technically. The Deck outputs are synchronized, so the delay from the master output from my mixer at that point is irrelevant, correct?

[Owen Williams (ywwg)]

what is wrong with using icecast directly? why go through mixxx?

Mixxx has a single audio callback, so all audio devices must be synchronized. This is not an unreasonable feature but I don't understand why you can't do what you want by other means.

[Jonathan Bastnagel (jonthebagel)]

Nothing is wrong with using icecast directly, I was just trying to better understand the requirements

[Daniel Schürmann (daschuer)]

MIxxx has an audio callback for each audio device (Sound Card) and should have only one at all. This is the root cause for Bug #1203249: a proper synchronization of different crystals is missing.

@Owen: Is there a n other sync issue if we implement it and you use a single soundcard?

IMHO it would be very convenient to allow the Mixxx audio path to be routed though an external audio hardware or thought Jack effect applications.

[RJ Skerry-Ryan (rryan)]

Using a single soundcard there shouldn't be any issues here. With multiple soundcards we could run into buffer-over/underruns in the same way we do with using multiple soundcards for output. (e.g. sidechain is published to at a rate faster or slower than the source soundcard is producing input samples).

[Owen Williams (ywwg)]

So I guess the feature request is, optionally create an audio input for the mixing / EQ / broadcasting engine. I doubt it's worth making this option live-switchable, it should probably only be triggerable by changing audio hardware settings.

[RJ Skerry-Ryan (rryan)]

I think this will be solved by passthrough inputs in 1.12.0. You can route
the mix from your mixer into a passthrough input and enable the
passthrough. That way the master will just be the passthrough input. (These
are implemented but don't have skin support yet).

On Sun, Nov 17, 2013 at 1:21 PM, Owen Williams <email address hidden> wrote:

> So I guess the feature request is, optionally create an audio input for
> the mixing / EQ / broadcasting engine. I doubt it's worth making this
> option live-switchable, it should probably only be triggerable by
> changing audio hardware settings.
>
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> Title:
> Add override for Record and Broadcast inputs
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[RJ Skerry-Ryan (rryan)]

Coming back to this, I think the way forward here is definitely to use our new Aux/Passthrough inputs in 1.12. Marking this as a dupe of Bug #355945.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/7195