Re: [Audacity-devel] Multitrack recording

[Dominic M. <do...@mi...>]

Hello again,

Siegfried Kettlitz wrote:
> I have 4 SB-Live-Cards and synced them with a few wires. On my old K6-2 500Mhz 
> with a crappy MB it works most of the time. On my Athlon i can play with 
> audacity the last 8 tracks while recording 8 new ones and i didn't have any 
> noticable syncing problems with this.
> A problem was portaudio because the starting positions of the tracks need to 
> be corrected by up to 8000 samples.
> 
> Here is my application, you can test it when you have 2 or more soundcards 
> which run synchroneously (or do that almost).
> 
> http://www.area139.de/record/record.html
> (can anybody test that on windows/mac?)

Wow, I'm excited that you got that to work.

> Could i help with that one?
> When somebody likes to work with me we could implement the functionality of 
> this program in audacity.

Yes!

I'd very much like to have some of this code in Audacity.

Please be patient, because I'm busy with other things for
the next few weeks.

I've started just a little bit on a feature called "Smart
Record", which pops up a dialog that lets you do a recording
with extra features, including multitrack and timed recording.
It will have a limited GUI, which should lead to better
performance during recording.

I think it would be great for Smart Record to support
multitracking, including multiple sound cards, now.  Full
multitrack support in Audacity will have to come much later,
because it needs lots of GUI work, but just recording,
from within a separate dialog box, is no problem.

Can you abstract the code needed to configure the soundcards
and read/write from the multiple portaudio streams?  If you
could turn that into self-contained C files or C++ classes,
that would be great.

I'll look at your code when I have a chance.

> The things I need help for are:
> * GUI for configuring the soundcards (one to select the active cards and one 
> to configure the channels (channelname, rate, etc.) )
> * GUI for active recording (one window displaying the useful information while 
> recording, mostly the things my app does)
> * mixer access
> * converting and inserting 32bit-float into audacity with n-channels
> * forgot something?

None of this is a problem; I'm hoping to do most of this anyway
in the next 2-3 months.  Please keep in touch.

- Dominic