Re: Multiple output devices under CoreAudio with Quicktime
Re: Multiple output devices under CoreAudio with Quicktime
- Subject: Re: Multiple output devices under CoreAudio with Quicktime
- From: Dave Addey <email@hidden>
- Date: Mon, 14 Apr 2003 23:26:32 +0100
Hi Jeff,
Sorry - yes, I am using 10.2.5. You have, in fact, answered a question I
posted to the Quicktime-API mailing list, asking why I sometimes saw my
devices as separate sdevs, but not other times. I spent AGES trying to work
out what I needed to do in order to see them (it was random and
inconsistent), but now I know :-) This is the ideal solution!
I'd still like to investigate using CoreAudio directly, but this makes my
life much, much easier...
Thanks again,
Dave.
Thanks VERY much for your help - hopefully, I can now support several
devices on 10.2!
Dave.
On 14/4/03 7:51 pm, "Jeff Moore" <email@hidden> wrote:
>
You don't say what version of the system you are using, but in 10.2,
>
the Sound Manager was updated to create sdevs for all of the output
>
devices in the HAL. The catch is that you need to be sure you have
>
initialized the Sound Manager prior to trying to iterate through the
>
sdevs with FindNextComponent(). You can call something like
>
SndManagerStatus, to accomplish this.
>
>
On Monday, April 14, 2003, at 01:46 AM, Dave Addey wrote:
>
>
> Hi,
>
>
>
> I'm just about to start porting some Carbon Audio code to take
>
> advantage of
>
> CoreAudio, and I'm really struggling to get a grip on the best
>
> approach to
>
> take... Any help much appreciated! Questions below, after a brief
>
> explanation:
>
>
>
> I've written a Mac DJ application called DJ-1800 (see
>
> http://www.dj1800.com/) using REALbasic. It allows multiple output
>
> devices
>
> for DJing, and emulates 4 DJ-style "CD players" for controlling MP3
>
> playback.
>
>
>
> I'm currently working with a QuickTime movieplayer, which contains a
>
> movie
>
> with 3 MP3 tracks (all identical). I'm using
>
> MediaSetSoundOutputComponent
>
> from the Quicktime API to assign a different output device to each
>
> channel.
>
> (This allows my DJ application to play a song through a master device
>
> and a
>
> cue device at the same time).
>
>
>
> Via Quicktime, I'm looking for all OutputComponents of type 'sdev',
>
> but on
>
> OS X there are only the two - Mac OS Audio HAL, and Mac OS Audio HAL
>
> (system) - corresponding to the system out and the system alerts out
>
> respectively. I'm using these two to allow users to use two audio
>
> devices
>
> (typical their built-in device, and an iMic or similar) - one for
>
> headphones, and one for master oputput.
>
>
>
> This works to a point, on OS 9 and X using Quicktime. However, I have
>
> two
>
> major problems:
>
>
>
> 1) Users would like to be able to use more than two devices (e.g. an
>
> M-Audio
>
> Delta 1010lt soundcard (with 8 outputs)) to assign four different
>
> output
>
> devices (one to each CD player) - not possible with the current
>
> approach. I
>
> believe I need to use CoreAudio to access these extra "devices" under
>
> Mac OS
>
> X. How can I find all available output devices under CoreAudio, and
>
> assign
>
> them to the tracks of a QuickTime movie?
>
>
>
> 2) Ideally, I want to be able to assign multiple output devices to one
>
> track
>
> in a QT movie, rather than the clunky multi-track approach I'm having
>
> to use
>
> currently. Is this possible under CoreAudio?
>
>
>
> As I say, any help much appreciated...
>
>
>
> Thanks,
>
>
>
> Dave.
>
>
>
> ------------------------------------
>
> Dave Addey
>
> email@hidden
>
>
>
> DJ-1800
>
> Complete MP3 DJ solution for the Mac
>
> http://www.dj1800.com/
>
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>
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>
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------------------------------------
Dave Addey
email@hidden
DJ-1800
Complete MP3 DJ solution for the Mac
http://www.dj1800.com/
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